title: Eclipsing Binary Pulsars

abstract:
  The first eclipsing binary pulsar, PSR B1957+20, was discovered in 1987.
Since then, 13 other eclipsing low-mass binary pulsars have been found, 12 of
these are in globular clusters. In this paper we list the known eclipsing
binary pulsars and their properties, with special attention to the eclipsing
systems in 47 Tuc. We find that there are two fundamentally different groups of
eclipsing binary pulsars; separated by their companion masses.
  The less massive systems (M_c ~ 0.02 M_sun) are a product of predictable
stellar evolution in binary pulsars. The systems with more massive companions
(M_c ~ 0.2 M_sun) were formed by exchange encounters in globular clusters, and
for that reason are exclusive to those environments. This class of systems can
be used to learn about the neutron star recycling fraction in the globular
clusters actively forming pulsars. We suggest that most of these binary systems
are undetectable at radio wavelengths.


title: On the Formation and Evolution of Stellar Bars in Galaxies

abstract:
  We have done a detailed study on the structural and kinematical properties of
lenticular and early- and late-type spiral galaxies with bars, aiming to
explore the formation and evolution processes of stellar bars in galaxies, and
their implications on the global formation and evolution of galaxies. Using
spectra obtained along the major and minor axes of the bars in a sample of 14
galaxies, we have determined the stellar velocity distribution in the bars'
vertical axis. With these data, it was possible to develop a diagnostic tool
that allows one to estimate the ages of bars. Through realistic N-body
simulations, we have studied the necessary conditions to the formation of bars
in galaxies, as well as the time scale involved in the processes which give
bars an important vertical structure. Finally, using optical and near-infrared
imaging, we have performed a detailed galaxy structural analysis. Among the
main results obtained, we point out: (i) there are vertically thin and thick
bars and this difference is caused by a difference in the ages of the bars;
(ii) the bar thickening process, as we have determined, is slow (5-10 Gyr);
(iii) the current scenario for bar formation is not able to explain naturally
the existence of bars in galaxies which are kinematically hot and have
prominent bulges; (iv) we suggest a new mechanism for bar formation in
galaxies, which can account for the serious drawbacks confronted in the current
scenario; (v) bulges in lenticular and in spiral galaxies are, at least
partially, formed through the secular evolutionary processes in bars; (vi)
during its evolution, a bar grows stronger by capturing stars from the disk,
which becomes fainter, in agreement with recent numerical and analytical
results. [Abridged]


title: On the Kinetic Energy and Radiative Efficiency of Gamma-Ray Bursts

abstract:
  Using measured X-ray luminosities to 17 Gamma-Ray Bursts (GRBs) during the
afterglow phase and accounting for radiative losses, we calculate the kinetic
energy of these bursts and investigate its relation to other GRB properties. We
then use the observed radiated energy during the prompt phase to determine the
radiative efficiency of these bursts, and explore how the efficiency relates to
other GRB observables. We find that the kinetic energy in the afterglow phase
is directly correlated with the radiated energy, total energy as well as
possibly the jet opening angle and spectral peak energy. More importantly, we
find the intriguing fact that the efficiency is correlated with the radiated
energy, and mildly with the total energy, jet opening angle and spectral peak
energy. XRF020903 also seems to follow the trends we find for our GRB sample.
We discuss the implications of these results for the GRB radiation and jet
models.


title: The turbulent dynamo as an instability in a noisy medium

abstract:
  We study an example of instability in presence of a multiplicative noise,
namely the spontaneous generation of a magnetic field in a turbulent medium.
This so-called turbulent dynamo problem remains challenging, experimentally and
theoretically. In this field, the prevailing theory is the Mean-Field Dynamo
(Krause and R\"{a}dler, 1980) where the dynamo effect is monitored by the mean
magnetic field (other possible choices would be the energy, flux,...). In
recent years, it has been shown on stochastic oscillators that this type of
approach could be misleading. In this paper, we develop a stochastic
description of the turbulent dynamo effect which permits us to define
unambiguously a threshold for the dynamo effect, namely by globally analyzing
the probability density function of the magnetic field instead of a given
moment.


title: First Sources in Infrared Light: Stars, Supernovae and Miniquasars

abstract:
  The cosmic infrared background (IRB) at wavelengths between 1 micron and 3
microns provides a useful probe of early star-formation prior to and during
reionization. To explain the high optical depth to electron scattering, as
measured by the Wilkinson Microwave Anisotropy Probe (WMAP), one requires
significant star-formation activity at redshifts 10 and higher. In addition to
massive stars, the IRB flux may be contributed by a population of early
miniquasars. We study the relative contributions from first stars, supernovae
and quasars to the IRB for reasonable star formation rates at high redshift. If
miniquasars radiate efficiently at the Eddington-limit, current background
measurements limit the fraction of mass in first stars that is converted to
seed black holes to be roughly less than 10%. In the case of supernovae, though
an individual supernova is much brighter than the progenitor star, due to the
shorter lifetime of order few months, the fractional contribution to the IRB
remains at a level of 10% and below when compared to the same contribution from
stars. The bright supernovae may, however, be directly detectable by future
large ground-based and space telescopes.


title: Active Galactic Nuclei with Candidate Intermediate-Mass Black Holes

abstract:
  We present an initial sample of 19 intermediate-mass black hole candidates in
active galactic nuclei culled from the First Data Release of the Sloan Digital
Sky Survey. Using the linewidth-luminosity-mass scaling relation established
for broad-line active nuclei, we estimate black hole masses in the range of 8 x
10^4 - 10^6 solar masses, a regime in which only two objects are currently
known. The absolute magnitudes are faint for active galactic nuclei, ranging
from M_g of -15 to -18 mag, while the bolometric luminosities are all close to
the Eddington limit. The entire sample formally satisfies the linewidth
criterion for so-called narrow-line Seyfert 1 galaxies; however, they display a
wider range of FeII and [OIII] (5007) line strengths than is typically observed
in this class of objects. Although the available imaging data are of
insufficient quality to ascertain the detailed morphologies of the host
galaxies, it is likely that the majority of the hosts are relatively late-type
systems. The host galaxies have estimated g-band luminosities ~ 1 mag fainter
than M* for the general galaxy population at z of 0.1. Beyond simply extending
the known mass range of central black holes in galactic nuclei, these objects
provide unique observational constraints on the progenitors of supermassive
black holes. They are also expected to contribute significantly to the
integrated signal for future gravitational wave experiments.


title: Limits on deviations from the inverse-square law on megaparsec scales

abstract:
  We present an attempt to constrain deviations from the gravitational
inverse-square law on large-scale structure scales. A perturbed law modifies
the Poisson equation, which implies a scale-dependent growth of overdensities
in the linear regime and thus modifies the power spectrum shape. We use two
large-scale structure surveys (the Sloan Digital Sky survey and the
Anglo-Australian Two-degree field galaxy redshift survey) to constrain the
parameters of two simple modifications of the inverse-square law. We find no
evidence for deviations from normal gravity on the scales probed by these
surveys (~ 10^(23) m.)


title: Statistical Probes of Reionization With 21 cm Tomography

abstract:
  We consider the degree to which "21 cm tomography" of the high-redshift
Universe can distinguish different ionization histories. Using a new analytic
model for the size distribution of HII regions that associates these ionized
bubbles with large-scale galaxy overdensities, we compute the angular power
spectrum and other statistical properties of the 21 cm brightness temperature
during reionization. We show that the HII regions imprint features on the power
spectrum that allow us to separate histories with discrete bubbles from those
with partial uniform ionization (by, for example, X-rays). We also show that
"double reionization" scenarios will modify the morphology of the bubbles in
ways that depend on the mechanism through which the first generation of sources
shuts off. If, for example, the transition occurs globally at a fixed redshift,
the first generation imprints a persistent feature on the 21 cm power spectrum.
Finally, we compare our model to one in which voids are ionized first. While
the power spectra of these two models are qualitatively similar, we show that
the underlying distributions of neutral hydrogen differ dramatically and
suggest that other statistical tests can distinguish them. The next generation
of low-frequency radio telescopes will have the sensitivity to distinguish all
of these models and strongly constrain the history and morphology of
reionization.


title:
Anomalous X-ray Pulsar 1E 1048.1-5937: Pulsed Flux Flares and Large
  Torque Variations

abstract:
  We report on continued monitoring of the Anomalous X-ray pulsar (AXP) 1E
1048.1-5937 using the Rossi X-ray Timing Explorer. We confirm that this pulsar
has exhibited significant pulsed flux variability. The principal features of
this variability are two pulsed X-ray flares. Both flares lasted several months
and had well-resolved few-week-long rises. The long rise times of the flares
are a phenomenon not previously reported for this class of object. The epochs
of the flare peaks were MJD 52,218.8+/-4.5 and 52,444.4+/-7.0. Both flares had
shorter rise than fall times. The flares had peak fluxes of 2.21+/-0.16 and
3.00+/-0.13 times the quiescent value. We estimate a total 2-10 keV energy
release of ~2.7x10^40 ergs and ~2.8x10^41 ergs for the flares, assuming a
distance of 5 kpc. We also report large (factor of ~12) changes to the pulsar's
spin-down rate on time scales of weeks to months, shorter than has been
reported previously. We find marginal evidence for correlation between the flux
and spin-down rate variability, with probability of nonrandom correlation 6%.
We discuss the implications of our findings for AXP models.


title:
Rapporteur talk for Ultra High Energy Cosmic Rays (HE 1.3, 1.4, 1.5):
  Messengers of the Extreme Universe

abstract:
  In this report I summarize contributions on the highest energy cosmic rays to
the 28th International Cosmic Ray Conference in Tsukuba, Japan, Sections HE
1.3, 1.4 and 1.5 involved over 80 oral presentations and about 120 posters.
This large body of work attests to the vitality of a field committed to
resolving the mystery of the origin of ultra-high energy cosmic rays. These
cosmic rays with energies well above $10^{18}$ eV are messengers of an unknown
extremely high-energy universe.


title: A new mid-infrared map of the BN/KL region using the Keck telescope

abstract:
  We present a new mid-infrared (12.5micron) map of the BN/KL high-mass
star-forming complex in Orion using the LWS instrument at Keck I. Despite poor
weather we achieved nearly diffraction-limited images (FWHM = 0.38'') over a
roughly 25'' X 25'' region centered on IRc2 down to a flux limit of ~250 mJy.
Many of the known infrared (IR) sources in the region break up into smaller
sub-components. We have also detected 6 new mid-IR sources. Nearly all of the
sources are resolved in our mosaic. The near-IR source ''n'' is slightly
elongated in the mid-IR along a NW--SE axis and perfectly bisects the
double-peaked radio source ''L''. Source n has been identified as a candidate
for powering the large IR luminosity of the BN/KL region (L = 10^5 L_sun). We
postulate that the 12 micron emission arises in a circumstellar disk
surrounding source n. The morphology of the mid-IR emission and the Orion ''hot
core'' (as seen in NH_3 emission), along with the location of water and OH
masers, is very suggestive of a bipolar cavity centered on source n and aligned
with the rotation axis of the hypothetical circumstellar disk. IRc2, once
thought to be the dominant energy source for the BN/KL region, clearly breaks
into 4 sub-sources in our mosaic, as seen previously at 3.8 -- 5.0 micron. The
anti-correlation of mid-IR emission and NH_3 emission from the nearby hot core
indicates that the IRc2 sources are roughly coincident (or behind) the dense
hot core. The nature of IRc2 is not clear: neither self-luminous sources
(embedded protostars) nor external heating by source I can be definitively
ruled out. We also report the discovery of a new arc-like feature SW of the BN
object, and some curious morphology surrounding near-IR source ''t".


