title:
Cosmic Thermobiology: Thermal Constraints on the Origin and Evolution of
  Life in the Universe

abstract:
  We review the thermal history of the Universe. We obtain a new estimate for
the thermal history of the Earth over the past four billion years using a
biological thermometer based on (1) a rough estimate of the absolute time
calibration of the genetic distances in the 16S rRNA-based tree of terrestrial
life and (2) the maximum growth temperatures of the extant organisms used to
construct the tree. The only other thermometer on comparable time scales is
based on a controversial interpretation of the oxygen 18 abundances in chert.
These two thermometers are consistent with each other and with the idea of a
roughly linear decrease in the surface temperature of the Earth from ~ 90 C
four billion years ago to ~ 10 C today. Based on the hyperthermophilic
domination of the roots of the tree of terrestrial life, and the probably
universal nature of the thermal constraints on terrestrial biogenesis, we
speculate that hyperthermophilic organisms dominate the roots of life emerging
on any terrestrial planet.


title: Galaxy Alignments as a Probe of the Dynamical State of Clusters

abstract:
  We present indications, based on a sample of 303 Abell clusters, for a
relation between the dynamical state of clusters and the alignments of galaxy
members with their parent cluster major axis orientation as well as with the
large scale environment within which the clusters are embedded. The statistical
results are complemented with a deep, wide-field case study of galaxy
alignments in the cluster A521, which is characterised by multiple merging
events (Maurogrdato et al 2000, Ferrari et al. 2003) and whose galaxy members
show a strong alignment signal out to $\sim 5 h^{-1}$ Mpc. Our results show
that galaxy alignments appear to be stronger the more dynamically young is the
cluster, especially when found in high-density environments. This relation
complements the recently found {``Cluster Substructure - Alignment
Connection''} (Plionis & Basilakos 2002) by which dynamically young clusters,
found in high-density environments, show stronger cluster-cluster alignments.


title:
Intracluster stellar population properties from N-body cosmological
  simulations -- I. Constraints at $z=0$

abstract:
  We use a high resolution collisionless simulation of a Virgo--like cluster in
a $\Lambda$CDM cosmology to determine the velocity and clustering properties of
the diffuse stellar component in the intracluster region at the present epoch.
The simulated cluster builds up hierarchically and tidal interactions between
member galaxies and the cluster potential produce a diffuse stellar component
free-flying in the intracluster medium. Here we adopt an empirical scheme to
identify tracers of the stellar component in the simulation and hence study its
properties. We find that at $z=0$ the intracluster stellar light is mostly
unrelaxed in velocity space and clustered in structures whose typical
clustering radii are about 50 kpc at R=400--500 kpc from the cluster center,
and predict the radial velocity distribution expected in spectroscopic
follow-up surveys. Finally, we compare the spatial clustering in the simulation
with the properties of the Virgo intracluster stellar population, as traced by
ongoing intracluster planetary nebulae surveys in Virgo. The preliminary
results indicate a substantial agreement with the observed clustering
properties of the diffuse stellar population in Virgo.


title:
Iron and Nickel properties in the X-ray reflecting region of the
  Circinus Galaxy

abstract:
  We discuss the iron and nickel properties in the nuclear X-ray reflecting
region of the Circinus Galaxy, studied with XMM-Newton. The main results are:
a) from the depth of the Fe Kalpha edge, a value of A_Fe=1.7 in number with
respect to the cosmic value (as for Anders & Grevesse 1989) is measured, if the
(not directly visible) illuminating spectrum is assumed to be that measured by
BeppoSAX. If the slope of the primary power law is left free to vary, a steeper
spectrum and a lower iron abundance (about 1.2) are found. b) From the Ni to Fe
Kalpha lines flux ratio, a nickel-to-iron abundance ratio of 0.055-0.075 is
found. c) The Fe Kbeta/Kalpha flux ratio is slightly lower than expected,
possibly due to a mild ionization of iron (which however cannot be much more
ionized than X). d) The presence of the Fe Kalpha Compton Shoulder, already
discovered by Chandra, is confirmed, its relative flux implying Compton-thick
matter. This further supports the identification of the reflecting region with
the absorber.


title: SCUBA Observations of MAMBO Sources

abstract:
  We have observed 23 sources from the MAMBO 1200 micron survey with SCUBA at
850 microns, detecting 19 of the sources. The sources generally have low values
for the ratio of 850 micron to 1200 micron flux. Two possible explanations for
the low values are either that the sources are at very high redshift or that
the global properties of the dust in the MAMBO sources are different from the
global properties of dust in low-redshift galaxies. If the former explanation
is correct, we estimate that 15 of the MAMBO sources lie at z > 3.


title: Collapse/Flattening of Nucleonic Bags in Ultra-Strong Magnetic Field

abstract:
  It is shown explicitly using MIT bag model that in presence of ultra-strong
magnetic fields, a nucleon either flattens or collapses in the direction
transverse to the external magnetic field in the classical or quantum
mechanical picture respectively. Which gives rise to some kind of mechanical
instability. Alternatively, it is argued that the bag model of confinement may
not be applicable in this strange situation.


title: Nuclear composition and heating in accreting neutron-star crusts

abstract:
  Nuclear reactions in accreting neutron-star crusts and the heat release
accompanying them are studied, under different assumptions concerning the
composition of the outermost layer formed of the ashes of X-ray bursts.
Particular examples of ashes containing nuclides with A ~ 90-110 are considered
and compared with a standard A=56 case. In all cases, evolution of a crust
shell is followed from 10^8 g/cm^3 to a few times 10^{13} g/cm^3. The total
crustal heating produced in the non-equilibrium processes in the accreting
crust is 1.1-1.5 MeV per one accreted nucleon. The composition of the accreted
crust at densities exceeding the threshold for the pycnonuclear fusion is
essentially independent of the assumed initial composition of the X-ray burst
ashes.


title:
Disc-jet coupling in an atoll-type neutron star X-ray binary: 4U 1728-34
  (GX 354-0)

abstract:
  We have analysed 12 simultaneous radio (VLA) and X-ray (RXTE) observations of
the atoll-type X-ray binary 4U 1728-34, performed in two blocks in 2000 and
2001. We have found that the strongest and most variable emission seems to be
associated with repeated transitions between hard (island) and softer (lower
banana) X-ray states, while weaker, persistent radio emission is observed when
the source is steadily in the hard X-ray state. There is a significant positive
ranking correlation between the radio flux density at 8.46 GHz and the 2-10 keV
X-ray flux. Moreover, significant positive ranking correlations between radio
flux density and X-ray timing features (i.e. break and low-frequency Lorentzian
frequencies) have been found. These correlations represent the first evidence
for a coupling between disc and jet in an atoll-type X-ray binary. Furthermore,
drawing an analogy between the hard (island) state and the low/hard state of
black hole binaries, we confirm previous findings that accreting neutron stars
are a factor of ~30 less `radio loud' than black holes.


title:
Consistent distances from Baade-Wesselink analyses of Cepheids and RR
  Lyraes

abstract:
  By using the same algorithm in the Baade-Wesselink analyses of Galactic RR
Lyrae and Cepheid variables, it is shown that, within 0.03 mag (1 sigma)
statistical error, they yield the same distance modulus for the Large
Magellanic Cloud. By fixing the zero point of the color-temperature calibration
to those of the current infrared flux methods and using updated
period-luminosity-color relations, we get an average value of 18.55 for the
true distance modulus of the LMC.


title: Iron abundance in the ICM at high redshift

abstract:
  We present the analysis of the X-ray spectra of 18 distant clusters of
galaxies with redshift 0.3 < z < 1.3. Most of them were observed with the
Chandra satellite in long exposures ranging from 36 ks to 180 ks. For two of
the z>1 clusters we also use deep XMM-Newton observations. Overall, these
clusters probe the temperature range 3<kT<8 keV. Our analysis is aimed at
deriving the iron abundance in the Intra Cluster Medium (ICM) out to the
highest redshifts probed to date. Using a combined spectral fit of cluster
subsamples in different redshift bins, we investigate the evolution of the mean
ICM metallicity with cosmic epoch. We find that the mean Fe abundance at <z>
=0.8 is Z =0.25 +0.04 -0.06 Zo, consistent with the local canonical metallicity
value, Z ~0.3 Zo, within 1sigma confidence level. Medium and low temperature
clusters (kT <5 keV) tend to have larger iron abundances than hot clusters. At
redshift <z>~1.2 (4 clusters at z>1) we obtain a statistically significant
detection of the Fe-K line only in one cluster (Z>0.10 Zo at the 90% c.l.).
Combining all the current data set from Chandra and XMM at z>1, the average
metallicity is measured to be <Z> = 0.21 +0.10 -0.05 Zo (1sigma error), thus
suggesting no evolution of the mean iron abundance out to z~1.2.


title: Non-linear gravitational clustering in scalar field cosmologies

abstract:
  Non-linear gravitational clustering in a universe dominated by dark energy,
modelled by a `quintessence' scalar field, and cold dark matter with space-time
varying mass is studied. Models of this type, where the variable mass is
induced by dependence on the scalar field, as suggested by string theory or
extra-dimensions, have been proposed as a viable solution of the coincidence
problem. A general framework for the study of the non-linear phases of
structure formation in scalar field cosmologies is provided, starting from a
general relativistic treatment of the combined dark matter-dark energy system.
As a first application, the mildly non-linear evolution of dark matter
perturbations is obtained by a straightforward extension of the Zel'dovich
approximation. We argue that the dark energy fluctuations may play an active
role in cosmological structure formation if the scalar field effective
potential develops a temporary spinodal instability during the evolution.


title:
Eclipse observations of high-frequency oscillations in active region
  coronal loops

abstract:
  One of the mechanisms proposed for heating the corona above solar active
regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on
previous work, we provide observational evidence for the existence of
high-frequency MHD waves in coronal loops observed during the August 1999 total
solar eclipse. A wavelet analysis is used to identify twenty 4x4 arcsec2 areas
showing intensity oscillations. All detections lie in the frequency Hz (5-3 s),
last for at least 3 periods at a confidence level of more than 99% and arise
just outside known coronal loops. This leads us to suggest that they occur in
low emission-measure or different temperature loops associated with the active
region.


title:
LSS 1135: an O-Type Spectroscopic Binary in the galactic OB association
  Bochum 7

abstract:
  From radial velocities derived from optical spectroscopic observations
performed at CTIO, Chile, and CASLEO, Argentina, we have discovered that LSS
1135 is a single--lined O-type binary system with an orbital period of 2.7532
days. We present an analysis of the orbital elements of this system based on
radial velocities of the He absorption lines. We classify the spectrum of LSS
1135 as O6.5V((f)). We also present spectral classifications and radial
velocities for other seven OB stars in the region of Bochum 7, an OB
association to which LSS 1135 belongs. Our data indicate a distance of 5.0 kpc
for this star group.


