title:
The Wind of the B[e] Supergiant Hen S22 Viewed through a Reflection
  Nebula in DEM L 106

abstract:
  Narrow-band HST WFPC2 images reveal a bow-shock-like halo around the HII
region N30B toward the B[e] supergiant Hen S22 located within the larger DEM L
106 nebula in the Large Magellanic Cloud. High-dispersion spectra of N30B show
a narrow H-alpha emission component from the ionized gas; the velocity
variations indicate a gas flow of -5 to -10 km/s in the vicinity of the HII
regions, which is resultant from interactions with Hen S22's stellar wind and
responsible for the bow-shock morphology. Spectra of N30B's halo show broad
H-alpha profiles extending over >1000 km/s, similar to that of Hen S22,
indicating that the halo is a reflection nebula of Hen S22. Broad-band
morphologies of N30B's halo are also consistent with the reflection nebula
interpretation. We use dust-scattering properties and the observed brightnesses
of the reflection nebula and Hen S22 to constrain the reflection geometry. The
reflected stellar H-alpha emission and absorption vary across the reflection
nebula as a result of viewing S22's anisotropic wind across varying angles.
This reflection nebula, together with the edge-on orientation of Hen S22's
disk, provides an invaluable opportunity to study the disk and polar winds of a
B[e] supergiant.


title: $H_2^{+}$ molecular ion in a strong magnetic field: ground state

abstract:
  A detailed quantitative analysis of the system $(ppe)$ placed in magnetic
field ranging from $0 - 4.414 \times 10^{13} G$ is presented. The present study
is focused on the question of the existence of the molecular ion $H_2^{+}$ in a
magnetic field. As a tool, a variational method with an optimization of the
form of the vector potential (optimal gauge fixing) is used. It is shown that
in the domain of applicability of the non-relativistic approximation the system
$(ppe)$ in the Born-Oppenheimer approximation has a well-pronounced minimum in
the total energy at a finite interproton distance for $B \lesssim 10^{11} G$,
thus manifesting the existence of $H_2^{+}$. For $B \gtrsim 10^{11} G$ and
large inclinations (of the molecular axis with respect to the magnetic line)
the minimum disappears and hence the molecular ion $H_2^{+}$ does not exist. It
is shown that the most stable configuration of $H_2^{+}$ always corresponds to
protons situated along the magnetic line. With magnetic field growth the ion
$H_2^{+}$ becomes more and more tightly bound and compact, and the electronic
distribution evolves from a two-peak to a one-peak pattern. The domain of
inclinations where the $H_2^{+}$ ion exists reduces with magnetic field
increase and finally becomes $0^o - 25^o$ at $B = 4.414 \times 10^{13} G$.
Phase transition type behavior of variational parameters for some interproton
distances related to the beginning of the chemical reaction $H_2^{+}
\leftrightarrow H + p$ is found.


title: The XMM-Newton view of the Galactic Centre

abstract:
  In X-rays, the Galactic Centre (GC) Region appears as a complex of diffuse
thermal and non-thermal X-ray emission intermixed with a population of luminous
discrete sources. Here we present some new findings from the XMM-Newton GC
survey, focusing particularly on Sgr A*, Sgr A East, the Radio Arc region, and
a newly discovered X-ray non-thermal filament.


title: Lensing effects of misaligned disks in dark matter halos

abstract:
  We study the observational signatures of the lensing signal produced by dark
matter halos with embedded misaligned disks. This issue is of particular
interest at the present time since most of the observed multiple lens systems
have magnification ratios and image geometries that are not well-fit by
standard mass models. The presence of substructure exterior to the lens has
been invoked by several authors in the context of Cold Dark Matter (CDM) models
in order to explain the anamolous magnification ratios. We emphasize that the
anomalous magnification ratios may be an artifact of the simple one-component
mass models currently in use; the inclusion of a misaligned disk may be able to
mimic the effect of substructure. These slight spatial offsets between the dark
matter halo and the disk, which are likely to occur during or as a consequence
of interactions or mergers, lead to complex image configurations and
non-standard magnification ratios. We investigate two illustrative lens models:
a spiral disk embedded within a dark matter halo, and a compact disk-like
component within an elliptical galaxy. The expected fraction of galaxies with a
misaligned disk is estimated to be of the order of 10%. In such cases we find
that the resultant lensing geometries are unusual, with high image
multiplicities. The caustic structures - both radial and tangential - are
drastically modified and the magnification ratios differ compared to
expectations from standard lens models. The additional parameters required to
specify the relative alignment of the mass components in the primary lens
introduce yet another source of uncertainty in the mass modeling of
gravitational lens systems.


title:
Normal Parameters for an Analytic Description of the CMB Cosmological
  Parameter Likelihood

abstract:
  The normal parameters are a non--linear transformation of the cosmological
parameters whose likelihood function is very well--approximated by a normal
distribution. This transformation serves as an extreme form of data compression
allowing for practically instantaneous calculation of the likelihood of any
given model, as long as the model is in the parameter space originally
considered. The compression makes all the information about cosmological
parameter constraints from a given set of experiments available in a useable
manner. Here we explicitly define the normal parameters that work for the
current CMB data, and give their mean and covariance matrix which best fit the
likelihood function calculated by the Monte Carlo Markov Chain method. Along
with standard parameter estimation results, we propose that future CMB
parameter analyses define normal parameters and quote their mean and covariance
matrix.


title:
Discs in early-type lensing galaxies: effects on magnification ratios
  and measurements of $H_0$

abstract:
  Observations of early-type galaxies, both in the local universe and in
clusters at medium redshifts, suggest that these galaxies often contain discs
or disc-like structures. Using the results of Kelson et al. (2000) for the
incidence of disc-components among the galaxies in the redshift z=0.33 cluster
CL 1358+62, we investigate the effect of disc structures on the lensing
properties of early-type galaxies. Statistical properties, like magnification
cross sections and the expected number of quad (four-image) lens systems, are
not affected greatly by the inclusion of discs that contain less than about 10
per cent of the total stellar mass. However, the properties of individual lens
systems are affected. We estimate that 10-30 per cent of all quad lens systems,
with early-type deflector galaxies, would be affected measurably by the
presence of disc components. Intriguingly, the image magnification ratios are
altered significantly. The amplitude of the predicted change is sufficient to
explain the observed magnification ratios in systems like B1422+231 without
requiring compact substructure. Furthermore, time delays between images also
change; fitting a bulge-only model to early-type lenses that in fact contain a
disc would yield a value of the Hubble constant H_0 that is systematically too
low by about 25 per cent.


title: Observing Massive Galaxy Formation

abstract:
  A major goal of contemporary astrophysics is understanding the origin of the
most massive galaxies in the universe, particularly nearby ellipticals and
spirals. Theoretical models of galaxy formation have existed for many decades,
although low and high redshift observations are only beginning to put
constraints on different ideas. We briefly describe these observations and how
they are revealing the methods by which galaxies form by contrasting and
comparing fiducial rapid collapse and hierarchical formation model predictions.
The available data show that cluster ellipticals must have rapidly formed at z
> 2, and that up to 50% of all massive galaxies at z ~ 2.5 are involved in
major mergers. While the former is consistent with the monolithic collapse
picture, we argue that hierarchal formation is the only model that can
reproduce all the available observations.


title: How Massive Single Stars End their Life

abstract:
  How massive stars die -- what sort of explosion and remnant each produces --
depends chiefly on the masses of their helium cores and hydrogen envelopes at
death. For single stars, stellar winds are the only means of mass loss, and
these are chiefly a function of the metallicity of the star. We discuss how
metallicity, and a simplified prescription for its effect on mass loss, affects
the evolution and final fate of massive stars. We map, as a function of mass
and metallicity, where black holes and neutron stars are likely to form and
where different types of supernovae are produced. Integrating over an initial
mass function, we derive the relative populations as a function of metallicity.
Provided single stars rotate rapidly enough at death, we speculate upon stellar
populations that might produce gamma-ray bursts and jet-driven supernovae.


title: Parsec--scale radio jets in gamma--ray loud sources

abstract:
  We will present a multiepoch study of the three blazars 0954+658 (BL--Lac),
PKS1510--089 (HPQ) and 1749+096 (BL--Lac). The first two sources are known to
be $\gamma$--ray loud. Our study is based on milliarcsecond resolution
polarimetric observations carried out with the VLBA at 8.4 GHz. The
observations took place between January 1999 and May 2001. Superluminal motion
is detected along the jet of PKS1510--089 and 1749+096, with $\beta_{app} \sim
10$ for all features. Magnetic field structure is revealed along the jets of
0954+658 and PKS 1510--089. The polarisation properties of the parsec--scale
jets remain stationary in all sources, regardless of their total flux density
variability in the radio band and of the presence of superluminal features.


title: Quintessence with a constant equation of state in hyperbolic universes

abstract:
  Quintessence models leading to a constant equation of state are studied in
hyperbolic universes. General properties of the quintessence potentials V(phi)
are discussed, and for some special cases also the exact analytic expressions
for these potentials are derived. It is shown that the observed angular power
spectrum of the cosmic microwave background (CMB) is in excellent agreement
with some of the quintessence models even in cases with negative curvature. It
is emphasized that due to a (w_phi, Omega_phi, Omega_c)-degeneracy a universe
with negative spatial curvature cannot be excluded.


title: The impact of the Herbig Haro object HH2 on local dust and gas

abstract:
  We present results from a study of molecular gas and dust in the vicinity of
the Herbig Haro object HH2. Emission from the sub-mm continuum, 12CO and HCO+
was mapped with angular resolutions ranging from 14 arcsec to 5 arcsec (or
0.01pc at the distance of HH2). The continuum shows an extended dust clump of
mass 3.8Msun and temperature 22K, located downstream of the bright optical HH
knots. However, a compact emission peak lies within ~0.01pc of the
low-excitation H2-prominent shocks, with a luminosity consistent with local
heating by the outflow.
  The HCO+ emission shows two velocity components: firstly, ambient-velocity
gas lying in a region roughly corresponding to the dust clump, with abundance
enhanced by a factor of a few close to the H2-prominent knots. Secondly a
component of high-velocity emission (20 km/s linewidth), found mainly in a
collimated jet linking the low-excitation HH objects. In this high-velocity
jet, the line wings show an abundance ratio HCO+/CO proportional to v^2, with
an HCO+ enhancement compared with ambient gas of up to 10^3 at the most extreme
velocities. Such high abundances are consistent with models of shock chemistry
in turbulent mixing layers at the interaction boundaries of jets. Extrapolating
this effect to low velocities suggests that the more modest HCO+ enhancement in
the clump gas could be caused by low velocity shocks. A UV precursor may not,
therefore be necessary to explain the elevated HCO+ abundance in this gas.