title: Search for class II methanol masers at 23.1 GHz

abstract:
  In the early days of methanol maser discoveries the 9(2)-10(1) A+ transition
at 23.1 GHz was found to exhibit maser characteristics in the northern
star-forming region W3(OH), and probable maser emission in two other sources.
Attention subsequently turned to the 6.6-GHz 5(1)-6(0) A+ methanol maser
transition, which has proved a valuable tracer of early high-mass star
formation. We have undertaken a new search for 23.1-GHz methanol masers in 50
southern star formation regions using the Parkes radiotelescope. The target
sources all exhibit class II methanol maser emission at 6.6 GHz, with 20
sources also displaying maser features in the 107.0-GHz 3(1)-4(0) A+ methanol
line. Strong emission at 23.1 GHz in NGC 6334F was confirmed, but no emission
was detected in the remaining sources. Thus the 23.1-GHz methanol masers are
rare. A maser model in which methanol molecules are pumped to the second
torsionally excited state by radiation from warm dust can account for class II
maser activity in all the transitions in which it is observed. According to
this model the 23.1-GHz maser is favoured by conditions representing low gas
temperature, high external dust temperature, low gas density, and high column
density of methanol; the scarcity of this maser indicates that such
combinations of conditions are uncommon. We have undertaken new model
calculations to examine the range of parameters compatible with the upper
limits on 23.1-GHz emission from our survey.


title: Dark matter in the framework of shell-universe

abstract:
  We show that the shell-universe model, used to explain the observed expansion
rate of the universe without a dark energy component, provides also a natural
mechanism for local increasing of the shell's tension leading to the modified
Newton's law alternative to galactic dark matter.


title: Trajectory and orbit of the EN200204 Laskarzew fireball

abstract:
  The fireball of -10 mag was observed over Poland on February 20, 2004 at
18:54 UT. Except many visual observations the event was caught by two
photographic stations: one in the Czech Republic and one in Poland. A
description, ground track map, atmospheric trajectory and orbital data for the
fireball are presented.


title:
Estimating galaxy cluster magnetic fields by the classical and hadronic
  minimum energy criterion

abstract:
  We wish to estimate magnetic field strengths of radio emitting galaxy
clusters by minimising the non-thermal energy density contained in cosmic ray
electrons (CRe), protons (CRp), and magnetic fields. The classical minimum
energy estimate can be constructed independently of the origin of the radio
synchrotron emitting CRe yielding thus an absolute minimum of the non-thermal
energy density. Provided the observed synchrotron emission is generated by a
CRe population originating from hadronic interactions of CRp with the ambient
thermal gas of the intra-cluster medium, the parameter space of the classical
scenario can be tightened by means of the hadronic minimum energy criterion.
For both approaches, we derive the theoretically expected tolerance regions for
the inferred minimum energy densities. Application to the radio halo of the
Coma cluster and the radio mini-halo of the Perseus cluster yields
equipartition between cosmic rays and magnetic fields within the expected
tolerance regions. In the hadronic scenario, the inferred central magnetic
field strength ranges from 2.4 muG (Coma) to 8.8 muG (Perseus), while the
optimal CRp energy density is constrained to 2% +/- 1% of the thermal energy
density (Perseus). We discuss the possibility of a hadronic origin of the Coma
radio halo while current observations favour such a scenario for the Perseus
radio mini-halo. Combining future expected detections of radio synchrotron,
hard X-ray inverse Compton, and hadronically induced gamma-ray emission should
allow an estimate of volume averaged cluster magnetic fields and provide
information about their dynamical state.


title: Photometric and dynamic evolution of an isolated disc galaxy simulation

abstract:
  We present a detailed analysis of the evolution of a simulated isolated disc
galaxy. The simulation includes stars, gas, star formation and simple chemical
yields. Stellar particles are split in two populations: the old one is present
at the beginning of the simulation and is calibrated according to various ages
and metallicities; the new population borns in the course of the simulation and
inherits the metallicity of the gas particles. The results have been calibrated
in four wavebands with the spectro-photometric evolutionary model GISSEL2000
(Bruzual & Charlot 1993). Dust extinction has also been taken into account. A
rest-frame morphological and bidimensional photometric analysis has been
performed on simulated images, with the same tools as for observations. The
effects of the stellar bar formation and the linked star formation episode on
the global properties of the galaxy (mass and luminosity distribution, colours,
isophotal radii) have been analysed. In particular, we have disentangled the
effects of stellar evolution from dynamic evolution to explain the cause of the
isophotal radii variations. We show that the dynamic properties (e.g. mass) of
the area enclosed by any isophotal radius depends on the waveband and on the
level of star formation activity. It is also shown that the bar isophotes
remain thinner than mass isodensities a long time (> 0.7 Gyr) after the maximum
of star formation rate. We show that bar ellipticity is very wavelength
dependent as suggested by real observations. Effects of dust extinction on
photometric and morphological measurements are systematically quantified.


title:
Discovery of the optical counterpart to the X-ray pulsar SAX
  J2103.5+4545

abstract:
  We report optical and infrared photometric and spectroscopic observations
that identify the counterpart to the 358.6-s X-ray transient pulsar SAX
J2103.5+4545 with a moderately reddened V=14.2 B0Ve star. This identification
makes SAX J2103.5+4545 the Be/X-ray binary with the shortest orbital period
known, Porb= 12.7 days. The amount of absorption to the system has been
estimated to be Av=4.2+-0.3, which for such an early-type star implies a
distance of about 6.5 kpc. The optical spectra reveal major and rapid changes
in the strength and shape of the Halpha line. The Halpha line was initially
observed as a double peak profile with the ratio of the intensities of the blue
over the red peak greater than one (V/R > 1). Two weeks later this ratio
reversed (V/R< 1). Subsequently, in less than a month, the emission ceased and
Halpha appeared in absorption. This fast spectral variability is interpreted
within the viscous decretion disc model and demonstrates the significant role
of the neutron star on the evolution of the circumstellar disc around the Be
star. The implications of the small orbit and moderate eccentricity on the spin
period of the neutron star are discussed.


title: Interacting quintessence and the coincidence problem

abstract:
  We investigate the role of a possible coupling of dark matter and dark
energy. In particular, we explore the consequences of such an interaction for
the coincidence problem, i.e., for the question, why the energy densities of
dark matter and dark energy are of the same order just at the present epoch. We
demonstrate, that, with the help of a suitable coupling, it is possible to
reproduce any scaling solution $\rho_X \propto \rho_M a^\xi$, where $a$ is the
scale factor of the Robertson-Walker metric and $\xi$ is a constant parameter.
$\rho_X$ and $\rho_M$ are the densities of dark energy and dark matter,
respectively. Furthermore, we show that an interaction between dark matter and
dark energy can drive the transition from an early matter dominated era to a
phase of accelerated expansion with a stable, stationary ratio of the energy
densities of both components.


title:
Chemical abundances of the Galactic H II region NGC 3576 derived from
  VLT echelle spectrophotometry

abstract:
  We present echelle spectrophotometry of the Galactic H II region NGC 3576.
The data have been taken with the VLT UVES echelle spectrograph in the 3100 to
10400 angstroms range. We have measured the intensities of 458 emission lines,
344 are permitted lines of H0, He0, C+, N0, N+, N++, O0, O+, Ne+, S++, Si0,
Si+, Ar0 and Ar+; some of them are produced by recombination and others mainly
by fluorescence. Electron temperatures and densities have been determined using
different continuum and line intensity ratios. We have derived He+, C++, O+,
O++ and Ne++ ionic abundances from pure recombination lines. We have also
derived abundances from collisionally excited lines for a large number of ions
of different elements. Remarkably consistent estimations of t2 have been
obtained by comparing Balmer and Paschen to [O III] temperatures, and O++ and
Ne++ ionic abundances obtained from collisionally excited and recombination
lines. The chemical composition of NGC 3576 is compared with those of other
Galactic H II regions and with the one from the Sun. A first approach to the
gas-phase Galactic radial abundance gradient of C as well as of the C/O ratio
has been made.


title: Detection of a radio halo in the Virgo cluster

abstract:
  New Effelsberg 1.4 GHz observations of the central 10\degr x 10\degr of the
Virgo cluster are presented. NVSS data are used to subtract point sources from
our map. During the data reduction process special care is taken (i) to
disentangle emission from the North Polar Spur from emission from the Virgo
cluster, (ii) to disentangle emission from the strong M87 sidelobes from
emission from the Virgo cluster, and (iii) to correct for non-linear ground
emission due to the long scans. We detect a low surface brightness radio halo
with a flux density of 5 +/- 1.5 Jy centered close to the elliptical galaxy
M86. This halo is much weaker than that observed in the Coma cluster. It is
reminiscent of a past interaction between the intracluster medium of M86 and a
low density gas, belonging most probably to the Virgo cluster.


title:
Optical and infrared photometry of new very low-mass stars and brown
  dwarfs in the Sigma Orionis cluster

abstract:
  We present an RI photometric survey covering an area of 430 arcmin^2 around
the multiple star Sigma Orionis. The observations were conducted with the 0.8 m
IAC-80 Telescope at the Teide Observatory. The survey limiting R and I
magnitudes are 22.5 and 21, and completeness magnitudes 21 and 20,
respectively. We have selected 53 candidates from the I vs. R-I
colour-magnitude diagram (I=14-20) that follow the previously known photometric
sequence of the cluster. Adopting an age of 2-4 Myr for the cluster, we find
that these objects span a mass range from 0.35 Msol to 0.015 Msol. We have
performed J-band photometry of 52 candidates and Ks photometry for 12 of them,
with the result that 50 follow the expected infrared sequence for the cluster,
thus confirming with great confidence that the majority of the candidates are
bona fide members. JHKs photometry from the Two Micron All Sky Survey (2MASS)
is available for 50 of the candidates and are in good agreement with our data.
Out of 48 candidates, which have photometric accuracies better than 0.1 mag in
all bands, only three appear to show near-infrared excesses.


