title: The M-sigma Relation in Local Active Galaxies

abstract:
  We examine whether active galaxies obey the same relation between black hole
mass and stellar velocity dispersion as inactive systems, using the largest
published sample of velocity dispersions for active nuclei to date. The
combination of 56 original measurements with objects from the literature not
only increases the sample from the 15 considered previously to 88 objects, but
allows us to cover an unprecedented range in both stellar velocity dispersion
(30--268 km/s) and black hole mass (10^5-10^8.6 M_sun). In the M-sigma relation
of active galaxies we find a lower zeropoint than the best-fit relation of
Tremaine et al. (2002) for inactive galaxies, and an intrinsic scatter of 0.4
dex. There is also evidence for a flatter slope at low black hole masses. We
discuss potential contributors to the observed offsets, including variations in
the geometry of the broad-line region, evolution in the M-sigma relation, and
differential growth between black holes and galaxy bulges.


title: Measuring Stellar Velocity Dispersions in Active Galaxies

abstract:
  (ABRIDGED) We present stellar velocity dispersion (sigma*) measurements for a
significant sample of 40 broad-line (Type 1) active galaxies for use in testing
the well-known relation between black hole mass and stellar velocity
dispersion. The objects are selected to contain Ca II triplet, Mgb triplet, and
Ca H+K stellar absorption features in their optical spectra so that we may use
them to perform extensive tests of the systematic biases introduced by both
template mismatch and contamination from the active galactic nucleus (AGN). We
use the Ca II triplet as a benchmark to evaluate the utility of the other
spectral regions in the presence of AGN contamination. Broad Fe II emission,
extending from ~5050-5520 A, in combination with narrow coronal emission lines,
can seriously bias sigma* measurements from the Mgb region, highlighting the
need for extreme caution in its use. However, we argue that at luminosities
constituting a moderate fraction of the Eddington limit, when the Fe II lines
are both weak and smooth relative to the stellar lines, it is possible to
derive meaningful measurements with careful selection of the fitting region. In
particular, to avoid the contamination of coronal lines, we advocate the use of
the region 5250--5820 A, which is rich in Fe absorption features. We lay the
groundwork for an extensive comparison between black hole mass and bulge
velocity dispersion in active galaxies, as described in a companion paper by
Greene & Ho.


title: The Luminosity-Weighted or `Marked' Correlation Function

abstract:
  We present measurements of the redshift-space luminosity-weighted or `marked'
correlation function in the SDSS. These are compared with a model in which the
luminosity function and luminosity dependence of clustering are the same as
that observed, and in which the form of the luminosity-weighted correlation
function is entirely a consequence of the fact that massive halos populate
dense regions. We do this by using mock catalogs which are constrained to
reproduce the observed luminosity function and the luminosity dependence of
clustering, as well as by using the language of the redshift-space halo-model.
These analyses show that marked correlations may show a signal on large scales
even if there are no large-scale physical effects--the statistical correlation
between halos and their environment will produce a measureable signal. Our
model is in good agreement with the measurements, indicating that the halo mass
function in dense regions is top-heavy; the correlation between halo mass and
large scale environment is the primary driver for correlations between galaxy
properties and environment; and the luminosity of the central galaxy in a halo
is different from (in general, brighter than) that of the other objects in the
halo. Thus our measurement provides strong evidence for the accuracy of these
three standard assumptions of galaxy formation models. These assumptions also
form the basis of current halo-model based interpretations of galaxy
clustering.


title: Moving dark energy and the CMB dipole

abstract:
  We explore the possibility that the rest frames of CMB, matter and dark
energy differ one from another, i.e. they do not converge on very large scales.
In such a case, the usual interpretation of the CMB dipole as being due to the
relative motion of the observer with respect to the CMB rest frame is not
appropriate. Instead, we find that the measured dipole is due to the observer
motion relative to the cosmic center of mass rest frame. This means, in
particular, that even an observer at rest with respect to the CMB radiation
could measure a non-vanishing dipole anisotropy, provided dark energy is moving
with respect to the CMB. We also consider the consequences of moving dark
energy for the determination of cosmic bulk flows.


title:
The Mass Assembly History of Field Galaxies: Detection of an Evolving
  Mass Limit for Star Forming Galaxies

abstract:
  We characterize the mass-dependent evolution in a large sample of more than
8,000 galaxies using spectroscopic redshifts drawn from the DEEP2 Galaxy
Redshift Survey in the range 0.4 < z < 1.4 and stellar masses calculated from
K-band photometry obtained at Palomar Observatory. Using restframe (U-B) color
and [OII] equivalent widths, we distinguish star-forming from passive
populations in order to explore the nature of "downsizing''--a pattern in which
the sites of active star formation shift from high mass galaxies at early times
to lower mass systems at later epochs. Over the redshift range probed, we
identify a mass limit, M_Q, above which star formation appears to be quenched.
The physical mechanisms responsible for downsizing can thus be empirically
quantified by charting the evolution in this threshold mass. We find that M_Q
decreases with time by a factor of ~3 across the redshift range sampled
according with a redshift dependence of (1+z)^3.5. To further constrain
possible quenching mechanisms, we investigate how this downsizing signal
depends on local galaxy environment. For the majority of galaxies in regions
near the median density, there is no significant correlation between downsizing
and environment. However, a trend is observed in the comparison between more
extreme environments that are more than 3 times overdense or underdense
relative to the median. Here, we find that downsizing is accelerated in
overdense regions which host higher numbers of massive, early-type galaxies and
fewer late-types as compared to the underdense regions. Our results
significantly constrain recent suggestions for the origin of downsizing and
indicate that the process for quenching star formation must, primarily, be
internally driven. (Abridged)


title:
MAMBO 1.2 Millimeter observations of BzK-selected star-forming Galaxies
  at z~2

abstract:
  We present MAMBO 1.2 mm observations of five BzK-pre-selected vigorous
starburst galaxies at z~2. Two of these were detected at more than 99.5%
confidence levels, with 1.2 mm fluxes around 1.5 mJy. These millimeter fluxes
imply vigorous activity with star-formation rates (SFRs) approx. 500-1500
Msun/yr, confirmed also by detections at 24 microns with the MIPS camera on
board of the Spitzer satellite. The two detected galaxies are the ones in the
sample with the highest SFRs estimated from the rest-frame UV, and their
far-IR- and UV-derived SFRs agree reasonably well. This is different from local
ULIRGs and high-z submm/mm selected galaxies for which the UV is reported to
underestimate SFRs by factors of 10-100, but similar to the average BzK-ULIRG
galaxy at z~2. The two galaxies detected at 1.2 mm are brighter in K than the
typical NIR-counterparts of MAMBO and SCUBA sources, implying also a
significantly different K-band to submm/mm flux ratio. This suggests a scenario
in which z~2 galaxies, after their rapid (sub)mm brightest phase opaque to
optical/UV light, evolve into a longer lasting phase of K-band bright and
massive objects. Targeting the most UV active BzKs could yield substantial
detection rates at submm/mm wavelengths.