title:
Long-term spectroscopic monitoring of the Luminous Blue Variable
  HD160529

abstract:
  We have spectroscopically monitored the galactic Luminous Blue Variable HD
160529 and obtained an extensive high-resolution data set that covers the years
1991 to 2002. During this period, the star evolved from an extended photometric
minimum phase towards a new visual maximum. In several observing seasons, we
covered up to four months with almost daily spectra. Our spectra typically
cover most of the visual spectral range with a high spectral resolution (about
20,000 or more). This allows us to investigate the variability in many lines
and on many time scales from days to years. We find a correlation between the
photospheric HeI lines and the brightness of the star, both on a time scale of
months and on a time scale of years. The short-term variations are smaller and
do not follow the long-term trend, strongly suggesting different physical
mechanisms. Metal lines also show both short-term and long-term variations in
strength and also a long-term trend in radial velocity. Most of the
line-profile variations can be attributed to changing strengths of lines.
Propagating features in the line profiles are rarely observed. We find that the
mass-loss rate of HD 160529 is almost independent of temperature, i.e. visual
brightness.


title: Color Variability of AGNs

abstract:
  Optical spectral variability of quasars and BL Lac Objects is compared by
means of the spectral variability parameter beta (Trevese & Vagnetti 2002).
Both kinds of objects change their spectral slopes alpha, becoming bluer when
brighter, but BL Lac Objects have smaller beta values and are clearly separated
from quasars in the alpha-beta plane. Models accounting for the origin of the
variability are discussed for both classes of objects.


title: Black hole mass and binary model for BL Lac object OJ 287

abstract:
  Recent intensive observations of the BL Lac object OJ 287 raise a lot of
questions on the models of binary black holes, processing jets, rotating
helical jets and thermal instability of slim accretion disks. After carefully
analyzing their radio flux and polarization data, Valtaoja et al.
(\cite{valtaoja00}) propose a new binary model. Based on the black hole mass of
$4 \times 10^8 {\rm M_\odot}$ estimated with the tight correlations of the
black hole masses and the bulge luminosity or central velocity dispersion of
host galaxies, we computed the physical parameters of the new binary scenario.
The impact of the secondary on the accretion disk around the primary black hole
causes strong shocks propagating inwards and outwards, whose arrival at the jet
roots is identified with the rapid increase of optical polarization and the
large change of polarization angle at about 0.30 yr after the first main
optical flare. An increase of optical polarization, a large rotation of
positional angle and a small synchrotron flare at 2007.05 between the optical
outbursts at 2006.75 and 2007.89 are expected by the model. With the estimated
parameters, we predicated an increase of $\gamma$-ray flux appearing about 5
days after the first optical/IR peak, which is consistent with the EGRET
observations.


title:
Features of Muon Arrival Time Distributions of High Energy EAS at Large
  Distances From the Shower Axis

abstract:
  In view of the current efforts to extend the KASCADE experiment
(KASCADE-Grande) for observations of Extensive Air Showers (EAS) of primary
energies up to 1 EeV, the features of muon arrival time distributions and their
correlations with other observable EAS quantities have been scrutinised on
basis of high-energy EAS, simulated with the Monte Carlo code CORSIKA and using
in general the QGSJET model as generator. Methodically various correlations of
adequately defined arrival time parameters with other EAS parameters have been
investigated by invoking non-parametric methods for the analysis of
multivariate distributions, studying the classification and misclassification
probabilities of various observable sets. It turns out that adding the arrival
time information and the multiplicity of muons spanning the observed time
distributions has distinct effects improving the mass discrimination. A further
outcome of the studies is the feature that for the considered ranges of primary
energies and of distances from the shower axis the discrimination power of
global arrival time distributions referring to the arrival time of the shower
core is only marginally enhanced as compared to local distributions referring
to the arrival of the locally first muon.


title: A new list of extra-galactic radio jets

abstract:
  A catalogue of extra-galactic jets is very useful both in observational and
theoretical studies of active galaxies. With the use of new powerful radio
instruments, the detailed structures of very compact or weak radio sources are
investigated observationally and many new radio jets are detected. In this
paper, we give a list of 661 radio sources with detected radio jets known to us
prior to the end of December 2000. All references are collected for the
observations of jets in radio, IR, optical, UV and X-ray wave-bands.


title: A new survey of variability in the core of M15 with TRIFFID-2

abstract:
  A two-week campaign of high-resolution imaging of the centre of M15 using the
tip/tilt correcting TRIFFID-2 camera, followed by analysis with ISIS (image
matching & subtraction software), has produced the most sensitive survey to
date of variable stars in the central ~1x1 arcmin^2 - a total of 48 were
detected -, and constrains the size of the dwarf nova population.


title: The Evolutionary Stage of 5 Southern Galactic Unclassified B[e] Stars

abstract:
  The spectra of stars with the B[e] phenomenon are dominated by features that
are related to physical conditions of circumstellar material around these
objects and are not intrinsic to the stars. Because of this, they form a very
heterogeneous group. This group contains objects with different evolutionary
stages. Lamers et al. (1998) have suggested a new designation with five
sub-groups, which indicate the evolutionary stage. They are: supergiants,
pre-main sequence or Herbig Ae/Be, compact planetary nebulae, symbiotic and
unclassified. The unclassified group has many objects that need a better study
to resolve their evolutionary status. Forbidden lines can be a useful tool to
solve this problem. They can give informations about chemical composition,
ionization and density of the circunstellar medium and probably the
evolutionary phase of these objects. We analize spectra of some galactic
objects, obtained with FEROS and B&C spectrograph at 1.52 telescope in ESO (La
Silla-Chile), with a special focus on the forbidden lines. We have studied the
spectra of 5 B[e] stars of uncertain evolutionary stage. We find that one of
them is a pre-WN star, the other four are supergiant B[e] stars.


title: Subluminous B Stars and Progenitors of Helium Core White Dwarfs

abstract:
  Subluminous B (sdB) stars can result from stable Roche lobe overflow or
common envelope ejection in close binary systems. The companions are either low
mass main sequence stars or white dwarfs. We discuss mass determinations for
sdB stars from such systems and report the discovery of the bright nearby sdB
star, HD 188112, to be a close binary system of unusually low mass (0.23 solar
masses). From the mass function it is evident that the companion is a massive
compact object of at least 0.72 solar masses. The mass of the sdB HD 188112 is
too low for the star to evolve into a C/O white dwarf, but it probably is a
progenitor for a helium core white dwarf.


title: Energy Spectrum and Mass Composition around the Knee by EAS Measurements

abstract:
  Primary cosmic ray particles above energies of about 100 TeV are investigated
by large-area ground based detector installations, observing various components
of the development of extensive air-showers (EAS). By such an indirect access
to the primary cosmic ray spectrum a steepening of the power-law falls off at
around 3-5 PeV, known as the {\em knee} has been identified. Different
experimental techniques are used to deduce mass- and energy-sensitive
observables of EAS experiments. The experiments involve measurements of
secondary particle distributions at various observation levels and of muons
deep underground as well as of observables reconstructed by measuring the air
Cherenkov light emitted with the shower development in the atmosphere. Recently
methods for analysing multidimensional distributions get favoured since they
are able to take into account the correlations between different observables
and the influence of large intrinsic fluctuations of the air-shower
development. Additionally the use of a larger set of observables provides the
possibility to test simultaneously the consistency of the Monte-Carlo models
underlying the reconstruction procedures. By many experiments the existence of
the knee in the primary energy spectrum is confirmed and a tendency of an
increasing mean mass above the knee energy is indicated. Recent results show
that the knee originates from a decrease of the flux of light primary
particles, whereas heavy cosmic ray particles seem to miss a kink in the energy
range of 1 and 10 PeV.


title: A Photometric Method for estimating CNO Abundances in Globular Clusters

abstract:
  Stromgren indices v and b are combined with broad-band index I, and a new
index p, the short wavelength half of the v band, to estimate CN 4215A
molecular absorption in a sample of stars in M22. The results have been used to
estimate carbon and nitrogen abundances and suggest groups of stars within this
cluster, each with a characteristic nitrogen abundance, but with a range of
carbon abundances. The results suggest the possibility of stars consisting of
material which has undergone CNO recycling two or three times. The method can
be subsequently used for other globular clusters.


title: The theoretical model of a magnetic white dwarf

abstract:
  In this paper a theoretical model of a magnetic white dwarf is studied. All
numerical calculations are performed under the assumption of a spherically
symmetric star. The obtained equation of state is stiffer for the increasing
value of magnetic field B. The numerical values of the maximum mass and radius
are presented. Sensibility of the results to the choice of the magnetic field
strength is evident. Finally the departure from the condition of isothermality
of degenerated electron gas in gravitational field is discussed.


title: The Analysis of the Rotating Disk of some Southern Galactic B[e] Stars

abstract:
  The spectra of stars with the B[e] phenomenon are dominated by features that
are related to physical conditions of circumstellar material around these
objects and are not intrinsic to the stars. Previous studies have shown that
emission lines present in the optical spectra of these objects are formed in an
equatorial rotating disk. The analysis of high and low resolution spectra,
obtained by us with 1.52 telescope in ESO for some Southern Galactic B[e]
Stars, can give us information about the structure and velocity of the disk. We
will describe the analysis of the unclassified B[e] star Hen 2-90.


title:
Constraints on the Decomposition of the Rotation Curves of Spiral
  Galaxies

abstract:
  I discuss anew how arguments about the internal dynamics of galactic disks
set constraints on the otherwise ambiguous decomposition of the rotation curves
of spiral galaxies into the contributions by the various constituents of the
galaxies. Analyzing the two sample galaxies NGC 3198 and NGC 2985 I conclude
from the multiplicities of the spiral arms and the values of the Q disk
stability parameters that the disks of both galaxies are `maximum disks'.


title: The physics of jets in FR I radio galaxies

abstract:
  We model jets in low-luminosity (FR I) radio galaxies as intrinsically
symmetrical, axisymmetric, decelerating relativistic flows with transverse
velocity gradients. This allows us to derive velocity fields and the
three-dimensional distributions of magnetic-field ordering and rest-frame
emissivity. A conservation-law analysis, combining the kinematic model with
X-ray observations of the surrounding IGM, gives the profiles of internal
density, pressure, Mach number and entrainment rate along the jets. We
summarize our recently-published results on 3C 31 and outline new work on other
sources and adiabatic jet models.