title: Variable polarization in the optical afterglow of GRB 021004

abstract:
  We present polarimetric observations of the afterglow of gamma-ray burst
(GRB) 021004, obtained with the Nordic Optical Telescope (NOT) and the Very
Large Telescope (VLT) between 8 and 17 hours after the burst. Comparison among
the observations shows a 45 degree change in the position angle from 9 hours
after the burst to 16 hours after the burst, and comparison with published data
from later epochs even shows a 90 degree change between 9 and 89 hours after
the burst. The degree of linear polarization shows a marginal change, but is
also consistent with being constant in time. In the context of currently
available models for changes in the polarization of GRBs, a homogeneous jet
with an early break time of t_b ~ 1 day provides a good explanation of our
data. The break time is a factor 2 to 6 earlier than has been found from the
analysis of the optical light curve. The change in the position angle of the
polarization rules out a structured jet model for the GRB.


title:
The 160 Square Degree ROSAT Survey: the Revised Catalog of 201 Clusters
  with Spectroscopic Redshifts

abstract:
  We present the revised catalog of galaxy clusters detected as extended X-ray
sources in the 160 Square Degree ROSAT Survey, including spectroscopic
redshifts and X-ray luminosities for 200 of the 201 members. The median
redshift is z~0.25 and the median X-ray luminosity is 4.2e+43 erg/s/h50^2
(0.5-2.0 keV). This is the largest high-redshift sample of X-ray selected
clusters published to date. There are 73 objects at z>0.3 and 22 objects at
z>0.5 drawn from a statistically complete flux-limited survey with a median
object flux of 1.4d-13 erg/cm^2/s. We describe the optical follow-up of these
clusters with an emphasis on our spectroscopy which has yielded 155 cluster
redshifts, 110 of which are presented here for the first time. These
measurements combined with 45 from the literature and other sources provide
near-complete spectroscopic coverage for our survey. We discuss the final
optical identifications for the extended X-ray sources in the survey region and
compare our results to similar X-ray cluster searches.


title:
Properties of Faint Distant Galaxies as seen through Gravitational
  Telescopes

abstract:
  This paper reviews the most recent developments related to the use of lensing
clusters of galaxies as Gravitational Telescopes in deep Universe studies. We
summarize the state of the art and the most recent results aiming at studying
the physical properties of distant galaxies beyond the limits of conventional
spectroscopy. The application of photometric redshift techniques in the context
of gravitational lensing is emphasized for the study of both lensing structures
and the background population of lensed galaxies. A presently ongoing search
for the first building blocks of galaxies behind lensing clusters is presented
and discussed.


title: The complete submillimetre spectrum of NGC 891

abstract:
  Submillimetre maps of NGC 891 have been obtained with the PRONAOS
balloon-borne telescope and with the ISOPHOT instrument on board the ISO
satellite. In this article, we also gather data from IRAS and SCUBA to present
the complete submillimetre spectrum of this nearby edge-on spiral galaxy. We
derive submillimetre emission profiles along the major axis. The modified
blackbody fits, assuming a single dust component, lead to temperatures of 19-24
K toward the centre and 18-20 K toward the edges, with possible variations of
the dust spectral index from 1.4 to 2. The two-component fits lead to a warm
component temperature of 29 K all along the galaxy with a cold component at 16
K. The interstellar medium masses derived by these two methods are quite
different: 4.6 x 10^9 Mo in the case of the one-component model and 12 x 10^9
Mo in the case of the two-component one. This two-component fit indicates that
the cold dust to warm dust ratio is 20 to 40, the highest values being in the
wings of this galaxy. Comparing to dust mass estimates, both estimations of the
ISM mass are consistent with a gas to dust mass ratio of 240, which is close to
the Milky Way value. Our results illustrate the importance of accurate
submillimetre spectra to derive masses of the interstellar medium in galaxies.


title:
A universal radio/X-ray correlation in low/hard state black hole
  binaries

abstract:
  We present a comprehensive study of (quasi-)simultaneous radio:X-ray
observations of stellar black hole binaries during the spectrally hard X-ray
state, finding evidence for a strong correlation between these two bands over
more than three orders of magnitude in X-ray luminosity. The correlation
extends from the quiescent regime up to close to the soft state transition,
where radio emission starts to decline, sometimes below detectable levels,
probably corresponding to the physical disappearance of the jet. The X-ray
transient V 404 Cygni is found to display the same functional relationship
already reported for GX 339-4 between radio and X-ray flux, namely S_radio
\propto S_X **(+0.7). In fact the data for all low/hard state black holes is
consistent with a universal relation between the radio and X-ray luminosity of
the form L_radio \propto L_X **(+0.7), implying that - as L_X decreases - the
jet becomes more radiatively efficient with respect to the X-rays. Under the
hypothesis of common physics driving the disc-jet coupling in different
sources, the observed spread to the best-fit relation can be interpreted in
terms of a distribution in Doppler factors. Monte Carlo simulations show that,
assuming little or no X-ray beaming, the measured scatter in radio power is
consistent with Lorentz factors < 2 for the outflows in the low/hard state,
significantly less relativistic than the jets associated with X-ray transients.
When combined radio and X-ray beaming is considered, the range of possible jet
bulk velocities significantly broadens, allowing highly relativistic outflows,
but implying therefore severe X-ray selection effects.


title: I Zw 1: Decomposition of the Nearby QSO Host

abstract:
  The paper presents an analysis of the nearby QSO host I Zw 1 based on new
J-band imaging data, obtained with ISAAC at the Very Large Telescope (VLT) of
the European Southern Observatory (ESO). As one of the best-studied QSOs with
exceptional properties lying between those of QSOs, narrow-line Seyfert 1s, and
ultraluminous infrared galaxies, I Zw 1 is a prime candidate for a detailed
case study of a QSO host. With its high angular resolution and sensitivity, the
new J-band image provides strong evidence for an interaction between I Zw 1 and
the western companion galaxy. We present a procedure for subtracting the QSO
nucleus from the I Zw 1 image to obtain an undisturbed view on the underlying
host galaxy. Based on the derived surface brightness profile and the gas
rotation curve, the host is classified as a high-surface-brightness Freeman
type I galaxy with a central disk surface brightness significantly larger than
that of normal spirals. The surface-brightness profile is decomposed into a
Plummer bulge and a Kuzmin disk with similar luminosities and a bulge-to-disk
scale length ratio of 0.29, comparable to that of nearby spiral hosts with
active galactic nuclei (AGN). Different models for the decomposition of the gas
rotation curve are discussed. The resulting J-band mass-to-light ratio (M/L) of
(0.7+/-0.4) M_sun/L_sun for the disk component suggests a mean solar-type
stellar population with a tendency towards young stars. The bulge exhibits a
lower M/L of 0.4+/-0.2 M_sun/L_sun, which supports previous findings of
enhanced starburst activity in the nuclear and circumnuclear region.


title: Quasars: the characteristic spectrum and the induced radiative heating

abstract:
  Using information on the cosmic X-ray background and the cumulative light of
active galactic nuclei at infrared wavelengths, the estimated local mass
density of galactic massive black holes (MBHs) and published AGN composite
spectra in the optical, UV and X-ray, we compute the characteristic
angular-integrated, broad-band spectral energy distribution of the average
quasar in the universe. We demonstrate that the radiation from such sources can
photoionize and Compton heat the plasma surrounding them up to an equilibrium
Compton temperature (Tc) of 2x10^7 K. It is shown that circumnuclear
obscuration cannot significantly affect the net gas Compton heating and cooling
rates, so that the above Tc value is approximately characteristic of both
obscured and unobscured quasars. This temperature is above typical gas
temperatures in elliptical galaxies and just above the virial temperatures of
giant ellipticals. The general results of this work can be used for accurate
calculations of the feedback effect of MBHs on both their immediate environs
and the more distant interstellar medium of their host galaxies.


title: Gamma Ray Astronomy With IceCube

abstract:
  We demonstrate that the South Pole kilometer-scale neutrino observatory
IceCube can detect multi-TeV gamma rays continuously over a large fraction of
the southern sky. While not as sensitive as pointing atmospheric Cerenkov
telescopes, IceCube can roughly match the sensitivity of Milagro. Also, IceCube
is complementary to Milagro because it will observe, without interruption, a
relatively poorly studied fraction of the southern sky. The information which
IceCube must record to function as a gamma ray observatory is only the
directions and possibly energies of down-going muons.


title: Giant Pulses from PSR B0540-69 in the Large Magellanic Cloud

abstract:
  We report the discovery of the first giant pulses from an extragalactic radio
pulsar. Observations of PSR B0540-69 in the Large Magellanic Cloud made with
the Parkes radio telescope at 1.38 GHz show single pulses with energy more than
5000 times that of the average pulse energy. This is only the second young
pulsar, after the Crab, to show giant pulse emission. Similar to the Crab
pulsar, the giant pulses occur in two distinct phase ranges and have
significant arrival time jitter within these ranges. The location of the giant
pulses appears to lag the peak of the (sinusoidal) X-ray profile by 0.37 and
0.64 phase, although absolute timing between the radio and X-ray data is not
yet secure. The dispersion measure of the giant pulses is 146.5 pc/cc, in
agreement with the detection of the pulsar at 0.64 GHz by Manchester et al.
(1993). The giant pulses are scatter broadened at 1.4 GHz with an exponential
scattering time of 0.4 ms and have an emission bandwidth of at least 256 MHz.
In 8 hr of integration we have failed to detect any integrated flux density
from the pulsar to a level of 13 microJy, assuming a duty cycle of 10%. This
implies the spectral index between 0.64 and 1.38 GHz is steeper than -4.4.


title: A search for 85.5- and 86.6-GHz methanol maser emission

abstract:
  We have used the Australia Telescope National Facility Mopra 22m millimetre
telescope to search for emission from the 85.5-GHz and 86.6-GHz transitions of
methanol. The search was targeted towards 22 star formation regions which
exhibit maser emission in the 107.0-GHz methanol transition, as well as in the
6.6-GHz transition characteristic of class II methanol maser sources. A total
of 22 regions were searched at 85.5 GHz resulting in 5 detections, of which 1
appears to be a newly discovered maser. For the 86.6-GHz transition
observations were made of 18 regions which yielded 2 detections, but no new
maser sources. This search demonstrates that emission from the 85.5- and
86.6-GHz transitions is rare. Detection of maser emission from either of these
transitions therefore indicates the presence of special conditions, different
from those in the majority of methanol maser sources. We have observed temporal
variability in the 86.6-GHz emission towards 345.010+1.792, which along with
the very narrow line width, confirms that the emission is a maser in this
source. We have combined our current observations with published data for the
6.6-, 12.1-, 85.5-, 86.6-, 107.0-, 108.8- and 156.6-GHz transitions for
comparison with the maser model of Sobolev & Deguchi (1994). This has allowed
us to estimate the likely ranges of dust temperature, gas density, and methanol
column density, both for typical methanol maser sources and for those sources
which also show 107.0-GHz emission.