title:
Primordial pollution of globular clusters within their host dwarfs
  embedded in dark matter halos at high redshifts

abstract:
  Recent observational studies have revealed star-to-star abundance
inhomogeneity among light elements (e.g., C, N, O, Na, and Al) of stars on the
main sequence in the Galactic globular clusters (GCs). One of promising
interpretations for this result is that the observed abundance inhomogeneity is
due to the second generation of stars formed from ejecta of the first
generation of evolved stars (e.g., AGB stars) within GCs. However it remains
unclear whether and how this primordial pollution can occur within GCs. We here
propose a new scenario in which primordial pollution of GCs is highly likely to
occur if GCs are located in the central regions of high redshift dark matter
subhalos that can host low-mass dwarf galaxies. In this scenario, gas ejected
from the first generation of stars of GCs can be effectively trapped in the
deep gravitational potential of their host halos and consequently can be
consumed for the formation of the second generation of stars without losing a
significant amount of gas by ram pressure stripping of interstellar and
intergalactic medium. During merging of these halos with the proto-Galaxy, the
halos are completely destroyed owing to the strong tidal field of the Galaxy.
The self-polluted GCs located initially in the central regions of the halos can
survive from tidal destruction owing to their compactness and finally become
the Galactic halo GCs. In this scenario, ejecta of field stars surrounding the
central GCs can be also converted into stars within their host dwarfs and
finally become the second generation of stars of GCs. We also discuss the
origin of the difference in the degree of abundance inhomogeneity between
different GCs, such as $\omega$ Centauri and NGC 6752, in terms of the
difference in physical properties between host halos from which GC originate.


title:
Stellar masses: the comparison of theoretical predictions and
  measurement data

abstract:
  The Euler equation has been accepted as the basic postulate of stellar
physics long before the plasma physics was developed. The existence of
electrical interaction between particles of interstellar plasma poses the
question, how this interaction must be accounted for. We argue that the right
way is in formulation of a new postulate. On the base of the new postulate, the
theory of a hot star interior is developed. Using this theory we obtain the
distribution of stars over their masses and mass-radius, mass-temperature and
mass-luminosity dependencies. All these theoretical predictions are in a good
agreement with the known measurement data, which confirms the validity of the
new postulate.


title:
Observation of Gamma Rays from the Galactic Center with the MAGIC
  Telescope

abstract:
  Recently, the Galactic Center has been reported to be a source of very high
energy (VHE) gamma-rays by the VERITAS, CANGAROO and HESS experiments. The
energy spectra as measured by these experiments show substantial differences.
In this Letter we present MAGIC observations of the Galactic Center, resulting
in the detection of a differential gamma-ray flux consistent with a steady,
hard-slope power law, described as dN/(dA dt dE) = (2.9+/-0.6)*10^{-12}
(E/TeV)^{-2.2+/-0.2} cm^{-2}s^{-1}TeV^{-1}. The gamma-ray source is centered at
(Ra, Dec)=(17h 45m 20s, -29deg 2'. This result confirms the previous
measurements by the HESS experiment and indicates a steady source of TeV
gamma-rays. We briefly describe the observational technique used, the procedure
implemented for the data analysis, and discuss the results in the perspective
of different models proposed for the acceleration of the VHE gamma-rays.


title:
An observational survey of molecular emission ahead of Herbig-Haro
  objects

abstract:
  Context. A molecular survey recently performed ahead of HH~2 supports the
idea that the observed molecular enhancement is due to UV radiation from the HH
object. Aims. The aim of the present work is to determine whether all HH
objects with enhanced HCO$^+$ emission ahead of them also exhibit the same
enhanced chemistry as HH~2. We thus observed several molecular lines at several
positions ahead of five Herbig-Haro objects where enhanced HCO$^+$ emission was
previously observed. Methods. We mapped the five Herbig-Haro objects using the
IRAM-30 m. For each position we searched for more than one molecular species,
and where possible for more than one transition per species. We then estimated
the averaged beam column densities for all species observed and also performed
LVG analyses to constrain the physical properties of the gas. Results. The
chemically richest quiescent gas is found ahead of the HH~7-11 complex, in
particular at the HH~7-11 A position. In some regions we also detected a high
velocity gas component. We find that the gas densities are always higher than
those typical of a molecular cloud while the derived temperatures are always
quite low, ranging from 10 to 25 K. The emission of most species seems to be
enhanced with respect to that of a typical dense clump, probably due to the
exposure to a high UV radiation from the HH objects. Chemical differentiation
among the positions is also observed. We attempt a very simple chemical
analysis to explain such differentiation.


title:
The Intra-Night Optical Variability of the bright BL Lac object S5
  0716+714

abstract:
  We address the topic of the Intra-Night Optical Variability of the BL Lac
object S5 0716+714. To this purpose a long term observational campaign was
performed, from 1996 to 2003, which allowed the collection of a very large data
set, containing 10,675 photometric measurements obtained in 102 nights. The
source brightness varied in a range of about 2 mag, although the majority of
observations were performed when it was in the range 13.0 < R < 13.75.
Variability time scales were estimated from the rates of magnitude variation,
which were found to have a distribution function well fitted by an exponential
law with a mean value of 0.027 mag/h, corresponding to an e-folding time scale
of the flux tau_F = 37.6 h. The highest rates of magnitude variation were
around 0.10--0.12 mag/h and lasted less than 2 h. These rates were observed
only when the source had an R magnitude < 13.4, but this finding cannot be
considered significant because of the low statistical occurrence. The
distribution of tau_F has a well defined modal value at 19 h. Assuming the
recent estimate of the beaming factor delta about 20, we derived a typical size
of the emitting region of about 5 times 10^{16}/(1 + z) cm. The possibility to
search for a possible correlation between the mean magnitude variation rate and
the long term changes of the velocity of superluminal components in the jet is
discussed.


title:
Development of twist in an emerging magnetic flux tube by poloidal field
  accretion

abstract:
  Following an earlier proposal by Choudhuri (2003) for the origin of twist in
the magnetic fields of solar active regions, we model the penetration of a
wrapped up background poloidal field into a toroidal magnetic flux tube rising
through the solar convective zone. The rise of the straight, cylindrical flux
tube is followed by numerically solving the induction equation in a comoving
Lagrangian frame, while an external poloidal magnetic field is assumed to be
radially advected onto the tube with a speed corresponding to the rise
velocity. One prediction of our model is the existence of a ring of reverse
current helicity on the periphery of active regions. On the other hand, the
amplitude of the resulting twist depends sensitively on the assumed structure
(diffuse vs. concentrated/intermittent) of the active region magnetic field
right before its emergence, and on the assumed vertical profile of the poloidal
field. Nevertheless, in the model with the most plausible choice of assumptions
a mean twist comparable to the observations can result rather naturally. Our
results indicate that the contribution of this mechanism to the twist can be
quite significant, and under favourable circumstances it can potentially
account for most of the current helicity observed in active regions.


title:
Multi-wavelength study of the gravitational lens system RXS
  J113155.4-123155: I. Multi-epoch optical and near infrared imaging

abstract:
  (abridged) Aims: RXS J113155.4-123155 (z=0.66) is a quadruply imaged lensed
quasar with a resolved Einstein Ring. The goal of this paper is to provide a
full characterization of this system, and more particularly accurate astrometry
and photometry.
  Method: Visible and near-infrared imaging observations of RXS
J113155.4-123155 were carried out at various epochs using several ground based
telescopes and the HST. The frames have been deconvolved using the MCS
algorithm. A Singular Isothermal Ellipsoid (SIE) + external shear has been used
to model the lensing galaxy potential.
  Results: MCS deconvolution enables us to separate the flux of the QSO
(point-like images) from that of its host galaxy and to accurately track the
flux variations of the point-like images in various filters. The deconvolved
frames unveil several multiply imaged structures in the Einstein ring and an
unidentified object in the vicinity of the lensing galaxy. We discuss the
lightcurves and the chromatic flux ratio variations and deduce that both
intrinsic variability and microlensing took place during a span longer than one
year.
  We demonstrate that microlensing may easily account for the so called
anomalous flux ratios presented in the discovery paper. However, the observed
flux ratios are still poorly reproduced when modeling the lens potential with a
SIE+shear. We argue that this disagreement can hardly be explained by
milli-lensing caused by substructures in the lensing galaxy. A solution
proposed in Paper II consists in a more complex lens model including an
octupole term to the lens gravitational potential.