title: Preliminary INTEGRAL Analysis of GRB040106

abstract:
  On January 6th 2004, the IBAS burst alert system triggered the 8th gamma-ray
burst (GRB) to be detected by the INTEGRAL satellite. The position was
determined and publicly distributed within 12s, enabling ESA's XMM-Newton to
take advantage of a ToO observation just 5 hours later during which the x-ray
afterglow was detected. Observations at optical wavelengths also revealed the
existence of a fading optical source. The GRB is ~52s long with 2 distinct
peaks separated by ~24s. At gamma-ray energies the burst was the weakest
detected by INTEGRAL up to that time with a flux in the 20-200 keV band of 0.57
photons/cm^2/s. Nevertheless, it was possible to determine its position and
extract spectra and fluxes. Here we present light curves and the results of
imaging, spectral and temporal analyses of the prompt emission and the onset of
the afterglow from INTEGRAL data.


title: Galactic cannibalism and CDM density profiles

abstract:
  Using N-body simulations we show that the process of formation of the
brightest cluster galaxy through dissipationless galactic cannibalism can
affect the inner cluster dark matter density profile. In particular, we use as
realistic test case the dynamical evolution of the galaxy cluster C0337-2522 at
redshift z=0.59, hosting in its centre a group of five elliptical galaxies
which are likely to be the progenitor of a central giant elliptical. After the
formation of the brightest cluster galaxy, the inner cluster dark matter
density profile is significantly flatter (logarithmic slope 0.49<beta<0.90)
than the original cusp (beta=1), as a consequence of dynamical friction heating
of the massive galaxies against the diffuse cluster dark matter. In our
simulations we have assumed that the cluster galaxies are made of stars only.
We also show that the presence of galactic dark matter haloes can steepen the
cluster central density profile. We conclude that galactic cannibalism could be
a viable physical mechanism to reconcile - at least at the cluster scale - the
flat dark matter haloes inferred observationally in some galaxy clusters with
the steep haloes predicted by cosmological simulations.


title: Variability in the quiescent state of neutron star transients

abstract:
  Variability studies represent a powerful tool to assess the emission
mechanism(s) at work in the quiescent state of transient low mass X-ray
binaries. Here we report on Chandra and XMM-Newton observations of two well
known transient sources: Aql X-1 and Cen X-4. Long and short term variability
is observed. This variability can be easily interpreted in view of an active
millisecond radio pulsar emitting X-rays at the shock between a radio pulsar
wind and inflowing matter from the companion star.


title:
Number Counts of Bright Extremely Red Objects: Evolved Massive Galaxies
  at z~1

abstract:
  We present results on number counts of Extremely Red Objects (EROs) in a 2850
arcmin^2 near-infrared survey performed in European Large Area ISO Survey
(ELAIS) fields at K<17.5. Counts of EROs are extended to brighter levels than
available previously, giving 0.002 +/- 0.001 arcmin^-2 at K<16.5 and consistent
numbers with literature values at fainter magnitudes. Photometric redshifts
from HYPERZ as well as GRASIL model SEDs of galaxies imply that our EROs are
located in the range z=0.7-1.5, with the bulk of the population at z~1. Taking
advantage of the ISO data in the fields, we use mid-IR detections to constrain
the number of dusty EROs, and also discuss the superior capabilities of Spitzer
Space Telescope to detect dusty EROs. Both the mid-IR data and the use of
colour-colour diagrammes indicate that at most 10-20% of the EROs in this
bright regime are dusty starbursting systems. The space density of our EROs,
interpreted to be counterparts of local >2-3L^star massive galaxies at around
z~1, is estimated to be approx. 2x10^-5 Mpc^-3, which is consistent with local
values. Furthermore, the cumulative number counts at our bright magnitudes are
remarkably well fitted by pure luminosity evolution models.


title: Connecting Quantum and Cosmic Scales by a Decreasing-Light-Speed Model

abstract:
  In this paper we point out that the radius R, the age t and the mass M of the
observable Universe are proportional to Planck units for length lp, time tp and
mass mp.This hypothesis is related, by a cosmological model linking the
universal expansion to the speed of light, with a time variation of c and of
the Planck constant, which implies that lp and tp increase with time while mp
remains constant. We discuss some of the implications these relationships could
have on quantum cosmology and obtain that the Universe entropy associated to
the event horizon is constant along its history. Quantum effects were smaller
in the past, in such a way that their conflict with general relativity about
the Planck era vanishes.


title: Observing z>7 sources with the GTC

abstract:
  We present the first results obtained from our pilot ultra-deep near-IR
survey with ISAAC/VLT, aimed at the detection of z>7 sources using lensing
clusters as natural Gravitational Telescopes. Evolutionary synthesis models of
PopIII and extremely metal-poor starbursts have been used to derive
observational properties expected for these high-z galaxies, such as expected
magnitudes and colors, line fluxes for the main emission lines, etc. These
models have allowed us to define fairly robust selection criteria to find z~
7-10 galaxies based on broad-band near-IR photometry in combination with the
traditional Lyman drop-out technique. The magnification in the core of lensing
clusters improves the search efficiency and subsequent spectroscopic follow up.
The method used to identify sources and the first results obtained are
presented, in particular the first spectroscopic confirmation of a z=10
candidate. The research efficiency will be significantly improved by the future
near-IR multi-object facilities such as EMIR/GTC and KMOS/VLT-2, and later by
the JWST.


title: Probing Turbulence in the Coma Galaxy Cluster

abstract:
  Spatially-resolved gas pressure maps of the Coma galaxy cluster are obtained
from a mosaic of XMM-Newton observations in the scale range between a
resolution of 20 kpc and an extent of 2.8 Mpc. A Fourier analysis of the data
reveals the presence of a scale-invariant pressure fluctuation spectrum in the
range between 40 and 90 kpc and is found to be well described by a projected
Kolmogorov/Oboukhov-type turbulence spectrum. Deprojection and integration of
the spectrum yields the lower limit of $\sim 10$ percent of the total
intracluster medium pressure in turbulent form. The results also provide
observational constraints on the viscosity of the gas.


title:
Strong Emission Line HII Galaxies in the Sloan Digital Sky Survey. I.
  Catalog of DR1 Objects with Oxygen Abundances from Te easurements

abstract:
  We present the first edition of the {S}DSS {H}II-galaxies with {O}xygen
abundances {C}atalog (SHOC), which is a listing of strong emission-line
galaxies (ELGs) from the Sloan Digital Sky Survey (SDSS). Oxygen abundances
have been obtained with the classic Te-method. We describe the method
exploiting the SDSS database to construct this sample. The selection procedures
are described and discussed in detail, as well as some problems encountered in
the process of deriving reliable emission line parameters. The method was
applied to the SDSS Data Release 1 (DR1). We present 612 SDSS emission-line
galaxies (624 separate SDSS targets in total), for which the oxygen abundances
12+log(O/H) have r.m.s. uncertainties <0.20 dex. The subsample of 263 ELGs have
an uncertainty <0.10 dex, while 459 ELGs have an uncertainty <0.15 dex. The
catalog includes the main parameters of all selected ELGs, the intensities and
equivalent widths of hydrogen and oxygen emission lines, as well as oxygen
abundances with their uncertainties. The information on the presence of
Wolf-Rayet blue and/or red bumps in 109 galaxies is also included. With the use
of combined g,r,i SDSS images we performed visual morphological classification
of all SHOC galaxies. 461 galaxies (~75%) are classified as confident or
probable blue compact galaxies (BCG/BCG?), 78 as irregular ones, 20 as low
surface brightness galaxies (LSBG), 10 as obviously interacting and 43 as
spiral galaxies. In creating the catalog, 30 narrow line AGN and 69 LINERs were
also identified; these are also presented apart of the main catalog. We outline
briefly the content of the catalog, and the prospects of its use for
statistical studies of the star formation and chemical evolution issues. Some
of these studies will be presented in the forthcoming paper (abridged).


title:
Cosmic microwave background power spectrum estimation with the
  destriping technique

abstract:
  Extraction of the CMB (Cosmic Microwave Background) angular power spectrum is
a challenging task for current and future CMB experiments due to the large data
sets involved. Here we describe an implementation of MASTER (Monte carlo
Apodised Spherical Transform EstimatoR) which exploits the destriping technique
as a map-making method. In this method a noise estimate based on destriped
noise-only MC (Monte Carlo) simulations is subtracted from the pseudo angular
power spectrum. As a working case we use realistic simulations of the PLANCK
LFI (Low Frequency Instrument). We found that the effect of destriping on a
pure sky signal is minimal and requires no correction. Instead we found an
effect related to the distribution of detector pointings, which affects the
high multipole part of the power spectrum. We correct for this by subtracting a
``signal bias'' estimated by MC simulations. We also give analytical estimates
for this signal bias. Our method is fast and accurate enough (the estimator is
un-biased and errors are close to theoretical expectations for maximal
accuracy) to estimate the CMB angular power spectra for current and future CMB
space missions. This study is related to PLANCK LFI activities.


title:
Collimated Escaping Vortical Polar e-e+ Jets Intrinsically Produced by
  Rotating Black Holes and Penrose Processes

abstract:
  In this paper, I present results from theoretical and numerical (Monte Carlo)
N-particle fully relativistic 4-D analysis of Penrose scattering processes
(Compton and gamma-gamma-->e-e+) in the ergosphere of a supermassive or stellar
mass Kerr (rotating) black hole. Specifically, the escape conditions and the
escaping orbits of the Penrose pair production (gamma-gamma-->e-e+) electrons
are analyzed, revealing that these particles escape along collimated, jet
geodesic trajectories encircling the polar axis. Such collimated vortical
tightly wound coil-like trajectories of relativistic particles are inherent
properties of rotating black holes. The helical polar angles of escape for
these e-e+ pairs range from 40 degrees to 0.5 degree (for the highest energy
particles). These jet distributions appear to be consistent with the
astrophysical jets of active galactic nuclei (AGNs) and galactic black holes
and suggest a mechanism for precollimation within the inner radius of the
dynamically stable accretion disk.


title: Globular Cluster X-ray Sources

abstract:
  After a brief historical overview we discuss the luminous X-ray sources in
globular clusters of our Galaxy. This is followed by an overview of the very
luminous X-ray sources studied in globular clusters of 14 other galaxies, and a
discussion of their formation and the relation to X-ray sources outside
globular clusters. We describe the discovery and classification of
low-luminosity X-ray sources, and end the review with some remarks on the
formation and evolution of X-ray sources in globular clusters. Observational
results are summarized in three tables. Comments are very welcome. Please send
them to F.W.M.Verbunt@astro.uu.nl and lewin@mit.edu.


title:
Study of Small-Scale Anisotropy of Ultrahigh Energy Cosmic Rays Observed
  in Stereo by HiRes

abstract:
  The High Resolution Fly's Eye (HiRes) experiment is an air fluorescence
detector which, operating in stereo mode, has a typical angular resolution of
0.6 degrees and is sensitive to cosmic rays with energies above 10^18 eV. HiRes
is thus an excellent instrument for the study of the arrival directions of
ultrahigh energy cosmic rays. We present the results of a search for
anisotropies in the distribution of arrival directions on small scales (<5
degrees) and at the highest energies (>10^19 eV). The search is based on data
recorded between 1999 December and 2004 January, with a total of 271 events
above 10^19 eV. No small-scale anisotropy is found, and the strongest
clustering found in the HiRes stereo data is consistent at the 52% level with
the null hypothesis of isotropically distributed arrival directions.