title: Morphology and luminosity segregation of galaxies in nearby loose groups

abstract:
  We study morphology and luminosity segregation of galaxies in loose groups.
We analyze the two catalogs of groups which have been identified in the Nearby
Optical Galaxy (NOG) sample, by means of hierarchical and percolation
``friends-of-friends'' methods (HG and PG catalogs, respectively). In the first
part of our analysis we consider 387 and 436 groups of HG and PG, respectively,
and compare morphology- (luminosity-) weighted to unweighted group properties:
velocity dispersion, mean pairwise distance, and mean groupcentric distance of
member galaxies. The second part of our analysis is based on two ensemble
systems, one for each catalog, built by suitably combining together galaxies of
all groups (1584 and 1882 galaxies for HG and PG groups, respectively). We find
that earlier-type (brighter) galaxies are more clustered and lie closer to the
group centers, both in position and in velocity, than later-type (fainter)
galaxies. Spatial segregations are stronger than kinematical segregations.
These effects are generally detected at the larger than 3-sigma level.
Luminosity segregation is shown to be independent of morphology segregation.
Our main conclusions are strengthened by the detection of segregation in both
hierarchical and percolation catalogs. Our results agree with a continuum of
segregation properties of galaxies in systems, from low-mass groups to massive
clusters.


title:
Search for an evidence of Fermi acceleration for SNR in a time
  dependence of metal abundance

abstract:
  A time dependence of a metal abundance of supernova remnant (SNR) have been
found by Hughes et al. (1998). We interpret this time dependence is due to
Fermi acceleration. If this interpretation is true, there is a metallicity
dependence of this time scale. However, we could not find an evidence of Fermi
acceleration.


title:
XMM-Newton spectral properties of the Narrow-Line Seyfert 1 galaxy IRAS
  13224--3809

abstract:
  We report on the first XMM-Newton observation of the highly X-ray variable,
radio-quiet, Narrow-Line Seyfert 1 galaxy IRAS 13224-3809 obtained during the
guaranteed time programme with a 64 ks exposure. The most remarkable spectral
feature is a sharp drop, by a factor ~5, in the spectrum at 8 keV. This is a
similar, but stronger, feature to that which we found in 1H0707-495.
Significant flattening of the hard X-ray spectrum occurs when the source flux
decreases. The flattening of the spectrum can be modelled as an increase in the
column density of the absorbing material and/or its covering fraction. Below ~
1.5 keV the spectrum is dominated by a giant soft X-ray excess, and at around ~
1.2 keV there is a significant absorption feature detected, most probably due
to ionized Fe L absorption. The new X-ray spectral properties detected with
XMM-Newton in IRAS 13224-3809 support a partial covering interpretation, i.e.
the presence of dense material inside the accretion-disc region partially
obscuring the emission from the accretion disc. However, the sharpness of the
feature, if due to photoelectric absorption, is surprising and may require an
alternative explanation. One possibility which does fit the whole spectrum is
that it is dominated by ionized reflection rather than absorption. The unusual
spectral properties detected with XMM-Newton from Narrow-Line Seyfert 1
galaxies increase the known spectral complexity of active galactic nuclei and
should further stimulate a combined theoretical and observational effort to
achieve a better understanding of the physics of the innermost regions of AGN.


title:
The consequences of parity symmetry for higher-order statistics of
  cosmic shear and other polar fields

abstract:
  We consider the parity transformation and the consequences of parity
invariance on the $n$-point correlation function of the cosmic shear, or any
other polar (or `spin-2') field. The decomposition of the shear field into E-
and B-modes then yields the result that any correlation function which contains
an odd number of B-mode shear components vanishes for parity-invariant random
shear fields. This result is at variance with some statements in the
literature, and the reasons for this is explained. We argue that the parity
invariance provides a very specific diagnostic of systematic effects in shear
data.


title: Las Campanas Loose Groups in the Supercluster-Void Network

abstract:
  We study the spatial distribution of loose groups from the Las Campanas
Redshift Survey, comparing it with the supercluster-void network delineated by
rich clusters of galaxies. We use density fields and the friends-of-friends
algorithm to identify the members of superclusters of Abell clusters among the
Las Campanas loose groups. We find that systems of loose groups tend to be
oriented perpendicularly to the line-of-sight, and discuss possible reasons for
that. We show that loose groups in richer systems (superclusters of Abell
clusters) are themselves also richer and more massive than groups in systems
without Abell clusters. Our results indicate that superclusters, as high
density environments, have a major role in the formation and evolution of
galaxy systems.


title: Feasibility of GRB with TeV gamma ray all sky monitor

abstract:
  We discuss feasibility of Gamma ray burst (GRB) with TeV gamma ray all sky
monitor and discuss necessity of TeV gamma ray cherenkov all sky monitor.


title: Polarization Studies of Comet C/2000 WM1 (LINEAR)

abstract:
  Linear polarization observations were carried out on comet C/2000 WM1 with
the 1.2m telescope at Mt. Abu Observatory during November 2001 and March 2002.
The observations in November were at low phase angle ($<~22\degr$) when the
polarization is negative and where the data for most of the comets are rather
meager. The observations during March were made when the phase angle was $\sim$
47\degr. Observations were conducted through the IHW narrow band and BVR broad
band filters. Based on these polarization observations we infer that the comet
C/2000 WM1 belongs to high polarization class i.e. the dusty comet family.


title:
Differences in carbon and nitrogen abundances between field and cluster
  early-type galaxies

abstract:
  Central line-strength indices were measured in the blue spectral region for a
sample of 98 early-type galaxies in different environments. For most indices
(Mgb and <Fe> in particular) ellipticals in rich clusters and in low-density
regions follow the same index-sigma relations. However, striking spectral
differences between field ellipticals and their counterparts in the central
region of the Coma cluster are found for the first time, with galaxies in the
denser environment showing significantly lower C4668 and CN2 absorption
strengths. The most convincing interpretation of these results is a difference
in abundance ratios, arising from a distinct star formation and chemical
enrichment histories of galaxies in different environments. An scenario in
which elliptical galaxies in clusters are fully assembled at earlier stages
than their low-density counterparts is discussed.


title:
Penetration at high-z of the Greenberg "yellow stuff": Eyes to the
  Future with NGST

abstract:
  Quantitative morphological dust-penetrated templates for galaxies in our
Local Universe may also serve as excellent templates for galaxies at high-z,
because of partial/total decouplings expected between gaseous and stellar
disks. NGC 922 is an optical irregular, which bears a striking resemblance to
objects such as HDF2-86 (z=0.749) in the HDF north (Block et al. 2001). Its
gaseous and stellar disk fully decouples; its stellar disk even presents
modulation of spiral arms, usually only found in grand design spiral galaxies
such as M81. Spiral galaxies in our Local Universe appear to be open systems,
that are still forming and accreting mass, doubling their disk masses every 10
billion years (Block et al. 2002; Bournaud & Combes 2002). Likewise, galaxies
at high-z may also be open systems, accreting mass, but herein NGST will
provide pivotal answers. In this paper, we simulate the appearance of spiral
galaxies (2--5" in angular diameter) with a class 6m Next Generation Space
Telescope (NGST) in their dust penetrated restframe K' (2.1um) regime at
redshifts of 0.7 and 1.2. Pitch angles, robustly derived from their Fourier
spectra, remain unchanged from the present to when the Universe was roughly one
half its present age. Furthermore, a ubiquity of low m (m=1 or m=2) spiral
wavelets or modes is maintained in restframe K' images at z=0.7 and z=1.2,
fully consistent with K' morphologies for spiral galaxies at z~0 in our local
Universe. This paper is dedicated to the memory of J. Mayo Greenberg, whose
final research delved into dust at high-z. Nominations for the 2004 Greenberg
lecture are invited.


title:
Some Good Reasons to Use Matched Filters for the Detection of Point
  Sources in CMB Maps

abstract:
  In this draft we comment on the results concerning the performances of
matched filters, scale adaptive filters and Mexican hat wavelet that recently
appeared in literature in the context of point source detection in Cosmic
Microwave Background maps. In particular, we show that, contrary to what has
been claimed, the use of the matched filters still appear to be the most
reliable and efficient method to disantangle point sources from the
backgrounds, even when using detection criterion that, differently from the
classic $n\sigma$ thresholding rule, takes into account not only the height of
the peaks in the signal corresponding to the candidate sources but also their
curvature.


title:
Measuring age, metallicity and abundance ratios from absorption line
  indices

abstract:
  In this study we present detailed calculations of absorption line indices on
the Lick System based on the stellar models by Salasnich et al. (2000)
calculated with enhanced mix of alpha-elements. Using the so-called Response
Functions (RFs) of Tripicco & Bell (1995, TB95), we calculate the indices for
SSPs of different age, metallicity and enhancement. We made use of the triplet
Hb, Mgb and <Fe>, and Minimum-Distance Method proposed by Trager et al. (2000,
TFWG00) to estimate the age, metallicity and enhancement degree for the
galaxies of the Gonzalez (1993) sample, and compare the results with those
TFWG00 and Thomas et al (2003). Since very large differences are found, in
particular as far as the age is concerned, we analyze in a great detail all
possible sources of disagreement, going from the stellar models and SSPs to
many technical details of the procedure to calculate the indices, and finally
the pattern of chemical elements (especially when alpha-enhanced mixtures are
adopted). The key issue of the analysis is that at given metallicity Z and
enhancement factor, the specific abundance ratios [Xel/Fe] adopted for some
elements (e.g. O, Mg, Ti, and likely others) dominate the scene because with
the TB95 RFs they may strongly affect indices like Hb and the age in turn.
Finally we have drawn some remarks on the interpretation of the distribution of
early-type galaxies in popular two-indices planes, like Hb vs. [MgFe]. We argue
that part of the scatter along the Hb axis observed in this plane could be
attributed instead of the age, the current explanation, to a spread both in the
degree of enhancement and some abundance ratios. The main conclusion of this
study is that deriving ages, metallicities and degree of enhancement from line
indices is a cumbersome affair whose results are still uncertain.


title:
Analysing large scale structure: II. Testing for primordial
  non-Gaussianity in CMB maps using surrogates

abstract:
  The identification of non-Gaussian signatures in cosmic microwave background
(CMB) temperature maps is one of the main cosmological challenges today. We
propose and investigate altenative methods to analyse CMB maps. Using the
technique of constrained randomisation we construct surrogate maps which mimic
both the power spectrum and the amplitude distribution of simulated CMB maps
containing non-Gaussian signals. Analysing the maps with weighted scaling
indices and Minkowski functionals yield in both cases statistically significant
identification of the primordial non-Gaussianities. We demonstrate that the
method is very robust with respect to noise. We also show that Minkowski
functionals are able to account for non-linearities at higher noise level when
applied in combination with surrogates than when only applied to noise added
CMB maps and phase randomised versions of them, which only reproduce the power
spectrum.


