title:
The Mysterious Absence of Neutral Hydrogen within One Mpc of a Luminous
  Quasar at Redshift 2.168

abstract:
  The intense UV radiation from a highly luminous QSO should excite fluorescent
Ly-alpha emission from any nearby neutral hydrogen clouds. We present a very
deep narrow-band search for such emission near the z=2.168 quasar PKS 0424-131,
obtained with the Taurus Tunable Filter on the Anglo-Australian Telescope. By
working in the UV, at high spectral resolution and by using charge shuffling,
we have been able to reach surface brightness limits as faint as 4.7E-19
erg/cm^2/s/arcsec^2.
  No fluorescent Ly-alpha emission is seen, whereas QSO absorption-line
statistics suggest that we should have seen ~6 clouds, unless the clouds are
larger than ~ 100 kpc in size. Furthermore, we do not even see the normal
population of Ly-alpha emitting galaxies found by other surveys at this
redshift. This is very different fromobservations of high redshift radio
galaxies, which seem to be surrounded by clusters of Ly-alpha emitters. We
tentatively conclude that there is a deficit of neutral hydrogen close to this
quasar, perhaps due to the photo-evaporation of nearby dwarf galaxies.


title:
Atmospheres of protoplanetary cores: critical mass for nucleated
  instability

abstract:
  We study quasi-static atmospheres of accreting protoplanetary cores for
different opacity behaviors and realistic planetesimal accretion rates in
various parts of protoplanetary nebula. Atmospheres segregate into those having
outer convective zone which smoothly merges with the nebular gas, and those
having almost isothermal outer radiative region decoupling atmospheric interior
from the nebula. Specific type of atmosphere depends only on the relations
between the Bondi radius of the core, photon mean free path in the nebular gas,
and the luminosity radius (roughly the size of the sphere which can radiate
luminosity of the core at effective temperature equal to the nebular
temperature). Cores in the inner parts of protoplanetary disk (within roughly
0.3 AU from the Sun) have large luminosity radii resulting in the atmospheres
of the first type, while cores in the giant planet region (beyond several AU)
have small luminosity radii and always accumulate massive atmospheres of the
second type. Critical core mass for nucleated instability is found to vary as a
function of distance from the Sun. It is 5-20 M_Earth at 0.1-1 AU which is too
large to permit the formation of ``hot Jupiters'' by nucleated instability near
the cores that have grown in situ. In the region of giant planets critical mass
is 20-60 M_Earth (for opacity 0.1 cm^2/g) if planetesimal accretion was fast
enough for protoplanetary cores to form prior to the nebular gas dissipation.
This might indicate that giant planets in the Solar System have gained their
atmospheres by nucleated instability only after their cores have accumulated
most of the mass in solids during the epoch of oligarchic growth, subsequent to
which planetesimal accretion slowed down and cores became supercritical.


title:
The Statistical Discrepancy between the IGM and Dark Matter Fields:
  One-Point Statistics

abstract:
  We investigate the relationship between the mass and velocity fields of the
intergalactic medium (IGM) and dark matter. Although the evolution of the IGM
is dynamically governed by the gravity of the underlying dark matter field,
some statistical properties of the IGM inevitably decouple from those of the
dark matter once the nonlinearity of the dynamical equations and the stochastic
nature of the field is considered. With simulation samples produced by a hybrid
cosmological hydrodynamic/N-body code, which is effective in capturing shocks
and complicated structures with high precision, we find that the one-point
distributions of the IGM field are systematically different from that of dark
matter as follows: 1.) the one-point distribution of the IGM peculiar velocity
field is exponential at least at redshifts less than 2, while the dark matter
velocity field is close to a Gaussian field; 2.) although the one-point
distributions of the IGM and dark matter are similar, the point-by-point
correlation between the IGM and dark matter density fields significantly
differs on all scales and redshifts analyzed; 3.) the one-point density
distributions of the difference between IGM and dark matter fields are highly
non-Gaussian and long tailed. These discrepancies violate the similarity
between the IGM and dark matter and cannot be explained simply as Jeans
smoothing of the IGM. However, these statistical discrepancies are consistent
with the fluids described by stochastic-force driven nonlinear dynamics.


title:
MMT Observations of the Black Hole Candidate XTE J1118+480 near and in
  Quiescence

abstract:
  We report on the analysis of new and previously published MMT optical spectra
of the black hole binary XTE J1118+480 during the decline from the 2000
outburst to true quiescence. From cross-correlation with template stars, we
measure the radial velocity of the secondary to derive a new spectroscopic
ephemeris. The observations acquired during approach to quiescence confirm the
earlier reported modulation in the centroid of the double-peaked Halpha
emission line. Additionally, our data combined with the results presented by
Zurita et al. (2002) provide support for a modulation with a periodicity in
agreement with the expected precession period of the accretion disk of ~52 day.
Doppler images during the decline phase of the Halpha emission line show
evidence for a hotspot and emission from the gas stream: the hotspot is
observed to vary its position, which may be due to the precession of the disk.
The data available during quiescence show that the centroid of the Halpha
emission line is offset by about -100 km/s from the systemic velocity which
suggests that the disk continues to precess. A Halpha tomogram reveals emission
from near the donor star after subtraction of the ring-like contribution from
the accretion disk which we attribute to chromospheric emission. No hotspot is
present suggesting that accretion from the secondary has stopped (or decreased
significantly) during quiescence. Finally, a comparison is made with the black
hole XRN GRO J0422+32: we show that the Halpha profile of this system also
exhibits a behaviour consistent with a precessing disk.


title: Nucleosynthesis inside Gamma-Ray Burst Accretion Disks

abstract:
  We investigate nucleosynthesis inside both a gamma-ray burst accretion disk
and a wind launched from an inner region of the disk using one-dimensional
models of the disk and wind and a nuclear reaction network. Far from a central
black hole, the composition of accreting gas is taken to be that of an O-rich
layer of a massive star before core collapse. We find that the disk consists of
five layers characterized by dominant elements: O16, Si28, Fe54 (and Ni56),
He4, and nucleons, and the individual layers shift inward with keeping the
overall profiles of compositions as the accretion rate decreases. Ni56 are
abundantly ejected through the wind from the inner region of the disk with the
electron fraction \simeq 0.5. In addition to iron group, elements heavier than
Cu, in particular Cu63 and Zn64, are massively produced through the wind.
Various neutron-rich nuclei can be also produced in the wind from neutron-rich
regions of the disk, though the estimated yields have large uncertainties.


title: ESO 3060170 -- a massive fossil galaxy group with a heated gas core?

abstract:
  We present a detailed study of the ESO 3060170 galaxy group combining
Chandra, XMM and optical observations. The system is found to be a fossil
galaxy group. The group X-ray emission is composed of a central dense cool core
(10 kpc in radius) and an isothermal medium beyond the central 10 kpc. The
region between 10 and 50 kpc (the cooling radius) has the same temperature as
the gas from 50 kpc to 400 kpc although the gas cooling time between 10 and 50
kpc (2 - 6 Gyr) is shorter than the Hubble time. Thus, the ESO 3060170 group
does not have a group-sized cooling core. We suggest that the group cooling
core may have been heated by a central AGN outburst in the past and the small
dense cool core is the truncated relic of a previous cooling core. The Chandra
observations also reveal a variety of X-ray features in the central region,
including a ``finger'', an edge-like feature and a small ``tail'', all aligned
along a north-south axis, as are the galaxy light and group galaxy
distribution. The proposed AGN outburst may cause gas ``sloshing'' around the
center and produce these asymmetric features. The observed flat temperature
profile to 1/3 R_vir is not consistent with the predicted temperature profile
in recent numerical simulations. We compare the entropy profile of the ESO
3060170 group with those of three other groups and find a flatter relation than
that predicted by simulations involving only shock heating, S $\propto$ r$^{~
0.85}$. This is direct evidence for the importance of non-gravitational
processes in group centers. We derive the mass profiles within 1/3 R_vir and
find the ESO 3060170 group is the most massive fossil group known (1 - 2 X
10$^{14}$ M$_{\odot}$). The M/L ratio of the system, ~ 150 at 0.3 R_vir, is
normal.


title: On the Environmental Dependence of Cluster Galaxy Assembly Timescale

abstract:
  We present estimates of CN and Mg overabundances with respect to Fe for
early-type galaxies in 8 clusters over a range of richness and morphology.
Spectra were taken from the Sloan Digital Sky Survey (SDSS) DR1, and from WHT
and CAHA observations. Abundances were derived from absorption lines and single
burst population models, by comparing galaxy spectra with appropriately
broadened synthetic model spectra. We detect correlations between [Mg/CN] and
[CN/Fe] and cluster X-ray luminosity. No correlation is observed for [Mg/Fe].
We also see a clear trend with the richness and morphology of the clusters.
This is interpreted given varying formation timescales for CN, Mg and Fe, and a
varying star formation history in early-type galaxies as a function of their
environment: intermediate-mass early-type galaxies in more massive clusters are
assembled on shorter timescales than in less massive clusters, with an upper
limit of ~1 Gyr.


title:
Evidence for TeV gamma ray emission from TeV J2032+4130 in Whipple
  archival data

abstract:
  A reanalysis of data taken on the Cygnus region in 1989-90 using the Whipple
Observatory atmospheric Cherenkov imaging telescope confirms the existence of
the TeV J2032+4130 source reported by the Crimean Astrophysical Observatory and
published by the HEGRA Collaboration. The significance at the a priori HEGRA
position is 3.3sigma. The peak signal was found at RA=20hr32min,
Dec=+41deg33min. This is 0.6deg north of Cygnus X-3 which was the original
target of the observations. The flux level (12% of the level of the Crab
Nebula) is intermediate between the two later observations and suggests that
the TeV source is variable.


title:
Can Supermassive Black Holes Sufficiently Heat Cool Cores of Galaxy
  Clusters?

abstract:
  Activities of a supermassive black hole or active galactic nucleus in the
central galaxy of a cluster of galaxies have been promising candidates for
heating sources of cool cluster cores. We estimate the masses of black holes
using known correlations between the mass of a black hole and the velocity
dispersion or the luminosity of the host galaxy. We find that the masses are
\~10^8-9 M_sun and the central X-ray luminosities of the host clusters (``the
strength of the cooling flow'') are well below the Eddington luminosities.
However, we do not find a correlation between the mass and the central X-ray
luminosity of the host cluster. If the heating is stable, this seems to
contradict a simple expectation if supermassive black holes are the main
heating source of a cluster core. Moreover, if we assume a canonical energy
conversion rate (10%), black holes alone are unable to sufficiently heat the
clusters with strong centrally peaked X-ray emission (``massive cooling
flows'') over the lifetime of cluster cores. These results may indicate that
massive cooling flows are a transient phenomenon, which may be because the
black holes are activated periodically. Alternatively, in the massive cooling
flow clusters, the energy conversion rate may be larger than 10%, that is, the
black holes may be Kerr black holes.