title: The ACS Virgo Cluster Survey. I. Introduction to the Survey

abstract:
  The Virgo Cluster is the dominant mass concentration in the Local
Supercluster and the largest collection of elliptical and lenticular galaxies
in the nearby universe. In this paper, we present an introduction to the ACS
Virgo Cluster Survey: a program to image, in the F475W and F850LP bandpasses
(Sloan g and z), 100 early-type galaxies in the Virgo Cluster using the
Advanced Camera for Surveys on the Hubble Space Telescope. We describe the
selection of the program galaxies and their ensemble properties, the choice of
filters, the field placement and orientation, the limiting magnitudes of the
survey, coordinated parallel observations of 100 "intergalactic" fields with
WFPC2, and supporting ground-based spectroscopic observations of the program
galaxies. In terms of depth, spatial resolution, sample size and homogeneity,
this represents the most comprehensive imaging survey to date of early-type
galaxies in a cluster environment. We briefly describe the main scientific
goals of the survey which include the measurement of luminosities,
metallicities, ages, and structural parameters for the many thousands of
globular clusters associated with these galaxies, a high-resolution isophotal
analysis of galaxies spanning a factor of ~ 450 in luminosity and sharing a
common environment, the measurement of accurate distances for the full sample
of galaxies using the method of surface brightness fluctuations, and a
determination of the three-dimensional structure of Virgo itself.


title: Nonthermal Radiation Processes in X-ray Jets

abstract:
  Analytic approximations for synchrotron, synchrotron self-Compton (SSC), and
external Compton (EC) processes are used to constrain model parameters for knot
and hot-spot emission in extended jets of radio galaxies. Equipartition
formulas are derived that relate the Doppler factor $\delta$ and comoving
magnetic field $B$ assuming a nonthermal synchrotron origin of the radio
emission, and synchrotron, SSC and EC origins of the X-ray emission.
Expressions are also derived for $\delta$ and $B$ that minimize the total jet
powers of the emitting region in synchrotron, SSC and EC models for the X-ray
emission. The results are applied to knot WK7.8 of PKS 0637-752. Predictions to
test two-component synchrotron and EC models are made for {\it Chandra} and
{\it GLAST}.


title:
Gamma-ray burst early afterglows: reverse shock emission from an
  arbitrarily magnetized ejecta

abstract:
  Evidence suggests that the gamma-ray burst (GRB) ejecta is likely magnetized,
although the degree of magnetization of the ejecta is unknown. We derive a
rigorous analytical solution for the relativistic 90 degree shocks under the
ideal MHD condition, and use them to study the reverse shock emission
properties of an arbitrarily magnetized ejecta. Contrary to the previous
belief, we find that strong relativistic shocks still exist in the high-sigma
limit. Assuming a constant density of the circumburst medium, we study the
shell-medium interaction in detail and categorize various critical radii for
shell evolution. With typical GRB parameters, a reverse shock exists when sigma
is less than a few tens or a few hundreds. The shell evolution can be still
categorized into the thick and thin shell regimes, but the separation between
the two regime now depends on sigma and the thick shell regime greatly shrinks
at high-sigma. The early optical afterglow lightcurves are calculated for GRBs
with a wide range of the sigma values. We find that the reverse shock emission
level increases steadily with sigma initially, but starts to decline when sigma
becomes larger than unity. In the high-sigma regime the reverse shock peak is
usually broadened due to the separation of the shock crossing radius and the
deceleration radius in the thin shell regime. The early afterglow data and
tight upper limits of known GRBs could be understood within the theoretical
framework developed in this paper, with the inferred sigma value varying in a
wide range.


title: Radio Observations of the 13hr XMM/ROSAT Deep X-ray Survey Area

abstract:
  In order to determine the relationship between the faint X-ray and faint
radio source populations, and hence to help understand the X-ray and radio
emission mechanisms in those faint source populations, we have made a deep
1.4GHz Very Large Array radio survey of the 13h +38deg XMM/ROSAT X-ray Survey
Area. From a combined data set of 10hours B configuration data and 14hours A
configuration data, maps with 3.35'' resolution and a noise limit of 7.5uJy
were constructed. A complete sample of 449 sources was detected within a 30'
diameter region above a 4sigma detection limit of 30uJy, at the map centre,
making this one of the deepest radio surveys at this frequency. The
differential source count shows a significant upturn at sub-milliJansky flux
densities, similar to that seen in other deep surveys at 1.4GHz (eg the Phoenix
survey), but larger than that seen in the HDF which may have been selected to
be under-dense. This upturn is well modelled by the emergence of a population
of medium redshift starforming galaxies which dominate at faint flux densities.
The brighter source counts are well modelled by AGNs.


title:
X-ray Temperatures for the EMSS High Redshift Cluster Sample:
  Constraints on Cosmology and the Dark Energy Equation of State

abstract:
  We measure the X-ray temperature (and luminosity) with ASCA of all but one
cluster in the Einstein Extended Medium Sensitivity Survey (EMSS) high redshift
(z > 0.3) sample. We compare these data to a complete sample of low redshift
clusters that also has temperature measurements, thereby providing cosmological
constraints. We incorporate many improvements over our previous work. We find
an allowed band in the Omega_{m0} - Omega_{Lambda0} plane of different
orientation to the band of constraints provided by the supernovae Ia Hubble
diagram and the cosmic microwave background fluctuations. All three bands
intersect at the same place: Omega_{m0} ~ 0.3, Omega_{Lambda0} ~ 0.7. We
measure the quintessence equation of state parameter to be w = -(0.42 pm 0.21)
(68% confidence for 1 interesting parameter), consistent with previously
determined upper limits. We measure the normalization of the mass fluctuation
power spectrum to be sigms_8 = 0.66 pm 0.16 (68% confidence for 3 interesting
parameters). Systematic errors are larger than the statistical errors only for
sigma_8 with our sample, thus the errors for it depends on the details of the
marginalization over the temperature - mass normalization.


title:
The Three-point Correlation Function of Galaxies: Comparing Halo
  Occupation Models with Observations

abstract:
  We present models for the three-point correlation function (3PCF) of both
dark matter and galaxies. We show that models based on the halo model can
reasonably match the dark matter 3PCF obtained from high-resolution $N$-body
simulations. On small scales ($r\la 0.5\mpch$) the 3PCF is sensitive to details
regarding the density distributions of dark matter haloes. On larger scales ($r
\ga 2.0\mpch$) the results are very sensitive to the abundance of the few most
prominant haloes. Using the conditional luminosity function, we also construct
models for the 3PCF of galaxies, which we test against large mock galaxy
samples. The bias of the galaxy distrubution with respect to the dark matter,
and the finite number of galaxies that can be hosted by individual haloes,
significantly reduce the normalized three-point correlation function with
respect to that of dark matter. Contrary to the 3PCF of the dark matter, the
galaxy 3PCF is much less sensitive to details regarding the spatial number
density distribution of galaxies in individual haloes or to the abundance of
the few most massive systems. Finally, we show that our model based on the
conditional luminosity function is in good agreement with results obtained from
the 2-degree Field Galaxy Redshift Survey. In particular, the model nicely
reproduces the observational finding that the 3PCF for early-type galaxies is
slightly higher than that of late-type galaxies, and that there is no
significant dependence of the 3PCF on galaxy luminosity.


title: A Model for the Optical/IR Emission from Magnetars

abstract:
  A number of Anomalous X-ray Pulsars (AXPs) have recently been detected in the
optical/IR wavelengths. We use their inferred brightness to place general
constraints on any model for this emission within the magnetar framework. We
find that neutron-star surface emission cannot account for the observations and
that the emission must be magnetospheric in origin. We propose a model for the
optical/IR emission in which a distribution of energetic electrons in the
neutron-star magnetosphere emits synchrotron radiation. This model can
naturally reproduce the observed brightness and the rising spectra of AXPs as
well as the observed pulsations at the stellar spin frequency and the
correlation of the IR flux with their bursting activity.


title:
A Chandra View of The Morphological And Spectral Evolution of Supernova
  Remnant 1987A

abstract:
  We present an update on the results of our monitoring observations of the
X-ray remnant of supernova (SN) 1987A with the {\it Chandra X-Ray Observatory}.
As of 2002 December, we have performed a total of seven observations of SN
1987A. The high angular resolution images from the latest data reveal
developments of new X-ray bright spots in the northwestern and the southwestern
portions of the remnant as well as changes on the eastern side. The latest
0.5-2 keV band flux ($f_X$ $\sim$ 6 $\times$ 10$^{-13}$ ergs cm$^{-2}$
s$^{-1}$) is four times brighter than three years earlier. The overall X-ray
emission is primarily from the blast wave shock with $kT$ $\sim$ 2.4 keV. As
the blast wave approaches the dense circumstellar material, the contribution
from the decelerated slow shock ($kT$ $\sim$ 0.22 keV) to the observed X-ray
emission is becoming significant. The increase of this slow shock contribution
over the last two years is particularly noticeable in the western half of the
remnant. These results indicate that the shock front is now reaching the main
body of the inner circumstellar ring. Based on the best-fit two-shock spectral
model, we derive approximate densities of the X-ray-emitting regions ($n_e$
$\sim$ 235 cm$^{-3}$ for the fast shock and $n_e$ $\sim$ 7500 cm$^{-3}$ for the
slow shock). We obtain an upper limit on the observed X-ray luminosity of any
embedded point source ($L_X$ $\le$ 1.5 $\times$ 10$^{34}$ ergs s$^{-1}$) in the
2$-$10 keV band. The X-ray remnant continues to expand linearly at a rate of
4167 km s$^{-1}$.


title: Cosmic acceleration in brane cosmology

abstract:
  Cosmic acceleration may be the result of unknown physical processes involving
either new fields in high energy physics or modifications of gravitation
theory. In the latter case, such modifications are usually related to the
existence of extra dimensions (which is also required by unification theories),
giving rise to the so-called brane cosmology. In this paper we investigate the
phenomenon of the acceleration of the Universe in a particular class of brane
scenarios in which a large scale modification of gravity arises due to a
gravitational \emph{leakage} into extra dimensions. By using the most recent
supernova observations we study the transition (deceleration/acceleration)
epoch as well as the constraints imposed on the parameters characterizing the
model. We show that these models provide a good description for the current
supernova data, which may be indicating that the existence of extra dimensions
play an important role not only in fundamental physics but also in cosmology.


