title: The Rest-Frame Optical Properties of SCUBA Galaxies

abstract:
  We present optical and near-IR photometry of 96 dusty, far-IR luminous
galaxies. We have precise spectroscopic redshifts for all these galaxies
yielding a median redshift of z=2.2. The majority, 78, are submm-detected
galaxies lying at z=0.2-3.6, while the remaining 18 are optically-faint uJy
radio galaxies at z=0.9-3.4 which are proposed to be similarly luminous, dusty
galaxies whose dust emission is too hot to be detected in the submm. We compare
the photometric and morphological properties of these distant, ultraluminous
galaxies to local samples. We confirm that spectroscopically-identified far-IR
luminous galaxies at z>1 display a wide variety in their optical-near-IR and
near-IR colors, with only a modest proportion red enough to classify as
unusually red. We show that on average luminous, high-z dusty galaxies are both
brighter and redder in restframe optical passbands than UV-selected
star-forming galaxies at similar z. HST ACS imaging of 20 sources demonstrates
both indications of mergers and interactions, which may have triggered their
activity, and structured dust within these galaxies. We derive a near-IR Hubble
diagram for far-IR luminous galaxies, showing that they are typically fainter
than high luminosity radio galaxies at similar z and exhibit more scatter in
their K-band magnitudes. The typical extinction-corrected optical luminosity of
the high-z population, assuming passive evolution, provides a good fit to the
bright end of the luminosity function of luminous spheroidal galaxies seen in
rich clusters at z<1. This adds to the growing evidence that these high z,
far-infrared luminous sources identify star-formation and AGN fueling events in
the early life of massive galaxies. [Abridged]


title: Dwarf Seyfert 1 Nuclei and the Low-Mass End of the M-sigma Relation

abstract:
  To examine the relationship between black hole mass and host galaxy velocity
dispersion for low black hole masses, we have measured the velocity dispersions
of 15 Seyfert 1 galaxies from the catalog of Greene & Ho (2004). These Seyferts
were selected from the Sloan Digital Sky Survey to have estimated black hole
masses below 10^6 solar masses. The data are consistent with a straightforward
downward extrapolation of the local M-sigma relation, indicating that this
correlation extends over a range of more than four orders of magnitude in black
hole mass. The rms scatter of the sample about the extrapolated M-sigma
relation is 0.57 dex, consistent with the expected scatter of single-epoch mass
estimates for Seyfert 1 galaxies.


title:
When Supermassive Black Holes were growing: Clues from Deep X-ray
  Surveys

abstract:
  Merging the Chandra and XMM-Newton deep surveys with the previously
identified ROSAT sample, almost 1000 AGN-1 covering five orders of magnitude in
0.5-2 keV flux limit and six orders of magnitude in survey solid angle were
identified with ~95% completeness. AGN-1 are by far the largest contributors to
the soft X-ray samples. Their evolution is responsible for the break in the
0.5-2 keV source counts. Their soft X-ray luminosity function clearly changes
shape as a function of redshift, confirming earlier reports of
luminosity--dependent density evolution. The space density with redshift
changes significantly for different luminosity classes, showing a strong
positive evolution up to a certain redshift and then a flattening. The
redshift, at which the evolution peaks, changes considerably with X-ray
luminosity. The amount of density evolution also depends strongly on X-ray
luminosity, more than a factor of 100 at high luminosities, but less than a
factor of 10 for low luminosities. For the first time, a significant decline of
the space density of X-ray selected AGN towards high redshift has been
detected. No significant evolution of the X-ray to optical spectral index is
found for AGN-1. The constraints from the AGN luminosity function and evolution
in comparison with the mass function of black holes in local galaxies
indicates, that the average supermassive black hole has built up its mass
through efficient accretion and is likely rapidly spinning.


title: The Properties of Ultraviolet-Luminous Galaxies at the Current Epoch

abstract:
  We have used the first matched set of GALEX and SDSS data to investigate the
properties of a sample of 74 nearby galaxies with far-ultraviolet luminosities
chosen to overlap the luminosity range of typical high-z Lyman Break Galaxies
(LBGs). GALEX deep surveys have shown that ultraviolet-luminous galaxies
(UVLGs) similar to these are the fastest evolving component of the UV galaxy
population. Model fits to the combined GALEX and SDSS photometry yield typical
FUV extinctions similar to LBGs. The implied star formation rates are SFR ~ 3
to 30 solar mass per year. This overlaps the range of SFRs for LBGs. We find a
strong inverse correlation between galaxy mass and far-ultraviolet surface
brightness, and on this basis divide the sample into ``large'' and ``compact''
UVLGs. The compact UVLGs have half-light radii of a few kpc or less (similar to
LBGs). They are relatively low mass galaxies (~10 billion solar masses) with
typical velocity dispersions of 60 to 150 km/s. They span a range in
metallicity from 0.3 to 1 times solar, have blue optical-UV colors, and are
forming stars at a rate sufficient to build the present galaxy in ~a Gigayear.
In all these respects they appear similar to the LBG population. These ``living
fossils'' may therefore provide an opportunity for detailed investigation of
the physical processes occurring in typical star forming galaxies in the early
universe.


title: Anti-GZK effect in Ultra High Energy Cosmic Rays diffusive propagation

abstract:
  We discuss the antiGZK effect in the diffusive propagation of ultra high
energy protons in intergalactic magnetic fields, which consists in a jump-like
increase of the maximum distance from which ultra high energy protons can reach
an observer. The position of this jump, $E_j \approx 2\times 10^{18}$ eV, is
determined exclusively by energy losses (transition from adiabatic to
pair-production energy losses) and it is independent of the diffusion
parameters. The diffuse spectrum presents a low-energy steepening approximately
at this energy, which is very close to the position of the second knee observed
in the cosmic ray spectrum. The dip, seen in the universal spectrum as a
signature of the interaction with the cosmic microwave background radiation, is
also present in the case of diffusive propagation in magnetic fields.


title:
Small-scale systems of galaxies. II. Properties of the NGC 4756 group of
  galaxies

abstract:
  We present results from a study of the NGC 4756 group which is dominated by
the elliptical galaxy NGC 5746. The characteristics of the group are
investigated through (a) the detailed investigation of the morphological,
photometric and spectroscopic properties of nine galaxies among the dominant
members of the group (b) the determination of the photometric parameters of the
faint galaxy population in an area of 34'x34' centered on NGC 4756 and (c) an
analysis of the X-ray emission in the area based upon archival data. The 9
member galaxies are located in the core part of the NGC 4756 group (a strip
diameter about 300 kpc in diameter which has a very loose configuration. The
central part of the NGC 4756 group contains a significant fraction of
early-type galaxies. Three new group members with previously unknown systemic
velocities are identified, one of which is a dE. At about 7.5' SW of NGC 4756 a
sub-structure of the group is detected, including IC 829, MCG -2-33-35, MCG
-2-33-36 and MCG -2-33-38, which meets the Hickson criteria for being a compact
group. Most of the galaxies in this sub-structure show interaction signatures.
We do not detect apparent fine structure and signatures of recent interaction
events in the early-type galaxy population, with the exception of a strong dust
lane in the elliptical MCG -2-33-38. This galaxy displays however signatures of
nuclear activity. Strong [O III], [N II] and [S II] line emission, combined
with comparatively weak, but broad H alpha emission suggest an intermediate
Seyfert type classification. Although the area is heavily contaminated by the
background cluster Abell 1631, X-ray data suggest the presence of a hot
intergalactic medium related to the group to the X-ray emission detected. The
present results are discussed in the context of group evolution.


title:
Doppler tomography of the Little Homunculus: High resolution spectra of
  [Fe II] 16435 around Eta Carinae

abstract:
  High-resolution spectra of [Fe II] 16435 around eta Carinae provide powerful
diagnostics of the geometry and kinematics of the ``Little Homunculus'' (LH)
growing inside the larger Homunculus nebula. The LH expansion is not perfectly
homologous: while low-latitudes are consistent with linear expansion since
1910, the polar caps imply ejection dates around 1920--1930. However, the
expansion speed of the LH is slower than the post-eruption wind, so the star's
powerful wind may accelerate it. With an initial ejection speed of 200 km/s in
1890, the LH would have been accelerated to its present speed if the mass is
roughly 0.1 Msun. This agrees with an independent estimate of the LH mass based
on its density and volume. In any case, an ejection after 1930 is ruled out.
Using the LH as a probe of the 1890 event, then, it is evident that its most
basic physical parameters (total mass and kinetic energy; 0.1 Msun and 10^46.9
ergs, respectively) are orders of magnitude less than during the giant eruption
in the 1840s. Thus, the ultimate energy sources were different for these two
events -- yet their ejecta have the same bipolar geometry. This clue may point
toward a collimation mechanism separate from the underlying causes of the
outbursts.


title:
Cosmic Microwave Background Fluctuations from Gravitational Waves: An
  Analytic Approach

abstract:
  We develop an analytic approach to calculation of the temperature and
polarisation power spectra of the cosmic microwave background due to
inflationary gravitational waves. This approach complements the more precise
numerical results by providing insight into the physical origins of the
features in the power spectra. We explore the use of analytic approximations
for the gravitational-wave evolution, making use of the WKB approach to handle
the radiation-matter transition. In the process, we describe scaling relations
for the temperature and polarisation power spectra. We illustrate the
dependence of the amplitude, shape, and peak locations on the details of
recombination, the gravitational-wave power spectrum, and the cosmological
parameters, and explain the origin of the peak locations in the temperature and
polarisation power spectra. The decline in power on small scales in the
polarisation power spectra is discussed in terms of phase-damping. In an
appendix we detail numerical techniques for integrating the gravitational-wave
evolution in the presence of anisotropic stress from free-streaming neutrinos.


title:
Blazing Cerenkov Flashes at the Horizons by Cosmic Rays and Neutrinos
  Induced Air-Showers

abstract:
  High Energy Cosmic Rays (C.R.) versus Neutrino and Neutralino induced
Air-Shower maybe tested at Horizons by their muons, gamma and Cerenkov blazing
signals. Inclined and Horizontal C.R. Showers (70-90 zenith angle) produce
secondary (gamma, e+, e-) mostly suppressed by high column atmosphere depth.
Earliest shower Cherenkov photons are diluted by large distances and by air
opacity, while secondary penetrating muons and their successive decay into
electrons and gamma, may revive additional Cerenkov lights. GeVs gamma
telescopes at the top of the mountains or in Space may detect at horizons PeVs
up to EeV C.R. and their secondaries. Details on arrival angle and column
depth, shower shape, timing signature of photon flash intensity, may inform us
on the altitude interaction and primary UHECR composition. Below the horizons,
at zenith angle among copious single albedo muons, rare up-going showers traced
by muon bundles would give evidence of rare tau Earth-Skimming neutrinos, at
EeVs energies. Their rate may be comparable with 6.3 PeVs anti-neutrino
electron induced air-shower (mostly hadronic) originated above and also below
horizons, in interposed atmosphere by W resonance at Glashow peak. Additional
and complementary UHE SUSY neutralinos at tens PeVs-EeV energy may blaze, by
its characteristic electromagnetic signature. Their secondary shower blazing
Cerenkov lights and distances might be disentangled from UHECR by Stereoscopic
Telescopes such as Magic ones or Hess array experiment. The horizontal
detection sensitivity of Magic in the present set up (if totally devoted to the
Horizons Shower search) maybe already be comparable to AMANDA underground
neutrino detector at PeVs energies.