title: Bright points in the inter-network quiet Sun

abstract:
  High resolution G-band images of the interior of a supergranulation cell show
ubiquitous Bright Points (some 0.3 BPs per Mm^2). They are located in
intergranular lanes and often form chains of elongated blobs whose smallest
dimension is at the resolution limit (135 km on the Sun). Most of them live for
a few minutes, having peak intensities from 0.8 to 1.8 times the mean
photospheric intensity. These BPs are probably tracing intense magnetic
concentrations, whose existence has been inferred in spectro-polarimetric
measurements. Our finding provides a new convenient tool for the study of the
inter-network magnetism, so far restricted to the interpretation weak
polarimetric signals.


title: The origins of X-ray emission from the hotspots of FRII radio sources

abstract:
  We use new and archival Chandra data to investigate the X-ray emission from a
large sample of compact hotspots of FRII radio galaxies and quasars from the 3C
catalogue. We find that only the most luminous hotspots tend to be in good
agreement with the predictions of a synchrotron self-Compton model with
equipartition magnetic fields. At low hotspot luminosities inverse-Compton
predictions are routinely exceeded by several orders of magnitude, but this is
never seen in more luminous hotspots. We argue that an additional synchrotron
component of the X-ray emission is present in low-luminosity hotspots, and that
the hotspot luminosity controls the ability of a given hotspot to produce
synchrotron X-rays, probably by determining the high-energy cutoff of the
electron energy spectrum. It remains plausible that all hotspots are close to
the equipartition condition.


title: Pulsars and the Warp of the Galaxy

abstract:
  This paper studies the asymmetries of pulsar distributions relative to the
Galactic plane in various Galactic longitudes. It is shown that the observed
asymmetric distribution may be explained by the warped and flaring (i.e.
increase of scale-height at the peripheries of the Galaxy) structure of the
Galaxy. At the peripheries of the Galaxy, the amplitude of the warp, derived
from these data, may be as high as nearly 1 kpc. The scale-height of the pulsar
distribution increases exponentially from nearly 0.5 kpc to nearly 1 kpc while
increasing the galactocentric distance from 5 kpc to 15 kpc. The warp and flare
parameters derived from the pulsar data are compared with the stellar and
gaseous warp and flare parameters of the Galaxy.


title: Unified phantom cosmologies

abstract:
  We present a general algorithm based on the concept of form-invariance which
can be used for generating phantom cosmologies. It involves linear
transformations between the kinetic energy and the potential of the scalar
field, and transforms solutions of the Einstein-Klein-Gordon equations which
preserve the weak energy condition into others which violate it, while keeping
the energy density of the field positive. All known solutions representing
phantom cosmologies are unified by this procedure. Using the general algorithm
we obtain those solutions and show the relations between them. In addition, the
scale factors of the product and seed solutions are related by a generalization
of the well-known $a\to a^{-1}$ duality.


title: Cubic anomalies in WMAP

abstract:
  We perform a frequentist analysis of the bispectrum of WMAP first year data.
We find clear signal domination up to l=200, with overall consistency with
Gaussianity except for the following features. There is a flat patch (i.e. a
low chi-squared region) in the same-l components of the bispectrum spanning the
range l=32-62; this may be interpreted as ruling out Gaussianity at the 99.6%
confidence level. There is also an asymmetry between the North and South
inter-l bispectrum components at the 99% confidence level. The preferred
asymmetry axis correlates well with the (l,b)=(57,10) direction quoted in the
literature for asymmetries in the power spectrum and three-point correlation
function. However our analysis of the quadrupole (its bispectrum and principal
axes) fail to make contact with previously claimed anomalies.


title: Detection of X-ray Resonance Scattering in Active Stellar Coronae

abstract:
  An analysis of Lyman series lines arising from hydrogen-like oxygen and neon
ions in the coronae of the active RS CVn-type binaries II Peg and IM Peg,
observed using the {\it Chandra} High Resolution Transmission Grating
Spectrograph, shows significant decrements in the Ly$\alpha$/Ly$\beta$ ratios
as compared with theoretical predictions and with the same ratios observed in
similar active binaries. We interpret these decrements in terms of resonance
scattering of line photons out of the line-of-sight; these observations present
the first strong evidence for this effect in active stellar coronae. The net
line photon loss implies a non-uniform and asymmetric surface distribution of
emitting structures on these stars. Escape probability arguments, together with
the observed line ratios and estimates of the emitting plasma density, imply
typical line-of-sight sizes of the coronal structures that dominate the X-ray
emission of $10^{10}$ cm at temperatures of $3\times 10^6$ K and of $10^8$ cm
at $10^7$ K. These sizes are an order of magnitude larger than predicted by
simple quasi-static coronal loops models, but are still very small compared to
the several $10^{11}$ cm radii of the underlying stars.


title:
A search for clusters and groups of galaxies on the line of sight
  towards 8 lensed quasars

abstract:
  In this paper we present new ESO/VLT FORS1 and ISAAC images of the fields
around eight gravitationally lensed quasars: CTQ414, HE0230-2130,
LBQS1009-0252, B1030+074, HE1104-1805, B1359+154, H1413+117 and HE2149-2745.
When available and deep enough, HST/WFPC2 data were also used to infer the
photometric redshifts of the galaxies around the quasars. The search of galaxy
overdensities in space and redshift, as well as a weak-shear analysis and a
mass reconstruction are presented in this paper. We find that there are most
probably galaxy groups towards CTQ414, HE0230-2130, B1359+154, H1413+117 and
HE2149-2745, with a mass ~ 4x10^14 M_sol h^-1. Considering its photometric
redshift, the galaxy group discovered in the field around HE1104-1805 is
associated with the quasar rather than with the lensing potential.


title: Detailed Calculation of Test-Mass Charging in the LISA Mission

abstract:
  The electrostatic charging of the LISA test masses due to exposure of the
spacecraft to energetic particles in the space environment has implications in
the design and operation of the gravitational inertial sensors and can affect
the quality of the science data. Robust predictions of charging rates and
associated stochastic fluctuations are therefore required for the exposure
scenarios expected throughout the mission. We report on detailed charging
simulations with the Geant4 toolkit, using comprehensive geometry and physics
models, for Galactic cosmic-ray protons and helium nuclei. These predict
positive charging rates of 50 +e/s (elementary charges per second) for solar
minimum conditions, decreasing by half at solar maximum, and current
fluctuations of up to 30 +e/s/Hz^{1/2}. Charging from sporadic solar events
involving energetic protons was also investigated. Using an event-size
distribution model, we conclude that their impact on the LISA science data is
manageable. Several physical processes hitherto unexplored as potential
charging mechanisms have also been assessed. Significantly, the kinetic
emission of very low-energy secondary electrons due to bombardment of the
inertial sensors by primary cosmic rays and their secondaries can produce
charging currents comparable with the Monte Carlo rates.


title:
Foreground analysis from the 1-year Wilkinson Microwave Anisotropy Probe
  (WMAP) data

abstract:
  We present a detailed analysis on the phases of the WMAP foregrounds
(synchrotron, free-free and dust emission) of the WMAP K-W bands in order to
estimate the significance of the variation of the spectral indices at different
components. We first extract the spectral-index varying signals by assuming
that the invariant part among different frequency bands have 100%
cross-correlation of phases. We then use the minimization of variance, which is
normally used for extracting the CMB signals, to extract the frequency
independent signals. Such a common signal in each foreground component could
play a significant role for any kind of component separation methods, because
the methods cannot discriminate frequency independent foregrounds and CMB.


title: Constraints on Intrinsic UV Absorption in NGC 3783

abstract:
  Results from an analysis of the intrinsic UV absorption in the Seyfert 1
galaxy NGC 3783 are presented. We focus on two new results that demonstrate
techniques for deriving important constraints on the physical conditions and
geometry of the absorbers. First, using variability in the spectrum, the
emission-line profile is separated into distinct kinematic components and the
effect on the interpretation of covering factors and column densities is
demonstrated. Second, measurements of the 2s2p 3^P metastable levels of C^+2
derived from the C III* 1175-76 absorption multiplet are presented. New
calculations of the metastable level populations are given and shown to provide
a powerful diagnostic of the density (and thus location) and temperature in an
absorber.


title: Gamma-Ray Burst Polarization: Limits from RHESSI Measurements

abstract:
  Using the RHESSI satellite as a Compton polarimeter, a recent study claimed
that the prompt emission of GRB021206 was almost fully linearly polarized. This
was challenged by a subsequent reanalysis. We present an novel approach,
applying our method to the same data. We identify Compton scattering candidates
by carefully filtering events in energy, time, and scattering geometry. Our
polarization search is based on time dependent scattering rates in
perpendicular directions, thus optimally excluding systematic errors. We
perform simulations to obtain the instrument's polarimetric sensitivity, and
these simulations include photon polarization. For GRB021206, we formally find
a linear polarization degree of 41% (+57% -44%), concluding that the data
quality is insufficient to constrain the polarization degree in this case. We
further applied our analysis to GRB030519B and found again a null result.


title: Probing the Canis Major stellar over-density as due to the Galactic warp

abstract:
  Proper-motion, star counts and photometric catalog simulations are used to
explain the detected stellar over-density in the region of Canis Major (CMa),
claimed to be the core of a disrupted dwarf galaxy (Martin et al. 2004,
Bellazzini et al. 2003), as due to the Galactic warp and flare in the external
disk. We compare the kinematics of CMa M-giant selected sample with surrounding
Galactic disk stars in the UCAC2 catalog and find no peculiar proper motion
signature: CMa stars mimic thick disk kinematics. Moreover, when taking into
account the Galactic warp and flare of the disk, 2MASS star count profiles
reproduce the CMa stellar over-density. This star count analysis is confirmed
by direct comparison with synthetic color-magnitude diagrams simulated with the
Besancon models (Robin et al. 2003) that include the warp and flare of the
disk. The presented evidence casts doubt on the identification of the CMa
over-density as the core of a disrupted Milky Way satellite. This however does
not make clear the origin of over-densities responsible for the ring structure
in the anticenter direction of the Galactic halo (Newberg et al. 2002; Yanny et
al. 2003; Zaggia et al. 2004, in preparation).