title: Spectroscopic metallicities for Fornax UCDs, GCs and dE,Ns

abstract:
  Various formation channels for the puzzling ultra-compact dwarf galaxies
(UCDs) have been proposed in the last few years. To better judge on some of the
competing scenarios, we present spectroscopic [Fe/H] estimates for a sample of
26 compact objects in the central region of the Fornax cluster, covering the
magnitude range of UCDs and bright globular clusters. We find a break in the
metallicity distribution of compact objects at M_V ~ -11 mag (~3*10^6 M_sun):
for M_V<-11 mag the mean metallicity is [Fe/H]=-0.62 +/- 0.05 dex, 0.56 +/-
0.15 dex higher than for M_V>-11 mag. This metallicity break is accompanied by
a change in the size-luminosity relation for compact objects, as deduced from
HST-imaging: for M_V<-11 mag, r_h scales with luminosity, while for M_V>-11
mag, r_h is almost luminosity-independent. We therefore assume a limiting
absolute magnitude of M_V=-11 mag between UCDs and globular clusters. The mean
metallicity of five Fornax dE,N nuclei included in our study is about 0.8 dex
lower than that of the UCDs, at 4.5 sigma significance. Because of this large
metallicity discrepancy we disfavor the hypothesis that most of the Fornax UCDs
are the remnant nuclei of tidally stripped dE,Ns. Our metallicity estimates for
UCDs are closer to but slightly below those derived for young massive clusters
(YMCs) of comparable masses. We therefore favor a scenario where most UCDs in
Fornax are successors of merged YMCs produced in the course of violent
galaxy-galaxy mergers. It is noted that in contrast to that, the properties of
Virgo UCDs are more consistent with the stripping scenario, suggesting that
different UCD formation channels may dominate in either cluster.


title:
Shapley Optical Survey. I: Luminosity Functions in the Supercluster
  Environment

abstract:
  We present the Shapley Optical Survey, a photometric study covering a 2 deg^2
region of the Shapley Supercluster core at z ~ 0.05 in two bands (B and R). The
galaxy sample is complete to B=22.5 (>M^*+6, N_{gal}=16588), and R=22.0
(>M^*+7, N_{gal}=28008). The galaxy luminosity function cannot be described by
a single Schechter function due to dips apparent at B ~ 17.5 (M_B ~ -19.3) and
R ~ 17.0 (M_R ~ -19.8) and the clear upturn in the counts for galaxies fainter
than B and R ~18 mag. We find, instead, that the sum of a Gaussian and a
Schechter function, for bright and faint galaxies respectively, is a suitable
representation of the data. We study the effects of the environment on the
photometric properties of galaxies, deriving the galaxy luminosity functions in
three regions selected according to the local galaxy density, and find a marked
luminosity segregation, in the sense that the LF faint-end is different at more
than 3sigma confidence level in regions with different densities. In addition,
the luminosity functions of red and blue galaxy populations show very different
behaviours: while red sequence counts are very similar to those obtained for
the global galaxy population, the blue galaxy luminosity functions are well
described by a single Schechter function and do not vary with the density. Such
large environmentally-dependent deviations from a single Schechter function are
difficult to produce solely within galaxy merging or suffocation scenarios.
Instead the data support the idea that mechanisms related to the cluster
environment, such as galaxy harassment or ram-pressure stripping, shape the
galaxy LFs by terminating star-formation and producing mass loss in galaxies at
\~M^*+2, a magnitude range where blue late-type spirals used to dominate
cluster populations, but are now absent.


title: A Synoptic, Multiwavelength Analysis of a Large Quasar Sample

abstract:
  We present variability and multi-wavelength photometric information for the
933 known quasars in the QUEST Variability Survey. These quasars are grouped
into variable and non-variable populations based on measured variability
confidence levels. In a time-limited synoptic survey, we detect an
anti-correlation between redshift and the likelihood of variability. Our
comparison of variability likelihood to radio, IR, and X-ray data is consistent
with earlier quasar studies. Using already-known quasars as a template, we
introduce a light curve morphology algorithm that provides an efficient method
for discriminating variable quasars from periodic variable objects in the
absence of spectroscopic information. The establishment of statistically robust
trends and efficient, non-spectroscopic selection algorithms will aid in quasar
identification and categorization in upcoming massive synoptic surveys.
Finally, we report on three interesting variable quasars, including variability
confirmation of the BL Lac candidate PKS 1222+037.


title: Gas Giant Protoplanets Formed by Disk Instability in Binary Star Systems

abstract:
  We present a suite of three dimensional radiative gravitational hydrodynamics
models suggesting that binary stars may be quite capable of forming planetary
systems similar to our own. The new models with binary companions do not employ
any explicit artificial viscosity, and also include the third (vertical)
dimension in the hydrodynamic calculations, allowing for transient phases of
convective cooling. The calculations of the evolution of initially marginally
gravitationally stable disks show that the presence of a binary star companion
may actually help to trigger the formation of dense clumps that could become
giant planets. We also show that in models without binary companions, which
begin their evolution as gravitationally stable disks, the disks evolve to form
dense rings, which then break-up into self-gravitating clumps. These latter
models suggest that the evolution of any self-gravitating disk with sufficient
mass to form gas giant planets is likely to lead to a period of disk
instability, even in the absence of a trigger such as a binary star companion.


title: A Keplerian Disk around the Herbig Ae star HD169142

abstract:
  We present Submillimeter Array observations of the Herbig Ae star HD169142 in
1.3 millimeter continuum emission and 12CO J=2-1 line emission at 1.5 arcsecond
resolution that reveal a circumstellar disk. The continuum emission is centered
on the star position and resolved, and provides a mass estimate of about 0.02
solar masses for the disk. The CO images show patterns in position and velocity
that are well matched by a disk in Keplerian rotation with low inclination to
the line-of-sight. We use radiative transfer calculations based on a flared,
passive disk model to constrain the disk parameters by comparison to the
spectral line emission. The derived disk radius is 235 AU, and the inclination
is 13 degrees. The model also necessitates modest depletion of the CO
molecules, similar to that found in Keplerian disks around T Tauri stars.


title:
Cosmogenic Neutrinos from Cosmic Ray Interactions with Extragalactic
  Infrared Photons

abstract:
  We discuss the production of cosmogenic neutrinos on extragalactic infrared
photons in a model of its cosmological evolution. The relative importance of
these infrared photons as a target for proton interactions is significant,
especially in the case of steep injection spectra of the ultrahigh energy
cosmic rays. For an E$^{-2.5}$ cosmic ray injection spectrum, for example, the
event rate of neutrinos of energy above 1 PeV is more than doubled.