title: Limits on I-band microvariability of the Galactic Bulge Miras

abstract:
  We search for microvariability in a sample of 485 Mira variables with high
quality I-band light curves from the second generation Optical Gravitational
Lensing Experiment (OGLE-II). Rapid variations with amplitudes in the ~0.2-1.1
mag range lasting hours to days were discovered in Hipparcos data by de Laverny
et al. (1998). Our search is primarily sensitive to events with time-scales of
about 1 day, but retains a few percent efficiency (per object) for detecting
unresolved microvariability events as short as 2 hours. We do not detect any
candidate events. Assuming that the distribution of the event time profiles is
identical to that from the Hipparcos light curves we derive the 95% confidence
level upper limit of 0.038 per year per star for the rate of such events (1 per
26 years per average object of the ensemble). The high event rates of the order
of 1 per year per star implied by the Hipparcos study in the H_P band are
excluded with high confidence by the OGLE-II data in the I band. Our
non-detection could still be explained by much redder spectral response of the
I filter compared to the H_P band or by population differences between the
bulge and the solar neighborhood. In any case, the OGLE-II I-band data provide
the first limit on the rate of the postulated microvariability events in Mira
stars and offer new quantitative constraints on their properties. Similar
limits are obtained for other pulse shapes and a range of the assumed
time-scales and size-frequency distributions.


title:
A Keck/HIRES Study of Kinematics of the Cold Interstellar Medium in
  Dwarf Starburst Galaxies

abstract:
  We have obtained high resolution Echelle spectra (R = 30,000-50,000) of the
Na D absorption doublet (5890A, 5896A) for six dwarf starburst galaxies and two
more luminous starbursts: M82 and NGC 1614. The absorption features were
separated into multiple components and separated into stellar and interstellar
parts based on kinematics. We find that three of the dwarfs show outflows, with
an average blueshift of 27 km/s. This is small compared to the highest velocity
components in NGC 1614 and M82 (blueshifted by 150 km/s and 91 km/s,
respectively); these two brighter galaxies also show more complex absorption
profiles than the dwarfs. None of the outflow speeds clearly exceed the escape
velocity of the host galaxy. Sightlines in NGC 2363 and NGC4214 apparently
intersect expanding shells. We compare the shocked gas velocity (v_NaD) to the
ionized gas velocity (v_Halpha) and interpret the velocity difference as either
a trapped ionization front (NGC 4214) or a leaky HII region (NGC 2363). The
dwarfs show N(NaD) = 10^(11.8-13.7) cm^-2, while the Na D columns in M82 and
NGC 1614 are 10^13.7 cm^-2 and 10^14.0 cm^-2, respectively. The mass of
expelled gas is highly sensitive to outflow geometry, dust depletion, and
ionization fraction, but with a simple shell model we estimate neutral outflow
gas masses from ~10^6 M_solar to ~10^10 M_solar.


title:
Green Bank Telescope Measurement of the Systemic Velocity of the Double
  Pulsar Binary J0737-3039 and Implications for its Formation

abstract:
  We report on the measurement at 820- and 1400-MHz of orbital modulation of
the diffractive scintillation timescale from pulsar A in the double-pulsar
system J0737-3039 using the Green Bank Telescope. Fits to this modulation
determine the systemic velocity in the plane of the sky to be V_iss ~ 140.9 +/-
6.2 km/s. The parallel and perpendicular components of this velocity with
respect to the line of nodes of the pulsar's orbit are V_plane ~ 96.0 +/- 3.7
km/s and V_perp ~ 103.1 +/- 7.7 km/s respectively. The large V_perp implies
that pulsar B was born with a kick speed of >~ 100 km/s. Future VLBA
determination of the angular proper motion in conjunction with improved V_iss
measurements should provide a precise distance to the system. Using
high-precision timing data and the V_iss model, we estimate a best-fit orbital
inclination of i = 88.7 +/- 0.9 deg.


title:
Measuring transverse velocities in gravitationally lensed extragalactic
  systems using an annual parallax effect

abstract:
  A parallax method to determine transverse velocity in a gravitationally
lensed system is described. Using the annual motion of the Earth around the Sun
allows us to probe the local structure of the magnification map that, under
certain assumptions, can be used to infer the effective transverse velocity.
The method is applied to OGLE data for QSO2237+0305 and the velocity value is
estimated to be about (15 +/- 10) km/s if attributed to the lensing galaxy or
about (420 +/- 300) km/s if attributed to the quasar. We find this estimate
unreasonably small and conclude that we have not measured a parallax effect. We
give a short list of properties that a system should possess to allow a
successful implementation of this method.


title:
Detections of the 2175 \AA Dust Feature at 1.4z 1.5 from the Sloan
  Digital Sky Survey

abstract:
  The strongest spectroscopic dust extinction feature in the Milky Way, the
broad absorption bump at 2175 \AA, is generally believed to be caused by
aromatic carbonaceous materials -- very likely a mixture of Polycyclic Aromatic
Hydrocarbon (PAH) molecules, the most abundant and widespread organic molecules
in the Milky Way galaxy. In this paper we report identifications of this
absorption feature in three galaxies at $1.4 \lesssim z \lesssim 1.5$ which
produce intervening MgII absorption toward quasars discovered by the Sloan
Digital Sky Survey (SDSS). The observed spectra can be fit using Galactic-type
extinction laws, characterized by parameters [R_V, E(B-V)] ~ [0.7, 0.14], [1.9,
0.13], and [5.5, 0.23], respectively, where R_V=A_V/E(B-V) is the
total-to-selective extinction ratio, E(B-V) = A_B-A_V is the color-excess.
These discoveries imply that the dust in these distant quasar absorption
systems is similar in composition to that of Milky Way, but with a range of
different grain size distributions. The presence of complex aromatic
hydrocarbon molecules in such distant galaxies is important for both
astrophysical and astrobiological investigations.


title:
General Relativistic Magnetohydrodynamic Simulations of Collapsars:
  Rotating Black Hole Cases

abstract:
  We have performed 2.5-dimensional general relativistic magnetohydrodynamic
(MHD) simulations of collapsars including a rotating black hole. This paper is
an extension of our previous paper (Mizuno et al. 2004). The current
calculation focuses on the effect of black hole rotation using general
relativistic MHD with simplified microphysics. Initially, we assume that the
core collapse is failed in this star. A few solar mass rotating black hole is
inserted by hand into the calculation. We consider two cases, the co-rotating
case and counter-rotating case with respect to the black hole rotation.
Although the counter-rotating case may be unrealistic for collapsar, we perform
as a maximally dragging case of magnetic field. The simulation results show the
formation of a disk-like structure and the generation of a jet-like outflow
near the central black hole. The jet-like outflow propagates outwardly with the
twisted magnetic field and becomes collimated. We have found that the jets are
generated and accelerated mainly by the magnetic field. The total jet velocity
in the rotating black hole case is comparable to that of the non-rotating black
hole case (Mizuno et al. 2004), 0.3c. When the rotation of the black hole is
faster, the magnetic field is twisted strongly owing to the frame-dragging
effect. The magnetic energy stored by the twisting magnetic field is converted
to kinetic energy of the jet directly rather than propagating as an Alfven
wave. Thus, as the rotation of the black hole becomes faster, the poloidal
velocity of the jet becomes faster. In the rapidly rotating black hole case the
jet-like outflow can be produced by the frame dragging effect only through the
twisting of magnetic field even if there is no stellar rotation.


title:
Global dynamics of radiatively inefficient accretion flows: advection
  versus convection

abstract:
  We obtain global solutions of radiatively inefficiently accretion flows
around black holes. Whether and where convection develops in a flow are
self-consistently determined with the mixing-length theory. The solutions can
be divided into three types according to the strength of normal viscosity. Type
I solution corresponds to large viscosity parameter $\alpha \ga 0.1$, which is
purely advection-dominated and with no convection, and has been extensively
studied in the literature. Type II solution is for moderate $\alpha \sim 0.01$,
which has a three-zone structure. The inner zone is advection-dominated, the
middle zone is convection-dominated and ranges from a few tens to a few
thousands of gravitational radii, and the outer zone is convectively stable and
matches outward a Keplerian disc. The net energy flux throughout the flow is
inward as in type I solution. Type III solution which is for small $\alpha \la
0.001$ consists of two zones as Abramowicz et al. suggested previously: an
inner advection-dominated zone and an outer convection-dominated zone,
separated at a radius of a few tens of gravitational radii. This type of
solution has an outward net energy flux. In both type II and III solutions the
radial density profile is between the 1/2 law of self-similar
convection-dominated accretion flow model and the 3/2 law of self-similar
advection-dominated accretion flow model, and the efficiency of energy release
is found to be extremely low. Our results are in good agreement with those of
recent numerical simulations.


title:
Phantom-like GCG and the constraints of its parameters via cosmological
  dynamics

abstract:
  We extend the equation of state of GCG (Generalized Chaplygin Gas) to $w<-1$
regime and show, from the point of view of dynamics, that the parameters of GCG
should be in the range of $0<\alpha<1$. Also, dynamical analysis indicate that
the phase $w_{g}=-1$ is a dynamical attractor and the equation of state of GCG
approaches it from either $w_{g}>-1$ or $w_{g}<-1$ depending on the choice of
its initial cosmic density parameter and the ratio of pressure to critical
energy density.


title: The WEBT BL Lacertae Campaign 2001 and its extension

abstract:
  BL Lacertae has been the target of four observing campaigns by the Whole
Earth Blazar Telescope (WEBT) collaboration. In this paper we present $UBVRI$
light curves obtained by the WEBT from 1994 to 2002, including the last,
extended BL Lac 2001 campaign. A total of about 7500 optical observations
performed by 31 telescopes from Japan to Mexico have been collected, to be
added to the $\sim 15600$ observations of the BL Lac Campaign 2000. All these
data allow one to follow the source optical emission behaviour with
unprecedented detail. The analysis of the colour indices reveals that the flux
variability can be interpreted in terms of two components: longer-term
variations occurring on a few-day time scale appear as mildly-chromatic events,
while a strong bluer-when-brighter chromatism characterizes very fast
(intraday) flares. By decoupling the two components, we quantify the degree of
chromatism inferring that longer-term flux changes imply moving along a $\sim
0.1$ bluer-when-brighter slope in the $B-R$ versus $R$ plane; a steeper slope
of $\sim 0.4$ would distinguish the shorter-term variations. This means that,
when considering the long-term trend, the $B$-band flux level is related to the
$R$-band one according to a power law of index $\sim 1.1$. Doppler factor
variations on a "convex" spectrum could be the mechanism accounting for both
the long-term variations and their slight chromatism.


title: Phenomenological Analogies in Black Hole Systems of all Masses

abstract:
  I review the progress made on the physics of relativistic jets from black
hole systems in the context of the analogy between AGN and microquasars that
was proposed one decade ago. If the emerging empirical correlations between the
observational properties of stellar and supermassive black holes will become
more robust, we will use them to determine the mass and spin of black holes,
independently of theoretical models. Microquasars are fossils of sources of
Gamma-ray bursts (GRBs) of long duration, and their kinematics provides
observational clues on the physics of collapsars. If jets in GRBs, microquasars
and AGN are due to a unique universal magnetohydrodynamic mechanism, synergy
between the research on these three different classes of cosmic objects will
lead to further progress in black hole physics and astrophysics.


title:
A large area search for radio-loud quasars within the epoch of
  reionization

abstract:
  The Universe became fully reionized, and observable optically, at a time
corresponding to redshift z ~ 6.5, so it is only by studying the HI and
molecular absorption lines against higher-redshift, radio-loud sources that one
can hope to make detailed studies of the earliest stages of galaxy formation.
At present no targets for such studies are known. In these proceedings we
describe a survey which is underway to find radio-loud quasars at z > 6.5, and
present broad-band SEDs of our most promising candidates.