title: The signature of dark energy on the local Hubble flow

abstract:
  Using N-body simulations of flat, dark energy dominated cosmologies, we show
that galaxies around simulated binary systems resembling the Local Group (LG)
have low peculiar velocities, in good agreement with observational data. We
have compared results for LG-like systems selected from large, high resolution
simulations of three cosmologies: a LCDM model, a LWDM model with a 2 keV warm
dark matter candidate and a quintessence model (QCDM) with an equation of state
parameter w=-0.6.
  The Hubble flow is significant colder around LGs selected in a flat, Lambda
dominated cosmology than around LGs in open or critical models, showing that a
dark energy component manifests itself on the scales of nearby galaxies,
cooling galaxy peculiar motions. Flows in the LWDM and QCDM models are
marginally colder than in the LCDM one.
  The results of our simulations have been compared to existing data and a new
data set of 28 nearby galaxies with robust distance measures (Cepheids and
Surface Brightness Fluctuations). The measured line-of-sight velocity
dispersion is sigma = 88 +- 20 km/sec x (R/7 Mpc). The best agreement with
observations is found for LGs selected in the $\Lambda$CDM cosmology in
environments with -0.1 <delta_rho/rho < 0.6 on scales of 7 Mpc, in agreement
with existing observational estimates on the local matter density.
  These results provide new, independent evidence for the presence of dark
energy on scales of few Mpc, corroborating the evidence gathered from
observations of distant objects and the early Universe.


title: Chemical Abundance Inhomogeneities in Globular Cluster Stars

abstract:
  It is now clear that abundance variations from star-to-star among the light
elements, particularly C, N, O, Na and Al, are ubiquitous within galactic
globular clusters; they appear seen whenever data of high quality is obtained
for a sufficiently large sample of stars within such a cluster. The
correlations and anti-correlations among these elements and the range of
variation of each element appear to be independent of stellar evolutionary
state, with the exception that enhanced depletion of C and of O is sometimes
seen just at the RGB tip. While the latter behavior is almost certainly due to
internal production and mixing, the internal mixing hypothesis can now be ruled
out for producing the bulk of the variations seen. We focus on the implications
of our new data for any explanation invoking primordial variations in the
proto-cluster or accretion of polluted material from a neighboring AGB star.


title: Starbursts and Galaxy Evolution

abstract:
  Starbursts are extreme concentrations of star-forming activity with mass
conversion surface densities reaching over 1000 times higher than normal for
disk galaxies. They are responsible for a large fraction of all cosmic star
formation. They have shaped the cosmic landscape not just in individual
galaxies but though the effects of "superwinds" that enrich the intergalactic
gas, constrain supermassive black hole growth, and perhaps facilitate cosmic
reionization. This conference provided vivid testimony to the importance of
starbursts in galaxy evolution and to the speed with which our understanding of
them is being transformed by a flood of new pan-spectral data, especially at
high redshifts. A key result is that it appears possible to scale the physics
of smaller star-forming events upward to encompass starbursts.


title: Structure Formation With a Long-Range Scalar Dark Matter Interaction

abstract:
  Numerical simulations show that a long-range scalar interaction in a single
species of massive dark matter particles causes voids between the
concentrations of large galaxies to be more nearly empty, suppresses accretion
of intergalactic matter onto galaxies at low redshift, and produces an early
generation of dense dark matter halos. These three effects, in moderation, seem
to be improvements over the Lambda CDM model predictions for cosmic structure
formation. Because the scalar interaction in this model has negligible effect
on laboratory physics and the classical cosmological tests, it offers an
observationally attractive example of cosmology with complicated physics in the
dark sector, notably a large violation of the weak equivalence principle.


title:
The Local Instability of Steady Astrophysical Flows with non Circular
  Streamlines with Application to Differentially Rotating Disks with Free
  Eccentricity

abstract:
  We carry out a general study of the stability of astrophysical flows that
appear steady in a uniformly rotating frame. Such a flow might correspond to a
stellar pulsation mode or an accretion disk with a free global distortion
giving it finite eccentricity. We consider perturbations arbitrarily localized
in the neighbourhood of unperturbed fluid streamlines.When conditions do not
vary around them, perturbations take the form of oscillatory inertial or
gravity modes. However, when conditions do vary so that a circulating fluid
element is subject to periodic variations, parametric instability may occur.
For nearly circular streamlines, the dense spectra associated with inertial or
gravity modes ensure that resonance conditions can always be satisfied when
twice the period of circulation round a streamline falls within. We apply our
formalism to a differentially rotating disk for which the streamlines are
Keplerian ellipses, with free eccentricity up to 0.7, which do not precess in
an inertial frame. We show that for small $e,$ the instability involves
parametric excitation of two modes with azimuthal mode number differing by
unity in magnitude which have a period of twice the period of variation as
viewed from a circulating unperturbed fluid element. Instability persists over
a widening range of wave numbers with increasing growth rates for larger
eccentricities. The nonlinear outcome is studied in a follow up paper which
indicates development of small scale subsonic turbulence.


title: A sample of X-ray emitting normal galaxies from the BMW -- HRI Catalogue

abstract:
  We have obtained a sample of 143 normal galaxies with X-ray luminosity in the
range $10^{38} - 10^{43}$ erg s$^{-1}$ from the cross-correlation of the ROSAT
HRI Brera Multi-scale Wavelet (BMW -- HRI) Catalogue with the Lyon-Meudon
Extragalactic Database (LEDA). We find that the average X-ray properties of
this sample are in good agreement with those of other samples of galaxies in
the literature. We have selected a complete flux limited serendipitous sample
of 32 galaxies from which we have derived the logN-logS distribution of normal
galaxies in the flux range $1.1 - 110 \times 10^{-14}$ erg cm$^{-2}$ s$^{-1}$.
The resulting distribution is consistent with the euclidean -1.5 slope.
Comparisons with other samples, such as the Extended Medium Sensitivity Survey,
the ROSAT All Sky Survey, the XMM - Newton/2dF survey and the Chandra Deep
Field Survey indicate that the logN-logS distribution of normal galaxies is
consistent with an euclidean slope over a flux range of about 6 decades.


title:
Probing the environment in Gamma-ray bursts: the case of an X-ray
  precursor, afterglow late onset and wind vs constant density profile in
  GRB011121 and GRB011211

abstract:
  In this paper we present BeppoSax and XMM observations of two long Gamma-ray
bursts, the X-ray rich event of December 11, 2001 (GRB011211) and the hard and
very bright event of November 21, 2001 (GRB011121). In both events we find
evidence of a late X-ray burst, taking place several minutes after the prompt
emission. The temporal and spectral behaviour of this phenomenon suggest that
it represents the onset of the afterglow. Broad band spectral modelling of the
afterglow indicate that the fireball evolution in the December burst takes
place in a ISM environment. On the contrary in the November burst the wind case
is revealed by an X-ray decay slower than that observed in the optical
($\delta_{\rm X}=1.29\pm0.04$ vs $\delta_{\rm O}=1.66\pm0.06$). The wind
profile should change into a constant density profile at large radii, in order
to reconcile late-time radio data with a jet. Two other results are obtained
for this burst. An X-ray burst is preceding by about 30 s the much harder GRB.
Contrary to the prediction of simple models of precursor activity for
collapsars, its spectrum is not consistent with a black body. Finally, a
substantial absorption column ($\NH=(7\pm2)\times10^{22}$ cm$^{-2}$) is
detected during the early part of the prompt emission. This is much greater
than that of the wind, and it is thus likely associated with the region
surrounding the burst.


title:
Precise measurement of CMB polarisation from Dome-C: the BRAIN and
  CLOVER experiments

abstract:
  The characterisation of CMB polarisation is one of the next challenge in
observationnal cosmology. This is especially true for the so-called B-modes
that are at least 3 order of magnitude lower than CMB temperature fluctuations.
A precise measurement of the angular power spectrum of these B-modes will give
important constraints on inflation parameters. In this talk, I will describe
two complementary experiments, BRAIN and CLOVER, dedicated to CMB polarisation
measurement. These experiments are proposed to be installed in Dome-C,
Antarctica, to take advantage of the extreme dryness of the atmosphere and to
allow long integration time.


title: QGSJET-II: results for extensive air showers

abstract:
  The new hadronic Monte Carlo model QGSJET-II is applied for extensive air
shower (EAS) calculations. The obtained results are compared to the predictions
of the original QGSJET and of the SIBYLL 2.1 interaction models. It is shown
that non-linear effects change substantially model predictions for
hadron-nucleus interactions and produce observable effects for calculated EAS
characteristics. Finally the impact of the new model on the interpretation of
air shower array data is discussed.


title:
Chandra-LETGS observation of Mrk 279: modeling the AGN internal
  structure

abstract:
  We present the Chandra-LETGS analysis of Mrk 279, a bright Seyfert 1 galaxy.
The spectrum shows a variety of features arising from different physical
environments in the vicinity of the black hole. We detect three absorption
components, located at the redshift of the source. One of them is likely to
arise from the host galaxy. An additional component due to absorption by a
collisionally ionized gas at z=0 is also observed. Such an absorption can be
produced in the outskirts of our Galaxy or in the local group. The emission
spectrum is rich in narrow and broad emission features. We tested the
hypothesis that the broad emission lines originate in the Broad Line Region
(BLR), as studied in the UV band. We find that at least 2 components with
different ionization parameters are necessary to simultaneously interpret the
broad emission line measured in the UV (by HST-STIS and FUSE) and in the
X-rays.


title:
Secular Decrease and Random Variations of Cassiopeia A at 151.5 and 927
  MHz

abstract:
  Long-term measurements of the radio flux density of Cassiopeia A relative to
Cygnus A have been carried out at 927 and 151.5 MHz. It was found the following
mean secular decrease rates of the radio emission of Cassiopeia A: $(0.72\pm
0.03)% \hbox{year}^{-1}$ at 927 MHz (for the period 1977--2002) and $(0.88\pm
0.09)% \hbox{year}^{-1}$ at 151.5 MHz (for the period 1980--2002). These values
of the secular decrease rate obtained over the period of the last 25 years are
substantially less than those of Baars et al. (1977). This indicates to the
slowing down of Cassiopeia A radio emission secular decrease. In addition to
this large scale time variation of Cassiopeia A flux density the measurements
have also shown a small scale (a few years) time variations over the smooth
secular decrease.