title: Epsilon Indi B: a new benchmark T dwarf

abstract:
  We have identified a new early T dwarf only 3.6pc from the Sun, as a common
proper motion companion (separation 1459AU) to the K5V star Epsilon Indi
(HD209100). As such, Epsilon Indi B is one of the highest proper motion sources
outside the solar system (~4.7 arcsec/yr), part of one of the twenty nearest
stellar systems, and the nearest brown dwarf to the Sun. Optical photometry
obtained from the SuperCOSMOS Sky Survey was combined with approximate infrared
photometry from the 2MASS Quicklook survey data release, yielding colours for
the source typical of early T dwarfs. Follow up infrared spectroscopy using the
ESO NTT and SOFI confirmed its spectral type to be T2.5+/-0.5. With Ks=11.2,
Epsilon Indi B is 1.7 magnitudes brighter than any previously known T dwarf and
4 magnitudes brighter than the typical object in its class, making it highly
amenable to detailed study. Also, as a companion to a bright nearby star, it
has a precisely known distance (3.626pc) and relatively well-known age
(0.8-2Gyr), allowing us to estimate its luminosity as logL/Lsun=-4.67, its
effective temperature as 1260K, and its mass as ~40-60Mjup. Epsilon Indi B
represents an important addition to the census of the Solar neighbourhood and,
equally importantly, a new benchmark object in our understanding of substellar
objects.


title: Stellar wind signatures in sdB stars?

abstract:
  Subdwarf B (sdB) stars form the blue end of the horizonal branch (EHB). Their
peculiar atmospheric abundance patterns are due to diffusion processes.
However, diffusion models fail to explain these anomalies quantitatively. Weak
mass loss has been invoked to solve these discrepancies, but up to now has not
been observed. We report first observational evidence for stellar winds in four
sdB stars from a NLTE model atmosphere analysis of high quality optical
spectra.


title:
Towards asteroseismology of the non-radial pulsating sdB star PG
  1605+072

abstract:
  The recently discovered new class of sdB pulsators (sdBV) offers a powerful
possibility for the investigation of their interior and thus their evolutionary
history. The first step towards applying asteroseismologic tools is the
identification of pulsation modes. We reoport on simultaneous spectroscopic and
multi-band photometric time series observations of PG 1605+072 and analyse its
radial velocity and light curve.


title:
Rotation and outflow in the central kiloparsec of the water megamaser
  galaxies IC 2560, NGC 1386, NGC 1052, and Mrk 1210

abstract:
  Optical emission-line profiles were evaluated in order to explore the
structure of galactic nuclei containing H2O megamaser sources. Galactic
rotation and outflow of narrow-line gas are common features of this sample of
water megamaser galaxies. All decomposed line-systems exhibit AGN typical line
ratios. Recent detections of H2O megamasers in starburst galaxies and the
apparent asssociation of one megamaser with a Seyfert 1 AGN suggest that
megamasers can possibly be triggered by optically detectable outflows. The
frequently encountered edge-on geometry favoring large molecular column
densities appears to be verified for NGC 1386 and IC 2560. For NGC 1052 and Mrk
1210, maser emission triggered by the optically detected outflow components
cannot be ruled out.


title:
SICANE: a Detector Array for the Measurement of Nuclear Recoil Quenching
  Factors using Monoenergetic Neutron Beam

abstract:
  SICANE is a neutron scattering multidetector facility for the determination
of the quenching factor (ratio of the response to nuclear recoils and to
electrons) of cryogenic detectors used in direct WIMP searches. Well collimated
monoenergetic neutron beams are obtained with inverse (p,n) reactions. The
facility is described, and results obtained for the quenching factors of
scintillation in NaI(Tl) and of heat and ionization in Ge are presented.


title:
Submillimeter Studies of Prestellar Cores and Protostars: Probing the
  Initial Conditions for Protostellar Collapse

abstract:
  Improving our understanding of the initial conditions and earliest stages of
protostellar collapse is crucial to gain insight into the origin of stellar
masses, multiple systems, and protoplanetary disks. Observationally, there are
two complementary approaches to this problem: (1) studying the structure and
kinematics of prestellar cores observed prior to protostar formation, and (2)
studying the structure of young (e.g. Class 0) accreting protostars observed
soon after point mass formation. We discuss recent advances made in this area
thanks to (sub)millimeter mapping observations with large single-dish
telescopes and interferometers. In particular, we argue that the beginning of
protostellar collapse is much more violent in cluster-forming clouds than in
regions of distributed star formation. Major breakthroughs are expected in this
field from future large submillimeter instruments such as Herschel and ALMA.


title: Stellar wind signatures in sdB stars?

abstract:
  Subdwarf B (sdB) stars form the blue end of the horizonal branch. Their
peculiar atmospheric abundance patterns are due to diffusion processes.
However, diffusion models fail to explain these anomalies quantitatively. From
a NLTE model atmosphere analysis of 40 sdB stars, we found that the more
luminous (i.e. more evolved) stars have anomalous H alpha and HeI 6678Ang line
profiles, i.e, the lines are too broad and shallow and may even show some
emission. We interpret these anomalies as the signatures of a stellar wind, the
first such detection in this class of star (if confirmed). Mass loss may also
explain the peculiar abundance patterns seen in sdB stars. High-quality UV
spectra are needed to confirm that these stars do have stellar winds.


title: The efficiency of the spiral-in of a black hole to the Galactic centre

abstract:
  We study the efficiency at which a black hole or dense star cluster
spirals-in to the Galactic centre. This process takes place on a dynamical
friction time scale, which depends on the value of the Coulomb logarithm ln(L).
We determine the accurate value of this parameter using the direct N-body
method, a tree algorithm and a particle-mesh technique with up to 2 million
plus one particles. The three different techniques are in excellent agreement.
Our result for the Coulomb logarithm appears to be independent of the number of
particles. We conclude that ln(L) = 6.6 +/- 0.6 for a massive point particle in
the inner few parsec of the Galactic bulge. For an extended object, like a
dense star cluster, ln(L) is smaller, with a value of the logarithm argument L
inversely proportional to the object size.


title: The CMB power spectrum out to l=1400 measured by the VSA

abstract:
  We have observed the cosmic microwave background (CMB) in three regions of
sky using the Very Small Array (VSA) in an extended configuration with antennas
of beamwidth 2 degrees at 34 GHz. Combined with data from previous VSA
observations using a more compact array with larger beamwidth, we measure the
power spectrum of the primordial CMB anisotropies between angular multipoles l
= 160 - 1400. Such measurements at high l are vital for breaking degeneracies
in parameter estimation from the CMB power spectrum and other cosmological
data. The power spectrum clearly resolves the first three acoustic peaks, shows
the expected fall off in power at high l and starts to constrain the position
and height of a fourth peak.


title: Memberships and CM Diagrams of the Open Cluster NGC 7243

abstract:
  The results of astrometric and photometric investigations of the open cluster
NGC 7243 are presented. Proper motions of 2165 stars with root-mean-square
error of 1.1 mas/yr were obtained by means of PDS scanning of astrometric
plates covering the time interval of 97 years. A total of 211 cluster members
down to V=15.5 mag have been identified. V and B magnitudes have been
determined for 2118 and 2110 stars respectively. Estimations of mass (348Mo < M
< 522Mo), age (t=2.5x10^8 yr), distance (r=698 pc) and reddening (E(B-V)=0.24)
of the cluster NGC 7243 have been made.


title:
Cosmological parameter estimation and Bayesian model comparison using
  VSA data

abstract:
  We constrain the basic comological parameters using the first observations by
the Very Small Array (VSA) in its extended configuration, together with
existing cosmic microwave background data and other cosmological observations.
We estimate cosmological parameters for four different models of increasing
complexity. In each case, careful consideration is given to implied priors and
the Bayesian evidence is calculated in order to perform model selection. We
find that the data are most convincingly explained by a simple flat Lambda-CDM
cosmology without tensor modes. In this case, combining just the VSA and COBE
data sets yields the 68 per cent confidence intervals Omega_b h^2=0.034
(+0.007, -0.007), Omega_dm h^2 = 0.18 (+0.06, -0.04), h=0.72 (+0.15,-0.13),
n_s=1.07 (+0.06,-0.06) and sigma_8=1.17 (+0.25, -0.20). The most general model
considered includes spatial curvature, tensor modes, massive neutrinos and a
parameterised equation of state for the dark energy. In this case, by combining
all recent cosmological data, we find, in particular, 95 percent limit on the
tensor-to-scalar ratio R < 0.63 and on the fraction of massive neutrinos f_nu <
0.11; we also obtain the 68 per cent confidence interval w=-1.06 (+0.20, -0.25)
on the equation of state of dark energy.


title:
XMM-Newton Studies of the Source Population and the Hot Interstellar
  Medium in Nearby Galaxies

abstract:
  First results of X-ray source population studies in nearby galaxies show the
potential of XMM-Newton observations. I will report on first XMM-Newton M31
results and on three of our XMM-Newton projects, an X-ray source population
study in the Magellanic Clouds (MCs), a deep raster survey of M33, and an
investigation of the hot interstellar medium (ISM) in the halo of edge-on
galaxies. XMM-Newton results on several other galaxies and sources within are
presented by other authors in these proceedings. Our MC study is build up of
deep pointings probing MC sources down to 10^33 erg s^-1 and shallower
pointings to confirm candidates from our ROSAT derived lists of X-ray binaries,
super-soft sources, and supernova remnants. First XMM-Newton detections of a
455 s pulsar in the Small Magellanic Cloud and the results of the Large
Magellanic Cloud deep field confirm the validity of our strategy.
  Our M33 raster pointing aims for luminosities as low as 10^35 erg s^-1, a
factor of 10 below the sensitivity limit of the ROSAT observations. The survey
will allow us to characterize the sources using extent, spectra, hardness
ratios and time variability to build up an unprecedented census of the X-ray
source content of M33. Of specific interest are the active source in the
nuclear area and the diffuse emission in the inner disk.
  XMM-Newton observations of the active galaxy NGC 3079 and of the starburst
galaxy NGC 253 are used to characterize the point-like sources and the hot ISM
in the disk and from the halo of these galaxies.


title:
Twenty Years of Galactic Observations in Searching for Bursts of
  Collapse Neutrinos with the Baksan Underground Scintillation Telescope

abstract:
  The results of twenty-year-long Galactic observations in neutrino radiation
are summarized. Except for the recording of a neutrino signal from the
supernova SN 1987A, no Galactic bursts of collapse neutrinos have been
detected. An upper bound on the mean frequency of gravitational collapses in
our Galaxy was obtained, $f_{collapse} (90% {confidence}) < 0.13 {yr}^{-1}$.