title:
RR Lyrae stars in the outer region of the globular cluster M3: a
  shortage of long periods at r ~ 3.5 to 6 arcmin ?

abstract:
  An analysis of the radial distribution of ab-type RR Lyrae star periods in
the outer region of the globular cluster M3 at r >= 0.83 arcmin has been
performed. That analysis points towards a real shortage of stars with long
periods in the radial distance range 3.5 to 6 arcmin (or about 7 to 12 core
radii). A brief discussion is presented. The origin of the phenomenon remains
an open question.


title: Probing Relativistic Winds: The case of PSRJ07370-3039 A & B

abstract:
  We propose synchrotron absorption in a magnetosheath forming a cocoon around
the magnetosphere of pulsar B to be the origin of the eclipse phenomena seen in
the recently discovered double pulsar system PSRJ07370-3039 A & B. The model
predicts the eclipses will clear at frequencies higher than those of the
observations reported to date (nominally, above $\nu \sim 5$ GHz.) The model
also predicts synchrotron emission at the level of a few to 10 $\mu$Jy, peaking
at $\nu \sim 2-5$ GHz with possible orbital modulation. We use simplified
semi-analytic models and particle-in-cell simulations to elucidate the
structure of the B magnetosphere, showing that B's magnetic field is confined
to within a radius less than 50,000 km from B,on the side facing A. We estimate
a ``propellor'' spindown torque on B, which is the dominant torque on this
star, which yields a polar dipole field $\sim 7 \times 10^{11}$ Gauss (magnetic
moment $\mu_B \sim 3.5 \times 10^{29}$ cgs). The model can explain the known
eclipses only if the A wind's density is at least 4 orders of magnitude greater
than is expected from popular pair creation models, and discuss the
implications of this result for our general understanding of pulsar physics.
Our proposal was outlined in Kaspi et al. (2004) and Demorest et al. (2004); a
similar proposal has been made by Lyutikov (2004).


title:
Magnetohydrodynamic Simulations of the Formation of Cold Fronts in
  Clusters of Galaxies including Heat Conduction

abstract:
  Recent Chandra observations of clusters of galaxies revealed the existence of
a sharp ridge in the X-ray surface brightness where the temperature drops
across the front. This front is called the cold front. We present the results
of two-dimensional magnetohydrodynamic simulations of the time evolution of a
dense subcluster plasma moving in a cluster of galaxies. Anisotropic heat
conduction along the magnetic field lines is included. In the models without
magnetic fields, the numerical results indicate that the heat conduction from
the hot ambient plasma heats the cold dense plasma of the subcluster and
diffuses out the cold front. When magnetic fields exist in a cluster of
galaxies, however, cold fronts can be maintained because the heat conduction
across the magnetic field lines is suppressed. We found that, even when the
magnetic fields in a cluster of galaxies are disordered, heat conduction across
the front is restricted because the magnetic field lines are stretched along
the front. Numerical results reproduced the X-ray intensity distribution
observed in the A3667 cluster of galaxies.


title: The Delta Scuti star FG Vir. V. The 2002 photometric multisite campaign

abstract:
  A high-accuracy multisite campaign was carried out from 2002 January to May
with a photometric coverage of 398 hours at five observatories. The
concentration on a few selected sites gives better consistency and accuracy
than collecting smaller amounts from a larger number of sites. 23 frequencies
were detected with a high statistical significance. 6 of these are new. The 17
frequencies found in common with the 1992-1995 data are the modes with highest
amplitudes. This indicates that the pulsation spectrum of FG Vir is relatively
stable over the ten-year period. Two frequencies have variable amplitudes and
phases from year to year as well as during 2002. These were both found to be
double modes with close frequencies. For the mode at 12.15 c/d this leads to an
apparent modulation with a time scale of about 129d. The close frequencies at
12.15 c/d are composed of a radial and a nonradial mode, suggesting a
similarity with the Blazhko Effect seen in RR Lyrae stars.


title:
Long-term optical variability of the blazars PKS 2005-489 and PKS
  2155-304

abstract:
  We present optical light curves for the period 1996-2000, of two of the
brightest known EGRET BL Lac objects: PKS 2005-489 and PKS 2155-304, the latter
also one of the few known TeV sources. For both objects, quiescent epochs of
low level of variability were followed by active periods, without any
indication of periodicity. In PKS 2005-489, several variability events with
duration of about 20 days were observed. In PKS 2155-304 fast drops and
subsequent rises in luminosity occurred in time scales of days. We proposed an
explanation in which a region moving along the relativistic jet is eclipsed by
broad line region clouds or star clusters in the host galaxy. We compare our
light curves with contemporaneous X-ray observations from All-Sky Monitor/RXTE.
Correlations between optical and X-ray activity were not found in any of the
sources at long time scales. However in PKS 2005-489 possible correlations were
observed in 1997 and 1998 at short time scales, with optical variability
preceding X-rays by 30 days in 1997 and succeeding them by about 10 days in
1998. The analysis of the SED, using the optical data presented here and
BeppoSAX contemporaneous observations obtained from the literature, shows only
small shifts in the synchrotron peak as the X-ray flux density changes.


title: Periodic bursts of Star Formation in Irregular Galaxies

abstract:
  We present N-body/SPH simulations of the evolution of an isolated dwarf
galaxy including a detailed model for the ISM, star formation and stellar
feedback. Depending on the strength of the feedback, the modelled dwarf galaxy
shows periodic or quasi-periodic bursts of star formation of moderate strength.
The period of the variations is related to the dynamical timescale, of the
order of $1.5~10^8$ yr. We show that the results of these simulations are in
good agreement with recent detailed observations of dwarf irregulars (dIrr) and
that the peculiar kinematic and morphological properties of these objects,as
revealed by high resolution HI studies, are fully reproduced. We discuss these
results in the context of recent surveys of dwarf galaxies and point out that
if the star formation pattern of our model galaxy is typical for dwarf
irregulars this could explain the scatter of observed properties of dwarf
galaxies. Specifically, we show that the time sampled distribution of the ratio
between the instanteneous star formation rate (SFR) and the mean SFR is similar
to that distribution in observed sample of dwarf galaxies.


title: Thick Disks of Lenticular Galaxies

abstract:
  Thick disks are faint and extended stellar components found around several
disk galaxies including our Milky Way. The Milky Way thick disk, the only one
studied in detail, contains mostly old disk stars (~10 Gyr), so that thick
disks are likely to trace the early stages of disk evolution. Previous
detections of thick disk stellar light in external galaxies have been
originally made for early-type, edge-on galaxies but detailed 2D thick/thin
disk decompositions have been reported for only a scant handful of mostly
late-type disk galaxies. We present in this paper for the first time explicit
3D thick/thin disk decompositions characterising the presence and properties
(eg scalelength and scaleheight) for a sample of eight lenticular galaxies by
fitting 3D disk models to the data. For six out of the eight galaxies we were
able to derive a consistent thin/thick disk model. The mean scaleheight of the
thick disk is 3.6 times larger than that of the thin disk. The scalelength of
the thick disk is about twice, and its central luminosity density between 3-10%
of, the thin disk value. Both thin and thick disk are truncated at similar
radii. This implies that thick disks extend over fewer scalelengths than thin
disks, and turning a thin disk into a thick one requires therefore vertical but
little radial heating. All these structural parameters are similar to thick
disk parameters for later Hubble-type galaxies previously studied. We discuss
our data in respect to present models for the origin of thick disks, either as
pre- or post-thin-disk structures, providing new observational constraints.


title: Direct Urca Process in a Neutron Star Mantle

abstract:
  We show that the direct Urca process of neutrino emission is allowed in two
possible phases of nonspherical nuclei (inverse cylinders and inverse spheres)
in the mantle of a neutron star near the crust-core interface. The process is
open because neutrons and protons move in a periodic potential created by
inhomogeneous nuclear structures. In this way the nucleons acquire large
quasimomenta needed to satisfy momentum-conservation in the neutrino reaction.
The appropriate neutrino emissivity in a nonsuperfluid matter is about 2--3
orders of magnitude higher than the emissivity of the modified Urca process in
the stellar core. The process may noticeably accelerate the cooling of low-mass
neutron stars.


title:
Planetary Migration and Extrasolar Planets in the 2/1 Mean-Motion
  Resonance

abstract:
  We analyze the possible relationship between the current orbital elements
fits of known exoplanets in the 2/1 mean-motion resonance and the expected
orbital configuration due to migration. It is found that, as long as the
orbital decay was sufficiently slow to be approximated by an adiabatic process,
all captured planets should be in apsidal corotations. In other words, they
should show a simultaneous libration of both the resonant angle and the
difference in longitudes of pericenter.
  We present a complete set of corotational solutions for the 2/1
commensurability, including previously known solutions and new results.
Comparisons with observed exoplanets show that current orbital fits of three
known planetary systems in this resonance are either consistent with apsidal
corotations (GJ876 and HD82943) or correspond to bodies with uncertain orbits
(HD160691).
  Finally, we discuss the applicability of these results as a test for the
planetary migration hypothesis itself. If all future systems in this
commensurability are found to be consistent with corotational solutions, then
resonance capture of these bodies through planetary migration is a working
hypothesis. Conversely, If any planetary pair is found in a different
configuration, then either migration did not occur for those bodies, or it took
a different form than currently believed.


title: Three New Binary Pulsars Discovered With Parkes

abstract:
  We present three new binary pulsars discovered during a search for pulsations
in 56 unidentified mid-latitude EGRET gamma-ray error boxes with the Parkes
multibeam receiver. Timing observations of these sources is on-going with both
the Parkes and the Green Bank telescopes. We discuss the place of these new
systems in the population of binary pulsars and suggest that they are all
somewhat atypical systems.


title: Modeling Galaxy-Mass Correlations in Dissipationless Simulations

abstract:
  We use high-resolution dissipationless simulations of the concordance flat
LCDM model to make predictions for the galaxy--mass (GM) correlations and
compare them to the recent SDSS weak lensing measurements.We use a simple
observationally motivated scheme to assign luminosities and colors to the
halos.This allows us to closely match the selection criteria used to define
observational samples.The simulations reproduce the observed GM correlation
function and its observed dependencies on luminosity and color.The luminosity
dependence of the correlation function is primarily determined by the changing
relative contribution of central and satellite galaxies at different
luminosities. The color dependence of the GM correlations reflects the
difference in the typical environments of blue and red galaxies. We also find
agreement between the predicted and observed cross-bias, b_x=b/r,at all probed
scales.The GM correlation coefficient, r, is close to unity on scales >1/h
Mpc.The cross bias is thus expected to measure the actual bias of galaxy
clustering on these scales.The aperture mass-to-light ratio is independent of
galaxy color.The aperture mass scales approximately linearly with luminosity at
L_r>10^{10}h^{-2} Lsun, while at lower luminosities the scaling is shallower:
L_r^{0.5}. We show that most of the luminous galaxies (M_r<-21) are near the
centers of their halos and their GM correlation function at r<100/h kpc can
therefore be interpreted as the average dark matter density profile of these
galaxies. We find that for galaxies in a given narrow luminosity range, there
is a broad and possibly non-gaussian distribution of halo virial masses.
Therefore, the average relation between mass and luminosity derived from the
weak lensing analyses should be interpreted with caution.