title: Projected Three-Point Correlation Functions and Galaxy Bias

abstract:
  The three-point correlation function (3PCF) can now be measured in large
galaxy redshift surveys, but in three dimensions its interpretation is
complicated by the presence of redshift-space distortions. I investigate the
projected 3PCF, where these distortions are eliminated by integrating over the
redshift dimension, as is commonly done for the two-point correlation function.
The calculation of the projected 3PCF from the real-space, three-dimensional
bispectrum is greatly simplified by expanding both quantities in Fourier
components, analogous to Szapudi's (2004) expansion of the three-dimensional
quantities in multipole components. In the weakly nonlinear regime, the
bispectrum can be well represented by the first few Fourier components. There
is a well-known relation between the reduced 3PCFs of matter and galaxies in
the weakly nonlinear regime, which can be used to infer galaxy bias factors if
the real-space three-dimensional galaxy correlation functions (two-point and
three-point) can be measured. I show that the same relation holds for the
reduced {\it projected} 3PCFs if these are properly defined. These results
should aid determinations of galaxy bias from large redshift surveys by
eliminating the complication of redshift-space distortions.


title:
Cross-Correlation Studies between CMB Temperature Anisotropies and 21 cm
  Fluctuations

abstract:
  During the transition from a neutral to a fully reionized universe,
scattering of cosmic microwave background (CMB) photons via free-electrons
leads to a new anisotropy contribution to the temperature distribution. If the
reionization process is inhomogeneous and patchy, the era of reionization is
also visible via brightness temperature fluctuations in the redshifted 21 cm
line emission from neutral Hydrogen. Since regions containing electrons and
neutral Hydrogen are expected to trace the same underlying density field, the
two are (anti) correlated and this is expected to be reflected in the
anisotropy maps via a correlation between arcminute-scale CMB temperature and
the 21 cm background. In terms of the angular cross-power spectrum,
unfortunately, this correlation is insignificant due to a geometric
cancellation associated with second order CMB anisotropies. The same
cross-correlation between ionized and neutral regions, however, can be studied
using a bispectrum involving large scale velocity field of ionized regions from
the Doppler effect, arcminute scale CMB anisotropies during reionization, and
the 21 cm background. While the geometric cancellation is partly avoided, the
signal-to-noise ratio related to this bispectrum is reduced due to the large
cosmic variance related to velocity fluctuations traced by the Doppler effect.
Unless the velocity field during reionization can be independently established,
it is unlikely that the correlation information related to the relative
distribution of ionized electrons and regions containing neutral Hydrogen can
be obtained with a combined study involving CMB and 21 cm fluctuations.


title: New Measurements of the Motion of the Zodiacal Dust

abstract:
  Using the Wisconsin H-Alpha Mapper (WHAM), we have measured at high spectral
resolution and high signal-to-noise the profile of the scattered solar Mg I
5184 absorption line in the zodiacal light. The observations were carried out
toward 49 directions that sampled the ecliptic equator from solar elongations
of 48\dg (evening sky) to 334\dg (morning sky) plus observations near +47\dg
and +90\dg ecliptic latitude. The spectra show a clear prograde kinematic
signature that is inconsistent with dust confined to the ecliptic plane and in
circular orbits influenced only by the sun's gravity. In particular, the
broadened widths of the profiles, together with large amplitude variations in
the centroid velocity with elongation angle, indicate that a significant
population of dust is on eccentric orbits. In addition, the wide, flat-bottomed
line profile toward the ecliptic pole indicates a broad distribution of orbital
inclinations extending up to about 30\dg - 40\dg with respect to the ecliptic
plane. The absence of pronounced asymmetries in the shape of the profiles
limits the retrograde population to less than 10% of the prograde population
and also places constraints on the scattering phase function of the particles.
These results do not show the radial outflow or evening--morning velocity
amplitude asymmetry reported in some earlier investigations. The reduction of
the spectra included the discovery and removal of extremely faint, unidentified
terrestrial emission lines that contaminate and distort the underlying Mg I
profile. This atmospheric emission is too weak to have been seen in earlier,
lower signal-to-noise observations, but it probably affected the line centroid
measurements of previous investigations.


title: A map of OMC-1 in CO 9-8

abstract:
  The distribution of 12C16O J=9-8 (1.037 THz) emission has been mapped in
OMC-1 at 35 points with 84" resolution. This is the first map of this source in
this transition and only the second velocity-resolved ground-based observation
of a line in the terahertz frequency band. There is emission present at all
points in the map, a region roughly 4' by 6' in size, with peak antenna
temperature dropping only near the edges. Away from the Orion KL outflow, the
velocity structure suggests that most of the emission comes from the OMC-1
photon-dominated region, with a typical linewidthof 3-6 km/s. Large velocity
gradient modeling of the emission in J=9-8 and six lower transitions suggests
that the lines originate in regions with temperatures around 120 K and
densities of at least 10^(3.5) cm^(-3) near theta^(1) C Ori and at the Orion
Bar, and from 70 K gas at around 10^(4) cm^(-3) southeast and west of the bar.
These observations are among the first made with the 0.8 m Smithsonian
Astrophysical Observatory Receiver Lab Telescope, a new instrument designed to
observe at frequencies above 1 THz from an extremely high and dry site in
northern Chile.


title:
Superbubbles and Energetic Particles in the Galaxy. I: Collective
  effects of particle acceleration

abstract:
  Observations indicate that most massive stars in the Galaxy appear in groups,
called OB associations, where their strong wind activity generates large
structures known as superbubbles, inside which the subsequent supernovae (SNe)
explode, in tight space and time correlation. Acknowledging this fact, we
investigate four main questions: 1) does the clustering of massive stars and SN
explosions influence the particle acceleration process usually associated with
SNe, and induce collective effects which would not manifest around isolated
supernova remnants?; 2) does it make a difference for the general phenomenology
of Galactic Cosmic Rays (GCRs), notably for their energy spectrum and
composition?; 3) can this help alleviate some of the problems encountered
within the standard GCR source model?; and 4) Is the link between superbubbles
and energetic particles supported by observational data, and can it be further
tested and constrained? We argue for a positive answer to all these questions.
Theoretical, phenomenological and observational aspects are treated in separate
papers. Here, we discuss the interaction of massive stellar winds and SN shocks
inside superbubbles and indicate how this leads to specific acceleration
effects. We also show that due to the high SN explosion rate and low diffusion
coefficient, low-energy particles experience repeated shock acceleration inside
superbubbles.


title:
Rapporteur talk: Cosmic Ray Propagation and Acceleration (sessions OG
  1.3, 1.4, and a part of HE 1.2)

abstract:
  Theoretical views on particle acceleration in astrophysical sources and
propagation of cosmic rays (CR) depend very much on the quality of the data,
which become increasingly accurate each year and therefore more constraining.
On the other hand, direct measurements of CR are possible in only one location
on the outskirts of the Milky Way and present only a snapshot of very dynamic
processes. The theoretical papers presented during the conference offer
exciting insights into the physics of cosmic accelerators and processes which
underlie the measured abundances and spectra of CR species.
  This paper is based on a rapporteur talk given at the 28th International
Cosmic Ray Conference held on July 31-August 7, 2003 at Tsukuba. It covers the
sessions OG 1.3 Cosmic ray propagation, OG 1.4 Acceleration of cosmic rays, and
a part of HE 1.2 Theory and simulations (including origins of the knee).


title:
Orbital roulette: a new method of gravity estimation from observed
  motions

abstract:
  The traditional way of estimating the gravitational field from observed
motions of test objects is based on the virial relation between their kinetic
and potential energy. We find a more efficient method. It is based on the
natural presumption that the objects are observed at a random moment of time
and therefore have random orbital time phases. The proposed estimator, which we
call "orbital roulette", checks the randomness of the phases. The method has
the following advantages: (1) It estimates accurately Keplerian (point-mass)
potentials as well as non-Keplerian potentials where the unknown gravitating
mass is distributed in space. (2) It is a complete statistical estimator: it
checks a trial potential and accepts it or rules it out with a certain
significance level; the best-fit measurement is thus supplemented with error
bars at any confidence level. (3) It needs no a priori assumptions about the
distribution of orbital parameters of the test bodies. We test our estimator
with Monte-Carlo-generated motions and demonstrate its efficiency. Useful
applications include the Galactic Center, dark-matter halo of the Galaxy, and
clusters of stars or galaxies.


title: A View through Faraday's Fog 2: Parsec Scale Rotation Measures in 40 AGN

abstract:
  Results from a survey of the parsec scale Faraday rotation measure properties
for 40 quasars, radio galaxies and BL Lac objects are presented. Core rotation
measures for quasars vary from approximately 500 to several thousand radians
per meter squared. Quasar jets have rotation measures which are typically 500
radians per meter squared or less. The cores and jets of the BL Lac objects
have rotation measures similar to those found in quasar jets. The jets of radio
galaxies exhibit a range of rotation measures from a few hundred radians per
meter squared to almost 10,000 radians per meter squared for the jet of M87.
Radio galaxy cores are generally depolarized, and only one of four radio
galaxies (3C-120) has a detectable rotation measure in the core. Several
potential identities for the foreground Faraday screen are considered and we
believe the most promising candidate for all the AGN types considered is a
screen in close proximity to the jet. This constrains the path length to
approximately 10 parsecs, and magnetic field strengths of approximately 1
microGauss can account for the observed rotation measures. For 27 out of 34
quasars and BL Lacs their optically thick cores have good agreement to a lambda
squared law. This requires the different tau = 1 surfaces to have the same
intrinsic polarization angle independent of frequency and distance from the
black hole.


title: Sodium abundances in nearby disk stars

abstract:
  We present sodium abundances for a sample of nearby stars. All results have
been derived from NLTE statistical equilibrium calculations. The influence of
collisional interactions with electrons and hydrogen atoms is evaluated by
comparison of the solar spectrum with very precise fits to the Na I line cores.
The NLTE effects are more pronounced in metal-poor stars since the statistical
equilibrium is dominated by collisions of which at least the electronic
component is substantially reduced. The resulting influence on the
determination of sodium abundances is in a direction opposite to that found
previously for Mg and Al. The NLTE corrections are about -0.1 in thick-disk
stars with [Fe/H] about -0.6. Our [Na/Fe] abundance ratios are about solar for
thick- and thin-disk stars. The increase in [Na/Fe] as a function of [Fe/H] for
metal-rich stars found by Edvardsson et al. (1993) is confirmed. Our results
suggest that sodium yields increase with the metallicity, and quite large
amounts of sodium may be produced by AGB stars. We find that [Na/Fe]ratios,
together with either [Mg/Fe] ratio, kinematic data or stellar evolutionary
ages, make possible the individual discrimination between thin- and thick-disk
membership.