title: XMM-Newton Archival Study of the ULX Population in Nearby Galaxies

abstract:
  We present the results of an archival XMM-Newton study of the bright X-ray
point sources (L_X > 10^38 erg/s) in 32 nearby galaxies. From our list of
approximately 100 point sources, we attempt to determine if there is a
low-state counterpart to the Ultraluminous X-ray (ULX) population, searching
for a soft-hard state dichotomy similar to that known for Galactic X-ray
binaries and testing the specific predictions of the IMBH hypothesis. To this
end, we searched for "low-state" objects, which we defined as objects within
our sample which had a spectrum well fit by a simple absorbed power law, and
"high-state" objects, which we defined as objects better fit by a combined
blackbody and a power law. Assuming that ``low-state'' objects accrete at
approximately 10% of the Eddington luminosity (Done & Gierlinski 2003) and that
"high-state" objects accrete near the Eddington luminosity we further divided
our sample of sources into low and high state ULX sources. We classify 16
sources as low-state ULXs and 26 objects as high-state ULXs. As in Galactic
black hole systems, the spectral indices, Gamma, of the low-state objects, as
well as the luminosities, tend to be lower than those of the high-state
objects. The observed range of blackbody temperatures for the high state is
0.1-1 keV, with the most luminous systems tending toward the lowest
temperatures. We therefore divide our high-state ULXs into candidate IMBHs
(with blackbody temperatures of approximately 0.1 keV) and candidate stellar
mass BHs (with blackbody temperatures of approximately 1.0 keV). A subset of
the candidate stellar mass BHs have spectra that are well-fit by a
Comptonization model, a property similar of Galactic BHs radiating in the
"very-high" state near the Eddington limit.


title:
The Full Second-Order Radiation Transfer Function for Large-Scale CMB
  Anisotropies

abstract:
  We calculate the full second-order radiation transfer function for Cosmic
Microwave Background anisotropies on large angular scales in a flat universe
filled with matter and cosmological constant. It includes (i) the second-order
generalization of the Sachs-Wolfe effect, and of (ii) both the early and late
Integrated Sachs-Wolfe effects, (iii) the contribution of the second-order
tensor modes, and is valid for a generic set of initial conditions specifying
the level of primordial non-Gaussianity.


title:
Evolution of the Phase-Space Density of Dark Matter Halos and Mixing
  Effects in Merger Events

abstract:
  Cosmological N-body simulations were performed to study the evolution of the
phase-space density Q = rho/sigma^3 of dark matter halos. No significant
differences in the scale relations Q ~ sigma^(-2.1) or Q ~ M^(-0.82) are seen
for "cold" or "warm" dark matter models. The follow up of individual halos from
z = 10 up to the present time indicate the existence of two main evolutionary
phases: an early and fast one (10 > z > 6.5), in which Q decreases on the
average by a factor of 40 as a consequence of the randomization of bulk motions
and a late and long one (6.5 > z > 0), in which Q decreases by a factor of 20
because of mixing induced by merger events. The study of these halos has also
evidenced that rapid and positive variations of the velocity dispersion,
induced by merger episods, are related to a fast decrease of the phase density
Q.


title: Detection of orbital and superhump periods in Nova V2574 Ophiuchi (2004)

abstract:
  We present the results of 37 nights of CCD unfiltered photometry of nova
V2574 Oph (2004) from 2004 and 2005. We find two periods of 0.14164 d (~3.40 h)
and 0.14773 d (~3.55 h) in the 2005 data. The 2004 data show variability on a
similar timescale, but no coherent periodicity was found. We suggest that the
longer periodicity is the orbital period of the underlying binary system and
that the shorter period represents a negative superhump. The 3.40 h period is
about 4% shorter than the orbital period and obeys the relation between
superhump period deficit and binary period. The detection of superhumps in the
light curve is evidence of the presence of a precessing accretion disk in this
binary system shortly after the nova outburst. From the maximum magnitude -
rate of decline relation, we estimate the decay rate t_2 = 17+/-4 d and a
maximum absolute visual magnitude of M_Vmax = -7.7+/-1.7 mag.


title: Model selection as a science driver for dark energy surveys

abstract:
  A key science goal of upcoming dark energy surveys is to seek time evolution
of the dark energy. This problem is one of {\em model selection}, where the aim
is to differentiate between cosmological models with different numbers of
parameters. However, the power of these surveys is traditionally assessed by
estimating their ability to constrain parameters, which is a different
statistical problem. In this paper we use Bayesian model selection techniques,
specifically forecasting of the Bayes factors, to compare the abilities of
different proposed surveys in discovering dark energy evolution. We consider
six experiments -- supernova luminosity measurements by the Supernova Legacy
Survey, SNAP, JEDI, and ALPACA, and baryon acoustic oscillation measurements by
WFMOS and JEDI -- and use Bayes factor plots to compare their statistical
constraining power. The concept of Bayes factor forecasting has much broader
applicability than dark energy surveys.


title:
Soft X-rays from disk galaxy halos, Ly-alpha emission from forming
  galaxies, and the z~1 Tully-Fisher relation

abstract:
  Extended, soft X-ray emission from the halo of a very large disk galaxy has
been detected out to r~20-40 kpc. The luminosity and surface brightness
distribution is in very good agreement with predictions by recent, cosmological
galaxy formation models. Predictions of Ly-alpha emission, associated with
``cold'' accretion of filamentary gas onto galaxies, are presented. In
particular these predictions are compared to the properties of a recently
detected Ly-alpha ``blob'', which shows no obvious continuum counter-part in
any of 12 broad-bands, from X-rays (Chandra) to infrared (Spitzer). Finally,
the predicted evolution of the Tully-Fisher relation, going from z=0 to 1, is
discussed in relation to recent observations.


title:
X-ray Absorption Spectroscopy of the Multi-phase Interstellar Medium:
  Oxygen and Neon Abundances

abstract:
  X-ray absorption spectroscopy provides a potentially powerful tool in
determining the metal abundances in various phases of the interstellar medium
(ISM). We present a case study of the sight line toward 4U 1820-303 (Galactic
coordinates l, b=2.79, -7.91 and distance = 7.6 kpc), based on Chandra Grating
observations. The detection of OI, OII, OIII, OVII, OVIII, and NeIX Kalpha
absorption lines allows us to measure the atomic column densities of the
neutral, warm ionized, and hot phases of the ISM through much of the Galactic
disk. By comparing these measurements with the 21 cm hydrogen emission and with
the pulsar dispersion measure along the same sight line, we estimate the mean
oxygen abundances in the neutral and total ionized phases as 0.3(0.2, 0.6) and
2.2(1.1, 3.5) in units of Anders & Grevesse (1989) solar value. This
significant oxygen abundance difference is apparently a result of molecule/dust
grain destruction and recent metal enrichment in the warm ionized and hot
phases. We also measure the column density of neon from its absorption edge and
obtain the Ne/O ratio of the neutral plus warm ionized gas as 2.1(1.3, 3.5)
solar. Accounting for the expected oxygen contained in molecules and dust
grains would reduce the Ne/O ratio by a factor of ~1.5. From a joint-analysis
of the OVII, OVIII, and NeIX lines, we obtain the Ne/O abundance ratio of the
hot phase as 1.4(0.9, 2.1) solar, which is not sensitive to the exact
temperature distribution assumed in the absorption line modeling. These
comparable ISM Ne/O ratios for the hot and cooler gas are thus considerably
less than the value (2.85+-0.07; 1sigma) recently inferred from corona emission
of solar-like stars (Drake & Testa 2005). (abridged)


title: Semilocal Cosmic String Networks

abstract:
  We report on a large scale numerical study of networks of semilocal cosmic
strings in flat space in the parameter regime in which they are perturbatively
stable. We find a population of segments with an exponential length
distribution and indications of a scaling network without significant loop
formation. Very deep in the stability regime strings of superhorizon size grow
rapidly and ``percolate'' through the box. We believe these should lead at late
times to a population of infinite strings similar to topologically stable
strings. However, the strings are very light; scalar gradients dominate the
energy density and the network has thus a global texture-like signature. As a
result, the observational constraints, at least from the temperature power
spectrum of the CMB, on models predicting semilocal strings, should be closer
to those on global textures or monopoles, rather than on topologically stable
gauged cosmic strings.