title: Time-dependent secular evolution in galaxies

abstract:
  Lynden-Bell & Kalnajs (1972) presented a useful formula for computing the
long-range torque between spiral arms and the disk at large. The derivation
uses second-order perturbation theory and assumes that the perturbation slowly
grows over a very long time: the time-asymptotic limit. This formula has been
widely used to predict the angular momentum transport between spiral arms and
stellar bars between disks and dark-matter halos. However, this paper shows
that the LBK time-asymptotic limit is not appropriate because the
characteristic evolution time for galaxies is too close to the relevant
dynamical times. We demonstrate that transients, not present in the
time-asymptotic formula, can play a major role in the evolution for realistic
astronomical time scales. A generalisation for arbitrary time dependence is
presented and illustrated by the bar--halo and satellite--halo interaction. The
natural time dependence in bar-driven halo evolution causes quantitative
differences in the overall torque and qualitative differences in the physical-
and phase-space location of angular momentum transfer. The time-dependent
theory predicts that four principal resonances dominate the torque at different
times and accurately predicts the results of an N-body simulation. In addition,
we show that the Inner Lindblad Resonance (ILR) is responsible for the peak
angular momentum exchange but, due to the time dependence, the changes occur
over a broad range of energies, radii and frequencies. We describe the
implication of these findings for the satellite--halo interaction using a
simple model and end with a discussion of possible impact on other aspects
secular galaxy evolution.


title: Tidal Dynamics of Relativistic Flows Near Black Holes

abstract:
  We point out novel consequences of general relativity involving tidal
dynamics of ultrarelativistic relative motion. Specifically, we use the
generalized Jacobi equation and its extension to study the force-free dynamics
of relativistic flows near a massive rotating source. We show that along the
rotation axis of the gravitational source, relativistic tidal effects strongly
decelerate an initially ultrarelativistic flow with respect to the ambient
medium, contrary to Newtonian expectations. Moreover, an initially
ultrarelativistic flow perpendicular to the axis of rotation is strongly
accelerated by the relativistic tidal forces. The astrophysical implications of
these results for jets and ultrahigh energy cosmic rays are briefly mentioned.


title:
HS 0837+4717 -- a metal-deficient blue compact galaxy with large
  nitrogen excess

abstract:
  (Abridged) We present the results of high S/N long-slit spectroscopy with the
Multiple Mirror and the SAO 6-m telescopes, optical imaging with the Wise 1-m
telescope and HI observations with the Nancay Radio Telescope of the very
metal-deficient (12+log(O/H)=7.64) luminous (M_B=-18.1) blue compact galaxy
(BCG) HS 0837+4717. The blue bump near lambda4650, characteristic of WR stars
is detected in the central supergiant HII region, as well as the barely seen
red bump at lambda5808. The derived number of WR stars in the region of the
current starburst is ~1000. Evidence for fast motions in this region is also
seen as broad, low-contrast components in the Ha, Hb and strong [OIII] lines.
While the extinction of the narrow emission lines from the supergiant HII
region is low, the very large Balmer decrement of the broad components suggests
that the part of current starburst is highly obscured by dust. Abundance ratios
X/O for X=Ne, Ar, S, Fe and Cl in the supergiant HII region are in good
agreement with the mean values of other BCGs. Nitrogen, however, is
overabundant by a factor of ~6. This implies an unusually efficient N
enrichment in HS 0837+4717, and probably, a non-typical evolution scenario. The
Ha-line Position--Velocity diagrams for directions approximately along the
major and minor axes reveal disturbed motions of the ionized gas. The SW part
of the major axis P--V diagram looks like a rotation curve, with V_rot ~50--70
km/s at r=4.3 kpc. Its NE part displays, however, strong deviations, indicating
either counter-rotation, or strong outflow/supershell. The overall BCG
morphology is highly disturbed. With a "double-nucleus" structure, disturbed
velocities of ionized gas, and the very high power of the starburst this
suggests a possible explanation of the object as a recent merger.


title: Starburst activity in the host galaxy of the z=2.58 quasar J1409+5628

abstract:
  We report the detection of CO emission from the optically luminous,
radio-quiet quasar J140955.5+562827, at a redshift z_CO =2.583. We also present
VLA continuum mapping results and VLBA high spatial resolution observations at
1.4 GHz. Both the CO(3-2) and CO(7-6) emission lines are detected using the
IRAM Plateau de Bure interferometer. The 3-2/7-6 line luminosity ratio is about
1/3 indicating the presence of warm and dense molecular gas with an estimated
mass of 6x10^10 Msun. The infrared-to-CO luminosity ratio is L_FIR/L'_CO(1-0)
\approx 500 Lsun (Kkms^-1 pc^2)^-1,comparable with values found for other
high-z sources where CO line emission is seen.
  J1409+5628 is detected using the VLA with a 1.4 GHz rest-frame luminosity
density of 4.0x10^25 W Hz^-1. The radio to far-infrared ratio, q, has a value
of 2.0 which is consistent with the values found in star forming galaxies. At
the 30 mas resolution of the VLBA, J1409+5628 is not detected with a 4 sigma
upper limit to the surface brightness of 0.29 mJy beam^-1. This implies a limit
to the intrinsic brightness temperature of 2x10^5 K at 8 GHz, typical for
nuclear starbursts and two or more orders of magnitude weaker than typical
radio-loud active galactic nuclei. Both the properties of the CO line emission
and the radio emission from J1409+5628 are therefore consistent with those
expected for a star forming galaxy.
  In J1409+5628 young massive stars are the dominant source of dust heating,
accounting for most of the infrared luminosity, and the massive reservoir of
molecular gas can sustain the star formation rate of a few 1000 \Msun yr^-1
implied by the far-infrared luminosity for about 10 million years.


title:
Gravitational Wave and X-ray Signals from Stellar Disruption by a
  Massive Black Hole

abstract:
  Gravitational waves and X-ray flares are expected from tidal disruption of
stars by a massive black hole. Using a relativistic smoothed particle
hydrodynamics code, we investigate the fate of main sequence and Helium stars
in plunge orbits passing near Schwarzschild or a Kerr black holes of 10^5-6
Msun. We show that quadrupole gravitational waves emitted during the tidal
disruption process are described reasonable well by a point particle
approximation even in the strong encounter case. An additional hydrodynamic
calculation based on the Godunov method indicates that shocks develop for
sufficiently high tidal compressions. The shock-heating results in an X-ray
flare, which for solar-type stars disrupted by 10^6Msun black holes is in the
keV range, associated with the gravitational wave signal. The hardness and
duration of the X-ray flare may serve as a diagnostic of the mass of the
central black hole.


title:
Properties and Interpretations of Giant Micropulses and Giant Pulses
  from Pulsars

abstract:
  Giant pulses and giant micropulses from pulsars are distinguished from normal
pulsed emission by their large fluxes, rarity, approximately power-law
distribution of fluxes and, typically, occurrence in restricted phase windows.
Here existing observations of flux distributions are manipulated into a common
format and interpreted in terms of theories for wave growth in inhomogeneous
media, with the aim of constraining the emission mechanism and source physics
for giant pulses and micropulses. Giant micropulses near 2 GHz (PSRs B8033-45
and B1706-44) and 0.4 GHz (PSR B0950+08) have indices $\alpha = 6.5 \pm 0.7$
for the probability distribution $P(E)$ of the electric field $E$, with $P(E)
\propto E^{-\alpha}$. Giant pulses (PSRs B0531+24, B1937+214, and B1821-24)
have $\alpha$ ranging from $4.6 \pm 0.2$ to $9 \pm 2$, possibly increasing with
frequency. These are similar enough to regard giant micropulses and pulses as a
single phenomenon with a common physical explanation. The power-law functional
form and values of $\alpha$ observed are consistent with predictions for
nonlinear wave collapse, but inconsistent with known self-organized critical
systems, nonlinear decay processes, and elementary burst theory. While
relativistic beaming may be important, its statistics are yet to be predicted
theoretically and collapse is currently the favored interpretation. Other
possibilities remain, including stochastic growth theory (consistent with
normal pulse emission) and, less plausibly, refractive lensing. Unresolved
issues remain for all four interpretations and suggestions for further work are
given. The differences between normal and giant pulse emission suggest they
have distinct source regions and emission processes.


title:
Dusty, Radiation Pressure Dominated Photoionization. I. Model
  Description, Structure And Grids

abstract:
  We present the implementation of dusty, radiation pressure dominated
photoionization models applicable to the Narrow Line Regions (NLRs) of Active
Galactic Nuclei, using the \mapiii code. We give a grid of the predicted
intensities of the most commonly used diagnostic spectral lines in the UV,
optical and IR, covering a wide range of density, metallicity, the power-law
index characterizing the photoionizing source and photoionization parameter,
for use in the diagnosis of NLRs. We examine the temperature, density and
ionization structure of these models, investigating the effect of variation of
these parameters in order to gain a better understanding of NLR clouds
themselves.


title:
Dusty, Radiation Pressure Dominated Photoionization. II.
  Multi-Wavelength Emission Line Diagnostics for Narrow Line Regions

abstract:
  Seyfert narrow line region (NLR) emission line ratios are remarkably uniform,
displaying only ~0.5 dex variation between galaxies, and even less within an
individual object. Previous photoionization and shock models of this region
were unable to explain this observation without the introduction of arbitrary
assumptions or additional parameters. Dusty, radiation pressure dominated
photoionization models provide a simple physical mechanism which can reproduce
this spectral uniformity between different objects. In the first paper of this
series we described this model and its implementation in detail, as well as
presenting grids of model emission lines and examining the model structures.
Here we explore these models further, demonstrating their ability to reproduce
the observed Seyfert line ratios on standard line diagnostic diagrams in both
the optical and UV. We also investigate the effects that the variation of
metallicity, density and ionizing spectrum have upon both the new paradigm and
the standard photoionization models used hitherto. Along with the standard
diagnostic diagrams we provide several new diagnostic diagrams in the UV,
Optical and IR. These new diagrams can provide further tests of the dusty,
radiation pressure photoionization paradigm as well as being used as
diagnostics of the metallicity, density and ionizing spectrum of the emission
line clouds.


title:
Modelling the Pan-Spectral Energy Distributions of Starburst & Active
  Galaxies

abstract:
  We present results of a self-consistent model of the spectral energy
distribution (SED) of starburst galaxies. Two parameters control the IR SED,
the mean pressure in the ISM and the destruction timescale of molecular clouds.
Adding a simplified AGN spectrum provides mixing lines on IRAS color : color
diagrams. This reproduces the observed colors of both AGNs and starbursts.