title: A Minimum-Mass Extrasolar Nebula

abstract:
  By analogy with the minimum-mass solar nebula, we construct a surface-density
profile using the orbits of the 26 precise-Doppler planets found in multiple
planet systems: Sigma = 2200 grams per square centimeter (a/1 AU)^- beta, where
a is the circumstellar radius, and beta = 2.0 plus or minus 0.5. The
minimum-mass solar nebula is consistent with this model, but the uniform-alpha
accretion disk model is not. In a nebula with beta > 2, the center of the disk
is the likely cradle of planet formation.


title:
The Origin of the Mass--Metallicity Relation: Insights from 53,000
  Star-Forming Galaxies in the SDSS

abstract:
  We utilize Sloan Digital Sky Survey imaging and spectroscopy of ~53,000
star-forming galaxies at z~0.1 to study the relation between stellar mass and
gas-phase metallicity. We derive gas-phase oxygen abundances and stellar masses
using new techniques which make use of the latest stellar evolutionary
synthesis and photoionization models. We find a tight (+/-0.1 dex) correlation
between stellar mass and metallicity spanning over 3 orders of magnitude in
stellar mass and a factor of 10 in metallicity. The relation is relatively
steep from 10^{8.5} - 10^{10.5} M_sun, in good accord with known trends between
luminosity and metallicity, but flattens above 10^{10.5} M_sun. We use indirect
estimates of the gas mass based on the H-alpha luminosity to compare our data
to predictions from simple closed box chemical evolution models. We show that
metal loss is strongly anti-correlated with baryonic mass, with low mass dwarf
galaxies being 5 times more metal-depleted than L* galaxies at z~0.1. Evidence
for metal depletion is not confined to dwarf galaxies, but is found in galaxies
with masses as high as 10^{10} M_sun. We interpret this as strong evidence both
of the ubiquity of galactic winds and of their effectiveness in removing metals
from galaxy potential wells.


title:
Dynamics of solar coronal loops II. Catastrophic cooling and high-speed
  downflows

abstract:
  This work addresses the problem of plasma condensation and ``catastrophic
cooling'' in solar coronal loops. We have carried out numerical calculations of
coronal loops and find several classes of time-dependent solutions (static,
periodic, irregular), depending on the spatial distribution of a temporally
constant energy deposition in the loop. Dynamic loops exhibit recurrent plasma
condensations, accompanied by high-speed downflows and transient brightenings
of transition region lines, in good agreement with features observed with
TRACE. Furthermore, these results also offer an explanation for the recent EIT
observations of De Groof et al. (2004) of moving bright blobs in large coronal
loops. In contrast to earlier models, we suggest that the process of
catastrophic cooling is not initiated by a drastic decrease of the total loop
heating but rather results from a loss of equilibrium at the loop apex as a
natural consequence of heating concentrated at the footpoints of the loop, but
constant in time.


title: Chandra and XMM-Newton Observations of the Nucleus of Centaurus A

abstract:
  We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus
A from observations with the XMM-Newton EPIC CCD cameras (two exposures
separated by 12 months) and the Chandra HETGS. For the first time in an FRI
type galaxy, we resolve fluorescent K$\alpha$ emission from cold, neutral, or
near-neutral iron at 6.4 keV, with an rms line width of $\sim$20 eV. The Fe
line parameters observed are consistent with fluorescent emission from material
at a large distance from the AGN, either in the form of an absorber that nearly
completely surrounds the central engine or a torus that lies predominantly out
of the line of sight. Unresolved emission lines from neutral Si K$\alpha$ at
1.74 keV and neutral S K$\alpha$ at 2.30 keV are also detected. We find no
evidence in the data for a previously reported 6.8 keV broadened Fe line. The
continuum spectrum is well fitted with a combination of a heavily absorbed
power-law component that we relate, using Bondi theory, to accretion phenomena
in the form of a standard, geometrically thin, optically thick disk, and a
second, less absorbed, power-law component that we associate with emission from
the subparsec VLBI radio jet.


title:
Star formation history in early-type galaxies. I. The line absorption
  indices diagnostics

abstract:
  The bottom line of this study is (i) to check whether normal (quiescent) and
interacting EGs have a different behavior in the popular diagnostic planes such
as Hb vs. [MgFe] (and others); (ii) to seek whether the signature of mergers
and/or interactions may mirror in some specific changes of the indices that
could un-equivocally hint for burts of stellar activity; (iii) to evaluate the
intensity of those bursts or secondary episodes of star formation; (iv) to
explore whether other alternatives can exist, i.e. distinct from obvious ones
resting on large age range. The data show that both normal, field and
interacting galaxies have the same scattered but smooth distribution in the Hb
vs. [MgFe] diagnostic plane. There are two interpretations for this: (1) EGs
span larges ranges of ages and metallicities. (2) The bulk population of stars
is old but subsequent episodes of star formation scatter the object in the
diagnostic planes. Both these interpretation are not able to reproduce the
observed distribution. The above schemes are too demanding because of the many
ad hoc ingredients that have to be introduced. Furthermore they neglect the
observationally grounded hint that the stellar content of EGs is likely
enhanced in alfa-elements. We propose here a new scheme, in which the bulk
dispersion of galaxies in the index-index plane is caused by a different mean
degree of enhancement. The possibility that EGs span large ranges of [alpha/Fe]
and metallicities but narrow ranges of ages for the bulk population favors the
monolithic scheme.


title: Stellar Disk Truncations: Where do we stand ?

abstract:
  In the light of several recent developments we revisit the phenomenon of
galactic stellar disk truncations. Even 25 years since the first paper on outer
breaks in the radial light profiles of spiral galaxies, their origin is still
unclear. The two most promising explanations are that these 'outer edges'
either trace the maximum angular momentum during the galaxy formation epoch, or
are associated with global star formation thresholds. Depending on their true
physical nature, these outer edges may represent an improved size
characteristic (e.g., as compared to D_25) and might contain fossil evidence
imprinted by the galaxy formation and evolutionary history. We will address
several observational aspects of disk truncations: their existence, not only in
normal HSB galaxies, but also in LSB and even dwarf galaxies; their detailed
shape, not sharp cut-offs as thought before, but in fact demarcating the start
of a region with a steeper exponential distribution of starlight; their
possible association with bars; as well as problems related to the
line-of-sight integration for edge-on galaxies (the main targets for truncation
searches so far). Taken together, these observations currently favour the
star-formation threshold model, but more work is necessary to implement the
truncations as adequate parameters characterising galactic disks.


title:
Phase diversity restoration of sunspot images I. Relations between
  penumbral and photospheric features

abstract:
  We investigate the dynamics of and the relations between small-scale
penumbral and photospheric features near the outer penumbral boundary:
penumbral grains (PGs), dark penumbral fibrils, granules, and photospheric
G-band bright points. The analysis is based on a 2 h time sequence of a sunspot
close to disc center, taken simultaneously in the G-band and in the blue
continuum at 450.7 nm. Observations were performed at the Swedish Vacuum Solar
Telescope (La Palma) in July 1999. A total of 2564 images (46 arcsec x 75
arcsec) were corrected for telescope aberrations and turbulence perturbations
by applying the inversion method of phase diversity. Our findings can by
summarized as follows: (a) One third of the outward-moving PGs pass through the
outer penumbral boundary and then either continue moving as small bright
features or expand and develop into granules. (b) Former PGs and G-band bright
points next to the spot reveal a different nature. The latter have not been
identified as a continuation of PGs escaping from the penumbra. The G-band
bright points are mostly born close to dark penumbral fibrils where the
magnetic field is strong, whereas PGs stem from the less-magnetized penumbral
component and evolve presumably to non-magnetic granules or small bright
features.


title:
Transformations of galaxies in the environments of the cluster ABCG 209
  at z~0.2

abstract:
  We analyse the properties of galaxy populations in the rich Abell cluster
ABCG 209 at redshift z~0.21, on the basis of spectral classification of 102
member galaxies. We take advantage of available structural parameters to study
separately the properties of bulge-dominated and disk-dominated galaxies. The
star formation histories of the cluster galaxy populations are investigated by
using line strengths and the 4000 A break, through a comparison to stellar
population synthesis models. The dynamical properties of different spectral
classes are examined in order to infer the past merging history of ABCG 209.
The cluster is characterized by the presence of two components: an old galaxy
population, formed very early (z_f >~ 3.5), and a younger (z$_f >~ $ 1.2)
population of infalling galaxies. We find evidence of a merger with an
infalling group of galaxies occurred 3.5-4.5 Gyr ago. The correlation between
the position of the young H_delta-strong galaxies and the X-ray flux shows that
the hot intracluster medium triggered a starburst in this galaxy population ~ 3
Gyr ago.


title: Stochastic Inflation and the Lower Multipoles in the CMB Anisotropies

abstract:
  We generalize the treatment of inflationary perturbations to deal with the
non-Markovian colored noise emerging from any realistic approach to stochastic
inflation. We provide a calculation of the power-spectrum of the
gauge-invariant comoving curvature perturbation to first order in the slow-roll
parameters. Properly accounting for the constraint that our local patch of the
Universe is homogeneous on scales just above the present Hubble radius, we find
a blue tilt of the power-spectrum on the largest observable scales, in
agreement with the WMAP data which show an unexpected suppression of the low
multipoles of the CMB anisotropy. Our explanation of the anomalous behaviour of
the lower multipoles of the CMB anisotropies does not invoke any ad-hoc
introduction of new physical ingredients in the theory.


title: Estimation of Regularization Parameters in Multiple-Image Deblurring

abstract:
  We consider the estimation of the regularization parameter for the
simultaneous deblurring of multiple noisy images via Tikhonov regularization.
We approach the problem in three ways. We first reduce the problem to a
single-image deblurring for which the regularization parameter can be estimated
through a classic generalized cross-validation (GCV) method. A modification of
this function is used for correcting the undersmoothing typical of the original
technique. With a second method, we minimize an average least-squares fit to
the images and define a new GCV function. In the last approach, we use the
classical $GCV$ on a single higher-dimensional image obtained by concatanating
all the images into a single vector. With a reliable estimator of the
regularization parameter, one can fully exploit the excellent computational
characteristics typical of direct deblurring methods, which, especially for
large images, makes them competitive with the more flexible but much slower
iterative algorithms. The performance of the techniques is analyzed through
numerical experiments. We find that under the independent homoscedastic and
Gaussian assumptions made on the noise, the three approaches provide almost
identical results with the first single image providing the practical advantage
that no new software is required and the same image can be used with other
deblurring algorithms.