title:
Strange Quark Matter in Neutron Stars? - New Results from Chandra and
  XMM

abstract:
  It has been predicted that quark and hybrid stars, containing strange quark
matter in their core, have a significantly smaller radius than ordinary neutron
stars. Preliminary X-ray observations of isolated neutron stars indicated a
surprisingly small radius consistent with quark matter in the interior of the
star. However, a new analysis of the data led to a radius corresponding to an
ordinary neutron star. In the present talk we will discuss theoretical
calculations of the mass-radius relation for quark and hybrid stars, taking
into account medium effects in quark matter, and report on recent X-ray
observations by Chandra and XMM and their latest interpretation.


title:
A Theoretical Perspective on Galaxy Clusters: Physical Properties of the
  Dark Matter and Baryons

abstract:
  Clusters of galaxies are studied from a theoretical point of view, comparing
with observational results whenever possible. The problem is approached both
analytically as well as by means of high-resoultion numerical simulations. The
dark matter halo, the hot intracluster gas, and the stellar component are
investigated separately. Numerical clusters are consistent with a relatively
simple scenario, in which these objects form around local maxima of the
primordial density field, smoothed on Mpc sacales. Hot diffuse gas is in
approximate hydrostatic equilibrium with the dark matter potential, and it is
well described by a polytropic equation of state. Global X-ray properties are
closely interrelated, and deviations from self-similarity are expected even
when radiative processes are not considered. Star formation is severely reduced
in the inner regions of clusters, due to the fact that infalling galaxies loose
their hot gas reservoirs during the first orbit.


title: Shock Acceleration and gamma radiation in Clusters of Galaxies

abstract:
  The nonthermal radiation observed from a handfull of clusters of Galaxies is
the proof that particle acceleration occurs in the intracluster medium. It is
often believed that shock surfaces associated with either mergers of clusters
of galaxies, or with the cosmological inflow of matter onto clusters during
structure formation may be the sites for acceleration. We discuss here the
effectiveness of shock acceleration in the intracluster medium, stressing that
merger related shocks are typically weak, at least for the so-called major
mergers. We investigate the implications of shock strengths for gamma ray
emission from single clusters of galaxies and for their detectability with
future gamma ray experiments such as GLAST. We also discuss the contribution of
clusters of galaxies to the extragalactic diffuse gamma ray background.


title:
The Non-Linear Dependence of Flux on Black Hole Mass and Accretion Rate
  in Core Dominated Jets

abstract:
  We derive the non-linear relation between the core flux F_{nu} of accretion
powered jets at a given frequency and the mass M of the central compact object.
For scale invariant jet models, the mathematical structure of the equations
describing the synchrotron emission from jets enables us to cancel out the
model dependent complications of jet dynamics, retaining only a simple, model
independent algebraic relation between F_{nu} and M. This approach allows us to
derive the F_{nu}-M relation for any accretion disk scenario that provides a
set of input boundary conditions for the magnetic field and the relativistic
particle pressure in the jet, such as standard and advection dominated
accretion flow (ADAF) disk solutions. Surprisingly, the mass dependence of
F_{nu} is very similar in different accretion scenarios. For typical
flat-spectrum core dominated radio jets and standard accretion scenarios we
find F_{nu}~M^{17/12}. The 7-9 orders of magnitude difference in black hole
mass between microquasars and AGN jets imply that AGN jets must be about 3-4
orders of magnitude more radio loud than microquasars, i.e., the ratio of radio
to bolometric luminosity is much smaller in microquasars than in AGN jets.
Because of the generality of these results, measurements of this F_{nu}-M
dependence are a powerful probe of jet and accretion physics. We show how our
analysis can be extended to derive a similar scaling relation between the
accretion rate mdot and F_{nu} for different accretion disk models. For
radiatively inefficient accretion modes we find that the flat spectrum emission
follows F_{nu}~(mdot*M)^{17/12}.


title:
Narrow-Angle Astrometry with the Space Interferometry Mission: The
  Search for Extra-Solar Planets. II. Detection and Characterization of
  Planetary Systems

abstract:
  (Abridged) The probability of detecting additional companions is essentially
unchanged with respect to the single-planet configurations, but after fitting
and subtraction of orbits with astrometric signal-to-noise ratio
$\alpha/\sigma_d\to 1$ the false detection rates can be enhanced by up to a
factor 2; the periodogram approach results in robust multiple-planet detection
for systems with periods shorter than the SIM mission length, even at low
values of $\alpha/\sigma_d$, while the least squares technique combined with
Fourier series expansions is arguably preferable in the long-period regime. The
accuracy on multiple-planet orbit reconstruction and mass determination suffers
a typical degradation of 30-40% with respect to single-planet solutions; mass
and orbital inclination can be measured to better than 10% for periods as short
as 0.1 yr, and for $\alpha/\sigma_d$ as low as $\sim 5$, while
$\alpha/\sigma_d\simeq 100$ is required in order to measure with similar
accuracy systems harboring objects with periods as long as three times the
mission duration. For systems with all components producing
$\alpha/\sigma_d\simeq 10$ or greater, quasi-coplanarity can be reliably
established with uncertainties of a few degrees, for periods in the range
$0.1\leq T\leq 15$ yr; in systems where at least one component has
$\alpha/\sigma_d\to 1$, coplanarity measurements are compromised, with typical
uncertainties on the mutual inclinations of order of $30^\circ-40^\circ$. Our
findings are illustrative of the importance of the contribution SIM will make
to the fields of formation and evolution of planetary systems.


title: The shape of the CMB power spectrum

abstract:
  The recent WMAP data represents a milestone in cosmology and helps constrain
cosmological parameters with unprecedented accuracy. In this work we combine
the WMAP data with previous CMB anisotropy measurements at smaller angular
scales to characterize the shape of the CMB anisotropy power spectrum. We carry
out a phenomenological analysis of the data. By allowing non-physical shapes of
the power spectrum we analyse high and low frequency experiments separately and
together. We find that WMAP dramatically constrains the power spectrum up to l
\~ 700. On smaller scales, the data show discrepancies that can be associated
with experimental systematics. If we combine all types of experiments, the
observable features in the power spectrum are in excellent agreement with the
WMAP cosmological parameter estimation. This work illustrates the advantages of
a model-independent approach to understanding experimental systematics that
might affect CMB observations.


title:
Comments on the Evolution of Strongly Degenerate Neutrinos in the Early
  Universe

abstract:
  We reconsider the evolution of strongly degenerate neutrinos in the early
universe. Our chief concern is the validity of the entropy conservation after
the neutrino annihilation process has frozen out (so that the establishment of
chemical equilibrium is not trivial). We argue that the entropy indeed
conserves because elastic scattering keeps the neutrino and antineutrino
distribution functions in the equilibrium form and the sum of their chemical
potential keeps zero even after the neutrino annihilation freeze-out. We also
simulate the evolution of the degenerate neutrino spectrum to support the
argument. We conclude that the change in the neutrino degeneracy parameter when
the relativistic degrees of freedom in the universe decreases is calculated
using the entropy conservation and the lepton number conservation without
worrying about at what temperature the neutrino annihilation process freezes
out.


title:
Thermal structure and cooling of superfluid neutron stars with accreted
  magnetized envelopes

abstract:
  We study the thermal structure of neutron stars with magnetized envelopes
composed of accreted material, using updated thermal conductivities of plasmas
in quantizing magnetic fields, as well as equation of state and radiative
opacities for partially ionized hydrogen in strong magnetic fields. The
relation between the internal and local surface temperatures is calculated and
fitted by an analytic function of the internal temperature, magnetic field
strength, angle between the field lines and the normal to the surface, surface
gravity, and the mass of the accreted material. The luminosity of a neutron
star with a dipole magnetic field is calculated for various values of the
accreted mass, internal temperature, and magnetic field strength. Using these
results, we simulate cooling of superfluid neutron stars with magnetized
accreted envelopes. We consider slow and fast cooling regimes, paying special
attention to very slow cooling of low-mass superfluid neutron stars. In the
latter case, the cooling is strongly affected by the combined effect of
magnetized accreted envelopes and neutron superfluidity in the stellar crust.
Our results are important for interpretation of observations of isolated
neutron stars hottest for their age, such as RX J0822-43 and PSR B1055-52.


title:
A Quantitative Comparison of SMC, LMC, and Milky Way UV to NIR
  Extinction Curves

abstract:
  We present an exhaustive, quantitative comparison of all of the known
extinction curves in the Small and Large Magellanic Clouds (SMC and LMC) with
our understanding of the general behavior of Milky Way extinction curves. The
R_V dependent CCM relationship and the sample of extinction curves used to
derive this relationship is used to describe the general behavior of Milky Way
extinction curves. The ultraviolet portion of the SMC and LMC extinction curves
are derived from archival IUE data, except for one new SMC extinction curve
which was measured using HST/STIS observations. The optical extinction curves
are derived from new (for the SMC) and literature UBVRI photometry (for the
LMC). The near-infrared extinction curves are calculated mainly from 2MASS
photometry supplemented with DENIS and new JHK photometry. For each extinction
curve, we give R_V = A(V)/E(B-V) and N(HI) values which probe the same dust
column as the extinction curve. We compare the properties of the SMC and LMC
extinction curves with the CCM relationship three different ways: each curve by
itself, the behavior of extinction at different wavelengths with R_V, and
behavior of the extinction curve FM fit parameters with R_V. As has been found
previously, we find that a small number of LMC extinction curves are consistent
with the CCM relationship, but majority of the LMC and all of the SMC curves do
not follow the CCM relationship. For the first time, we find that the CCM
relationship seems to form a bound on the properties of all of the LMC and SMC
extinction curves. This result strengthens the picture of dust extinction
curves exhibit a continuum of properties between those found in the Milky Way
and the SMC Bar. (abridged)


title: Observation of Soft Gamma Repeaters with BeppoSAX

abstract:
  In this paper I will briefly review what are, in my view, the main
contributions of BeppoSAX to the understanding of the class of sources known as
Soft Gamma Repeaters. These enigmatic sources were firmly identified as steady
pulsars just during the operating lifetime of BeppoSAX. All the instruments
onboard BeppoSAX have at some level contributed in this field with specific
observations, always allowing high quality - sometimes unprecedented - studies
of the quiescent counterparts or the bursting behavior of these sources. I will
try to stress the results that were uniquely achieved by BeppoSAX and identify
their impact on the knowledge of the physics at work in these sources.