title:
The onset of a small-scale turbulent dynamo at low magnetic Prandtl
  numbers

abstract:
  We study numerically the dependence of the critical magnetic Reynolds number
Rmc for the turbulent small-scale dynamo on the hydrodynamic Reynolds number
Re. The turbulence is statistically homogeneous, isotropic, and
mirror--symmetric. We are interested in the regime of low magnetic Prandtl
number Pm=Rm/Re<1, which is relevant for stellar convective zones, protostellar
disks, and laboratory liquid-metal experiments. The two asymptotic
possibilities are Rmc->const as Re->infinity (a small-scale dynamo exists at
low Pm) or Rmc/Re=Pmc->const as Re->infinity (no small-scale dynamo exists at
low Pm). Results obtained in two independent sets of simulations of MHD
turbulence using grid and spectral codes are brought together and found to be
in quantitative agreement. We find that at currently accessible resolutions,
Rmc grows with Re with no sign of approaching a constant limit. We reach the
maximum values of Rmc~500 for Re~3000. By comparing simulations with Laplacian
viscosity, fourth-, sixth-, and eighth-order hyperviscosity and Smagorinsky
large-eddy viscosity, we find that Rmc is not sensitive to the particular form
of the viscous cutoff. This work represents a significant extension of the
studies previously published by Schekochihin et al. 2004, PRL 92, 054502 and
Haugen et al. 2004, PRE, 70, 016308 and the first detailed scan of the
numerically accessible part of the stability curve Rmc(Re).


title: A study of spectra of Cyg X-3 observed by BeppoSAX

abstract:
  We model the ~1-200 keV spectra of Cygnus X-3 observed by BeppoSAX. The
continuum, modeled by Comptonization in a hybrid plasma, is modified by the
strongly ionized plasma of the stellar wind of the Wolf-Rayet companion star.
Discrete absorption and emission spectral features are modeled with XSTAR. The
model has been applied to phase-resolved spectra in the hard and soft spectral
states.


title:
Gravitational Lensing & Stellar Dynamics: Dark-Matter and Baryons in
  Early-type Galaxies to z=1

abstract:
  Gravitational lensing and stellar dynamics provide two complementary, nearly
orthogonal, constraints on the mass distribution of early-type lens galaxies.
This allows the luminous and dark-matter distribution in higher-redshift
(z>0.1) galaxies to be studied beyond the limitations of each individual
method. Two surveys have been initiated to compile a large sample of early-type
galaxies suitable to lensing and dynamical studies: (1) The Lenses Structure &
Dynamics (LSD) Survey and (2) the Sloan Lens ACS (SLACS) Survey. Using
spherically symmetric mass models, I illustrated how lensing and dynamical
constraints can be used to measure the ``effective'' density slope (gamma') of
galaxies inside their Einstein radii and estimate the typical error on this
determination. The main results from the LSD survey thus far are: (i) Massive
(typically >L_*) early-type galaxies at z=0.5-1 contain a significant fraction
f_CDM=0.4-0.7 of dark matter inside their Einstein radii. [The null-hypothesis,
f_CDM=0, is excluded at the >99% in all analyzed systems.] (ii) The inner CDM
density slope is gamma_CDM=1.3^{+0.2}_{-0.3} (68% CL). (iii) The total density
slope gamma' = 1.9 +- 0.1 (with 0.3 rms scatter in the sample). The intrinsic
scatter of 15% in gamma' is consistent with local dynamical studies and can
lead to a 30% rms scatter in inferred values of H_0 from lens time-delays, when
purely isothermal mass models are assumed. Hence, the common practice to assume
that lens galaxies are perfectly isothermal should be abandoned, especially in
cases where this assumption is critical.


title: The evolution of black hole states

abstract:
  We discuss the evolution of black hole transients on the basis of a few
systems that were intensively observed with the Rossi X-ray Timing Explorer. We
focus on the global evolution and the observed state transitions. Rather than
giving a numerical recipe for classifying observations, we try to identify
times during outbursts at which clear changes occur in the X-ray variability,
X-ray spectral, or multi-wavelength properties.


title:
High Galactic latitude polarized emission at 1.4 GHz and implications
  for cosmic microwave background observations

abstract:
  We analyse the polarized emission at 1.4 GHz in a 3x3 deg^2 area at high
Galactic latitude (b ~ -40deg). The region, centred in (RA=5h, Dec=-49deg), was
observed with the Australia Telescope Compact Array radio-interferometer, whose
3-30 arcmin angular sensitivity range allows the study of scales appropriate
for CMB Polarization (CMBP) investigations. The angular behavior of the diffuse
emission is analysed through the E- and B-mode power spectra. These follow a
power law $C^X_l \propto l^{\beta_X}$ with slopes \beta_E = -1.97 \pm 0.08 and
\beta_B = -1.98 \pm 0.07. The emission is found to be about a factor 25 fainter
than in Galactic plane regions. The comparison of the power spectra with other
surveys indicates that this area is intermediate between strong and negligible
Faraday rotation effects. A similar conclusion can be reached by analysing both
the frequency and Galactic latitude behaviors of the diffuse Galactic emission
of the 408-1411 MHz Leiden survey data. We present an analysis of the Faraday
rotation effects on the polarized power spectra, and find that the observed
power spectra can be enhanced by a transfer of power from large to small
angular scales. The extrapolation of the spectra to 32 and 90GHz of the CMB
window suggests that Galactic synchrotron emission leaves the CMBP E-mode
uncontaminated at 32GHz. The level of the contamination at 90GHz is expected to
be more than 4 orders of magnitude below the CMBP spectrum. Extrapolating to
the relevant angular scales, this region also appears adequate for
investigation of the CMBP B-modes for models with tensor/scalar fluctuation
power ratio T/S>0.01. We also identify polarized point sources in the field,
providing a 9 object list which is complete down to the polarized flux limit of
S^p_lim = 2 mJy.


title: A Chandra observation of the X-ray environment and jet of 3C296

abstract:
  We have observed the twin-jet radio galaxy 3C296 with Chandra. X-ray emission
is detected from the nucleus, from the inner parts of the radio jet, and from a
small-scale thermal environment around the jet deceleration region. As we have
found in previous observations of other twin-jet radio galaxies, the X-ray jet
and a steep pressure gradient in the external thermal environment are
associated with the region where strong bulk deceleration of the jet material
is suggested by radio observations. Our observations provide additional
evidence that the inner jets of twin-jet objects are always associated with a
relatively cool, dense central X-ray emitting component with a short cooling
time.


title:
The discovery of a type-II quasar at z = 1.65 with integral-field
  spectroscopy

abstract:
  In this letter we report the serendipitous discovery of a genuine type-II
quasar at z = 1.65 using integral-field data from VIMOS on the VLT. This is the
first discovery of a type-II quasar at z > 1 from optical data alone.
J094531-242831, hereafter J0945-2428, exhibits strong narrow (v < 1500km/s)
emission lines, has a resolved host galaxy, and is undetected to a radio
flux-density limit of S_{5GHz} = 0.15 mJy (3 sigma). All of these lead us to
believe that J0945-2428 is a bona fide type-II quasar.
  The luminosity of the narrow-emission lines in this object suggest that the
intrinsic power of the central engine is similar to that found in powerful
radio galaxies, indicative of similarly large supermassive black hole of ~3 x
10^8 M_solar (assuming that it is accreting at its Eddington limit). However,
from near-infrared imaging observations we find that the old stellar population
in the host galaxy has a luminosity of ~0.2 L*, mildly inconsistent with the
correlation between black-hole mass and bulge luminosity found locally,
although the uncertainty in the black-hole mass estimate is large.
  This discovery highlights the power that integral-field units have in
discovering hidden populations of objects, particularly the sought after
type-II quasars which are invoked to explain the hard X-ray background. As
such, future large integral-field surveys could open up a new window on the
obscured accretion activity in the Universe.


title: Theoretical tools for CMB physics

abstract:
  This review presents, in a self-consistent manner, those analytical tools
that are relevant for the analysis of the physics of CMB anisotropies generated
in different theoretical models of the early Universe. After introducing the
physical foundations of the Sachs-Wolfe effect, the origin and evolution of the
scalar, tensor and vector modes of the geometry is treated in both
gauge-invariant and gauge-dependent descriptions. Some of the recent progresses
in the theory of cosmological perturbations are scrutinized with particular
attention to their implications for the adiabatic and isocurvature paradigms,
whose description is reviewed both within conventional fluid approaches and
within the the Einstein-Boltzmann treatment. Open problems and theoretical
challenges for a unified theory of the early Universe are outlined in light of
their implications for the generation of large-scale anisotropies in the CMB
sky and in light of the generation of stochastic backgrounds of relic gravitons
between few Hz and the GHz.


title:
Triggered massive-star formation on the borders of Galactic HII regions.
  I. A search for `collect and collapse' candidates

abstract:
  Young massive stars or clusters are often observed at the peripheries of HII
regions. What triggers star formation at such locations? Among the scenarios
that have been proposed, the `collect and collapse' process is particularly
attractive because it permits the formation of massive objects via the
fragmentation of the dense shocked layer of neutral gas surrounding the
expanding ionized zone. However, until our recent article on Sh 104, it had not
been convincingly demonstrated that this process actually takes place. In the
present paper we present our selection of seventeen candidate regions for this
process; all show high-luminosity near-IR clusters and/or mid-IR point sources
at their peripheries. The reality of a `collect and collapse' origin of these
presumably second-generation stars and clusters will be discussed in
forthcoming papers, using new near-IR and millimetre observations.


title: A variability and localization study of 3EG J1746-2851

abstract:
  I have studied the variability properties and localization of 3EG J1746-2851
based on EGRET data of the observing periods 1-4. Using corrections for know
systematic problems and performing various consistency checks I find no
evidence of variability with an amplitude exceeding 30% with the possible
exception of viewing period 429, for which a strong soft excess is observed.
3EG J1746-2851 is displaced from the exact Galactic Center towards positive
Galactic longitudes. Sgr A*, the center of Sgr A East, the pulsar J1747-2958,
and the TeV gamma-ray source observed with HESS seem to be excluded as possible
counterparts at the > 95% level.