title: Blue Stragglers, Be stars and X-ray binaries in open clusters

abstract:
  Combination of high-precision photometry and spectroscopy allows the detailed
study of the upper main sequence in open clusters. We are carrying out a
comprehensive study of a number of clusters containing Be stars in order to
evaluate the likelihood that a significant number of Be stars form through mass
exchange in a binary. Our first results show that most young open clusters
contain blue stragglers. In spite of the small number of clusters so far
analysed, some trends are beginning to emerge. In younger open clusters, such
as NGC 869 and NGC 663, there are many blue stragglers, most of which are not
Be stars. In older clusters, such as IC 4725, the fraction of Be stars among
blue stragglers is very high. Two Be blue stragglers are moderately strong
X-ray sources, one of them being a confirmed X-ray binary. Such objects must
have formed through binary evolution. We discuss the contribution of mass
transfer in a close binary to the formation of both blue stragglers and Be
stars


title:
No Universality for Electron's Power-Law Index (p) in Gamma-Ray Bursts
  and Other Relativistic Sources

abstract:
  The Gamma-Ray Burst (GRB) prompt emission is believed to be from highly
relativistic electrons accelerated in relativistic shocks. From the GRB
high-energy power-law spectral indices $\beta$ observed by the Burst and
Transient Source Experiment (BATSE) Large Area Detectors (LAD), we determine
the spectral index, $p$, of the electrons' energy distribution. Both the
theoretical calculations and numerical simulations of the particle acceleration
in relativistic shocks show that $p$ has a universal value $\approx 2.2-2.3$.
We show that the observed distribution of $p$ during GRBs is not consistent
with a $\delta$-function distribution or an universal $p$ value, with the width
of the distribution $\ge$ 0.54. The distributions of $p$ during X-ray
afterglows are also investigated and found to be inconsistent with a
$\delta$-function distribution. The $p$-distributions in blazars and pulsar
wind nebulae are also broad, inconsistent with a $\delta$-function
distribution.


title:
Protostellar Jets and Turbulence in Molecular Clouds: The Role of
  Interactions

abstract:
  We present a series of numerical studies of the interaction of colliding
radiative, hydrodynamic young stellar outflows. We study the effect of the
collision impact parameter on the acceleration of ambient material and the
degree to which the flow is isotropized by the collision as a mechanism for
driving turbulence in the parent molecular cloud. Our results indicate that the
high degrees of compression of outflow material, achieved through radiative
shocks near the vertex of the interaction, prevents the redirected outflow from
spraying over a large spatial region. Furthermore, the collision reduces the
redirected outflow's ability to entrain and impart momentum into the ambient
cloud. Consideration of the probabilities of outflow collisions leads us to
conclude that individual low velocity fossil outflows are the principle
coupling between outflows and the cloud.


title:
Orbits and photometry of Pluto's satellites: Charon, S/2005 P1 and
  S/2005 P2

abstract:
  We present new astrometry of Pluto's three satellites from images taken of
the Pluto system during 2002-3 with the High Resolution Camera (HRC) mode of
the Advanced Camera for Surveys (ACS) instrument on the Hubble Space Telescope.
The observations were designed to produce an albedo map of Pluto but they also
contain images of Charon and the two recently discovered satellites, S/2005 P1
and S/2005 P2. Orbits fitted to all three satellites are nearly co-planar and,
for Charon and P2, have eccentricities consistent with zero. The orbit of the
outermost satellite, P1, has a significant eccentricity of 0.0052 +/- 0.0011.
Orbital periods of P1, P2, and Charon are 38.2065 +/- 0.0014, 24.8562 +/-
00013, and 6.3872304 +/- 0.0000011 days, respectively. The total system mass
based on Charon's orbit is 1.4570 +/- 0.0009 x 10^22 kg. We confirm previous
results that orbital periods are close to the ratio of 6:4:1 (P1:P2:Charon)
indicative of mean-motion resonances, but our results formally preclude precise
integer period ratios. The orbits of P1 and P2, being about the barycenter
rather than Pluto, enable us to measure the Charon/Pluto mass ratio as 0.1165
+/- 0.0055. This new mass ratio implies a density of 1.65 +/- 0.06 g cm^-3 for
Charon (603.6 km radius) and 2.03 +/- 0.06 g cm^-3 for Pluto (1153 km radius)
thus adding confirmation that Charon is significantly less dense than Pluto.
Finally, by stacking all images, we can extract globally averaged photometry.
P1 has a mean opposition magnitude of V=24.39 +/- 0.09 and color of (B-V) =
0.64 +/- 0.12. P2 has a mean opposition magnitude of V=24.55 +/- 0.10 and color
of (B-V) = 0.91 +/- 0.15.


title: Evidence of the FIP effect in the coronae of late-type giants

abstract:
  $\beta$ Cet, 31 Com and $\mu$ Vel represent the main stages through which
late-type giants evolve during their lifetime (the Hertzsprung gap (31 Com),
the rapid braking zone ($\mu$ Vel) and the core helium burning ``clump'' phase
($\beta$ Cet)). An analysis of their high resolution {\it Chandra} X-ray
spectra reveals similar coronal characteristics in terms of both temperature
structure and element abundances for the more evolved stars ($\mu$ Vel and
$\beta$ Cet) with slight differences for the `younger' giant (31 Com). The
coronal temperature structure of 31 Com is significantly hotter showing a clear
peak while $\beta$ Cet and $\mu$ Vel show a plateau. $\beta$ Cet and $\mu$ Vel
show evidence for a FIP effect in which coronae are depleted in high FIP
elements relative to their photospheres by a factor of $\sim 2$. In contrast,
31 Com is characterized by a lack of FIP effect. In other words, neither
depletion nor enhancement relative to stellar photospheric values is found. We
conclude that the structural changes during the evolution of late-type giants
could be responsible for the observed differences in coronal abundances and
temperature structure. In particular, the size of the convection zone coupled
with the rotation rate seem obvious choices for playing a key role in
determining coronal characteristics.


title:
VOFilter, Bridging Virtual Observatory and Industrial Office
  Applications

abstract:
  VOFilter is an XML based filter developed by the Chinese Virtual Observatory
project to transform tabular data files from VOTable format into OpenDocument
format. VOTable is an XML format defined for the exchange of tabular data in
the context of the Virtual Observatory (VO). It is the first Proposed
Recommendation defined by International Virtual Observatory Alliance, and has
obtained wide support from both the VO community and many Astronomy projects.
OpenOffice.org is a mature, open source, front office applications suite with
the advantage of native support of industrial standard OpenDocument XML file
format. Using the VOFilter, VOTable files can be loaded in OpenOffice.org Calc,
a spreadsheet application, and then displayed and analyzed as other spreadsheet
files. Here, the VOFilter acts as a connector, bridging the coming VO with
current industrial office applications. Virtual Observatory and technical
background of the VOFilter are introduced. Its workflow, installation and usage
are presented. Existing problems and limitations are also discussed together
with the future development plans.