title:
The Cepheid Distance to NGC 1637: A Direct Test of the EPM Distance to
  SN 1999em

abstract:
  Type II-plateau supernovae (SNe II-P) are the classic variety of
core-collapse events that result from isolated, massive stars with thick
hydrogen envelopes intact at the time of explosion. Their distances are now
routinely estimated through two techniques: the expanding photosphere method
(EPM), a primary distance-determining method, and the recently developed
standard-candle method (SCM), a promising secondary technique. Using Cycle 10
HST observations, we identify 41 Cepheid variable stars in NGC 1637, the host
galaxy of the most thoroughly studied SN II-P to date, SN 1999em. Remarkably,
the Cepheid distance that we derive to NGC 1637, D = 11.7 +/- 1.0 Mpc, is
nearly 50% larger than earlier EPM distance estimates to SN 1999em. This is the
first direct comparison between these two primary distance determining methods
for a galaxy hosting a well-observed, spectroscopically and photometrically
normal, SN II-P. Extensive consistency checks show strong evidence to support
the Cepheid distance scale, so we are led to believe that either SN 1999em is
in some heretofore unsuspected way an unusual SN II-P, or that the SN II-P
distance scale must be revised. Assuming the latter, this one calibration
yields H_0(EPM) = 57 +/- 15 km/s/Mpc and H_0(SCM) = 59 +/- 11 km/s/Mpc;
additional calibrating galaxies are clearly desirable in order to test the
robustness of both determinations of H_0. The HST observations of NGC 1637 also
captured the fading SN 1999em two years after explosion, providing the latest
photometry ever obtained for an SN II-P. Through comparison with photometry of
SN 1987A at similar epochs, we conclude that a slightly greater amount of
radioactive Ni-56, ~0.09 M_sun, was ejected by SN 1999em than was derived for
SN 1987A (0.075 M_sun).


title: Probing dark energy with gamma-ray bursts

abstract:
  We propose a new method to use gamma-ray bursts (GRBs) as an alternative
probe of the dark energy. By calibrating luminosity-variability and
luminosity-lag time relations at low redshift where distance-redshift relations
have been already determined from type Ia supernova (SNIa), GRBs at high
redshift can be used as a distance indicator. We investigate the potential
impact of future GRB data on determining the current matter density
$\Omega_{m}$ and the dark energy equation of state $w$ which is assumed to be
constant. We show that a combined analysis of a data set expected from the {\it
Swift} and the current SNIa data results in excellent determination of both
$\Omega_{m}$ and $w$.


title: A fundamental plane of black hole activity

abstract:
  We examine the disc--jet connection in stellar mass and supermassive black
holes by investigating the properties of their compact emission in the X-ray
and radio bands. We compile a sample of ~100 active galactic nuclei with
measured mass, 5 GHz core emission, and 2-10 keV luminosity, together with 8
galactic black holes with a total of ~50 simultaneous observations in the radio
and X-ray bands. Using this sample, we study the correlations between the radio
(L_{R}) and the X-ray (L_{X}) luminosity and the black hole mass (M). We find
that the radio luminosity is correlated with {\em both} M and L_{X}, at a
highly significant level. In particular, we show that the sources define a
``fundamental plane'' in the three-dimensional (log L_{R},log L_{X},log M)
space, given by log L_{R}=(0.60^{+0.11}_{-0.11}) log L_{X}
+(0.78^{+0.11}_{-0.09}) log M + 7.33^{+4.05}_{-4.07}, with a substantial
scatter of \sigma_{R}=0.88. We compare our results to the theoretical relations
between radio flux, black hole mass, and accretion rate derived by Heinz and
Sunyaev (2003). Such relations depend only on the assumed accretion model and
on the observed radio spectral index. Therefore, we are able to show that the
X-ray emission from black holes accreting at less than a few per cent of the
Eddington rate is unlikely to be produced by radiatively efficient accretion,
and is marginally consistent with optically thin synchrotron emission from the
jet. On the other hand, models for radiatively inefficient accretion flows seem
to agree well with the data.


title: Mass Segregation in Young LMC Clusters

abstract:
  We present the detailed analysis of Hubble Space Telescope observations of
the spatial distributions of different stellar species in two young compact
star clusters in the Large Magellanic Cloud (LMC), NGC 1805 and NGC 1818. Based
on a comparison of the characteristic relaxation times in their cores and at
their half-mass radii with the observed degree of mass segregation, it is most
likely that significant primordial mass segregation was present in both
clusters, particularly in NGC 1805. Both clusters were likely formed with very
similar initial mass functions (IMFs). In fact, we provide strong support for
the universality of the IMF in LMC clusters for stellar masses m >= 0.8 M_sun.


title:
How long before the end of inflation were observable perturbations
  produced?

abstract:
  We reconsider the issue of the number of e-foldings before the end of
inflation at which observable perturbations were generated. We determine a
plausible upper limit on that number for the standard cosmology which is around
60, with the expectation that the actual value will be up to 10 below this. We
also note a special property of the $\lambda \phi^4$ model which reduces the
uncertainties in that case and favours a higher value, giving a fairly definite
prediction of 64 e-foldings for that model. We note an extreme (and highly
implausible) situation where the number of e-foldings can be even higher,
possibly up to 100, and discuss the shortcomings of quantifying inflation by
e-foldings rather than by the change in $aH$. Finally, we discuss the impact of
non-standard evolution between the end of inflation and the present, showing
that again the expected number of e-foldings can be modified, and in some cases
significantly increased.


title:
Anomalous ultraviolet line flux ratios in the cataclysmic variables
  1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg observed with HST/STIS

abstract:
  Brief HST/STIS spectroscopic snapshot exposures of the cataclysmic variables
1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg reveal very large NV/CIV line
flux ratios, similar to those observed in AE Aqr. Such anomalous line flux
ratios have so far been observed in 10 systems, and presumably reflect a
different composition of the accreted material compared to the majority of
cataclysmic variables. We discuss the properties of this small sample in the
context of the recent proposal by Schenker et al. (2002) that a significant
fraction of the present-day population of cataclysmic variables may have passed
through a phase of thermal time-scale mass transfer.


title: Reconsidering the origin of the X-ray emission lines in GRB 011211

abstract:
  We reanalyze the XMM--Newton data of GRB 011211 showing that the spectral
features, interpreted by Reeves et al. (2002, 2003) as due thermal emission
from a collisionally ionized plasma, can be also reproduced by a reflection
model (with ionization parameter $\xi\sim 10^2$). We discuss the implications
of this interpretation, estimating the total mass required in the simplified
case of a funnel geometry. We conclude that a moderate clumping of the
reprocessing material (corresponding to a filling factor of the order of $f\sim
10^{-3}$) is required. Finally we show that, if this interpretation is correct,
a bright quasi--thermal component is expected in the optical--UV band
(containing about 90% of the luminosity of the illuminating continuum), whose
presence can be used to test the reflection model.


title:
Pulse-to-pulse intensity modulation and drifting subpulses in recycled
  pulsars

abstract:
  We report the detection of pulse-to-pulse periodic intensity modulations, in
observations of recycled pulsars. Even though the detection of individual
pulses was generally not possible due to their low flux density and short
duration, through the accumulation of statistics over sequences of 10^5--10^6
pulses we were able to determine the presence and properties of the
pulse-to-pulse intensity variations of six pulsars. In most cases we found that
the modulation included a weak, broadly quasi-periodic component. For two
pulsars the sensitivity was high enough to ascertain that the modulation phase
apparently varies systematically across the profile, indicating that the
modulation appears as drifting subpulses. We detected brighter than average
individual pulses in several pulsars, with energies up to 2--7 times higher
than the mean, similar to results from normal pulsars. We were sensitive to
giant pulses of a rate of occurrence equal to (and in many instances much lower
than) that of PSR B1937+21 at 1400 MHz (~30 times lower than at 430 MHz), but
none were detected, indicating that the phenomenon is rare in recycled pulsars.


title: Elemental Abundances in NGC 3516

abstract:
  We present RGS data from an XMM-Newton observation of the Seyfert 1 galaxy
NGC 3516, taken while the continuum source was in an extreme low state. The
spectrum shows numerous emission lines including the H-like lines of C, N and O
and the He-like lines of N, O and Ne. These data show that the N lines are far
stronger than would be expected from gas of solar abundances. Based on our
photoionization models, we find that N is overabundant compared to C, O and Ne
by at least a factor of 2.5. We suggest this is the result of secondary
production of N in intermediate mass stars, and indicative of the history of
star formation in NGC 3516.


title:
The CORALS Survey: A Review and Progress Report on The Search for Dust
  Obscured Quasar Absorption Line Systems

abstract:
  We present a brief overview of the ongoing Complete Optical and Radio
Absorption Line System (CORALS) survey. We review the results of our survey for
z>2.2 damped Lyman alpha systems (DLAs) and present the preliminary results of
an extended survey to lower redshifts (0.7<z<1.5). Although final observations
are still pending, our preliminary statistics do not find an excess of
absorption systems selected via MgII towards optically faint QSOs. We also
briefly review the results from some spin-off projects from CORALS including
the low alpha/Fe abundances of multiple DLAs and the possible excess of
absorbers within 3000 km/s of the QSO redshift.


title: Electromagnetic wave collapse in a radiation background

abstract:
  The nonlinear interaction, due to quantum electrodynamical (QED) effects,
between an electromagnetic pulse and a radiation background is investigated, by
combining the methods of radiation hydrodynamics with the QED theory for
photon-photon scattering. For the case of a single coherent electromagnetic
pulse we obtain a Zakharov-like system, where the radiation pressure of the
pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently
intense pulse and/or background energy density there is focusing and subsequent
collapse of the pulse. The relevance of our results for various astrophysical
applications are discussed.


title: 1RXSJ062518.2+733433: A new intermediate polar

abstract:
  We report the identification of the cataclysmic variable 1RXSJ062518.2+733433
as an intermediate polar. The orbital period of the system is determined to be
283.0+-2 min from the radial velocity variation of Halpha, measured in an
extensive set of time-resolved spectroscopy. Differential optical photometry
obtained over a base line of three weeks reveals the presence of coherent
variability with a period of 19.788+-0.002 min, which we suggest to be the
white dwarf spin period. The power spectrum of our photometry also contains a
strong signal near the spectroscopically determined orbital period. The
emission lines in 1RXSJ062518.2+733433 display a complex multicomponent
structure. In the trailed spectrogram of HeI 6678 we detect a narrow component
with a radial velocity semi-amplitude of ~140kms, consistent with a possible
origin on the irradiated face of the secondary. The absence of eclipses gives
an upper limit on the binary inclination of i<=60deg.