title: The Bispectrum and the Trispectrum of the Ostriker and Vishniac Effect

abstract:
  We present analytical expressions for the Fourier analog of the CMB
three-point and four-point correlation functions, the spatial bispectrum and
trispectrum, of the Ostriker and Vishniac effect in the linear and mildly
nonlinear regime. Through this systematic study, we illustrate a technique to
tackle the calculation of such statistics making use of the effects of its
small-angle and vector-like properties through the Limber approximation.
Finally we discuss its configuration dependence and detectability in the
context of Gaussian theories for the currently favored flat Lambda CDM
cosmology.


title:
Deep BVR Imaging of the Field of the Millisecond Pulsar PSR J0030+0451
  with the VLT

abstract:
  We report on deep BVR-imaging of the field of the nearby millisecond pulsar
PSR J0030+0451 obtained with the ESO/VLT/FORS2. We do not detect any optical
counterpart down to B>27.3, V>27.0 and R>27.0 in the immediate vicinity of the
radio pulsar position. The closest detected sources are offset by >3'', and
they are excluded as counterpart candidates by our astrometry. Using our upper
limits in the optical, and including recent XMM-Newton X-ray data we show that
any nonthermal power-law spectral component of neutron star magnetospheric
origin, as suggested by the interpretation of X-ray data, must be suppressed by
at least a factor of ~500 in the optical range. This either rules out the
nonthermal interpretation or suggests a dramatic spectral break in the
0.003-0.1 keV range of the power-law spectrum. Such a situation has never been
observed in the optical/X-ray spectral region of ordinary pulsars, and the
origin of such a break is unclear. An alternative interpretation with a purely
thermal X-ray spectrum is consistent with our optical upper limits. In this
case the X-ray emission is dominated by hot polar caps of the pulsar.


title: High Energy Emission from Galactic Black Hole Systems

abstract:
  In the last decade our knowledge on galactic black hole systems and in
particular on their high energy behavior has considerably improved. I will
briefly review here the main results obtained by the high-energy missions
SIGMA/GRANAT, Compton-GRO, Beppo-SAX and Rossi-XTE, on these objects and, in
particular, I will discuss the spectral shapes observed at energies higher than
30 keV and the detections of high energy features at > 300 keV. Galactic black
holes are indeed main targets for the ESA gamma-ray mission, INTEGRAL, to be
launched in October 2002, and for the next gamma-ray missions SWIFT, AGILE and
GLAST. We expect that a large amount of data will be collected in the next
years and the perspectives for the high energy astrophysics of galactic black
hole systems look very promising.


title:
Disk Accretion Flow Driven by Large-Scale Magnetic Fields: Solutions
  with Constant Specific Energy

abstract:
  (Abridged) We study the dynamical evolution of a stationary, axisymmetric,
and perfectly conducting cold accretion disk containing a large-scale magnetic
field around a Kerr black hole, trying to understand the relation between
accretion and the transportation of angular momentum and energy. We solve the
radial momentum equation for solutions corresponding to an accretion flow that
starts from a subsonic state at infinity, smoothly passes the fast critical
point, then supersonically falls into the horizon of the black hole. The
solutions always have the following features: 1) The specific energy of fluid
particles remains constant but the specific angular momentum is effectively
removed by the magnetic field. 2) At large radii, where the disk motion is
dominantly rotational, the energy density of the magnetic field is
equipartitioned with the rotational energy density of the disk. 3) Inside the
fast critical point, where radial motion becomes important, the ratio of the
electromagnetic energy density to the kinetic energy density drops quickly. The
results indicate that: 1) Disk accretion does not necessarily imply energy
dissipation since magnetic fields do not have to transport or dissipate a lot
of energy as they effectively transport angular momentum. 2) When resistivity
is small, the large-scale magnetic field is amplified by the shearing rotation
of the disk until the magnetic energy density is equipartitioned with the
rotational energy density, ending up with a geometrically thick disk. This is
in contrast with the evolution of small-scale magnetic fields where if the
resistivity is nonzero the magnetic energy density is likely to be
equipartitioned with the kinetic energy density associated with local random
motions (e.g., turbulence), making a thin Keplerian disk possible.


title: The Gamma-Ray Blazar Content of the Northern Sky

abstract:
  Using survey data, we have re-evaluated the correlation of flat spectrum
radio sources with EGRET sources in the Northern sky. A likelihood analysis
incorporating the radio and X-ray properties and the Gamma-ray source
localization is used to gauge the reliability of associations and to search for
counterparts of previously unidentified EGRET sources. Above |b|=10deg, where
the classification is complete, we find that 70% of the Northern EGRET sources
have counterparts similar to the bright EGRET blazars. For several of these we
identify known blazar counterparts more likely than the earlier proposed 3EG
association; for ~20 we have new identifications. Spectroscopic confirmation of
these candidates is in progress and we have found flat spectrum radio quasars
and BL Lac counterparts with redshifts as high as 4. We also find strong
evidence for a set of 28 objects with no plausible counterpart like the known
EGRET Blazars. These thus represent either a new extragalactic population or a
population of Galactic objects with a large scale height. The survey has been
extended into the plane, where we find several new blazar candidates; the bulk
of the sources are, however, Galactic. Looking ahead to the GLAST era we
predict that several of the present 3EG sources are composite and that higher
resolution data will break these into multiple Blazar IDs.


title:
Searching Gravitational Waves from Pulsars, Using Laser Beam
  Interferometers

abstract:
  We use recent population synthesis results to investigate the distribution of
pulsars in the frequency space, having a gravitational strain high enough to be
detected by the future generations of laser beam interferometers.
  We find that until detectors become able to recover the entire population,
the frequency distribution of the 'detectable' population will be very
dependent on the detector noise curve. Assuming a mean equatorial deformation
$\epsilon =10^{-6}$, the optimal frequency is around 450 Hz for interferometers
of the first generation (LIGO or VIRGO) and shifts toward 85 Hz for advanced
detectors. An interesting result for future detection stategies is the
significant narrowing of the distribution when improving the sensitivity: with
an advanced detector, it is possible to have 90% of detection probability while
exploring less than 20% of the parameter space (7.5% in the case of $\epsilon
=10^{-5}$). In addition, we show that in most cases the spindown of
'detectable' pulsars represents a period shift of less than a tens of
nanoseconds after one year of observation, making them easier to follow in the
frequency space.


title:
Interstellar Deuterium, Nitrogen, and Oxygen Abundances Toward GD 246,
  WD 2331$-$475, HZ 21, and Lan 23: Results from the FUSE Mission

abstract:
  The interstellar abundances of D I, N I, and O I in the local ISM are studied
us ing high-resolution spectra of four hot white dwarfs. The spectra of GD 246,
WD 2331$-$475, HZ 21, and Lan 23 were obtained with the {\it Far Ultraviolet
Spectroscopic Explorer} FUSE in the wavelength range 905-1187 A. The line of
sight to GD 246 probes the Local Interstellar Cloud and at least one other H I
cloud inside the Local Bubble, which contains most of the gas seen al ong this
line of sight. The column densities of H I, C II*, S II, and Si II are measured
using archival STIS echelle-mode observations. The H I column density is
determined by fitting the strong damping wings of inte rstellar Lyman alpha
using a model atmosphere to account for the stellar continuum. We combine the
different abundance ratios computed here with previous published values to
produce revised FUSE abundance ratios for DI/HI, OI/HI, NI/HI, DI/NI, DI/OI,
and OI/NI.


title: Observations of giant outbursts from Cygnus X-1

abstract:
  We present interplanetary network localization, spectral, and time history
information for 7 episodes of exceptionally intense gamma-ray emission from
Cygnus X-1. The outbursts occurred between 1995 and 2003, with durations up to
\~28000 seconds. The observed 15 - 300 keV peak fluxes and fluences reached
3E-7 erg /cm2 s, and 8E-4 erg / cm2 respectively. By combining the
triangulations of these outbursts we derive an ~1700 square arcminute (3 sigma)
error ellipse which contains Cygnus X-1 and no other known high energy sources.
The outbursts reported here occurred both when Cyg X-1 was in the hard state as
well as in the soft one, and at various orbital phases. The spectral data
indicate that these outbursts display the same parameters as those of the
underlying hard and soft states, suggesting that they represent another
manifestation of these states.


title: Host galaxies of z ~ 4.7 QSOs

abstract:
  2 micron broad- and narrow-band imaging with the Gemini-N telescope of five
z~4.7 QSOs, has resolved both the host galaxies and [O II] emission-line gas.
The resolved fluxes of the host galaxies fall within the extrapolated spread of
the K-z relationship for radio galaxies at lower redshifts, and their resolved
morphology is irregular. The [O II] images indicate knots coincident with many
continuum features and also some bright jet-like features near the nucleus. The
line emission total fluxes indicate overall equivalent widths of 5 to 10 A at
rest wavelengths. Two of the QSOs are in a local environment of faint galaxies
of similar magnitude to the hosts, and three have nearby galaxies with excess
narrow-band flux, which would be [O II] if they are at the QSO redshift.


title:
Improving the Angular Resolution of EGRET and New Limits on
  Supersymmetric Dark Matter Near the Galactic Center

abstract:
  Using the EGRET data and an improved point source analysis, including an
energy dependent point spread function and an unbinned maximum likelihood
technique, we have been able to place considerably lower limits on the gamma
ray flux from the galactic center region. We also test this method on known
sources, the Crab and Vela pulsars. In both cases, we find that our method
improves the angular precision of EGRET data over the 3EG catalog.
  This new limit on gamma rays from the galactic center can be used to test
models of annihilating supersymmetric dark matter and galactic halo profiles.
We find that the present EGRET data can limit many supersymmetric models if the
density of the galactic dark matter halo is cuspy or spiked toward the galactic
center. We also discuss the ability of GLAST to test these models.


title:
Current and future supernova constraints on decaying $\Lambda$
  cosmologies

abstract:
  We investigate observational constraints from present and future supernova
data on a large class of decaying vacuum cosmologies. In such scenarios the
present value of the vacuum energy density is quantified by a positive $\beta$
parameter smaller than unity. By assuming a Gaussian prior on the matter
density parameter ($\Omega_{\rm{m}} = 0.35 \pm 0.07$) we find $\Omega_{\rm{m}}
= 0.34^{+0.14}_{-0.12}$ and $\beta = 0.62^{+0.12}_{-0.24}$ (95% c.l.) as the
best fit values for the present data. We show that, while the current data
cannot provide restrictive constraints on the $\Omega_{\rm{m}} - \beta$ plane,
the future SNe data will limit considerably the allowed space of parameter. A
brief discussion about the equivalence between dynamical-$\Lambda$ scenarios
and scalar field cosmologies is also included.