title: An alternative to dark matter: do braneworld effects hold the key?

abstract:
  An alternative way of explaining astrophysical observations without dark
matter is proposed. In the braneworld scenario, where our universe is
visualised as a 4-dimensional hypersurface embedded in a higher dimensional
spacetime, the effective Einstein equation on the brane contains extra terms.
We show that the astrophysical observations which are usually explained by
particle dark matter, can be explained in this modified theory of gravity via
those extra terms, without the need for dark matter. As specific example, we
model X-ray profiles of clusters of galaxies and the galaxy rotation curves
which are consistent with observations. Further, we investigate whether
gravitational lensing can discriminate between the two possibilities.
Significant differences between the values of the deflection angles are
obtained, which can be tested in future observations.


title: Neutron-loaded outflows in gamma-ray bursts

abstract:
  Relativistic neutron-loaded outflows in gamma-ray bursts are studied at their
early stages, before deceleration by a surrounding medium. The outflow has four
components: radiation, electrons, protons and neutrons. The components interact
with each other and exchange energy as the outflow expands. The presence of
neutrons significantly changes the outflow evolution. Before neutrons decouple
from protons, friction between the two components increases their temperatures
by many orders of magnitude. After the decoupling, the gradual neutron decay
inside the outflow has a drag effect on the protons and reduces their final
Lorentz factor.


title:
Footpoint Motion of the Continuum Emission in the 2002 September 30
  White-Light Flare

abstract:
  We present observations of the 2002 September 30 white-light flare, in which
the optical continuum emission near the Halpha line is enhanced by ~10%. The
continuum emission exhibits a close temporal and spatial coincidence with the
hard X-ray (HXR) footpoint observed by RHESSI. We find a systematic motion of
the flare footpoint seen in the continuum emission; the motion history follows
roughly that of the HXR source. This gives strong evidence the this white-light
flare is powered by heating of nonthermal electrons. We note that the HXR
spectrum in 10-50 keV is quite soft with gamma being ~7 and there is no HXR
emission above 50 keV. The magnetic configuration of the flaring region implies
magnetic reconnection taking place at a relatively low altitude during the
flare. Despite a very soft spectrum of the electron beam, its energy content is
still sufficient to produce the heating in the lower atmosphere where the
continuum emission originates. This white-light flare highlights the importance
of radiative backwarming to transport the energy below when direct heating by
beam electrons is obviously impossible.


title: Constraining Galaxy Formation Models with Dwarf Ellipticals in Clusters

abstract:
  Recent observations demonstrate that dwarf elliptical (dE) galaxies in
clusters, despite their faintness, are likely a critical galaxy type for
understanding the processes behind galaxy formation. Dwarf ellipticals are the
most common galaxy type, and are particularly abundant in rich galaxy clusters.
The dwarf to giant ratio is in fact highest in rich clusters of galaxies,
suggesting that cluster dEs do not form in groups that later merge to form
clusters. Dwarf ellipticals are potentially the only galaxy type whose
formation is sensitive to global, rather than local, environment. The dominant
idea for explaining the formation of these systems, through Cold Dark Matter
models, is that dEs form early and within their present environments. Recent
results suggest that some dwarfs appear in clusters after the bulk of massive
galaxies form, a scenario not predicted in standard hierarchical structure
formation models. Many dEs have younger and more metal rich stellar populations
than dwarfs in lower density environments, suggesting processes induced by rich
clusters play an important role in dE formation. Several general galaxy cluster
observations, including steep luminosity functions, and the origin of
intracluster light, are natural outcomes of this delayed formation.


title:
Clustering of ultra-high energy cosmic ray arrival directions on medium
  scales

abstract:
  The two-point autocorrelation function of ultra-high energy cosmic ray
(UHECR) arrival directions has a broad maximum around 25 degrees, combining the
data with energies above $4\times 10^{19}$ eV (in the HiRes energy scale) of
the HiRes stereo, AGASA, Yakutsk and SUGAR experiments. This signal is not or
only marginally present analyzing events of a single experiment, but becomes
significant when data from several experiments are added. Both the energy
dependence of the signal and its angular scale might be interpreted as first
signatures of the large-scale structure of UHECR sources and of intervening
magnetic fields.


title: An Overview of Extremely Large Telescopes Projects

abstract:
  IAU Symposium 232 allows a snapshot of ELTs at a stage when design work in
several critical mass projects has been seriously underway for two to three
years. The status and som eof the main initial design choices are reviewed for
the North American Giant Magellan Telescope (GMT) and the Thirty Meter
Telescope (TMT) projects and the European Euro50 and the Overwhelmingly Large
(OWL) projects. All the projects are drawing from the same "basket" of science
requirements, although each project has somewhat different ambitions. The role
of the project offices in creating the balance between project scope, timeline
and cost, the "iron triangle" of project management, is emphasized with the OWL
project providing a striking demonstration at this meeting. There is a
reasonable case that the very broad range of science would be most effectively
undertaken on several complementary telescopes.


title: Observations of pre-stellar cores

abstract:
  Our understanding of the physical and chemical structure of pre-stellar
cores, the simplest star-forming sites, has significantly improved since the
last IAU Symposium on Astrochemistry (South Korea, 1999). Research done over
these years has revealed that major molecular species like CO and CS
systematically deplete onto dust grains at the interior of pre-stellar cores,
while species like N2H+ and NH3 survive in the gas phase and can usually be
detected towards the core centers. Such a selective behaviour of molecular
species gives rise to a differentiated (onion-like) chemical composition, and
manifests itself in molecular maps as a dichotomy between centrally peaked and
ring-shaped distributions. From the point of view of star-formation studies,
the identification of molecular inhomogeneities in cores helps to resolve past
discrepancies between observations made using different tracers, and brings the
possibility of self-consistent modelling of the core internal structure. Here I
present recent work on determining the physical and chemical structure of two
pre-stellar cores, L1498 and L1517B, using observations in a large number of
molecules and Monte Carlo radiative transfer analysis. These two cores are
typical examples of the pre-stellar core population, and their chemical
composition is characterized by the presence of large freeze out holes in most
molecular species. In contrast with these chemically processed objects, a new
population of chemically young cores has started to emerge. The characteristics
of its most extreme representative, L1521E, are briefly reviewed.


title:
The Origin of Magnetic Fields in Galaxies: Observational Tests with the
  Square Kilometre Array

abstract:
  The all-sky survey of Faraday rotation, a Key Science Project of the planned
Square Kilometre Array, will accumulate tens of millions of rotation measure
measurements toward background radio sources and will provide a unique database
for characterizing the overall magnetic geometry of magnetic fields in galaxies
and in the intergalactic medium. Deep imaging of the polarized synchrotron
emission from a large number of nearby galaxies, combined with Faraday rotation
data, will allow us to test the primordial, flow and dynamo models for field
origin and amplification. The SKA will find the first fields in young galaxies
and determine the timescale for building up small-scale turbulent and
large-scale coherent fields. The spectrum of dynamo modes, if existing, will be
resolved. The direction of the present-day coherent field keeps memory of the
direction of the seed field which can be used for mapping the structure of the
seed field before galaxy formation.