title:
An optimal filter for the detection of galaxy clusters through weak
  lensing

abstract:
  We construct a linear filter optimised for detecting dark-matter halos in
weak-lensing data. The filter assumes a mean radial profile of the halo shear
pattern and modifies that shape by the noise power spectrum. Aiming at
separating dark-matter halos from spurious peaks caused by large-scale
structure lensing, we model the noise as being composed of weak lensing by
large-scale structures and Poisson noise from random galaxy positions and
intrinsic ellipticities. Optimal filtering against the noise requires the
optimal filter scale to be smaller than typical halo sizes. Although a perfect
separation of halos from spurious large-scale structure peaks is strictly
impossible, we use numerical simulations to demonstrate that our filter
produces substantially more sensitive, reliable and stable results than the
conventionally used aperture-mass statistic.


title:
Source subtraction for the extended Very Small Array and 33-GHz source
  count estimates

abstract:
  We describe the source subtraction strategy and observations for the extended
Very Small Array, a CMB interferometer operating at 33 GHz. A total of 453
sources were monitored at 33 GHz using a dedicated source subtraction baseline.
131 sources brighter than 20 mJy were directly subtracted from the VSA
visibility data. Some characteristics of the subtracted sources, such as
spectra and variability, are discussed. The 33-GHz source counts are estimated
from a sample selected at 15 GHz. The selection of VSA fields in order to avoid
bright sources introduces a bias into the observed counts. This bias is
corrected and the resulting source count is estimated to be complete in the
flux-density range 20-114 mJy. The 33-GHz source counts are used to calculate a
correction to the VSA power spectrum for sources below the subtraction limit.


title:
Constraining the local radiation field and the grain size distribution
  in dust SED modelling of dwarf galaxies

abstract:
  I present a simple self-consistent dust spectral energy distribution (SED)
model that has been applied to fit the well-sampled observed UV-to-radio SED of
four nearby starbursting dwarf galaxies. The main originality of this model is
that numerous multi-wavelength observations, from UV to millimeter (mm),
constrain in a self-consistent manner, both the local radiation field and the
grain size distribution. I finally present the results of our model and discuss
the average dust properties in these dwarf galaxies.


title: Mapping on the HEALPix grid

abstract:
  The natural spherical projection associated with the Hierarchical Equal Area
and isoLatitude Pixelisation, HEALPix, is described and shown to be one of an
infinite class not previously documented in the cartographic literature.
Projection equations are derived for the class in general and it is shown that
the HEALPix projection suggests a simple method (a) of storing, and (b)
visualising data sampled on the grid of the HEALPix pixelisation, and also
suggests an extension of the pixelisation that is better suited for these
purposes. Potentially useful properties of other members of the class are
described. Finally, the formalism is defined for representing any member of the
class in the FITS data format.


title:
Iron Fluorescent Line Emission from Young Stellar Objects in the Orion
  Nebula

abstract:
  We present the result of a systematic search for the iron Kalpha fluorescent
line at 6.4 keV among 1616 X-ray sources detected by ultra-deep Chandra
observations of the Orion Nebula Cluster and the obscured Orion Molecular Cloud
1 population as part of the Chandra Orion Ultra-deep Project (COUP). Seven
sources are identified to have an excess emission at 6.4 keV among 127 control
sample sources with significant counts in the 6.0-9.0 keV band. These seven
sources are young stellar objects (YSOs) characterized by intense flare-like
flux variations, thermal spectra, and near-infrared (NIR) counterparts. The
observed equivalent widths of the line cannot be attributed to the fluorescence
by interstellar or circumstellar matter along the line of sight. The X-ray
spectral fits and NIR colors of the 6.4 keV sources show that these sources
have X-ray absorption of > 1x10^22 cm^(-2) and NIR excess emission, which is
not expected when the fluorescence occurs at the stellar photosphere. We
therefore conclude that the iron fluorescent line of YSOs arises from
reflection off of circumstellar disks, which are irradiated by the hard X-ray
continuum emission of magnetic reconnection flares.


title: Dark Energy, Scalar-Tensor Gravity and Large Extra Dimensions

abstract:
  We explore in detail a dilatonic scalar-tensor theory of gravity inspired by
large extra dimensions, where a radion field from compact extra dimensions
gives rise to quintessence in our 4-dimensional world. We show that the model
can give rise to other types of cosmologies as well, some more akin to
$k$-essence and possibly variants of phantom dark energy. In our model the
field (or radius) stabilization arises from quantum corrections to the
effective 4D Ricci scalar. We then show that various constraints nearly
determine the model parameters, and give an example of a quintessence-type
cosmology consistent with observations. We show that the upcoming
SNAP-experiment would easily distinguish the present model from a constant
$\Lambda$ model with an \emph{equal} amount of dark energy, but that the
SNAP-data alone will not be able distinguish it from a $\Lambda$ model with
about 5% less dark energy.


title: KASCADE: Astrophysical results and tests of hadronic interaction models

abstract:
  KASCADE is a multi-detector setup to get redundant information on single air
shower basis. The information is used to perform multiparameter analyses to
solve the threefold problem of the reconstruction of (i)the unknown primary
energy, (ii) the primary mass, and (iii) to quantify the characteristics of the
hadronic interactions in the air-shower development. In this talk recent
results of the KASCADE data analyses are summarized concerning cosmic ray
anisotropy studies, determination of flux spectra for different primary mass
groups, and approaches to test hadronic interaction models. Neither large scale
anisotropies nor point sources were found in the KASCADE data set. The energy
spectra of the light element groups result in a knee-like bending and a
steepening above the knee. The topology of the individual knee positions shows
a dependency on the primary particle. Though no hadronic interaction model is
fully able to describe the multi-parameter data of KASCADE consistently, the
more recent models or improved versions of older models reproduce the data
better than few years ago.


title:
CFC+: Improved dynamics and gravitational waveforms from relativistic
  core collapse simulations

abstract:
  Core collapse supernovae are a promising source of detectable gravitational
waves. Most of the existing (multidimensional) numerical simulations of core
collapse in general relativity have been done using approximations of the
Einstein field equations. As recently shown by Dimmelmeier et al (2002a,b), one
of the most interesting such approximation is the so-called conformal flatness
condition (CFC) of Isenberg, Wilson and Mathews. Building on this previous work
we present here new results from numerical simulations of relativistic
rotational core collapse in axisymmetry, aiming at improving the dynamics and
the gravitational waveforms. The computer code used for these simulations
evolves the coupled system of metric and fluid equations using the 3+1
formalism, specialized to a new framework for the gravitational field equations
which we call CFC+. In this approach we add new degrees of freedom to the
original CFC equations, which extend them by terms of second post-Newtonian
order. The corrections for CFC+ are computed solving a system of elliptic
linear equations. The new formalism is assessed with time evolutions of both
rotating neutron stars in equilibrium and gravitational core collapse of
rotating polytropes. Gravitational wave signals for a comprehensive sample of
collapse models are extracted using either the quadrupole formula or directly
from the metric. We discuss our results on the dynamics and the gravitational
wave emission through a detailed comparison between CFC and CFC+ simulations.
The main conclusion is that, for the neutron star spacetimes analyzed in the
present work, no significant differences are found among CFC, CFC+, and full
general relativity, which highlights the suitability of the former.


title:
Galaxy Collisions, Gas Stripping and Star Formation in the Evolution of
  Galaxies

abstract:
  A review of gravitational and hydrodynamical processes during formation of
clusters and evolution of galaxies is given. Early, at the advent of N-body
computer simulations, the importance of tidal fields in galaxy encounters has
been recognized. Orbits are crowded due to tides along spiral arms, where the
star formation is enhanced. Low relative velocity encounters lead to galaxy
mergers. The central dominating galaxies in future clusters form before the
clusters in a merging process in galaxy groups. Galaxy clusters are composed in
a hierarchical scenario due to relaxation processes between galaxies and galaxy
groups. As soon as the overall cluster gravitational potential is built, high
speed galaxy versus galaxy encounters start to play a role. These harassment
events gradually thicken and shorten spiral galaxy disks leading to the
formation of S0 galaxies and ellipticals. Another aspect of the high speed
motion in the hot and diluted Intracluster Medium (ICM) is the ram pressure
exerted on the Interstellar Matter (ISM) leading to stripping of the ISM from
parent spirals. The combinations of tides and ram pressure stripping
efficiently removes the gas from spirals, quenching the star formation in
galactic disks, while triggering it in the tidal arms and at the leading edge
of gaseous disk. Gas stripping from disks transports the metals to the ICM. In
some cases, the gas extracted from the galactic disks becomes self-gravitating
forming tidal dwarf galaxies.


title: Observing Trans-Planckian Signatures in the Cosmic Microwave Background

abstract:
  We examine the constraints cosmological observations can place on any
trans-Planckian corrections to the primordial spectrum of perturbations
underlying the anisotropies in the Cosmic Microwave Background. We focus on
models of trans-Planckian physics which lead to a modulated primordial
spectrum. Rather than looking at a generic modulated spectrum, our calculations
are based on a specific model, and are intended as a case study for the sort of
constraints one could hope to apply on a well-motivated model of
trans-Planckian physics. We present results for three different approaches -- a
grid search in a subset of the overall parameter space, a Fisher matrix
estimate of the likely error ellipses, and a Monte Carlo Markov Chain fit to a
simulated CMB sky. As was seen in previous analyses, the likelihood space has
multiple peaks, and we show that their distribution can be reproduced via a
simple semi-analytic argument. All three methods lead to broadly similar
results. We vary 10 cosmological parameters (including two related to the
trans-Planckian terms) and show that the amplitude of the tensor perturbations
is directly correlated with the detectability of any trans-Planckian
modulation. We argue that this is likely to be true for any trans-Planckian
modulation in the paradigm of slow-roll inflation. For the specific case we
consider, we conclude that if the tensor to scalar ratio, $r \sim 0.15$, the
ratio between the inflationary Hubble scale $H$, and the scale of new physics
$M$ has to be on the order of 0.004 if the modulation is detectable at the
2$\sigma$ level. For a lower value of $r$, the bound on $H/M$ becomes looser.


title: The end of the Dark Ages in MOND

abstract:
  We study the evolution of a spherically symmetric density perturbation in the
Modified Newtonian Dynamics (MOND) model applied to the net acceleration over
Hubble flow. The background cosmological model is a $\Lambda$-dominated,
low-$\Omega_b$ Friedmann model with no Cold Dark Matter. We include thermal
processes and non-equilibrium chemical evolution of the collapsing gas. We find
that under these assumptions the first low-mass objects ($M \le 3\times 10^4
M_{\odot}$) may collapse already for $z\sim 30$, which is in quite good
agreement with the recent WMAP results. A lower value of $a_0$ would lead to
much slower collapse of such objects.