title:
The Thermodynamical Arrow of Time: Reinterpreting the Boltzmann-Schuetz
  Argument

abstract:
  The recent surge of interest in the origin of the temporal asymmetry of
thermodynamical systems (including the accessible part of the universe itself)
put forward two possible explanatory approaches to this age-old problem. Hereby
we show that there is a third possible alternative, based on the generalization
of the classical ("Boltzmann-Schuetz") anthropic fluctuation picture of the
origin of the perceived entropy gradient. This alternative (which we dub the
Acausal-Anthropic approach) is based on accepting Boltzmann's statistical
measure at its face value, and accomodating it within the quantum cosmological
concept of the multiverse. We argue that conventional objections raised against
the Boltzmann-Schuetz view are less forceful and serious than it is usually
assumed. A fortiori, they are incapable of rendering the generalized theory
untenable. On the contrary, this analysis highlights some of the other
advantages of the multiverse approach to the thermodynamical arrow of time.


title: A layered edge-on circumstellar disk around HK Tau B

abstract:
  We present the first high angular resolution 1.4mm and 2.7mm continuum maps
of the T Tauri binary system HK Tau obtained with the Plateau de Bure
Interferometer. The contributions of both components are well disentangled at
1.4mm and the star previously known to host an edge-on circumstellar disk, HK
Tau B, is elongated along the disk's major axis. The optically bright primary
dominates the thermal emission from the system at both wavelengths, confirming
that it also has its own circumstellar disk. Its non-detection in scattered
light images indicates that the two disks in this binary system are not
parallel. Our data further indicate that the circumprimary disk is probably
significantly smaller than the circumsecondary disk.
  We model the millimeter thermal emission from the circumstellar disk
surrounding HK Tau B. We show that the disk mass derived from scattered light
images cannot reproduce the 1.4mm emission using opacities of the same
population of submicron dust grains. However, grain growth alone cannot match
all the observed properties of this disk. We propose that this disk contains
three separate layers: two thin outer surfaces which contain dust grains that
are very similar to those of the ISM, and a disk interior which is relatively
massive and/or has experienced limited grain growth with the largest grains
significantly smaller than 1mm. Such a structure could naturally result from
dust settling in a protoplanetary disk.


title: Are there cosmological evolution trends on Gamma-Ray Burst features?

abstract:
  The variability of gamma-ray burst (GRB) is thought to be correlated with its
absolute peak luminosity, and this relation had been used to derive an estimate
of the redshifts of GRBs. Recently Amati et al. presented the results of
spectral and energetic properties of several GRBs with known redshifts. Here we
analyse the properties of two group GRBs, one group with known redshift from
afterglow observation, and another group with redshift derived from the
luminosity - variability relation. We study the redshift dependence of various
GRBs features in their cosmological rest frames, including the burst duration,
the isotropic luminosity and radiated energy, and the peak energy $E_p$ of $\nu
F_\nu$ spectra. We find that, for these two group GRBs, their properties are
all redshift dependent, i.e. their intrinsic duration, luminosity, radiated
energy and peak energy $E_p$, are all correlated with the redshift, which means
that there are cosmological evolution effects on gamma-ray bursts features, and
this can provide an interesting clue to the nature of GRBs. If this is true,
then the results also imply that the redshift derived from the luminosity -
variability relation may be reliable.


title: GRB afterglow light curves from uniform and non-uniform jets

abstract:
  Here we calculate the GRB afterglow light curves from a relativistic jet as
seen by observers at a wide range of viewing angles from the jet axis, and the
jet is uniform or non-uniform. We find that, for uniform jet the afterglow
light curves for different viewing angles are somewhat different: in general,
there are two breaks in the light curve, corresponding to the time $\gamma\sim
(\theta_j-\theta_v)^{-1}$ and $\gamma\sim (\theta_j+\theta_v)^{-1}$
respectively. However, for non-uniform jet, the things become more complicated.
For the case $\theta_v=0$, we can obtain the analytical results, for
$k<8/(p+4)$ there should be two breaks in the light curve correspond to
$\gamma\sim\theta_c^{-1}$ and $\gamma\sim\theta_j^{-1}$ respectively, while for
$k>8/(p+4)$ there should be only one break corresponds to
$\gamma\sim\theta_c^{-1}$, and this provides a possible explanation for some
rapidly fading afterglows whose light curves have no breaks since the time at
which $\gamma\sim\theta_c^{-1}$ is much earlier than our first observation
time. For the case $\theta_v\neq 0$, our numerical results show that, the
afterglow light curves are strongly affected by the values of $\theta_v$,
$\theta_c$ and $k$. If the values of $\theta_v/\theta_c$ and $k$ are larger,
there will be a prominent flattening in the afterglow light curve, which is
quite different from the uniform jet, and after the flattening a very sharp
break will be occurred at the time $\gamma\sim (\theta_v + \theta_c)^{-1}.


title:
Linearized perturbation on stationary inflow solutions in an inviscid
  and thin accretion disc

abstract:
  The influence of a linearized perturbation on stationary inflow solutions in
an inviscid and thin accretion disc, has been studied here, and it has been
argued, that a perturbative technique would indicate that all possible classes
of inflow solutions would be stable. The choice of the driving potential,
Newtonian or pseudo-Newtonian, would not particularly affect the arguments
which establish the stability of solutions. It has then been surmised that in
the matter of the selection of a particular solution, adoption of a
non-perturbative technique, based on a more physical criterion, as in the case
of the selection of the transonic solution in spherically symmetric accretion,
would give a more conclusive indication about the choice of a particular branch
of the flow.


title:
Gas Dynamics in the Milky Way: Second Pattern Speed and Large-Scale
  Morphology

abstract:
  We present new gas flow models for the Milky Way inside the solar circle. To
this end we use SPH simulations in gravitational potentials determined from the
NIR luminosity distribution (including spiral arms) which are based on the
COBE/DIRBE maps. Gas flows in models which include massive spiral arms clearly
match the observed 12CO lvplot better than if the potential does not include
spiral structure. Besides single pattern speed models we investigate models
with separate pattern speeds for the bar and spiral arms. The most important
difference is that in the latter case the gas spiral arms go through the bar
corotation region, keeping the gas aligned with the arms there. In the (l,v)
plot this results in characteristic regions which appear to be nearly void of
gas.In single pattern speed models these regions are filled with gas because
the spiral arms dissolve in the bar corotation region. Comparing with the 12CO
data we find evidence for separate pattern speeds in the Milky Way.From a
series of models the preferred range for the bar pattern speed is Om_p=60\pm5
/Gyr, corresponding to corotation at 3.4\pm0.3kpc. The spiral pattern speed is
less well constrained, but our preferred value is Om_sp\approx 20 /Gyr. A
further series of gas models is computed for different bar angles, using
separately determined luminosity models and gravitational potentials in each
case. We find acceptable gas models for 20<=\phibar<=25. The model with
(\phibar=20, Om_p=60 /Gyr, Om_sp=20 /Gyr) gives an excellent fit to the spiral
arm ridges in the observed (l,v) plot.


title:
Estimates of Cosmological Parameters Using the CMB Angular Power
  Spectrum of ACBAR

abstract:
  We report an investigation of cosmological parameters based on the
measurements of anisotropy in the cosmic microwave background radiation (CMB)
made by ACBAR. We use the ACBAR data in concert with other recent CMB
measurements to derive Bayesian estimates of parameters in inflation-motivated
adiabatic cold dark matter models. We apply a series of additional cosmological
constraints on the shape and amplitude of the density power spectrum, the
Hubble parameter and from supernovae to further refine our parameter estimates.
Previous estimates of parameters are confirmed, with sensitive measurements of
the power spectrum now ranging from \ell \sim 3 to 2800. Comparing individual
best model fits, we find that the addition of \Omega_\Lambda as a parameter
dramatically improves the fits. We also use the high-\ell data of ACBAR, along
with similar data from CBI and BIMA, to investigate potential secondary
anisotropies from the Sunyaev-Zeldovich effect. We show that the results from
the three experiments are consistent under this interpretation, and use the
data, combined and individually, to estimate \sigma_8 from the
Sunyaev-Zeldovich component.


title: Coupled quintessence and the coincidence problem

abstract:
  We consider a model of interacting cosmological constant/quintessence, where
dark matter and dark energy behave as, respectively, two coexisting phases of a
fluid, a thermally excited Bose component and a condensate, respectively. In a
simple phenomenological model for the dark components interaction we find that
their energy density evolution is strongly coupled during the universe
evolution. This feature provides a possible way out for the coincidence problem
affecting many quintessence models.


title:
Stability of an Ultra-Relativistic Blast Wave in an External Medium with
  a Steep Power-Law Density Profile

abstract:
  We examine the stability of self-similar solutions for an accelerating
relativistic blast wave which is generated by a point explosion in an external
medium with a steep radial density profile of a power-law index > 4.134. These
accelerating solutions apply, for example, to the breakout of a gamma-ray burst
outflow from the boundary of a massive star, as assumed in the popular
collapsar model. We show that short wavelength perturbations may grow but only
by a modest factor <~ 10.


title: The Global, Local and Cluster Galaxy Luminosity Function

abstract:
  We review selected measurements of the galaxy luminosity function including
the global field, the local group, the local sphere, nearby clusters (Virgo,
Coma and Fornax) and clusters in general. We conclude that the overall cluster
luminosity function is consistent with the global luminosity function over the
magnitude range in common (-22 < M_B -5logh_0.68 < -17). We find that only in
the core regions of clusters (r < 300 kpc) does the overall form of the
luminosity function show significant variation. However when the luminosity
function is subdivided by spectral type some further variations are seen. We
argue that these results imply: substantial late infall, efficient
star-formation suppression, and the confinement of mass-changing evolutionary
processes to the core regions only.


title:
Structure and mass distribution of spiral galaxies at intermediate
  redshifts

abstract:
  Using the HST archive WFPC2 observations and rotation curves measeured by
Vogt et al. (1996), we constructed self-consistent light and mass distribution
models for three disk galaxies at redshifts z = 0.15, 0.90 and 0.99. The models
consist of three components: the bulge, the disk and the dark matter. Spatial
density distribution parameters for the components were calculated. After
applying k-corrections, mass-to-light ratios for galactic disks within the
maximum disk assumption are M/L_B = 4.4, 1.2 and 1.2, respectively.
Corresponding central densities of dark matter halos within a truncated
isothermal model are 0.0092, 0.028 and 0.015 in units M_sol/pc^3. The light
distribution of galaxies in outer parts is steeper than a simple exponential
disk.