title:
Updated results on prototype chalcogenide fibers for 10-um wavefront
  spatial filtering

abstract:
  The detection of terrestrial planets by Darwin/TPF missions will require
extremely high quality wavefronts. Single-mode fibers have proven to be
powerful beam cleaning components in the near-infrared, but are currently not
available in the mid-infrared where they would be critically needed for
Darwin/TPF. In this paper, we present updated measurements on the prototype
chalcogenide fibers we are developing for the purpose of mid-infrared spatial
filtering. We demonstrate the guiding property of our 3rd generation component
and we characterize its filtering performances on a 4 mm length: the far-field
radiation pattern matches a Gaussian profile at the level of 3% rms and 13%
pk-pk.


title: The Polarization of the Cosmic Microwave Background

abstract:
  We summarize the physical mechanism by which the Cosmic Microwave Background
acquires a small degree of polarization. We discuss the imprint left by
gravitational waves and the use of polarization as a test of the inflationary
paradigm. We discuss some physical processes that affect the CMB polarization
after recombination such as gravitational lensing and the reionization of the
universe.


title: The Vela Pulsar in the Near-Infrared

abstract:
  We report on the first detection of the Vela pulsar in the near-infrared with
the VLT/ISAAC in the Js and H bands. The pulsar magnitudes are Js=22.71 +/-
0.10 and H=22.04 +/- 0.16. We compare our results with the available
multiwavelength data and show that the dereddened phase-averaged optical
spectrum of the pulsar can be fitted with a power law F_nu propto
nu^(-alpha_nu) with alpha_nu = 0.12 +/- 0.05, assuming the color excess
E(B-V)=0.055 +/-0.005 based on recent spectral fits of the emission of the Vela
pulsar and its supernova remnant in X-rays. The negative slope of the pulsar
spectrum is different from the positive slope observed over a wide optical
range in the young Crab pulsar spectrum. The near-infrared part of the Vela
spectrum appears to have the same slope as the phase-averaged spectrum in the
high energy X-ray tail, obtained in the 2-10 keV range with the RXTE. Both of
these spectra can be fitted with a single power law suggesting their common
origin. Because the phase-averaged RXTE spectrum in this range is dominated by
the second X-ray peak of the pulsar light curve, coinciding with the second
main peak of its optical pulse profile, we suggest that this optical peak can
be redder than the first one. We also detect two faint extended structures in
the 1.5''-3.1'' vicinity of the pulsar, projected on and aligned with the
south-east jet and the inner arc of the pulsar wind nebula, detected in X-rays
with Chandra. We discuss their possible association with the nebula.


title:
Parameterization of the antiproton inclusive production cross section on
  nuclei

abstract:
  A new parameterization of the antiproton inclusive production cross section
in proton-proton and proton-nucleus collisions is proposed. A sample of
consistent pA->pbar X$ experimental data sets measured on 1<A<208 nuclei, from
12 GeV up to 400 GeV incident energy, have been used to constrain the
parameters. A broader energy domain is covered for the pp->pbar X reaction with
a simplified functional form used in the fits. The agreement obtained with the
data is good. The results are discussed.


title:
Detection of TeV Gamma-Rays from the BL Lac 1ES1959+650 in its low
  states and during a major outburst in 2002

abstract:
  TeV gamma-rays from the BL Lac object 1ES1959+650 have been measured during
the years 2000 and 2001 with a significance of 5.2 sigma at a value of 5.3% of
the Crab flux and in May 2002 during strong outbursts with > 23 sigma at a flux
level of up to 2.2 Crab, making 1ES1959+650 the TeV Blazar with the third best
event statistics. The deep observation of 197.4 h has been performed with the
HEGRA stereoscopic system of 5 imaging atmospheric Cherenkov telescopes (IACT
system). 1ES1959+650 is located at a redshift of z = 0.047, providing an
intermediate distance between the nearby Blazars Mkn 421 and Mkn 501, and the
much more distant object H1426+428. This makes 1ES1959+650 an important member
of the class of TeV Blazars in view of the absorption of TeV photons by the
diffuse extragalactic background radiation (DEBRA). The differential energy
spectrum of 1ES1959+650 during the flares can be fitted by a power law with a
spectral index of 2.83 +- 0.14_stat +- 0.08_sys or by a power law with an
exponential cut-off at (4.2^(+0.8)_(-0.6)_stat +- 0.9_sys) TeV and a spectral
index of 1.83 +- 0.15_stat +- 0.08_sys. The low state differential energy
spectrum obtained with lower statistics can be described by a pure power law
with a spectral index of 3.18 +- 0.17_stat +- 0.08_sys.


title: Near-Infrared photometry of LMC cluster Reticulum

abstract:
  We present near-infrared (JKs) time series data of the Large Magellanic Cloud
(LMC) cluster Reticulum. The observing strategy and data reduction
(DAOPHOTII/ALLFRAME) allowed us to reach a photometry accuracy of the order of
0.02 mag at limiting magnitudes typical of RR Lyrae stars. We are interested in
Reticulum, since it hosts a sizable sample of RR Lyrae (32), and therefore the
use of the K-band Period-Luminosity-Metallicity (PLZ_K) relation will allow us
to supply an accurate LMC distance evaluation. The main advantages in using
this method is that it is marginally affected by off-ZAHB evolutionary effects
and by reddening corrections. As a preliminary but robust result we find a true
distance in good agreement with the LMC Cepheid distance scale, i.e. DM = 18.47
+- 0.07 mag.


title: A Theory for the Radius of the Transiting Giant Planet HD 209458b

abstract:
  Using a full frequency-dependent atmosphere code that can incorporate
irradiation by a central primary star, we calculate self-consistent boundary
conditions for the evolution of the radius of the transiting planet HD 209458b.
Using a well-tested extrasolar giant planet evolutionary code, we then
calculate the behavior of this planet's radius with age. The measured radius is
in fact a transit radius that resides high in HD 209458b's inflated atmosphere.
Using our derived atmospheric and interior structures, we find that irradiation
plus the proper interpretation of the transit radius can yield a theoretical
radius that is within the measured error bars. We conclude that if HD 209458b's
true transit radius is at the lower end of the measured range, an extra source
of core heating power is not necessary to explain the transit observations.


title: The XMM-Newton/2dF survey I: X-ray properties of normal galaxies

abstract:
  This paper explores the X-ray properties of `normal' galaxies using a shallow
XMM-Newton survey covering an area of ~1.5deg2. The X-ray survey overlaps with
the 2dF Galaxy Redshift Survey. Compared with previous studies this has the
advantage of high quality spectra and spectral classifications to bj=19.4.
Moreover, sources with optical spectra revealing powerful AGNs can easily be
discarded from the normal galaxy sample used here. In particular, we present
stacking analysis results for 200 galaxies from the 2dFGRS at <z>=0.1. We
detect a strong signal for the whole sample (~6sigma) in the soft 0.5-2keV band
corresponding to a flux of ~7*10^-16cgs and a luminosity of ~2*10^40cgs. A
statistically significant signal is also detected for both the early and late
galaxy sub-samples with X-ray luminosities of ~3*10^40 and ~5*10^39cgs
respectively. In contrast, no signal is detected in the hard 2-8keV band for
any of the above samples. The mean L_X/L_B ratio of the spiral galaxy sample is
consistent with both local (<100Mpc) and distant (z~1) samples suggesting
little or no evolution of the X-ray emission mechanisms relative to the
optical. The 0.5-2keV XRB contribution of the spiral galaxy sub-sample at z~0.1
is estimated to be 0.4% in broad agreement with the XRB fractions estimated in
previous studies.Assuming that star-forming galaxies evolve with redshift as
(1+z)^{k} the present data combined with previous studies suggest k<3. The k
values are constrained by the relatively low fraction of the soft X-ray
background that remains unresolved by deep surveys (6-26%). The mean X-ray
emissivity of spiral galaxies at z~0.1 is also estimated and is found to be
consistent within the uncertainties with that of local HII galaxy samples.


title:
Far-UV Emissions of the Sun in Time: Probing Solar Magnetic Activity and
  Effects on Evolution of Paleo-Planetary Atmospheres

abstract:
  We present and analyze FUSE observations of six solar analogs. These are
single, main-sequence G0-5 strs selected as proxies for the Sun at several
stages of its main-sequence lifetime. The emission features in the FUSE
920-1180 A wavelength range allow for a critical probe of the hot plasma over
three decades in temperature. Using the flux ratio CIII 1176/977 as
diagnostics, we investigate the dependence of the electron pressure of the
transition region as a function of the rotation period, age and magnetic
activity. The results from these solar proxies indicate that the electron
pressure of the stellar ~10^5-K plasma decreases by a factor of about 70
between the young, fast-rotating magnetically active star and the old,
slow-rotating inactive star. Also, the observations indicate that the average
surface fluxes of emission features strongly decrease with increasing stellar
age and longer rotation period. The emission flux evolution with age or
rotation period is well fitted by power laws, which become steeper from cooler
chromospheric (10^4 K) to hotter coronal (10^7 K) plasma. The relationship for
the integrated (920-1180 A) FUSE flux indicates that the solar far-ultraviolet
emissions were about twice the present value 2.5 Gyr ago and about 4 times the
present value 3.5 Gyr ago. Note also that the FUSE/FUV flux of the Zero-Age
Main Sequence Sun could have been higher by as much as 50 times. Our analysis
suggests that the strong FUV emissions of the young Sun may have played a
crucial role in the developing planetary system, in particular through the
photoionization, photochemical evolution and possible erosion of the planetary
atmospheres. (abridged)


title: Summary Talk

abstract:
  Highlights of the meeting include new insights into r and s-processes and an
explosion of interesting abundance data on stars in the Galactic halo and in
dwarf spheroidal galaxies. I include in this summary a few suggestions on the
chemical evolution of the Thick and Thin disks, and on the present and past
distribution of baryons and metals in the universe.


title: Experiences with Airborne and Ground-Based Polarimetry

abstract:
  Polarimetry in the far-infrared and submillimeter has been valuable in
tracing magnetic fields in bright Galactic Clouds. We discuss the techniques we
have developed and trends we have found in polarization vs column density, and
vs wavelength. The polarization spectrum has proven to be more interesting than
had been anticipated. It is potentially valuable in explaining grain alignment
and in characterizing dust species. One can expect the infrared cirrus to be a
much simpler environment than the molecular clouds that have heretofore been
explored at multiple wavelengths. Although cirrus observations must deal with
low signals and wide extent, it is becoming possible to measure accurately the
spectral energy distribution from mid-infrared to microwave frequencies and it
should soon become feasible to determine the polarization spectrum over the
same range.