title:
The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy Cluster Survey. V. The
  cluster catalogue

abstract:
  We present the catalogue of the REFLEX Cluster Survey providing information
on the X-ray properties, redshifts, and some identification details of the
clusters in the REFLEX sample. The catalogue describes a statistically complete
X-ray flux-limited sample of 447 galaxy clusters above an X-ray flux of 3
10(-12) erg /s/cm**2 (0.1 to 2.4 keV) in an area of 4.24 ster in the southern
sky. The cluster candidates were first selected by their X-ray emission in the
ROSAT-All Sky Survey and subsequently spectroscopically identified in the frame
of an ESO key programme. In addition to the cluster catalogue we also describe
the complete selection criteria as a function of the sky position and the
conversion functions used to analyse the X-ray data. These are essential for
the precise statistical analysis of the large-scale cluster distribution. This
data set is at present the largest, statistically complete X-ray galaxy cluster
sample. Together with these data set we also provide for the first time the
full three-dimensional selection function. The sample forms the basis of
several cosmological studies, one of the most important applications being the
assessment of the statistics of the large-scale structure of the universe and
the test of cosmological models.


title: High Energy Emission and Cosmic Rays from Gamma-Ray Bursts

abstract:
  The paper is devoted to the analysis of particle acceleration in Gamma-Ray
Bursts and its radiative consequences. Therefore we get on one hand constraints
on the physics and on the other hand possible signatures of particle
acceleration that could be recorded by the new gamma ray instruments. We have
previously shown that UHECRs can be generated in GRBs even with conservative
assumptions on the magnetic field and the scattering capability of its
perturbations, provided that a suitable relativistic Fermi process is at work
during the so-called "internal shock" phase. We extend here the analysis of the
consequences of these assumptions to the whole prompt emission of both
electrons and protons. Indeed, assuming that the magnetic field decays in
$1/r^2$ and that the scattering time of particles is longer than the Bohm's
assumption, in particular with a rule derived from Kolmogorov scaling, we show
with no other parameter adaptation that the intensity of the subequipartition
magnetic field, that: i) UHECRs can be generated with a sufficient flux within
the GZK-sphere to account for the CR-spectrum at the ankle. ii) The peak energy
of the gamma spectrum around 100 keV, namely the so-called $E_{peak}$, is
conveniently explained. iii) A thermal component below the $E_{peak}$ is often
unavoidable. iv) The cosmic rays could radiate gamma rays around 67 MeV (in the
co-moving frame, which implies $\simeq 20$ GeV for the observer) due to
$\pi^0$-decay and a low energy neutrino emission (around 0.2 GeV) associated to
neutron decay and also neutrinos of energy between 5 and 150 GeV from muon
decay. v) The UHECRs radiate high energy gamma rays between a few tens of MeV
and 10 GeV (taking the pair creation process into account) due to their
synchrotron emission with a sufficient flux to be observable.


title: Monitoring the spin up in RX J0806+15

abstract:
  RX J0806+15 shows a prominent intensity variation on a period of 321.5 sec.
This has widely been interpreted as the binary orbital period, although this
remains controversial. We have been monitoring the precise period of RX
J0806+15 for a number of years. By measuring the rate of change we can help
distinguish between competing physical models. New observations obtained
between Nov 2003 and Feb 2004 show that the period decrease already reported by
Hakala et al (2003) and Strohmayer (2003) is continuing. We discuss how
reliably we can determine the period of RX J0806+15 using our technique and
evaluate the current models which have been proposed to account for the
observational properties of this source.


title: Ultra-High Energy Cosmic Ray Nuclei from Individual Magnetized Sources

abstract:
  We investigate the dependence of composition, spectrum and angular
distributions of ultra-high energy cosmic rays above 10^19 eV from individual
sources on their magnetization. We find that, especially for sources within a
few megaparsecs from the observer, observable spectra and composition are
severely modified if the source is surrounded by fields of ~ 10^-7 Gauss on
scales of a few megaparsecs. Low energy particles diffuse over larger distances
during their energy loss time. This leads to considerable hardening of the
spectrum up to the energy where the loss distance becomes comparable to the
source distance. Magnetized sources thus have very important consequences for
observations, even if cosmic rays arrive within a few degrees from the source
direction. At the same time, details in spectra and chemical composition may be
intrinsically unpredictable because they depend on the unknown magnetic field
structure. If primaries are predominantly nuclei of atomic mass A accelerated
up to a maximum energy E_max with spectra not much softer than E^-2, secondary
protons from photo-disintegration can produce a conspicuous peak in the
spectrum at energy ~ E_max/A. A related feature appears in the average mass
dependence on energy.


title: Direct Constraints on the Properties and Evolution of Dark Energy

abstract:
  We describe a method to derive the expansion and acceleration rates directly
from the data, without the need for the specification of a theory of gravity,
and without adopting an a priori parameterization of the form or redshift
evolution of the dark energy. If one also specifies a theory of gravity we can
also determine the pressure, energy density, and equation of state of the dark
energy as functions of redshift. We then apply this methodology on a modern
data set of distances to Supernovae and to radio galaxies. We find that the
universe transitions from deceleration to acceleration at a redshift of about
0.4, and the present value of deceleration parameter is -0.35 +/- 0.15. The
standard ``concordance model'' provides a reasonably good fit to the
dimensionless expansion rate as a function of redshift, though it fits the
dimensionless acceleration rate as a function of redshift less well. Adopting
General Relativity as the theory of gravity, we obtain the redshift trends for
the pressure, energy density, and equation of state of the dark energy out to a
redshift of about one. They are generally consistent with the concordance
model, at least out to a redshift of about 0.5, but the existing data preclude
any stronger conclusions at this point.


title:
EROS 2 photometry of probable R Coronae Borealis stars in the Small
  Magellanic Cloud

abstract:
  EROS 2 (Experience de Recherche d'Objets Sombres) conducted a survey of the
SMC between July 1996 and February 2003 in two EROS broad-band colours, V_E and
R_E. The photometric data of 4.2 million stars have been searched for behaviour
typical of R Coronae Borealis (RCB) candidates such as drastic changes in
magnitude. Five objects have been found, four of them being catalogued in the
Simbad database as RAW 21, RAW 233, RAW 476, and [MH95] 431 with confirmed
carbon-rich atmospheres, characteristic of RCB. From the EROS 2 light curve of
RAW 21 and its spectrum reported by Morgan et al. (2003), we confirm that it is
the first RCB to be found in the SMC. The other objects are new RCB candidates
with absolute luminosity and colour close to those found for RCBs in the LMC.
We propose that 2 of them are DY Per-like RCBs.


title: Triggering the Formation of Massive Clusters

abstract:
  There are at least 2 distinct mechanisms for the formation of young massive
clusters (YMC), all of which require galactic-scale processes. One operates in
harrassed fragile galaxies, in the dense cores of low mass galaxies, at the
ends of spiral arms, or in galactic tidal shocks where transient and peculiar
high pressures make massive clouds at high densities. The result of this
process is usually only one or two YMC without the usual morphologies of local
star formation, i.e., without hierarchical structure and a continuous power law
distribution of cluster masses up to the largest mass. The other operates in
the more usual way: continuously for long periods of time in large parts of the
interstellar medium where the ambient pressure is already high as a result of
the deep potential well from background stars and other gas. This second
process makes clusters in a hierarchical fashion with size-of-sample effects,
and tends to occur in nuclear rings, merger remnants, and even the ambient ISM
of normal galaxies if the star formation rate is high enough to sample out to
the YMC range.


title:
Predictions on the angular power spectrum of clustered extragalactic
  point sources at CMB frequencies from flat and all--sky 2D-simulations

abstract:
  We present predictions on the angular power spectrum of CMB fluctuations due
to extragalactic point sources (EPS) by using a method for simulating realistic
2D distributions of clustered EPS. Both radio and far--IR selected source
populations are taken into account. To analyze different clustering scenarios,
we exploit angular power spectra of EPS, $P(k)$, estimated either by data
coming from currently available surveys or by means of theoretical predictions.
By adopting the source number counts predicted by the Toffolatti et al. (1998)
evolution model -- capable of accounting well for the available data at radio
cm wavelengths -- we are able to reproduce current data on the two--point
angular correlation functions, $w(\theta)$, of radio sources. We can confirm
that the detection of primordial CMB anisotropies is not hampered by undetected
clustered sources at frequencies $\leq 150-200$ GHz. On the other hand, our
current findings show that at higher frequencies the clustering signal could
severely reduce the detectability of intrinsic CMB anisotropies, thus
confirming previous theoretical predictions. We also show that unsubtracted EPS
can account for the excess signal at high multipoles detected by recent CMB
anisotropy experiments. Moreover, the additional power due to the clustering of
sources gives rise to a small but not negligible contribution to the same
excess signal. As a final result, we also present an example of a currently
feasible {\it realistic map} of EPS at 70 GHz, by taking into account data on
bright detected sources as well as the previously quoted model for number
counts.


title: The COMPLETE Survey of Star-Forming Regions on its Second Birthday

abstract:
  At age two, humans are just learning to speak, and they see the world in an
unbiased way. At age two, the COMPLETE (COordinated Molecular Probe Line
Extinction Thermal Emission) Survey of Star-Forming Regions is just beginning
to hint at what it will do for our world view, and it is unbiased as well. The
coordinated observations that comprise COMPLETE have already shown us: 1) that
large (~10pc) scale bubbles created by winds from evolved stars dominate maps
of extended dust emission even in relatively low-mass star-forming regions
(e.g. Perseus and Ophiuchus); 2) that "giant" (>1 pc-scale) outflows from young
stars can be easily detected by applying statistical tools to an unbiased CO
survey (e.g. we have doubled the number of known outflows in Perseus using the
Spectral Correlation Function); and 3) that many apparent high column-density
"clouds" seen in projection are actually the superposition of many velocity
features (likely at different distances) along the line of sight. The upcoming
detailed analysis of these new observations will quantify the degree to which
the apparently ubiquitous spherical and collimated outflows can sculpt and stir
molecular clouds. Taken together with recent numerical simulations' results and
measurements of high velocities for some young stars, the COMPLETE Survey also
raises, and should soon answer, questions about how, when, and how far stars
move away from their birthplaces as functions of time.


title: Gravity, Turbulence, and Star Formation

abstract:
  The azimuthal power spectra of optical emission from star formation and dust
in spiral galaxies resembles the azimuthal power spectra of HI emission from
the LMC. These and other power spectra of whole galaxies all resemble that of
velocity in incompressible Kolmogorov turbulence. The reasons for this are
unknown but it could be simply that star and cloud formation are the result of
a mixture of processes and each gives a power spectrum similar to Kolmogorov
turbulence, within the observable errors. The important point is that star and
cloud formation are not random but are correlated over large distances by
forces that span several orders of magnitude in scale. These forces are
probably the usual combination of self-gravity, turbulence, and compression
from stellar winds and supernovae, but they have to work in concert to create
the structures we see in galaxies. In addition, the identification of
flocculant spirals with swing amplified instabilities opens the possibility
that a high fraction of turbulence in the ISM is the result of self-gravity.