title: Metallicity distributions of globular cluster systems in galaxies

abstract:
  We collected a sample of 100 galaxies for which different observers have
determined colour indices of globular cluster candidates. The sample includes
representatives of galaxies of various morphological types and different
luminosities. Colour indices (in most cases (V-I), but also (B-I) and (C-T1))
were transformed into metallicities [Fe/H] according to a relation by
Kissler-Patig (1998). These data were analysed with the KMM software in order
to estimate similarity of the distribution with uni- or bimodal Gaussian
distribution. We found that 45 of 100 systems have bimodal metallicity
distributions. Mean metallicity of the metal-poor component for these galaxies
is <[Fe/H]> = -1.40\pm 0.02, of the metal-rich component <[Fe/H]> = -0.69 \pm
0.03. Dispersions of the distributions are 0.15 and 0.18, respectively.
Distribution of unimodal metallicities is rather wide. These data will be
analysed in a subsequent paper in order to find correlations with parameters of
galaxies and galactic environment.


title: 2-Dust : a Dust Radiative Transfer Code for an Axisymmetric System

abstract:
  We have developed a general purpose dust radiative transfer code for an
axisymmetric system, 2-Dust, motivated by the recent increasing availability of
high-resolution images of circumstellar dust shells at various wavelengths.
This code solves the equation of radiative transfer following the principle of
long characteristic in a 2-D polar grid while considering a 3-D radiation field
at each grid point. A solution is sought through an iterative scheme in which
self-consistency of the solution is achieved by requiring a global luminosity
constancy throughout the shell. The dust opacities are calculated through Mie
theory from the given size distribution and optical properties of the dust
grains. The main focus of the code is to obtain insights on (1) the global
energetics of dust grains in the shell (2) the 2-D projected morphologies that
are strongly dependent on the mixed effects of the axisymmetric dust
distribution and inclination angle of the shell. Here, test models are
presented with discussion of the results. The code can be supplied with a
user-defined density distribution function, and thus, is applicable to a
variety of dusty astronomical objects possessing the axisymmetric geometry.


title: Spectral Slope Variability of BL Lac Objects in the Optical Band

abstract:
  Light curves of eight BL Lac objects in the BVRI bands have been analyzed.
All of the objects tend to be bluer when brighter. However spectral slope
changes differ quantitatively from those of a sample of QSOs analyzed in a
previous paper (Trevese & Vagnetti 2002) and appear consistent with a different
nature of the optical continuum. A simple model representing the variability of
a synchrotron component can explain the spectral changes. Constraints on a
possible thermal accretion disk component contributing to the optical
luminosity are discussed.


title:
Active star formation in N11B Nebula in the Large Magellanic Cloud: a
  sequential star formation scenario confirmed

abstract:
  The second largest HII region in the Large Magellanic Cloud, N11B has been
surveyed in the near IR.We present JHKs images of the N11B nebula.These images
are combined with CO(1-0) emission line data and with archival NTT and
HST/WFPC2 optical images to address the star formation activity of the
region.IR photometry of all the IR sources detected is given.We confirm that a
second generation of stars is currently forming in the N11B region. Our IR
images show the presence of several bright IR sources which appear located
towards the molecular cloud as seen from the CO emission in the area.Several of
these sources show IR colours with YSO characteristics and they are prime
candidates to be intermediate-mass Herbig Ae/Be stars.For the first time an
extragalactic methanol maser is directly associated with IR sources embedded in
a molecular core.Two IR sources are found at 2"(0.5 pc) of the methanol maser
reported position.Additionally, we present the association of the N11A compact
HII region to the molecular gas where we find that the young massive O stars
have eroded a cavity in the parental molecular cloud, typical of a champagne
flow. The N11 region turns out to be a very good laboratory for studying the
interaction of winds, UV radiation and molecular gas.Several photodissociation
regions are found.


title:
UV--NIR Restframe Luminosity Functions of the Galaxy Cluster EIS0048 at
  z~0.64

abstract:
  We derive the galaxy luminosity functions in V, R, I, and K bands of the
cluster EIS 0048 at z~0.64 from data taken at the ESO Very Large Telescope. The
data span the restframe wavelength range from UV, which is sensitive to even
low rates of star formation, to the NIR, which maps the bulk of the stellar
mass. By comparing our data and previous results with pure luminosity evolution
models, we conclude that bright (M<= M^*+1) cluster galaxies are already
assembled at z~1 and that star formation is almost completed at z~1.5.


title: Light Curves of Type Ia Supernovae as a Probe for an Explosion Model

abstract:
  We present theoretical UBVI- and bolometric light curves of SNe Ia for
several explosion models, computed with our multi-group radiation hydro code.
We employ our new corrected treatment for line opacity in the expanding medium.
The results are compared with observed light curves. Our goal is to find the
most viable thermonuclear SN model that gives good fits not only to a typical
SN Ia light curves, but also to X-ray observations of young SN Ia remnants. It
appears that classical 1D SN Ia models, such as deflagration model W7 and
delayed detonation one DD4, fit the light curves not so good as a new 3D
deflagration model by Reinecke et al. (which is averaged over angles for our LC
modelling). This model seems good also in reproducing X-ray observations of
Tycho SNR. We believe that the main feature of this model which allows us to
get correct radiation during the first month, as well as after a few hundred
years, when an SNR forms, is strong mixing that pushes material enriched in
iron and nickel to the outermost layers of SN ejecta.


title:
Evolution of the X-ray spectrum in the flare model of Active Galactic
  Nuclei

abstract:
  Nayakshin & Kazanas (2002) have considered the time-dependent illumination of
an accretion disc in Active Galactic Nuclei, in the lamppost model. We extend
their study to the flare model, which postulates the release of a large X-ray
flux above a small region of the accretion disc. A fundamental difference with
the lamppost model is that the region of the disc below the flare is not
illuminated before the onset of the flare.
  A few test models show that the spectrum which follows immediately the
increase in continuum flux should display the characteristics of a highly
illuminated but dense gas, i.e. very intense X-ray emission lines and
ionization edges in the soft X-ray range. The behaviour of the iron line is
different in the case of a "moderate" and a ``strong'' flare: for a moderate
flare, the spectrum displays a neutral component of the Fe K$\alpha$ line at
6.4 keV, gradually leading to more highly ionized lines. For a strong flare,
the lines are already emitted by FeXXV (around 6.7 keV) after the onset, and
have an equivalent width of several hundreds of eV. We find that the observed
correlations between $R$, $\Gamma$, and the X-ray flux, are well accounted by a
combination of flares having not achieved pressure equilibrium, strongly
suggesting that the observed spectrum is dominated by regions in non-pressure
equilibrium, typical of the onset of the flares. Finally a flare being confined
to a small region of the disc, the spectral lines should be narrow (except for
a weak Compton broadening), Doppler shifted, and moving.


title: Detection of Giant Pulses from the Pulsar PSR B1112+50

abstract:
  We detected giant pulses from the pulsar PSR B1112+50. A pulse with an
intensity that is a factor of 30 or more higher than the intensity of the
average pulse is encountered approximately once in 150 observed pulses. The
peak .ux density of the strongest pulse is about 180 Jy. This value is a factor
of 80 higher than the peak .ux density of the average pulse. The giant pulses
are narrower than the average prfile approximately by a factor of 5 and they
cluster about the center of the average profile.


title: Type Ia Supernova models: latest developments

abstract:
  Supernovae of type Ia (SNe Ia) are very important for cosmography. To exclude
systematic effects in linking the observed light of distant SNe Ia to the
parameters of cosmological models, one has to understand the nature of
supernova outbursts and to build accurate algorithms for predicting their
emission. We review the recent progress of modeling the propagation of nuclear
flame subject to numerous hydrodynamic instabilities inherent to the flame
front. The Rayleigh-Taylor (RT) instability is the main process governing the
corrugation of the front on the largest scales, while on the smallest scales
the front propagation is controlled by the Landau-Darrieus instability. Based
on several hydrodynamic explosion models, we predict the broad-band UBVI and
bolometric light curves of SNe Ia, using our 1D-hydro code which models
multi-group time-dependent non-equilibrium radiative transfer inside SN ejecta.
We employ our new corrected treatment for line opacity in the expanding medium,
which is important especially in UV and IR bands. The results are compared with
the observed light curves. Especially interesting is a recent 3D-deflagration
model computed at MPA, Garching, by M. Reinecke et al.


title:
The Andromeda Project. I. Deep HST-WFPC2 V,I photometry of 16 fields
  toward the disk and the halo of the M31 galaxy. Probing the stellar content
  and metallicity distribution

abstract:
  HST-WFPC2 F555W and F814W photometry were obtained for 16 fields of the
luminous nearby spiral galaxy M31, sampling the stellar content of the disk and
the halo at different distances from the center, from ~ 20 to ~ 150 arcmin
(i.e. ~ 4.5 to 35 kpc), down to limiting V and I magnitudes of ~ 27. The
Color-Magnitude diagrams (CMD) show the presence of complex stellar
populations, including an intermediate age/young population and older
populations with a wide range of metallicity. Those fields superposed on the
disk of M31 generally show a blue plume of stars which we identify with main
sequence members. Accordingly, the star formation rate over the last 0.5 Gyr
appears to have varied dramatically with location in the disk. All the CMDs
show a prominent Red Giant Branch (RGB) with a descending tip in the V band,
characteristic of metallicity higher than 1/10 Solar. A red clump is detected
in all of the fields, and a weak blue horizontal branch is frequently present.
The metallicity distributions (MDs), obtained by comparison of the RGB stars
with globular cluster templates, are basically similar in all the sampled
fields: they all show a long, albeit scantly populated metal-poor tail and a
main component at [Fe/H] ~ -0.6. However, some differences also exist, e.g. in
some fields a very metal-rich ([Fe/H] >= -0.2) component is present. Whereas
the fraction of metal-poor stars seems to be approximately constant in all
fields, the fraction of very-metal-rich stars varies with position and seems to
be more prominent in those fields superposed on the disk and/or with the
presence of streams or substructures. This might indicate and possibly trace
interaction effects with some companion, e.g. M32.


title:
Globular cluster candidates within the Fornax Cluster: intracluster
  globulars?

abstract:
  We present the results of a search for globular clusters in the surroundings
of 15 low surface brightness dwarf galaxies belonging to the Fornax Cluster,
which was carried out on CCD images obtained with the C and T1 filters of the
Washington photometric system. The globular cluster candidates show an extended
and probably bimodal (C-T1) color distribution, which is inconsistent with the
presence of a single population of metal-poor clusters detected in several
dwarf galaxies. The surface number density of these candidates shows no
concentration towards the respective dwarf galaxies, in whose outskirts they
have been identified. On the contrary, if we split the candidates in two groups
according to their projected distances to the center of the Fornax Cluster,
those located closer to the center show a higher projected density than those
located farther from it. These results suggest that the potential globular
clusters might not be bound to the dwarf galaxies. Alternatively, these
globulars could form part of the very peripheral regions of NGC 1399 (the
central galaxy of the Fornax Cluster) or even belong to the intracluster
medium.