title:
Dusty, Radiation Pressure Dominated Photoionization: The Solution to the
  Narrow Line Region Problem

abstract:
  Seyfert narrow line regions (NLR) have emission line ratios which are
remarkably uniform, displaying only ~0.5 dex variation between different
galaxies. Existing models have been unable to explain these observations
without the introduction of ad hoc assumptions, geometrical restrictions or new
parameters. Here we introduce a new model: dusty radiation pressure dominated
photoionization, which provides a natural self-regulating characteristic
leading to an invariance of the spectrum over a very wide range (>100) of
ionization parameter. The dusty model is able to reproduce both the range and
the absolute value of the observational line ratios not only in the standard
optical diagnostic diagrams but also in UV diagnostic plots, providing an
explanation to the problem in NLR observations.


title:
Cepheid distances from infrared long-baseline interferometry - II.
  Calibration of the Period-Radius and Period-Luminosity relations

abstract:
  Using our interferometric observations of seven classical Cepheids reported
in Kervella et al. (2003, Paper I), complemented by previously existing
measurements, we derive new calibrations of the Cepheids Period-Radius (P-R)
and Period-Luminosity (P-L) relations. We obtain a P-R relation of log R =
[0.767 +/- 0.009] log P + [1.091 +/- 0.011], only 1 sigma away from the
relation obtained by Gieren et al. (1998). We therefore confirm their P-R
relation at a level of Delta(log R) = +/- 0.02. We also derive an original
calibration of the P-L relation, assuming the slopes derived by Gieren et al.
(1998) from LMC Cepheids, alpha_K = -3.267 +/- 0.042 and alpha_V = -2.769 +/-
0.073. With a P-L relation of the form M = alpha (log P - 1) + beta, we obtain
log P = 1 reference points of beta(K) = -5.904 +/- 0.063 and beta(V) = -4.209
+/- 0.075. Our calibration in the V band is statistically identical to the
geometrical result of Lanoix et al. (1999).


title:
The angular size of dwarf stars and subgiants - Surface brightness
  relations calibrated by interferometry

abstract:
  The availability of a number of new interferometric measurements of Main
Sequence and subgiant stars makes it possible to calibrate the surface
brightness relations of these stars using exclusively direct angular diameter
measurements. These empirical laws allow to predict the limb darkened angular
diameters theta_LD of dwarfs and subgiants using their dereddened Johnson
magnitudes, or their effective temperature. The smallest intrinsic dispersions
of sigma < 1% on theta_LD are obtained for the relations based on the K and L
magnitudes, for instance log theta_LD = 0.0502 (B-L) + 0.5133 - 0.2 L or log
theta_LD = 0.0755 (V-K) + 0.5170 - 0.2 K. Our calibrations are valid between
the spectral types A0 and M2 for dwarf stars (with a possible extension to
later types when using the effective temperature), and between A0 and K0 for
subgiants. Such relations are particularly useful to estimate the angular size
of calibrators for long baseline interferometry from readily available
broadband photometry.


title: New Binary and Millisecond Pulsars from Arecibo Drift-Scan Searches

abstract:
  We discuss four recycled pulsars found in Arecibo drift-scan searches. PSR
J1944+0907 has a spin period of 5.2 ms and is isolated. The 5.8-ms pulsar
J1453+19 may have a low-mass companion. We discuss these pulsars in the context
of isolated millisecond pulsar formation and the minimum spin period of neutron
stars. The isolated 56-ms pulsar J0609+2130 is possibly the remnant of a
disrupted double neutron star binary. The 41-ms pulsar J1829+2456 is in a
relativistic orbit. Its companion is most likely another neutron star, making
this the eighth known double neutron star binary system.


title: On the ellipticity of galaxy clusters

abstract:
  We analysed 246 scanned ACO clusters and we do not find any dependence of
galaxy cluster ellipticity on redshift.


title: Luminous Infrared Starbursts in a Cluster of Galaxies

abstract:
  Analysing mid--infrared ISOCAM images of the cluster of galaxies J1888.16CL,
we identified among its members several particularly active galaxies with total
infrared luminosities well above 10^{11} Lsun. If powered by dust enshrouded
starbursts, as suggested by their optical spectra, these Luminous Infrared
Galaxies would exhibit star formation rates surprisingly high in the cluster
environment. The triggering mechanism is unclear but could be tidal collisions
within sub-structures or infalling groups.


title: The Large-Scale Environment of Groups & Clusters of Galaxies

abstract:
  It appears that the dynamical status of clusters and groups of galaxies is
related to the large-scale structure of the Universe. A few interesting trends
have been established:
  (1) The Cluster Substructure - Alignment Connection, by which clusters show a
strong correlation between their tendency to be aligned with their neighbors
and their dynamical state (as indicated by the existence of significant
substructres). (2) The Cluster Dynamics -Cluster Clustering Connection, by
which dynamically young clusters are more clustered than the overall cluster
population. (3) The Cluster- Supercluster Alignment Connection, by which
clusters of galaxies show a statistical significant tendency to be aligned with
the projected major axis orientation of their parent supercluster. (4) The
Galaxy Alignment - Cluster Dynamics Connection, by which red-sequence cluster
bright galaxies show a significant trend to be aligned with their parent
cluster major axis, especially in dynamically young clusters. (5) The Group
Richness - Shape Connection, by which groups of galaxies are flatter the poorer
they are.
  These are strong indications that clusters develop in a hierarchical fashion
by anisotropic merging of smaller units along the large-scale filamentary
structures within which they are embedded.


title: The Clustering of XMM-Newton Hard X-ray Sources

abstract:
  We present the clustering properties of hard (2-8 keV) X-ray selected sources
detected in a wide field (~2 deg^{2}) shallow [f(2-8 keV)~ 10^{-14} erg cm^{-2}
s^{-1}] and contiguous XMM-Newton survey. We perform an angular correlation
function analysis using a total of 171 sources to the above flux limit. We
detect a ~ 4\sigma correlation signal out to 300 arcsec with w(theta <
300^{''}) ~ 0.13 +- 0.03. Modeling the two point correlation function as a
power law of the usual form we find: theta_o=48.9^{+15.8}_{-24.5} arcsec and
gamma=2.2 +- 0.30. Fixing the correlation function slope to gamma=1.8 we obtain
theta_o=22.2^{+9.4}_{-8.6} arcsec. Using Limber's integral equation and a
variety of possible luminosity functions of the hard X-ray population, we find
a relatively large correlation length, ranging from r_o ~ 9 to 19 h^{-1} Mpc
(for gamma=1.8 and the concordance cosmological model), with this range
reflecting also different evolutionary models for the source luminosities and
clustering characteristics.


title:
Application of the Voronoi Tessellation Technique for Galaxy Cluster
  Search in the M\"{u}nster Red Sky Survey

abstract:
  We present the preliminary result of our project, consisting in studying the
properties of a large sample of galaxy clusters. The M\"{u}nster Red Sky
Survey, which is a large galaxy catalogue covering an area of about 5000 square
degrees on the southern hemisphere serves as our observational basis. It is
complete up to $r_F=18^m.3$. Creation of a cluster catalogue is the first step
of our investigation. We propose to use the 2D Voronoi tessellation technique
for identifying galaxy clusters in this 2D catalogue. Points with high values
of the inverse Voronoi tessel area will be regarded as galaxy cluster
centroids. We show that this approach works correctly.


title:
Iron Line Spectroscopy of NGC4593 with XMM-Newton: Where is the Black
  Hole Accretion Disk?

abstract:
  We present an analysis of the 2-10keV XMM-Newton/EPIC-pn spectrum of the
Seyfert-1 galaxy NGC4593. Apart from the presence of two narrow emission lines
corresponding to the Kalpha lines of cold and hydrogen-like iron, this spectrum
possesses a power-law form to within 3-5%. There is a marked lack of spectral
features from the relativistic regions of the black hole accretion disk. We
show that the data are, however, consistent with the presence of a
radiatively-efficient accretion disk extending right down to the radius of
marginal stability if it possesses low iron abundance, an appropriately ionized
surface, a very high inclination, or a very centrally concentrated emission
pattern (as has been observed during the Deep Minimum State of the Seyfert
galaxy MCG-6-30-15). Deeper observations of this source are required in order
to validate or reject these models.


title:
Orbital Periodicities in the Hard Emission from X-ray Transient - Black
  Hole Candidates Between Outbursts

abstract:
  During long-term observations of the Galactic Centre region in hard X-rays
(10-300 keV) in space experiments made on board Prognoz-9 satellite and "Mir"
orbital station (GRIF experiment) some periodic sources were revealed. They
include periodicities of hour and day range of period: 152 h, 98 h, 82 h
(4U1700-37), 69 h, 62 h, 13.3 h, 9.36 h, 8.03h, 8.15 h (Cen X-4), 4.38 h, 4.35h
(4U1755-33) and 3.45 h. For all the observed periodic processes the mean phase
profiles (light curves) in the different energy ranges were obtained. The mean
phase profiles of most of the observed periodic sources differ from both sine
and purely eclipse form. Among six sources with day ranges of period at least
three were identified with X-ray Novas - black hole candidates: 152 h
(H1705-25, Nov.Oph., 1977), 62 h (GRO J 1655-40, Nov. Sco., 1994), 13.3 h
(4U1543-47). The results of the GRO J 1655-40 and 4U1543-47 observations in the
Prognoz-9 and GRIF "Mir" experiments were compared with the observational data
obtained in space observatories CGRO,RXTE, BeppoSax. It should be noted that
the orbital periodicity is revealed in the hard emission of the X-ray transient
- black hole candidates GRO J 1655-40 and 4U1543-47 even in the epochs between
outbursts. Periodic processes with day ranges of periods can be typical for the
transient source like X-ray Nova - black-hole candidate. Such periodicity is
orbital but its origin is not connected with eclipses of the compact companion
of a binary system. Periodic processes in soft and hard X-rays can be
associated with orbital motion of binary system companions, but the physical
mechanisms and the regions of generation of soft and hard X-rays can be quite
different.


title:
Direct Evidence for Dynamical Evolution of Luminosity Functions of
  Globular Cluster Systems: HST/ACS observations of the 3-Gyr-old merger
  remnant NGC 1316

abstract:
  Recent observations of globular clusters (GCs) in intermediate-age (2-4 Gyr
old), early-type merger remnants have provided the hitherto `missing link'
between young merger remnants and `normal' elliptical galaxies in the form of a
GC subsystem with colors and luminosities consistent with population synthesis
model predictions for those ages and ~solar metallicity. Here we present new,
deep observations of the GC system of the intermediate-age merger remnant NGC
1316, using the ACS camera aboard Hubble Space Telescope, which allowed us to
create luminosity functions (LFs) as a function of galactocentric radius. We
find that the inner 50% of the `red' GC system shows a clear turnover in its
LF, at about 1 mag fainter than that of the `old' blue GCs. This constitutes
direct, dynamical evidence that metal-rich GC populations formed during a
gas-rich merger can evolve into the `red', metal-rich GC populations that are
ubiquitous in `normal' giant ellipticals.