title:
A Wide Field, Low Frequency Radio Survey of the Field of M31: I.
  Construction and Statistical Analysis of the Source Catalog

abstract:
  We present here the results of a 325 MHz radio survey of M31, conducted with
the A-configuration of the Very Large Array. The survey covered an area of 7.6
deg$^2$, and a total of 405 radio sources between $\la$6\arcsec and 170\arcsec
in extent were mapped with a resolution of 6\arcsec and a 1$\sigma$ sensitivity
of $\sim$0.6 \mjyb. For each source, its morphological class, major axis
$\theta_M$, minor axis $\theta_m$, position angle $\theta_{PA}$, peak flux $I$,
integrated flux density $S$, spectral index $\alpha$ and spectral curvature
parameter $\phi$ were calculated. A comparison of the flux and radial
distribution -- both in the plane of the sky and in the plane of M31 -- of
these sources with those of the XMM--LSS and WENSS radio surveys revealed that
a vast majority of sources detected are background radio galaxies. As a result
of this analysis, we expect that only a few sources are intrinsic to M31. These
sources are identified and discussed in an accompanying paper.


title:
XMM-Newton observations of the late-stage merger-remnant galaxies NGC
  3921 and NGC 7252

abstract:
  Using the high sensitivity of XMM, we have studied the X-ray emission of the
two proto-typical late-stage merger remnants, NGC 3921 and NGC 7252. In the
case of NGC 7252, this is complemented by archival Chandra data. We investigate
the nature of the discrete X-ray point source populations and the hot diffuse
gas components in these two galaxies, and compare them in the light of their
different merger ages and histories. We detect 3 candidate ultra-luminous X-ray
point sources in NGC 3921 and at least 6 in NGC 7252, for which we have high
spatial resolution Chandra data. These have luminosities ranging from
\~1.4x10^39-10^40 erg s^-1 (for H_0= 75 km s-1 Mpc^-1). We expect these ULXs to
be high mass X-ray binaries, associated with the recent star formation in these
two galaxies. Extended hot gas is observed in both galaxies. We have sufficient
counts in the XMM data to fit two-component hot plasma models to their X-ray
spectra and estimate the X-ray luminosities of the hot diffuse gas components
to be 2.75x10^40 erg s^-1 and 2.09x10^40 erg s^-1 in NGC 3921 and NGC 7252,
respectively. These luminosities are low compared with the luminosities
observed in typical mature elliptical galaxies LX ~10^(41-42) erg s^-1), into
which these merger remnants are expected to evolve. We do not see evidence that
the X-ray halos of these galaxies are currently being regenerated to the masses
and luminosities seen in typical elliptical galaxies. The mass of atomic gas
available to fall back into the main bodies of these galaxies and shock-heat to
X-ray temperatures is insufficient for this to be the sole halo regeneration
mechanism. We conclude that halo regeneration is most likely a long-term (>10
Gyr) process, occurring predominantly via mass loss from evolving stars, in a
sub-sonic outflow stage commencing ~2 Gyr after the merging event.


title:
Variations of Pickup Ion Distributions and their Relation to
  Interplanetary Conditions and Waves

abstract:
  Pickup ion distributions vary substantially on a variety of time scales,
although their sources may be relatively steady. This complicates their use as
probes of the heliospheric and local interstellar particle populations.
Interstellar He+ pickup ion observations from SOHO/CTOF and measurements of
interplanetary conditions from SOHO and WIND enable a quantitative statistical
analysis of these variations. Pickup ion distributions have been shown to
correlate with IMF orientation, solar wind density, and IMF strength.
Correlations of the pickup ions with IMF fluctuations are demonstrated, and it
is shown that these are consistent with pitch angle scattering by waves.
Further questions in pickup ion flux variations are discussed.


title: Revisiting the radial distribution of pulsars in the Galaxy

abstract:
  We study the Galactic distribution of normal pulsars with 1400 MHz
luminosities greater than 0.1 mJy kpc^2 refining the shape and parameters of
the radial distribution of pulsars. To estimate the distances to pulsars we
used the new NE2001 Galactic electron density model. The maximum galactocentric
distribution of pulsars is located at 3.2+/-0.4 kpc and the scale-length of
this distribution is 3.8+/-0.4 kpc for the assumed distances to the Galactic
center Ro=8.5 kpc. The surface density of pulsars near the Galactic center is
equal to or slightly higher than that in the solar neighborhood. For observable
normal pulsars with luminosities > 0.1 mJy kpc^2, we also re-estimate their
local surface density and birth-rate: 41+/-5 pulsars kpc^{-2} and 4.1+/-0.5
pulsars kpc^{-2} Myr^{-1} respectively. For the total number of potentially
observable pulsars in the Galaxy, we obtain (24+/-3)x10^3 and (240+/-30)x10^3
before and after applying beaming correction according the Tauris & Manchester
(1998) beaming model. Within the limits of errors of estimations these results
are in close agreement with the results of the previous studies of Lyne et al.
(1998). The dependence of these results on the NE2001 model and recommendations
for further improvement of electron density distribution are discussed.


title: ESC Observations of SN 2002er around Maximum Light

abstract:
  We present preliminary results of the observational campaign on SN 2002er
carried out by the European Supernova Collaboration (ESC). For this supernova
the optical coverage from epochs -11 days to +50 days is excellent, both in
imaging and spectroscopy. The extinction deduced from the photometry is
E(B-V)=0.35, while Deltam15=1.31. In general SN 2002er behaves like a "normal"
type Ia supernova, very similar to SN 1996X.


title: Stellar Populations in Active Galaxies

abstract:
  The role of stars and starbursts in AGN has been a recurring issue for nearly
as long as AGN have been recognized as hosts of interesting phenomena. The
heated ``starburst X monster'' controversy of the 80's and 90's was gradually
replaced by ``starburst plus monster'' studies, as observational work in the
past decade has firmly established that accretion onto a super-massive
black-hole and star-formation coexist in many galactic nuclei. Whereas the
physical link between starbursts and AGN remains unclear, there remains no
doubt that starbursts affect a number of properties traditionally associated to
the AGN alone, such as the so called ``featureless continuum'', emission line
ratios and luminosities. This contribution glosses over some of the techniques
used to diagnose stellar populations in AGN, focusing on recent results and how
this type of work can lead us well beyond what became known as the
starburst-AGN connection.


title:
Are Passive Spiral Galaxies Truly "Passive" and "Spiral"? :
  Near-Infrared Perspective

abstract:
  Passive spiral galaxies -- unusual galaxies with spiral morphology without
any sign of on-going star formation -- have recently been discovered to exist
preferentially in cluster infalling regions (at about the virial radius, or at
a local galaxy density of $\sim 1$ Mpc$^{-2}$). The discovery directly connects
the passive spiral galaxies to the cluster galaxy evolution studies such as the
Butcher-Oemler effect or the morphology-density relation, i.e., passive spiral
galaxies are likely to be transition objects between high-z blue, spiral
galaxies and low-z red, cluster early-type galaxies. Thus, detailed study of
passive spiral galaxies potentially could bring a new insight on the underlying
physical mechanisms governing cluster galaxy evolution. However, in previous
work, passive spiral galaxies are selected from the low resolution optical
images with $\sim 1.5$ arcsec of seeing. Therefore, passive spirals could be a
mis-identification of S0 galaxies; or dusty-starburst galaxies which are not
passive at all. To answer these questions, we performed a deep,
high-resolution, near-infrared imaging of 32 passive spiral galaxies. Our high
resolution $K$ band images show clear spiral arm structures. Thus, passive
spirals are not S0s. Optical-infrared colour does not show any signs of
dusty-starburst at all. Therefore, it is likely that they are truly ``passive''
and ``spiral'' galaxies in the midst of cluster galaxy evolution.


title: High resolution X-ray spectra of quasars

abstract:
  Past X-ray observations by ASCA suggest that warm absorbers (O VII and O VIII
edges) are apparently rare in high luminosity AGNs (quasars) while they are
more common in low luminosity AGNs (Seyferts). However, this could be a
selection effect if high luminosity AGNs have mostly narrow absorption lines
(with no strong bound free edges), which escaped detection by the low
resolution of ASCA. To check this hypothesis we are studying the
high-resolution X-ray spectra of quasars from grating spectrometers on board
Chandra and XMM-Newton in search for absorption lines. In this contribution we
present spectra of three quasars. The spectra show narrow (several hundred
km/s) absorption and emission X-ray lines from H-like and He-like ions of O,
Ne, Mg, and other abundant elements. We also detect absorption from iron
L-shell lines and iron M-shell unresolved transition array. We present the
analysis of MR2251-178 where we find that at least two, and probably three,
distinct warm absorbers are needed to explain the high resolution spectrum of
this object. We re-analyze the high-resolution X-ray spectrum of PG1211+143 and
suggest that an outflow velocity of about 3000 km/s provides an adequate
explanation to these data. We also present preliminary results form the
Chandra/HETGS observation of the quasar 4C74.26.


title: The Galactic Double-Neutron-Star Merger Rate: Most Current Estimates

abstract:
  We summarize our results on the Galactic merger rate of double neutron stars
(DNS) in view of the recent discovery of PSR J0737-3039. We also present
previously unpublished results for the 'global' probability distribution of
merger rate values that incorporate the presently known systematics from the
radio pulsar luminosity function. The most likely value obtained from the
global distribution is only ~15 per Myr, but a re-analysis of the current
pulsar sample and radio luminosities is needed for a reliable assessment of the
best fitting distribution. Finally, we use our theoretical understanding of DNS
formation to calculate a possible upper limit on the DNS merger rate from
current Type Ib/c supernova rate estimates.


title: Transition From Population III to Population II Stars

abstract:
  The transition from Population III to Population II stars is determined by
the presence of a sufficient amount of metals, in particular, oxygen and
carbon. The vastly different yields of these relevant metals between different
initial stellar mass functions would then cause such a transition to occur at
different times. We show that the transition from Pop III to Pop II stars is
likely to occur before the universe can be reionized, if the IMF is entirely
very massive stars (M > 140 M_sun). A factor of about 10 more ionizing photons
would be produced in the case with normal top-heavy IMF (e.g., M ~ 10-100
M_sun), when such a transition occurs. Thus, a high Thomson optical depth
(tau_e >= 0.11-0.14) may be indication that the Population III stars possess a
more conventional top-heavy IMF.