title: The clustering of ultra-high energy cosmic rays and their sources

abstract:
  The sky distribution of cosmic rays with energies above the 'GZK cutoff'
holds important clues to their origin. The AGASA data, although consistent with
isotropy, shows evidence for small-angle clustering, and it has been argued
that such clusters are aligned with BL Lacertae objects, implicating these as
sources. It has also been suggested that clusters can arise if the cosmic rays
come from the decays of very massive relic particles in the Galactic halo, due
to the expected clumping of cold dark matter. We examine these claims and show
that both are in fact not justified.


title:
Cosmic star formation history associated with QSO activity: an approach
  using the black hole to bulge mass correlation

abstract:
  The tight correlation between the masses of central black holes and their
host spheroids in nearby galaxies and active galactic nuclei suggests that
black hole growth is closely related to their spheroid formation. Based on our
previous work regarding such a joint evolutionary scheme and the consequential
black hole to bulge mass correlation, we use the X-ray luminosity function of
AGN and the cosmological evolution rate which are from ROSAT X-ray surveys to
estimate the cosmic star formation history associated with the black hole
growth. By the Basic assumption that the major black hole growth occurs during
the luminous AGN phase, the luminosity function of AGNs as a function of
redshift traces not only the accretion history of the black holes but also the
cosmic star formation history of the spheroids.
  Although the space density of the especially luminous QSOs is very low, we
show that the total amount of star formation associated with the massive black
hole growth is almost the same as that of Lyman Break Galaxies detected by the
current optical deep surveys. We thus argue that the optical deep surveys may
miss about half of the net star formation in our Universe, This is probably due
to in part significant dust extinction as well as the small field of view of
previous optical surveys which cannot sample such rare events with relatively
short time scale. However, the far infrared emission from the dust heated by
star fomation on-going during the black hole growth could sufficiently account
for the observed SCUBA number counts, and would be the probable dominating
energy source of the SUBA population.


title: Gravitational diffusion in the intra-cluster medium

abstract:
  We revisit the process of gravitational sedimentation of helium and heavy
elements in the intra-cluster medium. We find that helium applies an inward
drag force on heavy elements, boosting their sedimentation speed to nearly half
its own. This speed is almost independent of the mass and the electric charge
of heavy elements. In the absence of small-scale magnetic fields, helium
sedimentation can increase the He/H abundance ratio in the cores of hot
clusters by three orders of magnitude. It also steepens the baryonic density
profile yielding a higher X-ray luminosity, which offers an explanation of the
observed luminosity-temperature relation. If the primordial He/H ratio is
assumed, then the gas density inferred from the observed X-ray emissivity might
be underestimated by 30% in the cores of clusters and overestimated by 7% in
the outer regions. The dark matter density on the other hand might be
overestimated by a factor of 8/3 in the cores and underestimated by 18% in
outer regions.


title: High Energy Neutrinos from Gamma-Ray Bursts with Precursor Supernovae

abstract:
  The high energy neutrino signature from proton-proton and photo-meson
interactions in a supernova remnant shell ejected prior to a gamma-ray burst
provides a test for the precursor supernova, or supranova, model of gamma-ray
bursts. Protons in the supernova remnant shell, and photons entrapped from a
supernova explosion or a pulsar wind from a fast-rotating neutron star remnant
provide ample targets for protons escaping the internal shocks of the gamma-ray
burst to interact and produce high energy neutrinos. We calculate the expected
neutrino fluxes, which can be detected by current and future experiments.


title:
Evolutionary SED diagnostics of starburst galaxies: signature of
  bimodality

abstract:
  We construct an evolutionary spectral energy distribution (SED) model of a
starburst region, from the ultraviolet to submillimetre wavelengths. This model
allows us to derive the star formation rate, optical depth by dust and apparent
effective radius of starburst regions at various wavelengths; as a result, the
intrinsic surface brightness of starburst regions can be derived. Using this
SED model, we analyse 16 UV-selected starburst galaxies and 10 ultraluminous
infrared galaxies. The derived star formation rates and optical depths are
compared with emission line measurements and found to be consistent. The
derived apparent effective radii are also consistent with observations. From
the SED analysis, we find a bimodal property of the star formation rate with
the optical depth and the compactness of stellar distributions. While mild
starbursts have a limiting intrinsic surface brightness L(bol) x r_e^{-2} ~
10^{12} Lsun kpc^{-2}, intense starbursts tend to be more heavily obscured and
concentrated within a characteristic scale of r_e ~ 0.3 kpc. We suggest that
the mild starbursts can be triggered by a self-gravitating disc instability in
which feedback is effective in the shallow gravitational potential. On the
other hand, the intense starbursts can be induced via an external dynamical
perturbation like galaxy merging, in which feedback is less effective due to
the deep gravitational potential attained by the large gas concentration within
the central starburst region.


title: The Kinematic State of the Local Volume

abstract:
  The kinematics of galaxies with 10 megaparsecs (10 Mpc) of the Milky Way is
investigated using published distances and radial velocities. With respect to
the average Hubble flow (isotropic or simple anisotropic), there is NO
systematic relation between peculiar velocity dispersion and absolute magnitude
over a range of 10 magnitudes; neither is there any apparent variation with
galaxy type or between field and cluster members. There are several possible
explanations for the lack of variation, though all have difficulties: either
there is no relationship between light and mass on these scales, or the
peculiar velocities are not produced by gravitational interaction, or the
background dynamical picture is wrong in some systematic way. The extremely
cold local flow of 40-60 km/s dispersion reported by some authors is shown to
be an artifact of sparse data, a velocity dispersion of over 100 km/s being
closer to the actual value. Galaxies with a high (positive) radial velocity
have been selected against in studies of this volume, biasing numerical
results.


title: Polarized Gravitational Waves from Gamma-Ray Bursts

abstract:
  Significant gravitational wave emission is expected from gamma-ray bursts
arising from compact stellar mergers, and possibly also from bursts associated
with fast-rotating massive stellar core collapses. These models have in common
a high angular rotation rate, and observations provide evidence for jet
collimation of the photon emission, with properties depending on the polar
angle, which may also be of relevance for X-ray flashes. Here we consider the
gravitational wave emission and its polarization as a function of angle which
is expected from such sources. We discuss possible correlations between the
burst photon luminosity, or the delay between gravitational wave bursts and
X-ray flashes, and the polarization degree of the gravitational waves.


title:
Constraining the Structure of GRB Jets Through the Afterglow Light
  Curves

abstract:
  We investigate the effect that the structure of GRB jets has on the afterglow
light curves for observers located at different viewing angles, $\theta_{obs}$,
from the jet symmetry axis. The largest uncertainty in the jet dynamics is the
degree of lateral energy transfer. Thus, we use two simple models, that make
opposite and extreme assumptions for this point, and calculate the light curves
for an external density that is either homogeneous, or decreases as the square
of the distance from the source. The Lorentz factor and kinetic energy per unit
solid angle are initially taken to be power laws of the angle from the jet
axis. We perform a qualitative comparison between the resulting light curves
and afterglow observations. This constrains the jet structure, and poses
problems for a `universal' jet model, where all GRB jets are assumed to be
intrinsically identical, and differ only by our viewing angle, $\theta_{obs}$.


title: Neutron Stars in Supernova Remnants and Beyond

abstract:
  We discuss a concept of off-centred cavity supernova explosion as applied to
neutron star/supernova remnant associations and show how this concept could be
used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9)
and dismembering the Swan (Cygnus Loop), as well as to search for a stellar
remnant associated with the supernova remnant RCW86.


title:
On the Galactic Disk Metallicity Distribution from Open Clusters I. New
  Catalogues and Abundance Gradient

abstract:
  In this paper we have compiled two new open cluster catalogues. In the first
one, there are 119 objects with ages, distances and metallicities available,
while in the second one, 144 objects have both absolute proper motion and
radial velocity data, of which 45 clusters also with metallicity data
available. Taking advantages of the large number of objects included in our
sample, we present an iron radial gradient of about -0.063$\pm$0.008 dex/kpc
from the first sample. By dividing clusters into age groups, we show that iron
gradient was steeper in the past, which is consistent with the recent result
from Galactic planetary nebulae data, and also consistent with the inside-out
galactic disk formation scenarios. Based on the cluster sample, we also
discussed the metallicity distribution, cluster kinematics and space
distribution. A disk age-metallicity relation could be implied from those
properties, although we could not give conclusive result from the age
metallicity diagram based on the current sample. More observations are needed
for metal poor clusters.


title: Optical and Infrared Photometry of the Unusual Type Ia Supernova 2000cx

abstract:
  We present optical and infrared photometry of the unusual Type Ia supernova
2000cx. With the data of Li et al. (2001) and Jha (2002), this comprises the
largest dataset ever assembled for a Type Ia SN, more than 600 points in
UBVRIJHK. We confirm the finding of Li et al. regarding the unusually blue B-V
colors as SN 2000cx entered the nebular phase. Its I-band secondary hump was
extremely weak given its B-band decline rate. The V minus near infrared colors
likewise do not match loci based on other slowly declining Type Ia SNe, though
V-K is the least ``abnormal''. In several ways SN 2000cx resembles other slow
decliners, given its B-band decline rate (Delta m_15(B) = 0.93), the appearance
of Fe III lines and weakness of Si II in its pre-maximum spectrum, the V-K
colors and post-maximum V-H colors. If the distance modulus derived from
Surface Brightness Fluctuations of the host galaxy is correct, we find that the
rate of light increase prior to maximum, the characteristics of the bolometric
light curve, and the implied absolute magnitude at maximum are all consistent
with a sub-luminous object with Delta m_15(B) ~ 1.6-1.7 having a higher than
normal kinetic energy.


title: The Identification of Infrared Synchrotron Radiation from Cassiopeia A

abstract:
  We report the discovery of polarized flux at 2.2 micron from the bright shell
of the approximately 320 year old supernova remnant Cas A. The fractional
polarizations are comparable at 6 cm and 2.2 micron, and the polarization
angles are similar, demonstrating that synchrotron radiation from the same
relativistic plasma is being observed at these widely separated wavebands. The
relativistic electrons radiating at 2.2 micron have an energy of ~ 150 GeV,
(gamma ~ 3e5), assuming an ~500 microGauss magnetic field. The total intensity
at 2.2 micron lies close to the power law extrapolation from radio frequencies,
showing that relativistic particle acceleration is likely an ongoing process;
the infrared emitting electrons were accelerated no longer than ~80 years ago.
There is a small but significant concave curvature to the spectrum, as expected
if the accelerating shocks have been modified by the back pressure of the
cosmic rays; given calibration uncertainties, this conclusion must be
considered tentative at present. The 2.2 micron polarization angles and the
emission-line filaments observed by HST are both offset from the local radial
direction by 10 - 20 degrees, providing evidence that the magnetic fields in
Cas A are generated by Rayleigh-Taylor instabilities in the decelerating
ejecta.