title: Weak lensing measurements of dark matter halos of galaxies from COMBO-17

abstract:
  We present a measurement of mass estimates for dark matter halos around
galaxies from the COMBO-17 survey using weak gravitational lensing. COMBO-17 is
particularly useful for this kind of investigation because it covers
observations in 17 optical filters from which accurate photometric redshifts
and spectral classification for objects with $R<24$ are derived. This allows us
to select lens and source galaxies from their redshifts and to thus avoid any
uncertainties from estimates of the source redshift distribution. We study
galaxy lenses at redshifts $z_\mathrm{d}=0.2-0.7$ by fitting the normalization
of either singular isothermal spheres (SIS) or Navarro-Frenk-White (NFW)
profiles to the whole lens sample; we then consider halos around blue and red
subsamples separately. We also constrain the scaling of halo mass with light.
For the NFW model, we find virial masses
$M_\mathrm{vir}^*=3.9^{+3.3}_{-2.4}\times 10^{11}h^{-1}M_{\sun}$ (1-$\sigma$)
for blue and $M_\mathrm{vir}^*=7.1^{+7.1}_{-3.8}\times 10^{11}h^{-1}M_{\sun}$
for red galaxies of $L_\star=10^{10}h^{-2}L_{\sun}$, respectively. The derived
mass-to-light scaling relations suggest that the mass-to-light ratio might
decrease with increasing luminosity for blue galaxies but increase with
increasing luminosity for red galaxies. However, these differences between blue
and red galaxies are only marginally significant and both subsamples are
consistent with having the same mass-to-light ratio at all luminosities.
Finally, we compare our results to those obtained from the Red-Sequence Cluster
Survey (RCS) and the Sloan Digital Sky Survey (SDSS). Taking differences in the
actual modelling into account, we find very good agreement with these surveys.


title: Rapid H-alpha variability in T Coronae Borealis

abstract:
  We report our search for variability in the H-alpha emission line of the
recurrent novae T CrB with time resolution 10-15 minutes. This is comparable
with the time scale of the photometric flickering observed in this object. This
is the first time that observations of the short time scale variation in
emission lines have been made in this object. On two nights (990106 and 990107)
we detected statistically significant variability (at 0.99 confidence level) in
the line profile of H-alpha. This variability is confined in the central part
of the emission line (\pm 100 km/s) although FWZI(H-alpha) is ~800 km/s. The
variability in the line profile is accompanied with variability of the total
equivalent width, EW(H-alpha), \pm 8% for 990106, and \pm 6% for 990107
(calculated from the mean value of EW). Assuming Keplerian motion, the
variability is generated at a distance ~20-30 R_Solar from the white dwarf,
which is approximately the radius of the ring the stream of gas forms as it
flows away from L_1. On three other nights we are only able to put upper limits
on the variability, \Delta EW(H-alpha) \pm 2% for 980415, \pm 4% for 980802,
and \pm 3% for 980803.


title:
Search for Point Sources of Ultra-High Energy Cosmic Rays Above 40 EeV
  Using a Maximum Likelihood Ratio Test

abstract:
  We present the results of a search for cosmic ray point sources at energies
above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo
experiments. The analysis is based on a maximum likelihood ratio test using the
probability density function for each event rather than requiring an a priori
choice of a fixed angular bin size. No statistically significant clustering of
events consistent with a point source is found.


title:
Probing quantum decoherence in atmospheric neutrino oscillations with a
  neutrino telescope

abstract:
  Quantum decoherence, the evolution of pure states into mixed states, may be a
feature of quantum gravity. In this paper, we show how these effects can be
modelled for atmospheric neutrinos and illustrate how the standard oscillation
picture is modified. We examine how neutrino telescopes, such as ANTARES, are
able to place upper bounds on these quantum decoherence effects.


title: Exactly Solvable SFT Inspired Phantom Model

abstract:
  An exact solution to the Friedmann equations with a string inspired phantom
scalar matter field is constructed and the absence of the "Big Rip" singularity
is shown explicitly. The notable features of the concerned model are a ghost
sign of the kinetic term and a special polynomial form of the effective tachyon
potential. The constructed solution is stable with respect to small
fluctuations of the initial conditions and special deviations of the form of
the potential.


title: Indirect Evidence for WIMP Annihilation from Diffuse Galactic Gamma Rays

abstract:
  The EGRET excess in the diffuse galactic gamma ray data above 1 GeV shows all
the features expected from Dark Matter WIMP Annihilation: a)it is present and
has the same spectrum in all sky directions, not just in the galactic plane. b)
The intensity of the excess shows the $1/r^2$ profile expected for a flat
rotation curve outside the galactic disc with additionally an interesting
substructure in the disc in the form of a doughnut shaped ring at 14 kpc from
the centre of the galaxy. At this radius a ring of stars indicates the probable
infall of a dwarf galaxy, which can explain the increase in DM density.
  From the spectral shape of the excess the WIMP mass is estimated to be
between 50 and 100 GeV, while from the intensity the halo profile is
reconstructed. Given the mass and intensity of the WIMP's the mass of the ring
can be calculated, which is shown to explain the peculiar change of slope in
the rotation curve at about 11 kpc. These signals of Dark Matter Annihilation
are compatible with Supersymmetry and have a statistical significance of more
than 10 stnadard deviations in comparison with a fit of the conventional
galactic model to the EGRET data. The statistical significance combined with
all features mentioned above provide an intriguing hint that the EGRET excess
is indeed a signal from Dark Matter Annihilation.


title:
Evidence for transient clumps and gas chemical evolution in the CS core
  of L673

abstract:
  We present FCRAO maps as well as combined BIMA and FCRAO maps of the high
density molecular emission towards the CS core in the L673 region. With the
FCRAO telescope, we mapped the emission in the CS(2-1), C34S(2-1), HCO+(1-0),
and H13CO+(1-0) lines. The high density molecular emission, which arises from a
filamentary structure oriented in the NW-SE direction, shows clear
morphological differences for each molecule. We find that HCO+ has an extremely
high optical depth, and that the H13CO+ emission is well correlated with submm
sources. The BIMA and FCRAO combined maps recover emission from a lot of other
structure which was previously undetected or only marginally detected, and show
an overall aspect of a filamentary structure connecting several intense clumps.
We found a total 15 clumps in our combined data cube, all of them resolved by
our angular resolution, with diameters in the 0.03-0.09 pc range. We find a
clear segregation between the northern and southern region of the map: the
northern section shows the less chemically evolved gas and less massive but
more numerous clumps, while the southern region is dominated by the largest and
most massive clump, and contains the more evolved gas, as traced by emission of
late-time molecules. We find that the derived clump masses are below the virial
mass, and that the clumps masses become closer to the virial mass when they get
bigger and more massive. This supports the idea that these clumps must be
transient, and only the more massive ones have a chance to last long enough to
form stars. The clumps we detect are probably in an earlier evolutionary stage
than the ``starless cores'' reported recently in the literature. Only the most
massive one has properties similar to a ``starless core''.


title: Stellar Collisions and Black Hole Formation in Dense Star Clusters

abstract:
  Close encounters and physical collisions between stars in young dense
clusters may lead to the formation of very massive stars and black holes via
runaway merging. We examine critically some details of this process, using
N-body simulations and simple analytical estimates to place limits on the
cluster parameters for which it expected to occur. For small clusters, the mass
of the runaway is effectively limited by the total number of high-mass stars in
the system. For sufficiently dense larger clusters, the runaway mass is
determined by the fraction of stars that can mass segregate to the cluster core
while still on the main sequence. The result is in the range commonly cited for
intermediate-mass black holes, such as that recently reported in the Galactic
center.


title: Detection of Gamma-rays around 1TeV from RX J0852.0-4622 by CANGAROO-II

abstract:
  We have detected gamma-ray emission at the 6sigma level at energies greater
than 500GeV from the supernova remnant RX J0852.0-4622 (G266.2-1.2) using the
CANGAROO-II Imaging Atmospheric Cherenkov Telescope (IACT). The flux was 0.12
times of that of Crab at 1TeV. The signal centroid is consistent with the peak
of the X-ray emission in the north-west rim of the remnant.


title: Cosmological Evolution of Interacting Phantom Energy with Dark Matter

abstract:
  We investigate the cosmological evolution of an interacting phantom energy
model in which the phantom field has interaction with the dark matter. We
discuss the existence and stability of scaling solutions for two types of
specific interactions. One is motivated by the conformal transformation in
string theory and the other is motivated by analogy with dissipation. In the
former case, there exist no scaling solutions. In the latter case, there exist
stable scaling solutions, which may give a phenomenological solution of the
coincidence problem. Furthermore, the universe either accelerates forever or
ends with a singularity, which is determined by not only the model parameters
but also the initial velocity of the phantom field.


title:
Effects of rotation on the revival of a stalled shock in supernova
  explosions

abstract:
  In order to infer the effects of rotation on the revival of a stalled shock
in supernova explosions, we investigated steady accretion flows with a standing
shock. We first obtained a series of solutions for equations describing
non-rotating spherically symmetric flows and confirmed the results of preceding
papers that, for a given mass accretion rate, there is a critical luminosity of
irradiating neutrinos, above which there exists no steady solution. Below the
critical value, we found two branches of solutions; one is stable and the other
is unstable against radial perturbations. With a simple argument based on the
Riemann problem, we can identify the critical luminosity as the one, at which
the stalled shock revives. We also obtained the condition satisfied by the flow
velocity for the critical luminosity, which can be easily applied to the
rotational case. If a collapsing star rotates, the accretion flow is
non-spherical due to centrifugal forces. Flows are accelerated near the
rotation axis whereas they are decelerated near the equatorial plane. As a
result, the critical luminosity is lowered, that is, rotation assists the
revival of a stalled shock. According to our calculations, the critical
luminosity is $\sim25$% lower for the mass accretion rate of 1M$_{\odot}$/sec
and the rotation frequency of 0.1 Hz at a radius of 1000 km than that of the
spherically symmetric flow with the same mass accretion rate. We found that the
condition of the flow velocity at the critical luminosity is first satisfied at
the rotation axis. This suggests that the shock revival is triggered on the
rotation axis and a jet-like explosion ensues.


title: Galaxy Bias and Halo-Occupation Numbers from Large-Scale Clustering

abstract:
  We show that current surveys have at least as much signal to noise in
higher-order statistics as in the power spectrum at weakly nonlinear scales. We
discuss how one can use this information to determine the mean of the galaxy
halo occupation distribution (HOD) using only large-scale information, through
galaxy bias parameters determined from the galaxy bispectrum and trispectrum.
After introducing an averaged, reasonably fast to evaluate, trispectrum
estimator, we show that the expected errors on linear and quadratic bias
parameters can be reduced by at least 20-40%. Also, the inclusion of the
trispectrum information, which is sensitive to "three-dimensionality" of
structures, helps significantly in constraining the mass dependence of the HOD
mean. Our approach depends only on adequate modeling of the abundance and
large-scale clustering of halos and thus is independent of details of how
galaxies are distributed within halos. This provides a consistency check on the
traditional approach of using two-point statistics down to small scales, which
necessarily makes more assumptions. We present a detailed forecast of how well
our approach can be carried out in the case of the SDSS.