title: Discovery of New Ultracool White Dwarfs in the Sloan Digital Sky Survey

abstract:
  We report the discovery of five very cool white dwarfs in the Sloan Digital
Sky Survey (SDSS). Four are ultracool, exhibiting strong collision induced
absorption (CIA) from molecular hydrogen and are similar in color to the three
previously known coolest white dwarfs, SDSS J1337+00, LHS 3250 and LHS 1402.
The fifth, an ultracool white dwarf candidate, shows milder CIA flux
suppression and has a color and spectral shape similar to WD 0346+246. All five
new white dwarfs are faint (g > 18.9) and have significant proper motions. One
of the new ultracool white dwarfs, SDSS J0947, appears to be in a binary system
with a slightly warmer (T_{eff} ~ 5000K) white dwarf companion.


title: Dust and star formation in distant radio galaxies

abstract:
  We present the results of an observing program with the SCUBA bolometer array
to measure the submillimetre (submm) dust continuum emission of 24 distant (z >
1) radio galaxies. We detected submm emission in 12 galaxies with S/N > 3,
including 9 detections at z > 3. When added to previous published results these
data almost triple the number of radio galaxies with z > 3 detected in the
submm and yield a sample of 69 observed radio galaxies over the redshift range
z = 1-5. We find that the range in rest-frame far-infrared luminosities is
about a factor of 10. We have investigated the origin of this dispersion,
correlating the luminosities with radio source power, size, spectral index,
K-band magnitude and Lya luminosity. No strong correlations are apparent in the
combined data set. We confirm and strengthen the result from previous submm
observations of radio galaxies that the detection rate is a strong function of
redshift. We compare the redshift dependence of the submm properties of radio
galaxies with those of quasars and find that for both classes of objects the
observed submm flux density increases with redshift to z ~ 4, beyond which, for
the galaxies, we find tentative evidence for a decline. We find evidence for an
anti-correlation between submm luminosity and UV polarisation fraction, for a
subsample of 13 radio galaxies, indicating that starbursts are the dominant
source of heating for dust in radio galaxies.


title: Stars as thermonuclear reactors: their fuels and ashes

abstract:
  Atomic nuclei are transformed into each other in the cosmos by nuclear
reactions inside stars: -- the process of nucleosynthesis. The basic concepts
of determining nuclear reaction rates inside stars and how they manage to burn
their fuel so slowly most of the time are discussed. Thermonuclear reactions
involving protons in the hydrostatic burning of hydrogen in stars are discussed
first. This is followed by triple alpha reactions in the helium burning stage
and the issues of survival of carbon and oxygen in red giant stars connected
with nuclear structure of oxygen and neon. Advanced stages of nuclear burning
in quiescent reactions involving carbon, neon, oxygen and silicon are
discussed. The role of neutron induced reactions in nucleosynthesis beyond iron
is discussed briefly, as also the experimental detection of neutrinos from SN
1987A which confirmed broadly the ideas concerning gravitational collapse
leading to a supernova.


title:
Spectra and time variability of galactic black-hole X-ray sources in the
  low/hard state

abstract:
  we propose a jet model for the low/hard state of black-hole X-ray sources
which explains a) the X-ray spectra, b) the timelag spectra, c) the increase in
the amplitude (QPO and high frequency) with increasing photon energy, and d)
the narrowing of the autocorrelation function with increasing photon energy.
The model (in its simplest form) assumes that i) there is a uniform magnetic
field along the axis of the jet, ii) the electron density in the jet is
inversely proportional to distance and iii) the jet is "hotter" near its center
than at its periphery. We have performed Monte Carlo simulations of Compton
upscattering of soft photons from the accretion disk and have found power-law
high-energy spectra with photon number index in the range 1.5-2, power-law
timelags versus Fourier frequency with index ~0.8, and an increase of the rms
amplitude of the variability and a narrowing of the autocorrelation function
with photon energy as they have been observed in Cygnus X-1.


title: The soft X-ray absorption lines of the Seyfert 1 galaxy MCG--6-30-15

abstract:
  The absorption lines in the soft X-ray spectrum of MCG--6-30-15 are studied
using the Reflection Grating Spectrometer data from the 2001 XMM-Newton 320 ks
observation. A line search of the full time-averaged spectrum reveals 51
absorption lines and one emission line. The equivalent widths of the lines are
measured and the majority of the lines identified. We find lines produced by a
broad range of charge states for several elements, including almost all the
charge states oxygen and iron, suggesting a broad range of ionization
parameters is present in the warm absorber. The equivalent widths of the lines
are broadly consistent with the best fitting warm absorber models from Turner
et al (2003). The equivalent widths of the absorption lines allow confidence
limits on the column density of the species to be determined. For OVII a column
density of 10^18.36-10^18.86 cm^-2 is found. This column density of OVII, when
combined with the inferred FeI absorption, is sufficient to explain the drop in
flux at 0.7 keV as being due to absorption from the warm absorber. Fitting OI
K-edge absorption to the spectrum reveals a column of 10^17.51-10^17.67 cm^-2
of OI, suggesting an Fe:O ratio of ~1:2, consistent with the neutral iron being
in the form of iron oxide dust. Variability is seen in a few absorption lines,
but the majority of the absorption features, including the prominent absorption
edges, stay constant throughout the observation despite variability in the
continuum flux.


title:
X-ray sources and their optical counterparts in the globular cluster M
  22

abstract:
  Using XMM-Newton EPIC imaging data, we have detected 50 low-luminosity X-ray
sources in the field of view of M 22, where 5 +/- 3 of these sources are likely
to be related to the cluster. Using differential optical photometry, we have
identified probable counterparts to those sources belonging to the cluster.
Using X-ray spectroscopic and timing studies, supported by the optical colours,
we propose that the most central X-ray sources in the cluster are cataclysmic
variables, millisecond pulsars, active binaries and a blue straggler. We also
identify a cluster of galaxies behind this globular cluster.


title: Rotation curves of spiral galaxies: A general-relativistic model

abstract:
  Spiral galaxies are considered as static, spherically symmetric Dark Matter
Configurations (DMC)in which non-zero rest-mass particles (NZRPs) move along
appropriate trajectories. Using general relativity (GR), we show that a mass of
dark matter about 127 - 212 $\times 10^{11} M_{\odot}$ is required inside the
sphere of size $a \sim 10 $ kpc for agreement with the observed typical orbital
velocity ranging from 150 to 250 km sec$^{-1}$. In our model, it is possible to
obtain flat, slightly rising, and even declining rotation curves. The model
self-evidently explains the reason why most of the spirals show almost flat or
slightly rising rotation curves and very few show declining curves. The NZRPs
follow trajectories, and are finally trapped in circles of minimum radii $\sim
0.03a - 0.005a$ with rotation velocities reaching $\sim 6544-8445$ km sec
$^{-1}$. The velocity values are consistent with observations of central
regions of various galaxies. This scenario may also lead to conditions suitable
for evolution of relativistic supermassive stars and supermassive black holes
at the centres of various galaxies. Based on this study, we obtain the density
parameter $\Omega \sim 0.127 - 0.212 $, leading to an open model of the
Universe with an age of $\sim 16.8 - 17.6 $ Gyr, which is significantly higher
than the presently estimated age of globular clusters $\sim 13 - 15 $ Gyr.


title:
Why does the intermediate polar V405 Aurigae show a double-peaked spin
  pulse?

abstract:
  V405 Aurigae is an intermediate polar showing a double-peaked pulsation in
soft X-rays and a single-peaked pulsation in harder X-rays. From XMM-Newton
observations we find that the soft band is dominated by blackbody emission from
the heated white-dwarf surface. Such emission is at a maximum when either
magnetic pole points towards us, explaining the double-peaked pulsation. The
symmetry of the pulses requires that the angle between the magnetic and spin
axes be high.
  The single-peaked pulsation in harder X-rays is explained in the usual way,
as a result of opacity in the accretion curtains. However, the high dipole
inclination means that the accretion curtains are nearly in the plane. Thus the
outer regions of the curtains do not cross the line of sight to the accretion
footprints, explaining the absence of the deep absorption dip characteristic of
many intermediate polars. The sawtooth profile of this pulsation requires that
the magnetic axis be offset from the white-dwarf centre.
  We remark also on the double-peaked optical emission in this star. We suggest
that the difference between V405 Aur's spin pulse and those of other
intermediate polars is the result of its high dipole inclination.


title: Colour-detected clusters in the XMM Large Scale Structure Survey

abstract:
  We present first results on the use of a colour space filter for detecting
galaxy clusters at cosmological redshifts in the XMM Large Scale Structure
Survey. All clusters studied, but one, are successfully colour--detected in
spite of their large redshift (0.3<z<1.0), X-ray selection and intrinsic low
richness (R=0 or below). We experimentally show that the cluster redshift can
be derived, with good accuracy, from the colour of the red sequence, at
0.06<z<1 using a sample of about 160 clusters.


title:
Xspect, estimation of the angular power spectrum by computing
  cross-power spectra with analytical error bars

abstract:
  We present Xspect, a method to obtain estimates of the angular power spectrum
of the Cosmic Microwave Background (CMB) temperature anisotropies including
analytical error bars developed for the Archeops experiment. Cross-power
spectra are computed from a set of maps and each of them is in itself an
unbiased estimate of the power spectrum as long as the detector noises are
uncorrelated. Then, the cross-power spectra are combined into a final
temperature power spectrum with error bars analytically derived from the
cross-correlation matrix.
  This method presents three main useful properties : (1) no estimation of the
noise power spectrum is needed, (2) complex weighting schemes including sky
covering and map noise properties can be easily taken into account, and
corrected for, for each input map, (3) error bars are quickly computed
analytically from the data themselves with no Monte-Carlo simulations involved.
Xspect also permits the study of common fluctuations between maps from
different sky surveys such as CMB, Sunyaev-Zel'dovich effect or mass
fluctuations from weak lensing observations.


title: Metal Enrichment and Energetics of Galactic Winds in Galaxy Clusters

abstract:
  We investigate efficiency and time dependence of metal enrichment processes
in the Intra-Cluster Medium (ICM). In this presentation we concentrate on the
effects of galactic winds. The mass loss rates due to galactic winds are
calculated with a special algorithm, which takes into account cosmic rays and
magnetic fields. This algorithm is embedded in a combined N-body/hydrodynamic
code which calculates the dynamics and evolution of a cluster. We present mass
loss rates depending on galaxy properties like type, mass, gas mass fraction
and the surrounding ICM. In addition we show metallicity maps as they would be
observed with X-ray telescopes.