title:
The Building the Bridge survey for z=3 Ly-alpha emitting galaxies I:
  method and first results

abstract:
  We present the first results of an observational programme at the ESO Very
Large Telescope aimed at detecting a large sample of high-redshift galaxies
fainter than the current spectroscopic limit of R=25.5 for Lyman-Break
galaxies. In this paper, we describe the results of deep narrow and broad-band
imaging and subsequent follow-up multi-object spectroscopy of faint
high-redshift galaxies in the fields of the BRI1346-0322 and Q2138-4427. These
QSOs have intervening absorbers, at redshifts z=2.85 and z=3.15 respectively,
for which redshifted Ly-alpha emission falls within less than a few AA from the
central wavelengths of existing VLT (~60 AA wide) narrow-band filters. We
selected 37 and 27 candidate emission-line galaxies in the two fields
respectively. About 85% of the candidates have R-band magnitudes fainter than
R=25.5. The first spectroscopic follow-up of a sub-sample of the candidates
resulted in 41 confirmed candidates and 4 foreground galaxies (three [OII]
emitters and one CIV emitter). The confirmation rate is 82% and 68% in the
field of BRI1346-0322 and Q2138-4427 respectively. In addition, we
serendipitously detect a number of other emission-line sources on some of the
slitlets not used for candidates. Of these, 9 are also most likely Ly-alpha
emitters with redshifts ranging from 1.98 to 3.47. The redshift distribution of
confirmed candidates in the field of BRI1346-0322 is consistent with being
drawn from a uniform distribution weighted by the filter response curve,
whereas the galaxies in the field of Q2138-4427 have redshifts clustering very
close to the redshift of the damped Ly-alpha absorber. This latter fact
indicates the existence of a large `pancake'-like structure confirming the
earlier suggestions of Francis & Hewitt (1993).


title: Spin up in RX J0806+15 - the shortest period binary

abstract:
  RX J0806+15 has recently been identified as the binary system with the
shortest known orbital period. We present a series of observations of RX
J0806+15 including new optical observations taken one month apart. Using these
observations and archival data we find that the period of this system is
decreasing over time. Our measurements imply f_dot = 6.11x10^-16 Hz/s, which is
in agreement with a rate expected from the gravitational radiation for two
white dwarfs orbiting at a given period. However, a smaller value of f_dot =
3.14x10^-16 Hz/s cannot be ruled out. Our result supports the idea that the
321.5 s period is the orbital period and that the system is the shortest period
binary known so far and that it is one of the strongest sources of constant
gravitational radiation in the sky. Furthermore, the decrease of the period
strongly favours the unipolar inductor (or electric star) model rather than the
accretion models.


title: Detection of tau neutrinos in underwater neutrino telescopes

abstract:
  If neutrinos produced in astrophysics sources oscillate, neutrino telescopes
can have a chance to detect signals from tau-neutrinos. We present an estimate
of the 'double bang' event rate produced by tau neutrinos in cubic kilometer
scale detectors.


title: A Puzzling X-Ray Source Found in the chandra Deep Field South

abstract:
  In this letter we report the detection of an extremely strong X-ray emission
line in the 940ks chandra ACIS-I spectrum of CXO CDFS J033225.3-274219. The
source was identified as a Type1 AGN at redshift of z = 1.617, with 2.0 -- 10.0
keV rest frame X-ray luminosity of ~ 10^44 ergs s^-1. The emission line was
detected at 6.2^{+0.2}_{-0.1} keV, with an equivalent width (EW) of
4.4^{+3.2}_{-1.4} keV, both quantities referring to the observed frame. In the
rest frame, the line is at 16.2^{+0.4}_{-0.3} keV with an EW of
11.5^{+8.3}_{-3.7} keV. An X-ray emission line at similar energy (~ 17 keV,
rest frame) in QSO PKS 2149-306 was discovered before using ASCA data. We
reject the possibility that the line is due to a statistical or instrumental
artifact. The line is most likely due to blueshifted Fe-K emission from an
relativistic outflow, probably an inner X-ray jet, with velocities of the order
of ~ 0.6-0.7c. Other possible explanations are also discussed.


title: Cosmic Structure Growth and Dark Energy

abstract:
  Dark energy has a dramatic effect on the dynamics of the universe, causing
the recently discovered acceleration of the expansion. The dynamics are also
central to the behavior of the growth of large scale structure, offering the
possibility that observations of structure formation provide a sensitive probe
of the cosmology and dark energy characteristics. In particular, dark energy
with a time varying equation of state can have an influence on structure
formation stretching back well into the matter dominated epoch. We analyze this
impact, first calculating the linear perturbation results, including those for
weak gravitational lensing. These dynamical models possess definite observable
differences from constant equation of state models. Then we present a large
scale numerical simulation of structure formation, including the largest volume
to date involving a time varying equation of state. We find the halo mass
function is well described by the Jenkins et al. mass function formula. We also
show how to interpret modifications of the Friedmann equation in terms of a
time variable equation of state. The results presented here provide steps
toward realistic computation of the effect of dark energy in cosmological
probes involving large scale structure, such as cluster counts,
Sunyaev-Zel'dovich effect, or weak gravitational lensing.


title: The coalescence remnant of spinning binary black holes

abstract:
  We compute the gravitational radiation generated in the evolution of a family
of close binary black hole configurations, using a combination of numerical and
perturbative approximation methods. We evolve the binaries with spins, $s$,
aligned or counter-aligned with the orbital angular momentum from near the
innermost stable circular orbit (ISCO) down to the final single rotating black
hole. For the moderately spinning holes studied here the remnant Kerr black
hole formed at the end of an inspiral process have a rotation parameter
$a/M\approx0.72+0.32(s/m_H)$, suggesting it is difficult (though not excluded)
to end up with near maximally rotating holes from such scenarios.


title: On the Axisymmetric Force-Free Pulsar Magnetosphere

abstract:
  We investigate the axisymmetric magnetosphere of an aligned rotating magnetic
dipole surrounded by an ideal force-free plasma. We concentrate on the magnetic
field structure around the point of intersection of the separatrix between the
open and closed field-line regions and the equatorial plane. We first study the
case where this intersection point is located at the Light Cylinder. We find
that in this case the separatrix equilibrium condition implies that all the
poloidal current must return to the pulsar in the open-field region, i.e., that
there should be no finite current carried by the separatrix/equator current
sheet. We then perform an asymptotic analysis of the pulsar equation near the
intersection point and find a unique self-similar solution; however, a Light
Surface inevitably emerges right outside the Light Cylinder. We then perform a
similar analysis for the situation where the intersection point lies somewhere
inside the Light Cylinder, in which case a finite current flowing along the
separatrix and the equator is allowed. We find a very simple behavior in this
case, characterized by a 90-degree angle between the separatrix and the equator
and by finite vertical field in the closed-field region. Finally, we discuss
the implications of our results for global numerical studies of pulsar
magnetospheres.


title: A New Multiple Stellar System in the Solar Neighborhood

abstract:
  Adaptive optics corrected images obtained with the CIAO instrument at the
Subaru 8.2-meter telescope show the presence of two subarsecond companions to
the nearby (d=19.3 pc) young star GJ 900, which was previously classified as a
single member of the IC 2391 supercluster. The two companions share the same
proper motion as the primary and are redder. Their projected separations from
the primary are 10 AU and 14.5 AU for B and C, respectively. The estimated
masses for the two new companions depend strongly on the age of the system. For
the range of ages found in the literature for IC 2391 supercluster members
(from 35 Myr to 200 Myr), the expected masses range from 0.2 M$_\odot$ to 0.4
M$_\odot$ for the B component, and from 0.09 M$_\odot$ to 0.22 M$_\odot$ for
the C component. The determination of the dynamical mass of the faintest
component of GJ 900 will yield the age of the system using theoretical
evolutionary tracks. The apparent separations of the GJ 900 system components
meet the observational criterion for an unstable Trapezium-type system, but
this could be a projection effect. Further observations are needed to establish
the nature of this interesting low-mass multiple system.


title:
Spectral properties, generation order parameters and luminosities for
  spin-powered X-ray pulsars

abstract:
  We show the spectral properties of 15 spin-powered X-ray pulsars, and the
correlation between the average power-law photon index and spin-down rate.
Generation order parameters (GOPs) based on polar-cap models are introduced to
characterize the X-ray pulsars. We calculate three definitions of generation
order parameters due to the different effects of magnetic and electric fields
on photon absorption during cascade processes, and study the relations between
the GOPs and spectral properties of X-ray pulsars. There exists a possible
correlation between the photon index and GOP in our pulsar sample. Furthermore,
we present a method due to the concept of GOPs to estimate the non-thermal
X-ray luminosity for spin-powered pulsars. Then X-ray luminosity is calculated
in the context of our polar-cap accelerator model which is well consistent with
the most observed X-ray pulsar data. The ratio between X-ray luminosity
estimated by our method and the pulsar's spin-down power is well consistent
with the $L_{\rm X}\sim 10^{-3}L_{\rm sd}$ feature.


title:
Nonthermal Emission from the Arches Cluster (G0.121+0.017) and the
  Origin of $\gamma$-ray Emission from 3EG J1746-2851

abstract:
  High resolution VLA observations of the Arches cluster near the Galactic
center show evidence of continuum emission at $\lambda$3.6, 6, 20 and 90cm. The
continuum emission at $\lambda$90cm is particularly striking because thermal
sources generally become optically thick at longer wavelengths and fall off in
brightness whereas non-thermal sources increase in brightness. It is argued
that the radio emission from this unique source has compact and diffuse
components produced by thermal and nonthermal processes, respectively. Compact
sources within the cluster arise from stellar winds of mass-losing stars (Lang,
Goss & Rodriguez 2001a) whereas diffuse emission is likely to be due to
colliding wind shocks of the cluster flow generating relativistic particles due
to diffuse shock acceleration. We also discuss the possibility that
$\gamma$-ray emission from 3EG J1746--2851, located within 3.3$'$ of the Arches
cluster, results from the inverse Compton scattering of the radiation field of
the cluster.


title: Multiverses and physical cosmology

abstract:
  The idea of a multiverse -- an ensemble of universes -- has received
increasing attention in cosmology, both as the outcome of the originating
process that generated our own universe, and as an explanation for why our
universe appears to be fine-tuned for life and consciousness. Here we carefully
consider how multiverses should be defined, stressing the distinction between
the collection of all possible universes, and ensembles of really existing
universes that are essential for an anthropic argument. We show that such
realised multiverses are by no means unique. A proper measure on the space of
all really existing universes or universe domains is needed, so that
probabilities can be calculated, and major problems arise in terms of realised
infinities. As an illustration we examine these issues in the case of the set
of Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) universes. Then we briefly
summarise scenarios like chaotic inflation, which suggest how ensembles of
universe domains may be generated, and point out that the regularities which
must underlie any systematic description of truly disjoint multiverses must
imply some kind of common generating mechanism. Finally, we discuss the issue
of testability, which underlies the question of whether multiverse proposals
are really scientific propositions.