title: Photometric Observation And Period Study of GO Cygni

abstract:
  Photometric observations of GO Cyg were performed during the July-October
2002, in B and V bands of Johnson system. Based on Wilson's model, the light
curve analysis were carried out to find the photometric elements of the system.
The O-C diagram which is based on new observed times of minima suggests a
negative rate of period variation (dP/dt<0) for the system.


title: Spherical Collapse Model

abstract:
  We studied the spherical collapse model in the flat $\Lambda$CDM cosmology
and provided exact and analytical formulaes for the calculation of the two
important parameters in the application of Press-Schechter theory, the critical
density contrast and the ratio of cluster/background densities at the
virialization point in terms of a media variable which can be solved precisely
by numerical methods.


title: Observing Magnetic Fields on Large Scales

abstract:
  Observations of magnetic fields on scales up to several Mpc are important for
understanding cluster and large-scale structure evolution. Our current census
of such structures is heavily biased -- towards fields of several microG,
towards fields in deep potential wells, and towards high inferred field
strengths in cooling flow and other clusters from improper analysis of rotation
measure data. After reviewing these biases, I show some recent results on two
relics that are powered in very different ways. I describe new investigations
that are now uncovering weak diffuse fields in the outskirts of clusters and
other low density environments, and the good prospects for further progress.


title:
Cosmological Lower Bound on Dark Matter Masses from the Soft Gamma-ray
  Background

abstract:
  Motivated by a recent detection of 511 keV photons from the center of our
Galaxy, we calculate the spectrum of the soft gamma-ray background of the
redshifted 511 keV photons from cosmological halos. Annihilation of dark matter
particles into electron-positron pairs makes a substantial contribution to the
gamma-ray background. Mass of such dark matter particles must be <~ 100 MeV so
that resulting electron-positron pairs are on-relativistic. On the other hand,
we show that in order for the annihilation not to exceed the observed
background, the dark matter mass needs to be >~ 20 MeV. We include the
contribution from the active galactic nuclei and supernovae. The halo
substructures may increase the lower bound to >~ 60 MeV.


title:
Large Scale Clustering of Sloan Digital Sky Survey Quasars: Impact of
  the Baryon Density and the Cosmological Constant

abstract:
  We report the first result of the clustering analysis of Sloan Digital Sky
Survey (SDSS) quasars. We compute the two-point correlation function (2PCF) of
SDSS quasars in redshift space at $8h^{-1}{\rm Mpc} < s < 500h^{-1}{\rm Mpc}$,
with particular attention to its baryonic signature. Our sample consists of
19986 quasars extracted from the SDSS Data Release 4 (DR4). The redshift range
of the sample is $0.72 \le z \le 2.24$ (the mean redshift is $\bar z = 1.46$)
and the reddening-corrected $i$-band apparent magnitude range is $15.0 \le
m_{i,{\rm rc}} \le 19.1$. Due to the relatively low number density of the
quasar sample, the bump in the power spectrum due to the baryon density,
$\Omega_{\rm b}$, is not clearly visible. The effect of the baryon density is,
however, to distort the overall shape of the 2PCF.The degree of distortion
makes it an interesting alternate measure of the baryonic signature. Assuming a
scale-independent linear bias and the spatially flat universe, i.e.,
$\Omega_{\rm b} + \Omega_{\rm d} + \Omega_\Lambda =1$, where $\Omega_{\rm d}$
and $\Omega_\Lambda$ denote the density parameters of dark matter and the
cosmological constant, we combine the observed quasar 2PCF and the predicted
matter 2PCF to put constraints on $\Omega_{\rm b}$ and $\Omega_\Lambda$. Our
result is fitted as $0.80- 2.8\Omega_{\rm b} < \Omega_\Lambda < 0.90 -
1.4\Omega_{\rm b}$ at the 2$\sigma$ confidence level, which is consistent with
results from other cosmological observations such as WMAP. (abridged)


title: Covariance of the One-Dimensional Mass Power Spectrum

abstract:
  We analyse the covariance of the one-dimensional mass power spectrum along
lines of sight. The covariance reveals the correlation between different modes
of fluctuations in the cosmic density field and gives the sample variance error
for measurements of the mass power spectrum. For Gaussian random fields, the
covariance matrix is diagonal. As expected, the variance of the measured
one-dimensional mass power spectrum is inversely proportional to the number of
lines of sight that are sampled from each random field. The correlation between
lines of sight in a single field may alter the covariance. However, lines of
sight that are sampled far apart are only weakly correlated, so that they can
be treated as independent samples. Using N-body simulations, we find that the
covariance matrix of the one-dimensional mass power spectrum is not diagonal
for the cosmic density field due to the non-Gaussianity and that the variance
is much higher than that of Gaussian random fields. From the covariance, one
will be able to determine the cosmic variance in the measured one-dimensional
mass power spectrum as well as to estimate how many lines of sight are needed
to achieve a target precision.


title: The continuum and narrow line region of the NLS1 galaxy Mrk 766

abstract:
  We present the first spectroscopic observations in the interval 0.8-4.0
microns, complemented with HST/UV and optical spectroscopy, of the narrow line
Seyfert 1 galaxy Mrk766. The NIR spectrum is characterized by permitted lines
of HI, HeI, HeII and FeII, and forbidden lines of [SII], [SIII] and [FeII]
among others. High ionized species such as [SiIX], [SiX], [SIX] and [MgVII] are
also observed. The continuum has a complex shape, with contribution of the
central engine, circumnuclear stellar population and dust. This last component
is evidenced by the presence of an excess of emission peaking at 2.25 microns,
fitted by blackbody function with T_bb=1200K. That temperature is close to the
evaporation temperature of graphite grains. As such, it provides strong
evidence of hot dust, probably very close to the nucleus. Consistent modeling
of the line and broad band continuum spectrum by composite models, which
account for the photoionizing flux of the central engine and shocks, shows that
the shock velocities are between 100 and 500 km/s, the preshock densities
between 100 and 1000 cm^-3 and the radiation fluxes from the active centre
between 10^9 and 5x10^12 photons cm^-2 s^-1 eV^-1 at 1 Ryd with spectral
indices $\alpha_{UV}$=-1.5 and $\alpha_X$=-0.4. Adopting silicon grains,
dust-to-gas ratios are between 10^-{6} and 4x10$^{-4}$ by mass. The emitting
clouds are at an average distance of 160 pc from the centre, with high velocity
clouds closer and low velocity clouds farther from the centre. The N/H relative
abundance could be twice solar. In constrast, Fe is depleted from the gaseous
phase by a factor >2. Ratios of calculated to observed line ratios to Hbeta
indicate an average contribution of the broad line region to the observed Hbeta
of about 40%.


title:
Clarifying Inflation Models: the Precise Inflationary Potential from
  Effective Field Theory and the WMAP data

abstract:
  We clarify inflaton models by considering them as effective field theories in
the Ginzburg-Landau spirit.In this new approach, the precise form of the
inflationary potential is constructed from the present WMAP data, and a useful
scheme is prepared to confront with the forthcoming data. In this approach, the
WMAP statement excluding the pure phi^4 potential implies the presence of an
inflaton mass term at the scale m sim 10^{13}GeV. Chaotic, new and hybrid
inflation is studied in an unified way. In all cases the inflaton potential
takes the form V(phi) = m^2 M_{Pl}^2 v(phi/M_{Pl}), where all coefficients in
the polynomial v(x) are of order one. If such potential corresponds to super
symmetry breaking, the susy breaking scale is sqrt{m M_{Pl}} \sim 10^{16}GeV
which turns to coincide with the GUT scale. The inflaton mass is therefore
given by a see-saw formula m sim M_{GUT}^2/M_{Pl}. The observables turn to be
two valued functions: one branch corresponds to new inflation and the other to
chaotic inflation,the branch point being the pure quadratic potential.For red
tilt spectrum, the potential which fits the best the present data and which
best prepares the way for the forthcoming data is a trinomial polynomial
withnegative quadratic term (new inflation).For blue tilt spectrum, hybrid
inflation turns to be the best choice. In both cases we find a formula relating
the inflaton mass with the ratio r of tensor/scalar perturbations and the
spectral index ns of scalar perturbations: 10^6 m/M_{Pl}= 127 sqrt{r|1-n_s|}
;(the coefficient 127 follows from the WMAP amplitude.Implications for string
theory are discussed.


title: Population synthesis for low and intermediate mass binaries

abstract:
  A review of the basic principles of the population synthesis for binary stars
is presented. We discuss the break-up of low and intermediate mass close
binaries over different evolutionary scenarios and, as an example, briefly
consider results of the population synthesis for SN Ia.


title: X-ray Periodicity in AGN

abstract:
  Significant (marginal) detections of periodic signals have been recently
reported in 3 (4) Active Galactic Nuclei. Three of the detections were obtained
from long EUVE light curves of moderate-luminosity Seyfert galaxies; the fourth
was discovered in Chandra data from the low-luminosity Seyfert 1 galaxy NGC
4395. When compared with Cyg X-1, I find that the period is related to the
luminosity as $P\propto L^{2/3}$ rather than the expected one-to-one
relationship. This result might be explained if the QPO is associated with the
inner edge of the optically thick accretion disk, and the inner edge radius
depends on the source luminosity (or black hole mass). A discussion of
uncertainties in the period detection methodology is also discussed.


title:
A photometric study of the newly discovered eclipsing cataclysmic
  variable SDSS J040714.78-064425.1

abstract:
  We present the results obtained from unfiltered photometric CCD observations
of the newly discovered cataclysmic variable SDSS J040714.78-064425.1 made
during 7 nights in November 2003. We establish the dwarf nova nature of the
object as it was in outburst during our observations. We also confirm the
presence of deep eclipses with a period of 0.17017d+/-0.00003 in the optical
light curve of the star. In addition, we found periods of 0.166d+/-0.001 and
possibly also 5.3d+/-0.7 in the data. The 0.17017d periodicity is consistent
within the errors with the proposed orbital period of 0.165d (Szkody et. al.
2003) and 0.1700d (Monard 2004). Using the known relation between the orbital
and superhump periods, we interpret the 0.166d and 5.3d periods as the negative
superhump and the nodal precession period respectively. SDSS
J040714.78-064425.1 is then classified as a negative superhump system with one
of the largest orbital periods.


title: Supernovae constraints on models of dark energy revisited

abstract:
  We use the Type Ia Supernova gold sample data of Riess {\it et al} in order
to constrain three models of dark energy. We study the Cardassian model, the
Dvali-Turner gravity modified model and the generalized Chaplygin gas model of
dark energy - dark matter unification. In our best fit analysis for these three
dark energy proposals we consider flat model and the non-flat model priors. We
also discuss the degeneracy of the models with the XCDM model through the
computation of the so-called jerk parameter.