title:
Metal Enrichment of the Intra-Cluster Medium: Ram-Pressure Stripping of
  Cluster Galaxies

abstract:
  We present numerical simulations of the dynamical and chemical evolution of
galaxy clusters. X-ray spectra show that the intra-cluster medium contains a
significant amount of metals. As heavy elements are produced in the stars of
galaxies material from the galaxies must have been expelled to enrich the
ambient medium. We have performed hydrodynamic simulations investigating
various processes. In this presentation we show the feedback from gas which is
stripped from galaxies by ram-pressure stripping. The efficiency, resulting
spatial distribution of the metals and the time dependency of this enrichment
process on galaxy cluster scale is shown.


title:
Revealing the nature of the highly obscured galactic source IGR
  J16318-4848

abstract:
  The X-ray source IGR J16318-4848 was the first source discovered by INTEGRAL
on 2003, January 29. The high energy spectrum exhibits such a high column
density that the source is undetectable in X-rays below 2 keV. On 2003,
February, 23--25 we triggered a Target of Opportunity (ToO) program using the
EMMI and SOFI instruments on the New Technology Telescope of the European
Southern Observatory (La Silla) to get optical and near-infrared (NIR)
observations. We discovered the optical counterpart, and confirmed the already
proposed candidate in the NIR. We report here photometric measurements in the
R, I and J bands, upper flux limits in the Bb and V bands, lower flux limits in
the H and Ks bands. We also got NIR spectroscopy between 0.95 and 2.52 microns,
revealing a large amount of emission lines, including forbidden iron lines and
P-Cygni profiles, and showing a strong similarity with CI Cam, another strongly
absorbed source. Together with the Spectral Energy Distribution (SED), these
data point to a high luminosity, high temperature source, with an intrinsic
absorption greater than the interstellar absorption, but two orders of
magnitude below the X-ray absorption. We propose the following picture to match
the data: the source is a High Mass X-ray binary (HMXB) at a distance between
0.9 and 6.2 kpc, the optical/NIR counterpart corresponds to the mass donor,
which is an early-type star, probably a sgB[e] star, surrounded by a dense and
absorbing circumstellar material. This would make the second HMXB with a sgB[e]
star as the mass donor after CI Cam. Such sources may represent a different
evolutionary state of X-ray binaries previously undetected with the lower
energy space telescopes; if it is so, a new class of strongly absorbed X-ray
binaries is being unveiled by INTEGRAL.


title: Formation of Young Star Clusters

abstract:
  Turbulence, self-gravity, and cooling convert most of the interstellar medium
into cloudy structures that form stars. Turbulence compresses the gas into
clouds directly and it moves pre-existing clouds around passively when there
are multiple phases of temperature. Self-gravity also partitions the gas into
clouds, forming giant regular complexes in spiral arms and in resonance rings
and contributing to the scale-free motions generated by turbulence. Dense
clusters form in the most strongly self-gravitating cores of these clouds,
often triggered by compression from local stars. Pre-star formation processes
inside clusters are not well observed, but the high formation rates and high
densities of pre-stellar objects, and their power law mass functions suggest
that turbulence, self-gravity, and energy dissipation are involved there too.


title:
X-ray spectroscopy of the unsteady quiescent corona of AD Leo with
  Chandra

abstract:
  We present the analysis and interpretation of an observation of the flare
star AD Leo (dM3e) with Chandra/LETG. The high resolution X-ray spectrum
allowed us to infer the plasma emission measure distribution (EMD) vs.
temperature, and the abundances of individual elements in the corona of this
magnetically-active star, during a typical state characterized by significant
variability but no large flaring event. We have also measured plasma densities
at various temperatures using spectroscopic diagnostics provided by He-like
triplets and Fe XXI lines. We show that the present EMD is similar to those
previously obtained from EUVE spectra during quiescent and flaring states,
confirming the long-term stability of the corona of AD Leo. At variance with
the case of other active stars, the EMD of AD Leo is characterized by a
significantly shallower slope, compatible with that predicted by static models
of isobaric loops with constant cross-section and uniform heating. We discuss
such coronal modeling to infer the average properties of the corona in terms of
loop populations, including estimates of the surface filling factor. We also
show that the EMD is compatible with the model of a corona continuously heated
by flares. The coronal composition is such that the element abundances,
relative to solar values, tend to increase with the First Ionization Potential,
with few exceptions. The line to continuum ratios suggest a nearly solar
coronal metallicity.


title:
The Araucaria Project. An improved distance to the Sculptor spiral
  galaxy NGC 300 from its Cepheid variables

abstract:
  In a previous paper, we reported on the discovery of more than a hundred new
Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images
taken in the B and V photometric bands at ESO/La Silla. In this paper, we
present additional VI data, derive improved periods and mean magnitudes for the
variables, and construct period-luminosity relations in the V, I and the
reddening-independent (V-I) Wesenheit bands using 58 Cepheid variables with
periods between 11 and 90 days. We obtain tightly defined relations, and by
fitting the slopes determined for the LMC Cepheids by the OGLE II Project we
obtain reddening-corrected distances to the galaxy in all bands. We adopt as
our best value the distance derived from the reddening-free Wesenheit
magnitudes, which is 26.43 $\pm$ 0.04 (random) $\pm$ 0.05 (systematic) mag. We
argue that our current distance result for NGC 300 is the most accurate which
has so far been obtained using Cepheid variables, and that it is largely free
from systematic effects due to metallicity, blending, and sample selection. It
agrees very well with the recent distance determination from the tip of the red
giant branch method obtained from HST data by Butler et al. (2004), and it is
consistent with the Cepheid distance to NGC 300 which was derived by Freedman
et al. (2001) from CCD photometry of a smaller sample of stars.


title:
Very Small Array observations of the Sunyaev-Zel'dovich effect in nearby
  galaxy clusters

abstract:
  We present VSA observations (~34GHz) on scales ~20 arcmin towards a complete,
X-ray-flux-limited sample of seven clusters at redshift z<0.1. Four have
significant SZ detections in the presence of CMB primordial anisotropy. We use
a bayesian MCMC method for inference from the VSA data, with X-ray priors on
cluster positions and temperatures, and radio priors on sources. We make
assumptions of beta-model gas distributions and of hydrostatic equilibrium, to
evaluate probability densities for the gas mass and total mass out to r_200.
Our combined estimate of the gas fraction is 0.08^{+0.06}_{-0.04}h^{-1} The
random errors are poor (note that the errors are higher than would have been
obtained with the usual chi-squared method) but the control of bias is good. We
have described the MCMC analysis method specifically in terms of SZ but hope
the description will be of more general use. We find that the effects of
primordial CMB contamination tend to be similar in the estimates of both the
gas mass and total mass over our narrow range of angular scales, so that there
is little effect of primordials on the gas fraction determination. Using our
total mass estimates we find a normalisation of the mass-temperature relation
based on the profiles from the VSA cluster pressure maps that is in good
agreement with recent M-T determinations from X-ray cluster measurements.


title: Neutralinos, Big Bang Nucleosynthesis and 6Li in Low-Metallicity Stars

abstract:
  The synthesis of Li6 during the epoch of Big Bang nucleosynthesis (BBN) due
to residual annihilation of dark matter particles is considered. By comparing
the predicted Li6 to observations of this isotope in low-metallicity stars,
generic constraints on s-wave dark matter annihilation rates into quarks, gauge
bosons, and Higgs bosons are derived. It may be shown that, for example, wino
dark matter in anomaly-mediated SUSY breaking scenarios with masses Mx < 250
GeV or light neutralinos with Mx < 20 GeV annihilating into light quarks are,
taken face value, ruled out. These constraints may only be circumvented if
significant Li6 depletion has occurred in all three low-metallicity stars in
which this isotope has been observed to date. In general, scenarios invoking
non-thermally generated neutralinos with enhanced annihilation rates for a
putative explanation of cosmic ray positron or galactic center as well as
diffuse background gamma-ray signals by present-day neutralino annihilation
will have to face a stringent Li6 overproduction problem. On the other hand, it
is possible that Li6 as observed in low-metallicity stars is entirely due to
residual dark matter annihilation during BBN, even for neutralinos undergoing a
standard thermal freeze-out.


title: The Lyman-alpha forest according to LUQAS

abstract:
  We use the LUQAS sample of 27 high resolution, high signal-to-noise QSO
absorption spectra (Kim et al. 2004) and the results from Croft et al. (2002)
together with a suite of high-resolution hydro-dynamical simulations run with
the GADGET-II code, to infer the linear dark matter power spectrum on scales of
\~ 0.3-30 Mpc at z=2.125 and at z=2.72.


title:
Super-massive Black Hole Demography: the Match between the Local and
  Accreted Mass Functions

abstract:
  We have performed a detailed analysis of the local super-massive black-hole
(SMBH) mass function based on both kinematic and photometric data and derived
an accurate analytical fit in the range 10^6 <= (M_BH/M_sun) <= 5*10^9. We find
a total SMBH mass density of (4.2+/-1.1)*10^5 M_sun/Mpc^3, about 25% of which
is contributed by SMBHs residing in bulges of late type galaxies. Exploiting
up-to-date luminosity functions of hard X-ray and optically selected AGNs, we
have studied the accretion history of the SMBH population. If most of the
accretion happens at constant \dot{M_BH}/M_BH the local SMBH mass function is
fully accounted for by mass accreted by X-ray selected AGNs, with bolometric
corrections indicated by current observations and a standard mass-to-light
conversion efficiency \epsilon ~10%. The analysis of the accretion history
highlights that the most massive BHs accreted their mass faster and at higher
redshifts (z>1.5), while the lower mass BHs responsible for most of the hard
X-ray background have mostly grown at z<1.5. The accreted mass function matches
the local SMBH mass function if \epsilon ~0.09(+0.04,-0.03) and the Eddington
ratio \lambda=L/L_Edd \~0.3(+0.3,-0.1) (68% confidence errors). The visibility
time, during which AGNs are luminous enough to be detected by the currently
available X-ray surveys, ranges from ~0.1 Gyr for present day BH masses
M_BH(z=0) ~10^6 M_sun to ~0.3 Gyr for M_BH(z=0) >= 10^9 M_sun. The mass
accreted during luminous phases is >= 25-30% even if we assume extreme values
of \epsilon (\epsilon \~0.3-0.4). An unlikely fine tuning of the parameters
would be required to account for the local SMBH mass function accomodating a
dominant contribution from 'dark' BH growth (due, e.g., to BH coalescence).


title: Spectroscopic investigation of unstudied southern PNe

abstract:
  We present a spectroscopic investigation of two hitherto unstudied galactic
planetary nebulae (MeWe 1-10 and MeWe 1-11) and one candidate object (MeWe
2-5). The candidate object clearly has been identified as a bipolar hourglass
shaped PN. The galactic foreground extinction was derived and using
photoionization models with CLOUDY the two round objects were classified as
highly evolved nebulae.