title: The Near-Infrared properties of the host galaxies of radio quasars

abstract:
  We present K-band images of 31 radio quasars selected from the B3-VLA quasar
sample. A new method has been developed to detect and restore the host galaxies
of these quasars. We have detected the host galaxies of 16 of them. Using these
data together with previous data from the B3-VLA quasars (Carballo et al. 1998,
hereafter Paper I) and literature data from other samples, we have analyzed a
sample of 69 hosts of radio quasars, covering a redshift range between 0<z<3.
  The host galaxies are large (r_e}~15kpc) and luminous elliptical galaxies
(~75% of them brighter than L_*), with an evolution similar to that of radio
galaxies. A significant fraction (~40%) of them shows evidence of a possible
collision/merging process. They follow a mu_e-r_e relation similar to that of
normal elliptical galaxies. The morphological and photometric similarities
between these galaxies and radio galaxies in this wide range of redshifts is a
good test of the reliability of unification schemes. All of them show little
evolution from z=3 to the present epoch. Their K-z distribution is consistent
with a no-evolution model, with a fraction of the dispersion due to differences
in radio power. We have found a correlation between the quasar radio power and
the host luminosity. We have also found a correlation between the host and
nuclear source luminosities. These correlations could be induced by a physical
relation between the central black hole and the bulge mass (Magorrian et al.
1998).


title:
Beyond the Hubble Deep Field Limiting Magnitude: Faint Galaxy Number
  Counts from Surface-Brightness Fluctuations

abstract:
  The faint end of the differential galaxy number counts, n(m), in the Hubble
Deep Field (HDF) North has been determined for the F450W, F606W, and F814W
filters by means of surface-brightness fluctuation (SBF) measurements. This
technique allows us to explore n(m) beyond the limiting magnitude of the HDF,
providing new, stronger constraints on the faint end of n(m). This has allowed
us to test the validity of previous number count studies and to produce a new
determination of the faint end of n(m) for magnitudes fainter than 28.8 in the
AB system and to extend this estimate down to 31. This value represents an
extension of more than two magnitudes beyond the limits of previous photometric
studies. The obtained n(m) slopes are \gamma=0.27, 0.21, and 0.26 in B_{450},
V_{606}, and I_{814}, respectively.


title: Gas physics and dynamics in the central 50 pc of the Galaxy

abstract:
  We present models the gas physics and dynamics of the inner 50 pc of the
Galaxy. In a first step the gas properties of an isolated clumpy circumnuclear
disk were analytically investigated. We took the external UV radiation field,
the gravitational potential, and the observed gas temperature into account. The
model includes a description of the properties of individual gas clumps on
small scales, and a treatment of the circumnuclear disk as a quasi-continuous
accretion disk on large scales. In a second step the dynamics of an isolated
circumnuclear disk were investigated with the help of a collisional N-body
code. The environment of the disk is taken into account in a third step, where
we calculated a pro- and a retrograde encounter of an infalling gas cloud with
a pre-existing circumnuclear disk. In order to constrain the dynamical model,
we used the NIR absorption of the giant molecular clouds located within the
inner 50 pc of the Galaxy to reconstruct their line-of-sight distribution.


title: Are we missing baryons in Galaxy Clusters?

abstract:
  The recent constraints on the cosmological parameters put from the
observations of the WMAP satellite limit the cosmic baryon fraction in a range
that is larger than, and marginally consistent with, what is measured in galaxy
clusters. This rises the question whether or not we are considering all the
ingredients of cluster baryonic budget. Making a careful weight of the baryons
in X-ray emitting plasma and stars in cluster galaxies, I conclude that the
cluster baryonic pie is made by 13 (with a 1 sigma range of 8-19) per cent of
stars, 70 (56-89) per cent of intracluster hot medium and 17 (0-33) per cent,
and a probability of 73 per cent to be larger than 0, of ``other'' baryons,
presumably in the form of warm (1e5-1e7 Kelvin) material.


title: A New Method to Map Flares in Quasars

abstract:
  Recently, Chartas et al. (2001) detected a rapid X-ray flare in the
gravitationally lensed, multiple image quasar RX J0911.4+0551. Dramatic events,
such as rapid X-ray flares, are useful in providing high precision measurements
of the time delays between multiple images.
  In this paper, we argue that there is a new possibility in measurements of
time delays between multiple images of gravitationally lensed quasars;
constrain the locations of putative flares that give rise to the intrinsic
rapid variabilities of quasars. The realization, however, of these goals cannot
be presently achieved due to the limited accuracy of the current measurements.
We predict that timing flares with accuracies of the order of a few seconds
will be needed to probe the location of the flares. Our proposing method will
work with better instruments in near future, such as XEUS.


title: The quasar epoch and the stellar ages of early-type galaxies

abstract:
  We investigate the hypothesis that quasars formed together with the stellar
populations of early-type galaxies. This hypothesis, in conjunction with the
stellar ages of early-type galaxies from population synthesis models, the
relation of black hole mass to bulge velocity dispersion, and the velocity
dispersion distribution from the Sloan Digital Sky Survey, completely
determines the cosmic accretion hystory of supermassive black holes and the
redshift evolution of the characteristic luminosity. On the other hand the
precise shape of the luminosity function of quasars depends on the light curve
of quasars and, in the optical, but not so much in X-rays, on the covering
factor of the dust surrounding the AGN. We find a plausible set of assumptions
for which the coeval formation of supermassive black holes and elliptical
galaxies is in good agreement with the observed B-band and X-ray luminosity
functions of quasars.


title: On the nature of the ISO-selected sources in the ELAIS S2 region

abstract:
  We have studied the optical, near-IR and radio properties of a complete
sample of 43 sources detected at 15-micron in one of the deeper ELAIS
repeatedly observed region. The extragalactic objects in this sample have
15-micron flux densities in the range 0.4-10 mJy, where the source counts start
diverging from no evolution models. About 90% of the sources (39 out of 43)
have optical counterparts brighter than I=21 mag. Eight of these 39 sources
have been identified with stars on the basis of imaging data, while for another
22 sources we have obtained optical spectroscopy, reaching a high
identification percentage (30/43, ~70%). All but one of the 28 sources with
flux density > 0.7 mJy are identified. Most of the extragalactic objects are
normal spiral or starburst galaxies at moderate redshift (z_med~0.2); four
objects are Active Galactic Nuclei. We have used the 15-micron, H_alpha and
1.4-GHz luminosities as indicators of star-formation rate and we have compared
the results obtained in these three bands. While 1.4-GHz and 15-micron
estimates are in good agreement, showing that our galaxies are forming stars at
a median rate of ~40 Mo/yr, the raw H_alpha-based estimates are a factor ~5-10
lower and need a mean correction of ~2 mag to be brought on the same scale as
the other two indicators. A correction of ~2 mag is consistent with what
suggested by the Balmer decrements H_alpha/H_beta and by the optical colours.
Moreover, it is intermediate between the correction found locally for normal
spirals and the correction needed for high-luminosity 15-micron objects,
suggesting that the average extinction suffered by galaxies increases with
infrared luminosity.


title:
Extended Press-Schechter theory and the density profiles of dark matter
  haloes

abstract:
  An inside-out model for the formation of haloes in a hierarchical clustering
scenario is studied. The method combines the picture of the spherical infall
model and a modification of the extended Press-Schechter theory. The mass
accretion rate of a halo is defined to be the rate of its mass increase due to
minor mergers. The accreted mass is deposited at the outer shells without
changing the density profile of the halo inside its current virial radius. We
applied the method to a flat $\Lambda CDM$ Universe. The resulting density
profiles are compared to analytical models proposed in the literature, and a
very good agreement is found. A trend is found of the inner density profile
becoming steeper for larger halo mass, that also results from recent N-body
simulations. Additionally, present-day concentrations as well as their time
evolution are derived and it is shown that they reproduce the results of large
cosmological N-body simulations.


title:
The PDS vs. Markarian starburst galaxies: comparing strong and weak IRAS
  emitter at 12$\mu$m and 25$\mu$m in the nearby universe

abstract:
  (Abridged) The characteristics of the starburst galaxies from the Pico dos
Dias survey (PDS) are compared with those of the nearby UV-bright Markarian
starburst galaxies, having the same limit in redshift ($v_h < 7500$ km
s$^{-1}$) and absolute $B$ magnitude ($M_B < -18$). An important difference is
found: the Markarian galaxies are generally undetected at 12$\mu$m and 25$\mu$m
in \textit{IRAS}. This is consistent with the UV excess shown by these galaxies
and suggests that the youngest star forming regions dominating these galaxies
are relatively free of dust.
  The FIR selection criteria for the PDS is shown to introduce a strong bias
towards massive (luminous) and large size late-type spiral galaxies. This is
contrary to the Markarian galaxies, which are found to be remarkably rich in
smaller size early-type galaxies. These results suggest that only late-type
spirals with a large and massive disk are strong emitter at 12$\mu$m and
25$\mu$m in \textit{IRAS} in the nearby universe.


title: Results from the BAIKAL neutrino telescope

abstract:
  We review the present status of the Baikal Neutrino Project, present updated
results on the search for high energy extraterrestrial neutrinos, fast magnetic
monopoles and neutrinos induced by WIMP annihilation in the center of the Earth
and compare the recorded atmospheric neutrino flux to predictions. We describe
the moderate upgrade of NT-200 toward $\sim$10 Mton scale detector NT-200 +.


title:
Fluorine Abundances in the Large Magellanic Cloud and Omega Centauri:
  Evidence for Neutrino Nucleosynthesis?

abstract:
  The behavior of fluorine with metallicity has not yet been probed in any
stellar population. In this work, we present the first fluorine abundances
measured outside of the Milky Way from a sample of red giants in the Large
Magellanic Cloud (LMC), as well the Galactic globular cluster Omega Centauri.
The fluorine abundances are derived from vibration-rotation transitions of HF
using infrared spectra obtained with the Phoenix spectrograph on the Gemini
South 8.1m telescope. It is found that the abundance ratio of F/O declines as
the oxygen abundance decreases. The values of F/O are especially low in the two
Omega Cen giants; this very low value of F/O probably indicates that 19F
synthesis in asymptotic giant branch (AGB) stars is not the dominant source of
fluorine in stellar populations. The observed decline in F/O with lower O
abundances is in qualitative agreement with what is expected if 19F is produced
via H- and He-burning sequences in very massive stars, with this fluorine then
ejected in high mass-loss rate Wolf-Rayet winds. A quantitative comparison of
observations with this process awaits results from more detailed chemical
evolution models incorporating the yields from Wolf-Rayet winds. Perhaps of
more significance is the quantitative agreement between the Galactic and LMC
results with predictions from models in which 19F is produced from neutrino
nucleosynthesis during core collpase in supernovae of Type II. The very low
values of F/O in Omega Cen are also in agreement with neutrino nucleosynthesis
models if the ``peculiar'' star formation history of Omega Cen, with 2-4
distinct episodes of star formation, is considered.