title: Neutrino Phenomenology

abstract:
  A general overview of neutrino physics is given, starting with a historical
account of the development of our understanding of neutrinos and how they
helped to unravel the structure of the Standard Model. We discuss why it is so
important to establish if neutrinos are massive and the indications in favor of
non-zero neutrino masses are discussed, including the recent results on
atmospheric and solar neutrinos and their confirmation with artificial neutrino
sources.


title:
Search for solar antineutrinos and constraints on the neutrino
  background from PBHs

abstract:
  We obtain the constraints on the diffuse neutrino background from primordial
black hole evaporations using the recent data of KamLAND experiment setting an
upper limit on the antineutrino flux from the Sun.


title: The ATNF Pulsar Catalogue

abstract:
  We have compiled a new and complete catalog of the main properties of the
1509 pulsars for which published information currently exists. The catalog
includes all spin-powered pulsars as well as anomalous X-ray pulsars and soft
gamma-ray repeaters showing coherent pulsed emission, but excludes
accretion-powered systems. References are given for all data listed. We have
also developed a new web interface for accessing and displaying either tabular
or plotted data with the option of selecting pulsars to be displayed via
logical conditions on parameter expressions. The web interface has an
``expert'' mode giving access to a wider range of parameters and allowing the
use of custom databases. For users with locally installed software and database
on unix or linux systems, the catalog may be accessed from a command-line
interface. C-language functions to access specified parameters are also
available. The catalog is updated from time to time to include new information.


title: Shower spectrum and detection of tau from Earth-skimming neutrinos

abstract:
  A Monte-Carlo simulation code was described for simulation of Earth skimming
tau-neutrinos. The Earth density and composition profile, charged/neutral
current interaction, energy loss of tau leptons, and tau decay are all included
in the code. This paper compares the tau spectrum calculated from two methods,
analytical formula and Monte-Carlo simulation. the results consistent with each
other, which proves the algorithms are all correct in this simulation code.


title:
The two-fluid analysis of the Kelvin-Helmholtz instability in dusty
  layer of a protoplanetary disk: A possible path toward the planetesimal
  formation through the gravitational instability

abstract:
  We analyze the stability of dust layer in protoplanetary disk to understand
the effect of the relative motion between gas and dust. The previous analyses
not including the effect of relative motion between gas and dust show that the
shear-induced turbulence may prevent the dust grains from settling sufficiently
to be gravitationally unstable. We determine the growth rate of
Kelvin-Helmholtz instability in wide range of parameter space, and propose a
possible path toward the planetesimal formation through the gravitational
instability. We expect the density of dust layer becomes
$\rho_\mathrm{d}/\rho_\mathrm{g} \sim 200$ if the dust grains can grow up to
5m.


title:
Model atmospheres and X-ray spectra of iron-rich bursting neutron stars.
  II. Iron rich Comptonized Spectra

abstract:
  This paper presents the set of plane-parallel model atmosphere equations for
a very hot neutron star (X-ray burst source). The model equations assume both
hydrostatic and radiative equilibrium, and the equation of state of an ideal
gas in local thermodynamic equilibrium (LTE). The equation of radiative
transfer includes terms describing Compton scattering of photons on free
electrons in fully relativistic thermal motion, for photon energies approaching
m_e *c^2. Model equations take into account many bound-free and free-free
energy-dependent opacities of hydrogen, helium, and the iron ions, and also a
dozen bound-bound opacities for the highest ions of iron. We solve model
equations by partial linearisation and the technique of variable Eddington
factors. Large grid of H-He-Fe model atmospheres of X-ray burst sources has
been computed for 10^7 < T_eff < 3*10^7 K, a wide range of surface gravity, and
various iron abundances. We demonstrate that the spectra of X-ray bursters with
iron present in the accreting matter differ significantly from pure H-He
spectra (published in an earlier paper), and also from blackbody spectra.
Comptonized spectra with significant iron abundance are generally closer to
blackbody spectra than spectra of H-He atmospheres. The ratio of color to
effective temperatures in our grid always remains in the range 1.2 < T_c/T_eff
< 1.85. The present grid of model atmospheres and theoretical X-ray spectra
will be used to determine the effective temperatures, radii and M/R ratios of
bursting neutron stars from observational data.


title:
The All Sky Automated Survey. The Catalog of Variable Stars. IV.18^h -
  24^h Quarter of the Southern Hemisphere

abstract:
  In this paper we present the fourth part of the photometric data from the 9x9
deg ASAS camera monitoring the whole southern hemisphere in V-band. Preliminary
list (based on observations obtained since January 2001) of variable stars
located between RA 18^h - 24^h is released. 10311 stars brighter than V=14 were
found to be variable (1641 eclipsing, 1116 regularly pulsating, 938 Mira and
6616 other stars). Light curves have been classified using the automated
algorithm taking into account periods, amplitudes, fourier coefficients of the
light curves, 2MASS colors and IRAS infrared fluxes. Basic photometric
properties are presented in the tables and some examples of thumbnail light
curves are printed for reference. All photometric data are available over the
INTERNET at http://www.astrouw.edu.pl/~gp/asas/asas.html or
http://archive.princeton.edu/~asas


title:
An analytic study of the gravitational wave pulsar signal with spin down
  effects

abstract:
  In this work, we present the analytic treatment of the Fourier Transform (FT)
of the Gravitational Wave (GW) signal from a pulsar including spin down
corrections in a parametrized model discussed by Brady et. al. The formalism
lends itself to a development of the FT in terms of well known special
functions and integrals defining the spin down moments.


title: May Gravity detect Tsunami ?

abstract:
  The present gravitational wave detectors are reaching lowest metric deviation
fields able to detect galactic and extra-galactic gravitational waves, related
to Supernova explosions up to Virgo cluster. The same gravitational wave
detector are nevertheless almost able to reveal, in principle, near field
Newtonian gravitational perturbations due to fast huge mass displacements as
the ones occurring during largest Earth-Quake or Tsunami as the last on 26nd
December 2004 in Asiatic area. Virgo and Ligo detector are unfortunately
recording on high frequencies (above tens Hz) while the signal of the Tsunami
lay at much lower range (below 0.1 Hz). Nevertheless prompt gravitational near
field deformation by the Tsunami might reach the future LISA threshold
sensitivity and frequency windows if such an array is located nearby
(3000-10000) km distances. Unfortunately the present LISA system should be
located at Lagrange point too far (1.5 million km. far away). We note however
that the later continental mass rearrangement and their gravitational field
assessment on Earth must induce, for Richter Magnitude 9-like Tsunami, a
different terrestrial inertia momentum and a different principal rotation axis.
In conclusion we remind that gravitational geodetic deviation on new precise
satellites (GOCE 2006), assisted by GPS network, might nevertheless reach in
the near future the needed threshold and accuracy to reveal Tsunami by their
prompt tidal gravity field deviations . An array of such geoid detector maybe
correlated with LISA-like satellite on Earth orbits may offer the fastest alarm
system.


title:
The Discovery of Primeval Large-Scale Structures with Forming Clusters
  at Redshift 6

abstract:
  We report the discovery of primeval large-scale structures (LSSs) including
two proto-clusters in a forming phase at z=5.7. We carried out extensive deep
narrow-band imaging in the 1 deg^2 sky of the Subaru/XMM-Newton Deep Field, and
obtained a cosmic map of 515 Ly alpha emitters (LAEs) in a volume with a
transverse dimension of 180 Mpc x 180 Mpc and a depth of ~40 Mpc in comoving
units. This cosmic map shows filamentary LSSs, including clusters and
surrounding 10-40 Mpc scale voids, similar to the present-day LSSs. Our
spectroscopic follow-up observations identify overdense regions in which two
dense clumps of LAEs with a sphere of 1-Mpc diameter in physical units are
included. These clumps show about 130 times higher star-formation rate density,
mainly due to a large overdensity, ~80, of LAEs. These clumps would be clusters
in a formation phase involving a burst of galaxy formation.


title:
Limits on variations in fundamental constants from 21-cm and ultraviolet
  quasar absorption lines

abstract:
  Quasar absorption spectra at 21-cm and UV rest-wavelengths are used to
estimate the time variation of x=alpha^2 g_p mu, where alpha is the fine
structure constant, g_p the proton g factor, and m_e/m_p=mu the electron/proton
mass ratio. Over a redshift range 0.24 ~< z_abs ~< 2.04, <Delta
x/x>_total_weighted=(1.17+-1.01) x 10^-5. A linear fit gives
d/dt{x}/x=(-1.43+-1.27) x 10^-15 yr^-1. Two previous results on varying alpha
yield the strong limits Delta mu/mu=(2.31+-1.03) x 10^-5 and Delta
mu/mu=(1.29+-1.01) x 10^-5. Our sample, 8x larger than any previous, provides
the first direct estimate of the intrinsic 21-cm and UV velocity differences ~6
km s^-1.


title:
Interstellar scintillation as a probe of microarcsecond scale structure
  in quasars

abstract:
  Observations over the last two decades have shown that a significant fraction
of all flat-spectrum, extragalactic radio sources exhibit flux density
variations on timescales of a day or less at frequencies of several GHz. It has
been demonstrated that interstellar scintillation (ISS) is the principal cause
of such rapid variability. Observations of ISS can be used to probe very
compact, microarcsecond-scale structure in quasar inner jets, as well as
properties of turbulence in the local Galactic ISM. A few sources show
unusually rapid, intra-hour variations, evidently due to scattering in very
nearby, localized turbulence. We present recent findings for the rapidly
scintillating quasar PKS 1257-326. The large-scale MASIV VLA Survey showed that
such sources are extremely rare, implying that for most scintillating sources,
longer-term, dedicated monitoring programs are required to extract detailed
information on source structures.


title: Compact Structure in FIRST Survey Sources

abstract:
  We present preliminary results from a statistical survey of compact structure
in faint radio sources. Around 1000 sources from the VLA FIRST survey (flux
densities larger than 1 mJy at 1.4 GHz) have been observed with the
single-baseline interferometer Effelsberg-Arecibo. We observed each source,
selected from a narrow strip of sky at declination 28 deg, for just one minute.
The baseline sensitivity at 1.4 GHz, using 512 Mb/s recording, is such that any
FIRST source, selected at random, would be detected if most of its flux density
is in compact structure. We discuss the detection-rate statistics from one
epoch of these observations.


title:
An alternative to the dark matter paradigm: relativistic MOND
  gravitation

abstract:
  MOND, invented by Milgrom, is a phenomenological scheme whose basic premise
is that the visible matter distribution in a galaxy or cluster of galaxies
alone determines its dynamics. MOND fits many observations surprisingly well.
Could it be that there is no dark matter in these systems and we witness rather
a violation of Newton's universal gravity law ? If so, Einstein's general
relativity would also be violated. For long conceptual problems have prevented
construction of a consistent relativistic substitute which does not obviously
run afoul of the facts. Here I sketch TeVeS, a tensor-vector-scalar field
theory which seems to fit the bill: it has no obvious conceptual problems and
has a MOND and Newtonian limits under the proper circumstances. It also passes
the elementary solar system tests of gravity theory.