title: Astrometric precision of observations at VLT/FORS2

abstract:
  In this paper we test the astrometric precision of VLT/FORS2 observations
using a serie of CCD frames taken in Galactic bulge area. A special reduction
method based on symmetrization of reference fields was used to reduce the
atmospheric image motion. Positional precision of unsaturated R=16 mag star
images at 17 sec exposure and 0.55 arcsec seeing was found to be equal to 300
microarcsec. The total error of observations was decomposed into components. It
was shown that astrometric error depends largely on the photon centroiding
error of the target (250 microarcsec for 16 mag stars) while the image motion
is much less (110 microarcsec). At galactic latitudes to about 20 degrees,
precision for a serie of frames with a 10 min total exposure is estimated to be
30-50 microarcsec for 14-16 mag stars providing the images are not overexposed
and the filter R "special" is used. Error estimates for fields with smaller sky
star density are given. We conclude that astrometric observations with large
telescopes, under optimal reduction, are never atmospheric limited. The bias
caused by differential chromatic refraction and residual chromatism of LADC is
considered and expressions valid for correcting color effects in the measured
positions are given.


title: The dynamical M/L-profile and distance of the globular cluster M15

abstract:
  We construct orbit-based axisymmetric dynamical models for the globular
cluster M15 which fit groundbased line-of-sight velocities and Hubble Space
Telescope line-of-sight velocities and proper motions. This allows us to
constrain the variation of the mass-to-light ratio M/L as a function of radius
in the cluster, and to measure the distance and inclination of the cluster. We
obtain a best-fitting inclination of 60+/-15 degrees, a dynamical distance of
10.3+/-0.4 kpc and an M/L profile with a central peak. The inferred mass in the
central 0.05 parsec is 3400 Msun, implying a central density of at least
7.4x10^6 Msun pc^-3. We cannot distinguish the nature of the central mass
concentration. It could be an IMBH or it could be large number of compact
objects, or it could be a combination. The central 4 arcsec of M15 appears to
contain a rapidly spinning core, and we speculate on its origin.


title: Gravitational Scattering

abstract:
  We review some modern applications of the theory of few-body encounters
between binaries and single stars. Then we focus on a new treatment of
adiabatic encounters, in a regime which is of importance in encounters between
a star and a planetary system in a star cluster.


title: Elemental Abundance Survey of The Galactic Thick Disk

abstract:
  [Abridged abstract] We have performed an abundance analysis for 176 F- and G-
dwarfs of the Galactic thick disk component. Using accurate radial velocities
combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic
orbital parameters were computed. We estimate the probability for a star to
belong to the thin disk, the thick disk or the halo.
  Abundances of C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Y, Ba, Ce, Nd, and Eu have been obtained. The abundances for thick disk
stars are compared with those for thin disk members from Reddy et al. (2003).
The ratios of $\alpha$-elements (O, Mg, Si, Ca and Ti) to iron for thick disk
disk stars show a clear enhancement compared to thin disk members in the range
$-0.3 <$ [Fe/H] $ < -1.2$. There are also other elements -- Al, Sc, V, Co, and
possibly Zn -- which show enhanced ratios to iron in the thick disk relative to
the thin disk. The abundances of Na, Cr, Mn, Ni, and Cu (relative to Fe) are
very similar for thin and thick disk stars. The dispersion in abundance ratios
[X/Fe] at given [Fe/H] for thick disk stars is consistent with the expected
scatter due to measurement errors, suggesting a lack of `cosmic' scatter. The
observed compositions of the thin and thick disks seem to be consistent with
models of galaxy formation by hierarchical clustering in a $\Lambda$CDM
universe. In particular, the distinct abundance patterns observed in the thin
and thick disks, and the chemical homogeneity of the thick disk at different
galactocentric distances favor a scenario in which the majority of thick-disk
stars were formed {\it in situ}, from gas rich merging blocks.


title:
Hot and Cooled baryons in SPH simulations of galaxy clusters: physics
  and numerics

abstract:
  We discuss an extended set of Tree+SPH simulations of galaxy clusters, with
the goal of investigating the interplay between numerical resolution effects
and star-formation/feedback processes. The simulated clusters span the mass
range (0.1-2.3) 10^{15}Msun/h, with mass resolution varying by several decades.
At the highest achieved resolution, we resolve the virial region of a
Virgo-like cluster with more than 2 million gas particles and with at least as
many dark-matter (DM) particles. Our resolution study confirms that, in the
absence of an efficient feedback mechanism, runaway cooling leads to about 35
per cent of baryons in clusters to be locked up in long lived stars at our
highest resolution, with no evidence of convergence. However, including
feedback causes the fraction of cooled baryons to converge at about 15 per cent
already at modest resolution. Feedback also stabilizes other gas-related
quantities, such as radial profiles of entropy, gas density and temperature,
against variations due to changes in resolution. We also investigate the
influence of the gravitational force softening length, and that of numerical
heating of the gas induced by two-body encounters between DM and lighter gas
particles. We show that simulations where more DM than gas particles are used,
show a significantly enhanced efficiency of star formation at z>3. Our results
are important for establishing and delineating the regime of numerical
reliability of the present generation of hydrodynamical simulations of galaxy
clusters.


title: Modeling Tidal Streams in evolving dark matter halos

abstract:
  We explore whether stellar tidal streams can provide information on the
secular, cosmological evolution of the Milky Way's gravitational potential and
on the presence of subhalos. We carry out long-term (~t_hubble) N-body
simulations of disrupting satellite galaxies in a semi-analytic Galaxy
potential where the dark matter halo and the subhalos evolve according to a
LCDM cosmogony. All simulations are constrained to end up with the same
position and velocity at present. Our simulations account for: (i) the secular
evolution of the host halo's mass, size and shape, (ii) the presence of
subhalos and (iii) dynamical friction. We find that tidal stream particles
respond adiabatically to the Galaxy growth so that, at present, the energy and
angular momentum distribution is exclusively determined by the present Galaxy
potential. In other words, all present-day observables can only constrain the
present mass distribution of the Galaxy independent of its past evolution. We
also show that, if the full phase-space distribution of a tidal stream is
available, we can accurately determine (i) the present Galaxy's shape and (ii)
the amount of mass loss from the stream's progenitor, even if this evolution
spanned a cosmologically significant epoch.


title:
Theoretical Uncertainties in Red Giant Branch Evolution: The Red Giant
  Branch Bump

abstract:
  A Monte Carlo simulation exploring uncertainties in standard stellar
evolution theory on the red giant branch of metal-poor globular clusters has
been conducted. Confidence limits are derived on the absolute V-band magnitude
of the bump in the red giant branch luminosity function (M_v,b) and the excess
number of stars in thebump, R_b. The analysis takes into account uncertainties
in the primordial helium abundance, abundance of alpha-capture elements,
radiative and conductive opacities, nuclear reaction rates, neutrino energy
losses, the treatments of diffusion and convection, the surface boundary
conditions, and color transformations.
  The uncertainty in theoretical values for the red giant bump magnitude varies
with metallicity between +0.13/-0.12 mag at [Fe/H] = -2.4 and +0.23/-0.21 mag
at [Fe/H] = -1.0$. The dominant sources of uncertainty are the abundance of the
alpha-capture elements, the mixing length, and the low-temperature opacities.
The theoretical values of M_v,b are in good agreement with observations. The
uncertainty in the theoretical value of R_b is +/-0.01 at all metallicities
studied. The dominant sources of uncertainty are the abundance of the
alpha-capture elements, the mixing length, and the high-temperature opacities.
The median value of R_b varies from 0.44 at [Fe/H] = -2.4$ to 0.50 at [Fe/H] =
-1.0. These theoretical values for R_b are in agreement with observations.