title: Origin of the metallicity distribution of the NGC 5128 stellar halo

abstract:
  Recent {\it Hubble Space Telescope} photometry in the nearby elliptical
galaxy NGC 5128 shows that its halo field star population is dominated by
moderately metal-rich stars, with a peak at [m/H] $\simeq$ -0.4 and with a very
small fraction of metal-poor ([m/H] $<$ -1.0) stars. In order to investigate
the physical processes which may have produced this metallicity distribution
function (MDF), we consider a model in which NGC 5128 is formed by merging of
two major spiral galaxies. We find that the halo of an elliptical formed this
way is predominantly populated by moderately metal-rich stars with [m/H] $\sim$
-0.4 which were initially within the outer parts of the two merging discs and
were tidally stripped during the merger. To match the NGC 5128 data, we find
that the progenitor spiral discs must have rather steep metallicity gradients
similar to the one defined by the Milky Way open clusters, as well as sparse
metal-poor haloes (5% or less of the disc mass). Very few stars from the
central bulges of the spiral galaxies end up in the halo, so the results are
not sensitive to the relative sizes (bulge-to-disc ratios) or metallicities of
the initial bulges. Finally, we discuss the effects on the globular cluster
system (GCS). The emergent elliptical will end up with metal-poor halo clusters
from the original spiral haloes, but with moderately metal-rich halo stars from
the progenitor discs, thus creating a mean offset between the MDFs of the halo
stars and the GCS.


title:
Iron is not Depleted in High-Ionization Nuclear Emission-Line Regions of
  Active Galactic Nuclei

abstract:
  In order to examine whether or not high-ionization nuclear emission-line
regions (HINERs) in narrow-line regions of active galactic nuclei are dusty, we
focus on two high-ionization forbidden emission lines, [Fe VII]6087 and [Ne
V]3426. We perform photoionization model calculations to investigate possible
dependences of the flux ratio of [Fe VII]6087/[Ne V]3426 on various gas
properties, in order to investigate how useful this flux ratio to explore the
dust abundances in HINERs. Based on our photoionization model calculations, we
show that the observed range of the flux ratio of [Fe VII]6087/[Ne V]3426 is
consistent with the dust-free models while that is hard to be explained by the
dusty models. This suggests that iron is not depleted at HINERs, which implies
that the HINERs are not dusty. This results is consistent with the idea that
the HINERs are located closer than the dust-sublimation radius (i.e., inner
radius of dusty tori) and thus can be hidden by dusty tori when seen from a
edge-on view toward the tori, which has been also suggested by the AGN-type
dependence of the visibility of high-ionization emission lines.


title: Arp 194: Evidence of Tidal Stripping of Gas and Cross-Fueling

abstract:
  We present new imaging and spectroscopic observations of the interacting
system Arp 194 (= UGC 06945 = VV 126). The northern component (A194N) is a
distorted spiral or ring galaxy likely disrupted by a collision or close
encounter with a southern galaxy (A194S). There is evidence that a third galaxy
with similar recession velocity is projected on A194N but its role is likely
secondary. A194S is connected to A194N by a string of emission knots which
motivates our interpretation that the former was the intruder. Three of the
knots are easily discernible in B,R, and H-alpha images and are assumed to
trace the path of the intruder following the encounter, which we estimate
occurred a few 10^8 yr ago.
  Both A194S and N are experiencing strong bursts of star formation: the
H-alpha luminosity indicates a total star formation rate ~ 10 solar masses per
year. The lack of detectable J and K emission from the blobs, along with strong
H-alpha emission, indicates that an evolved stellar population is not likely to
be present. The brightest knot (closest to A194S) shows a star formation rate
of ~1.2 solar masses per year which, if sustained over a time ~ 7 10^7 yr,
could explain the spectral energy distribution. This suggests that the stripped
matter was originally predominantly gaseous. The brightest knot is detected as
a FIRST radio source and this is likely the signature of supernova remnants
related to enhanced star formation. Motions in the gas between the brightest
knot and A194S, traced by an emission line link of increasing radial velocity,
suggests infall toward the center of the intruder. Arp 194 is therefore one of
the few galaxies where evidence of ``cross-fueling'' is observed [LaTeX
removed].


title: Chaotic infaltion with a quadratic potential in all dimensions

abstract:
  We study chaotic inflation with a quadratic potential in all dimensions. The
spectral indices of scalar and tensor perturbations and also their running have
been calculated in all dimensions.


title:
On the formation of an eccentric disk via disruption of a bulge core
  near a massive black hole

abstract:
  We consider the possibility that an infalling bulge core or stellar cluster
could form an eccentric disk, following tidal disruption by a massive black
hole in the center of a galaxy. As a function of central black hole mass, we
constrain the core radii and central densities of cluster progenitors capable
of becoming nearly Keplerian disks which can support lopsided slow modes. We
find that progenitor stellar clusters with core radii less than a pc and
densities above a few times 10^5 Msol/pc^3 are likely eccentric disk
progenitors near a massive black hole of mass 10^7 to 10^8 Msol. Lower density
and larger progenitor cores are capable of causing eccentric stellar disks near
more massive black holes. Our constraints on the progenitor cores are
consistent with existing N-body simulations, which in one case has produced an
eccentric disk. For M31 and NGC 4486B, the estimated progenitor cluster cores
are dense and compact compared to Galactic globular clusters, however the cores
of nearby galaxies such as M33, M32 and M31 itself are in the right regime. If
galaxy mergers can create eccentric disks, then they would be a natural
consequence of hierarchical galaxy formation.


title: The Vegetation Red Edge Spectroscopic Feature as a Surface Biomarker

abstract:
  The search for Earth-like extrasolar planets is in part motivated by the
potential detection of spectroscopic biomarkers. Spectroscopic biomarkers are
spectral features that are either consistent with life, indicative of
habitability, or provide clues to a planet's habitability. Most attention so
far has been given to atmospheric biomarkers, gases such as O2, O3, H2O, CO,
and CH4. Here we discuss surface biomarkers. Surface biomarkers that have
large, distinct, abrupt changes in their spectra may be detectable in an
extrasolar planet's spectrum at wavelengths that penetrate to the planetary
surface. Earth has such a surface biomarker: the vegetation "red edge"
spectroscopic feature. Recent interest in Earth's surface biomarker has
motivated Earthshine observations of the spatially unresolved Earth and two
recent studies may have detected the vegetation red edge feature in Earth's
hemispherically integrated spectrum. A photometric time series in different
colors should help in detecting unusual surface features in extrasolar
Earth-like planets.


title: Characterizing Earth-like Planets with Terrestrial Planet Finder

abstract:
  For the first time in human history the possibility of detecting and studying
Earth-like planets is on the horizon. Terrestrial Planet Finder (TPF), with a
launch date in the 2015 timeframe, is being planned by NASA to find and
characterize planets in the habitable zones of nearby stars. The mission Darwin
from ESA has similar goals. The motivation for both of these space missions is
the detection and spectroscopic characterization of extrasolar terrestrial
planet atmospheres. Of special interest are atmospheric biomarkers--such as O2,
O3, H2O, CO and CH4--which are either indicative of life as we know it,
essential to life, or can provide clues to a planet's habitability. A mission
capable of measuring these spectral features would also obtain sufficient
signal-to-noise to characterize other terrestrial planet properties. For
example, physical characteristics such as temperature and planetary radius can
be constrained from low- resolution spectra. In addition, planet
characteristics such as weather, rotation rate, presence of large oceans or
surface ice, and existence of seasons could be derived from photometric
measurements of the planet's variability. We will review the potential to
characterize terrestrial planets beyond their spectral signatures. We will also
discuss the possibility to detect strong surface biomarkers--such as Earth's
vegetation red edge near 700 nm--that are different from any known atomic,
molecular, or mineralogical signature.


title: Cosmology from Large Scale Structure

abstract:
  We report on the linear matter power spectrum reconstructed from the Lyman
alpha forest, on baryonic wiggles in the galaxy power spectrum, and on how to
measure real space (as opposed to redshift space) power.


title: Towards the Unified Theory of Galactic Bar-Modes

abstract:
  The arguments in favor of the unified formation mechanism for both slow
(Lynden-Bell's) bars and common fast bars are given. This mechanism consists in
a certain instability that is akin to the well-known radial orbit instability;
it is caused by the mutual attraction and alignment of axes of precessing star
orbits (up to now, such a way of formation was considered only for slow bars).
  The general theory of the low-frequency modes of a disk consisting of
precessing orbits (at different angular velocities) is presented. The problem
of determining these modes is reduced to the integral equations of a rather
simple structure. The characteristic pattern speeds ($\Omega_p$) of the
low-frequency modes are of order of the mean orbit precession speeds
($\bar\Omega_{pr}$). The bar-modes also belong to this type of modes. The slow
bars have $\Omega_p \approx \bar\Omega_{pr}$; for the fast bars, $\Omega_p$ may
far exceed even the maximum precessing speed of disk orbits (however,
$\Omega_p$ remains to be of order of these precessing speeds). The possibility
of such an excess of $\Omega_p$ over $\Omega_{pr}^{\max}$ is connected with the
effect of ``repelling'' orbits that tend to move in the direction opposite to
that they are being pushed.
  The preliminary analysis of the orbit precession patterns for a number of
typical potentials is given. It is noted that the maximum radius of the
``attracting'' circular orbits ($r_c$) may be used as a reasonable estimate of
a bar length.


title: Optical Spectropolarimetry of the GRB 020813 Afterglow

abstract:
  The optical afterglow of gamma-ray burst 020813 was observed for 3 hours with
the LRIS spectropolarimeter at the Keck-I telescope, beginning 4.7 hours after
the burst was detected by HETE-2. The spectrum reveals numerous metal
absorption lines that we identify with two systems at z=1.223 and z=1.255. We
also detect an O II 3727 emission line at z=1.255 and we identify this galaxy
as the likely host of the GRB. After a correction for Galactic interstellar
polarization, the optical afterglow has a linear polarization of 1.8-2.4%
during 4.7-7.9 hours after the burst. A measurement of p = 0.80% +/- 0.16% on
the following night by Covino et al. demonstrates significant polarization
variability over the next 14 hours. The lack of strong variability in the
position angle of linear polarization indicates that the magnetic field in the
jet is likely to be globally ordered rather than composed of a number of
randomly oriented cells. Within the framework of afterglow models with
collimated flows, the relatively low observed polarization suggests that the
magnetic field components perpendicular and parallel to the shock front are
only different by about 20%.