title: VLBI polarimetric observations of 3C147

abstract:
  We present multi-frequency VLBI observations of the Compact Steep-spectrum
Quasar 3C147 (0538+498) made with the VLBA at the four frequencies in the
available 5 GHz band and at 8.4 GHz (still under analysis), from which we
derived millarcsecond-resolution images of the total intensity, polarization,
and rotation measure distributions. The source shows a core-jet structure, with
a compact feature and a jet, extending about 200 mas to the South-West. We
detect polarized emission in two bright features in the inner jet; the rotation
measure of this features (aprox -1630 rad m(-2), aprox -540 rad m(-2)).


title: Calculations of fission rates for r-process nucleosynthesis

abstract:
  Fission plays an important role in the r-process which is responsible not
only for the yields of transuranium isotopes, but may have a strong influence
on the formation of the majority of heavy nuclei due to fission recycling. We
present calculations of beta-delayed and neutron-induced fission rates, taking
into account different fission barriers predictions and mass formulae.
  It is shown that an increase of fission barriers results naturally in a
reduction of fission rates, but that nevertheless fission leads to the
termination of the r-process. Furthermore, it is discussed that the probability
of triple fission could be high for $A>260$ and have an effect on the formation
of the abundances of heavy nuclei. Fission after beta-delayed neutron emission
is discussed as well as different aspects of the influence of fission upon
r-process calculations.


title: Tracking the curved jet in PKS 1502+106

abstract:
  We carried out a multifrequency and multiepoch study of the highly polarized
quasar, PKS 1502+106 at radio frequencies. The analysis is based on an EVN
dataset at 5 GHz, archive VLBA datasets at 2.3, 8.3, 24.4 and 43.1 GHz and an
archive MERLIN dataset at 5 GHz. The various datasets span over a period of 10
years. The source is characterized by a multi-component one-sided jet at all
epochs. The VLBI images show that a complex curved jet is located to the
southeast and east of the core, with the position angle (PA) of the jet axis
wiggling between 80 deg and 130 deg. The MERLIN image reveals that the jet
extends to 0.6 arcsec at a PA 135+-12 degr. The radio core in the VLBI images
has a brightness temperature approaching the equipartition limit, indicating
highly relativistic plasma beamed towards us. Delta PA in the source, the
misalignment of the kpc- and pc-scale radio structure, is estimated about 32
degr, suggesting that PKS 1502+106 belongs to the aligned population. Four
superluminal components are detected in the parsec scale jet, whose velocities
are 24.2 h{-1}c, 14.3 h{-1}c, 6.8 h{-1}c and 18.1 h{-1}c. Our analysis supports
the idea that the relativistic jet in PKS 1502+106 is characterised by extreme
beaming and that its radio properties are similar to those of gamma-ray loud
sources.


title: An extremely curved relativistic jet in PKS 2136+141

abstract:
  We report the discovery of an extremely curved jet in the high frequency
peaking GPS quasar PKS 2136+141. Our multi-frequency VLBA images show a bending
jet making a turn-around of 210 degrees on the plane of the sky, which is, to
our knowledge, the largest ever observed change in a structural position angle
of an extragalactic jet. Images taken at six different frequencies, from 2 to
43 GHz, beautifully reveal a spiral-like trajectory. We discuss possibilities
to constrain the 3-D geometry of the source and suggest that it could be used
as a testbed for models describing the bending of the relativistic jets.


title: The asymmetric compact jet of GRS 1915+105

abstract:
  We present multiepoch VLBA observations of the compact jet of GRS 1915+105
conducted at 15.0 and 8.4 GHz during a {\it plateau} state of the source in
2003 March-April. These observations show that the compact jet is clearly
asymmetric. Assuming an intrinsically symmetric continuous jet flow, using
Doppler boosting arguments and an angle to the line of sight of
$\theta=70\degr$, we obtain values for the velocity of the flow in the range
0.3--0.5$c$. These values are much higher than in previous observations of such
compact jet, although much lower than the highly relativistic values found
during individual ejection events. These preliminary results are compatible
with current ideas on the jet flow velocity for black holes in the low/hard
state.


title: Kinematics and dynamics of relativistic jets on large and small scales

abstract:
  Modelling of deep VLA images of the jets in FR I radio galaxies has allowed
us to derive their three-dimensional distributions of velocity, emissivity and
magnetic-field structure on kiloparsec scales. By combining our models of jet
kinematics with measurements of the external pressure and density derived from
Chandra observations, we can also determine the jet dynamics via a
conservation-law approach. The result is a detailed and quantitative picture of
jet deceleration. We discuss the potential application of these techniques on
VLBI scales. Our fundamental assumption is that the jets are intrinsically
symmetrical, axisymmetric, relativistic flows. Although this is likely to be a
good approximation on average, the effects of non-stationarity in the flow
(e.g. shocks/knots) may limit its applicability on pc scales. We also stress
the need for both the main and counter-jet to be detected with good transverse
resolution in linear polarization as well as total intensity. Two foreground
effects (free-free absorption and Faraday rotation) must also be corrected. We
comment on the implications of observed VLBI polarization and Faraday rotation
for the field structure (and, by implication, collimation) of pc-scale jets.
Where our VLA observations start to resolve the jets, about 1 kpc from the
nucleus, they are travelling at about 0.8c. We briefly discuss the deceleration
of jets from a much faster initial speed.


title: A detailed study of the nuclear region of Mrk 273

abstract:
  We present 5 GHz EVN+MERLIN observations of the nuclear region of the ultra
luminous infrared galaxy Mrk 273. These observations confirms the detection, on
the mas scale, of two resolved component labelled as N and SE in the
literature. We use published VLBA observations at 1.4 GHz, at the same
resolution, to derive spectral index information of component N and SE and
discuss these findings in relation with different hypothesis (compact starburst
or AGN) for the origin of the radio emission.


title: The highest redshift radio quasar as seen with the EVN and the VLA

abstract:
  We report on European VLBI Network (EVN) and Very Large Array (VLA)
observations of SDSS J0836+0054, the most distant radio-loud quasar known at
present z=5.774). The source, with a total flux density of 1.1 mJy, shows a
compact structure at 10 mas angular resolution at 1.6 GHz frequency, with no
indication of multiple images produced by gravitational lensing within a 4x4
arcsec field above the brightness level of 100 microJy/beam. More recent 5 GHz
EVN observations are being analysed now. As a by-product, a two-sided mas-scale
jet structure is suspected in one of the phase-reference calibrator quasars,
PKS 0837+012.


title:
Spitzer 24 micron imaging of Faint Radio Sources in the FLSv: a new
  radio-loud, Mid-IR/optically obscured population?

abstract:
  Data from the Spitzer Space Telescope (the First Look Survey - FLS) have
recently been made public. We have compared the 24 micron images with very deep
WSRT 1.4 GHz observations (Morganti et al. 2004), centred on the FLS
verification strip (FLSv). Approximately 75% of the radio sources have
corresponding 24 micron identifications. Such a close correspondence is
expected, especially at the fainter radio flux density levels, where star
forming galaxies are thought to dominate both the radio and mid-IR source
counts. Spitzer detects many sources that have no counter-part in the radio.
However, a significant fraction of radio sources detected by the WSRT (about
25%) have no mid-IR identification in the FLSv (implying a 24 micron flux
density less than 100 microJy). The fraction of radio sources without a
counterpart in the mid-IR appears to increase with increasing radio flux
density, perhaps indicating that some fraction of the AGN population may be
detected more readily at radio than Mid-IR wavelenghts. We present initial
results on the nature of the radio sources without Spitzer identification,
using data from various multi-waveband instruments, including the publicly
available R-band data from the Kitt Peak 4-m telescope.


title: On the polar caps of the 3 Musketeers

abstract:
  XMM-Newton observations of PSR B0656+14, PSR B1055-52 and Geminga have
substantially increased the statistics available for these three isolated
neutron stars, so apparently similar to deserve the nickname of "Three
Musketeers" (Becker & Truemper, 1997). Here we shall take advantage of the EPIC
statistics to perform phase resolved spectroscopy for all three objects. The
phase-averaged spectrum of the three musketeers is best described by a three
component model. This includes two blackbody components, a cooler one, possibly
originating from the bulk of the star surface, and a hotter one, coming from a
smaller portion of the star surface (a "hot spot"), plus a power law. The
relative contributions of the three components are seen to vary as a function
of phase, as the stars' rotation bring into view different emitting regions.
The hot spots, which have very different apparent dimensions (in spite of the
similarity of the three neutron stars polar cap radii) are responsible for the
bulk of the phase variation. The amplitude of the observed phase modulation is
also markedly different for the three sources. Another striking aspect of our
phase-resolved phenomenology is the apparent lack of any common phase
alignement between the observed modulation patterns for the two blackbody
components. They are seen to vary in phase in the case of PSR B1055-52, but in
anti-phase in the case of PSR B0656+14. These findings do not support standard
and simplistic models of neutron star magnetic field configuration and surface
temperature distribution.


title: Evolution of dense stellar clusters

abstract:
  A qualitative study is made of the evolutionary tracks of various dense
clusters, with allowance for the evaporation of stars, and for head-on
collisions, until relativistic collapse occures or the cluster breaks up.


title: Titan's Wind and Unanticipated Temperature Asymmetry

abstract:
  Saturn's largest satellite, Titan, has stratospheric wind speeds that may be
up to ~210 m/sec [1], circling Titan in about a day compared to Titan's slow
16-day rotation. Theoretical models to explain such super-rotating winds are
not well constrained [2,3,4,5,6] by observations of Titan or a similar slow
rotator, Venus. Titan's stratospheric temperature and the abundance of the
important constituent ethane (C2H6) should be zonally invariant due to long
photochemical and radiative lifetimes and rapid transport and mixing by high
zonal winds. Here, we report new measurements of zonal wind in Titan's
equatorial region, including the Cassini Huygens probe entry latitude [7].
Prograde zonal winds of 190+/-90 m/sec are found from Doppler-shifted ethane
gas infrared emission near 12 micron wavelength, confirming high wind velocity
even near the equator. Surprisingly, we find a temperature difference of 6+/-3
K between the East and West hemispheres of Titan at ~240 km altitude. Common
direct processes such as diurnal heating by sunlight do not adequately explain
the asymmetry, suggesting other processes, such as unknown atmospheric
dynamics, may be responsible. The origin of the temperature difference is
enigmatic and currently unexplained.