title:
Constraints on sterile neutrino as a dark matter candidate from the
  diffuse X-ray background

abstract:
  Sterile neutrinos with masses in the keV range are viable candidates for the
warm dark matter. We analyze existing data for the extragalactic diffuse X-ray
background for signatures of sterile neutrino decay. The absence of detectable
signal within current uncertainties of background measurements puts
model-independent constraints on allowed values of sterile neutrino mass and
mixing angle, which we present in this work.


title: Chemical Composition of the Planet-Harboring Star TrES-1

abstract:
  We present a detailed chemical abundance analysis of the parent star of the
transiting extrasolar planet TrES-1. Based on high-resolution Keck/HIRES and
HET/HRS spectra, we have determined abundances relative to the Sun for 16
elements (Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, and Ba).
The resulting average abundance of $<[$$X$/H$]>$ $= -0.02\pm0.06$ is in good
agreement with initial estimates of solar metallicity based on iron. We compare
the elemental abundances of TrES-1 with those of the sample of stars with
planets, searching for possible chemical abundance anomalies. TrES-1 appears
not to be chemically peculiar in any measurable way. We investigate possible
signs of selective accretion of refractory elements in TrES-1 and other stars
with planets, and find no statistically significant trends of metallicity
[$X$/H] with condensation temperature $T_c$. We use published abundances and
kinematic information for the sample of planet-hosting stars (including TrES-1)
and several statistical indicators to provide an updated classification in
terms of their likelihood to belong to either the thin disk or the thick disk
of the Milky Way Galaxy. TrES-1 is found to be a very likely member of the thin
disk population. By comparing $\alpha$-element abundances of planet hosts and a
large control sample of field stars, we also find that metal-rich
([Fe/H]$\gtrsim 0.0$) stars with planets appear to be systematically
underabundant in [$\alpha$/Fe] by $\approx 0.1$ dex with respect to comparison
field stars. The reason for this signature is unclear, but systematic
differences in the analysis procedures adopted by different groups cannot be
ruled out.


title: AO Velorum: a young quadruple system with a ZAMS eclipsing BpSi primary

abstract:
  Using recent spectroscopic observations, we show that the triple system AO
Vel with an eclipsing BpSi primary is in fact a remarkable quadruple system
formed by two double-lined spectroscopic binaries with components close to the
ZAMS. All available data have been reanalyzed to derive proper orbital
parameters for both binary systems and to calculate absolute parameters of the
eclipsing system. For the first time, direct determination of the radius and
the mass have been obtained for a BpSi star. The study of the physical
parameters of this unique system is especially important since it can be used
as a test of evolutionary models for very young stars of intermediate mass.


title: Stable quark matter in cosmic rays?

abstract:
  Stable lumps of quark matter may be present in cosmic rays at a flux level,
which can be detected by high precision cosmic ray experiments sensitive to
anomalous "nuclei" with high mass-to-charge ratio. The properties of these
lumps, called strangelets, are described, and so is the production and
propagation of strangelets in cosmic rays. Two experiments underway which are
sensitive to a strangelet flux in the predicted range are briefly described.
Finally it is summarized how strangelets circumvent the acceleration problem
encountered by conventional candidates for ultra-high energy cosmic rays and
move the Greisen-Zatsepin-Kuzmin cutoff to energies well above the observed
maximum energies.


title: High Shear Regions in Weak Lensing Surveys Determine Cosmology

abstract:
  We propose to use a simple observable, the fractional area of "hot spots" in
weak lensing mass maps which are detected with high significance, to determine
background cosmological parameters. Because these high-shear regions are
directly related to the physical non-linear structures of the universe, they
derive cosmological information mainly from the non-linear regime of density
fluctuations. We show that in combination with future cosmic microwave
background (CMB) anisotropy measurements, this method can place constraints on
cosmological parameters that are comparable to those from the redshift
distribution of galaxy cluster abundances. In particular, adding the
information from this simple shear statistic derived from an LSST-like survey
to CMB anisotropy information from a Planck-like experiment improves the
constraints on the dark energy parameters (energy density and equation of
state) and the normalization of the matter power spectrum by over a factor of
ten. The main advantage of the statistic proposed in this paper is that
projection effects, normally the main source of uncertainty when determining
the presence and the mass of a galaxy cluster, here serve as a source of
information.


title: Harmonic analysis of the Ha velocity field of NGC 4254

abstract:
  The ionized gas kinematics of the Virgo Cluster galaxy NGC 4254 (Messier 99)
is analyzed by an harmonic decomposition of the velocity field into Fourier
coefficients. The aims of this study are to measure the kinematical asymmetries
of Virgo cluster galaxies and to connect them to the environment. The analysis
reveals significant $m=1,2,4$ terms which origins are discussed.


title:
A size of ~1 AU for the radio source Sgr A* at the centre of the Milky
  Way

abstract:
  Although it is widely accepted that most galaxies have supermassive black
holes (SMBHs) at their centers^{1-3}, concrete proof has proved elusive.
Sagittarius A* (Sgr A*)^4, an extremely compact radio source at the center of
our Galaxy, is the best candidate for proof^{5-7}, because it is the closest.
Previous Very Long Baseline Interferometry (VLBI) observations (at 7mm) have
detected that Sgr A* is ~2 astronomical unit (AU) in size^8, but this is still
larger than the "shadow" (a remarkably dim inner region encircled by a bright
ring) arising from general relativistic effects near the event horizon^9.
Moreover, the measured size is wavelength dependent^{10}. Here we report a
radio image of Sgr A* at a wavelength of 3.5mm, demonstrating that its size is
\~1 AU. When combined with the lower limit on its mass^{11}, the lower limit on
the mass density is 6.5x10^{21} Msun pc^{-3}, which provides the most stringent
evidence to date that Sgr A* is an SMBH. The power-law relationship between
wavelength and intrinsic size (The size is proportional to wavelength^{1.09}),
explicitly rules out explanations other than those emission models with
stratified structure, which predict a smaller emitting region observed at a
shorter radio wavelength.


title:
The 21 Centimeter Background from the Cosmic Dark Ages: Minihalos and
  the Intergalactic Medium before Reionization

abstract:
  The H atoms inside minihalos (i.e. halos with virial temperatures T_vir <
10^4 K, in the mass range roughly from 10^4 M_sun to 10^8 M_sun) during the
cosmic dark ages in a LambdaCDM universe produce a redshifted background of
collisionally-pumped 21-cm line radiation which can be seen in emission
relative to the cosmic microwave background (CMB). Previously, we used
semi-analytical calculations of the 21-cm signal from individual halos of
different mass and redshift and the evolving mass function of minihalos to
predict the mean brightness temperature of this 21-cm background and its
angular fluctuations. Here we use high-resolution cosmological N-body and
hydrodynamic simulations of structure formation at high redshift (z>8) to
compute the mean brightness temperature of this background from both minihalos
and the intergalactic medium (IGM) prior to the onset of Ly-alpha radiative
pumping. We find that the 21-cm signal from gas in collapsed, virialized
minihalos dominates over that from the diffuse shocked gas in the IGM.


title:
The Irradiation Origin of Beryllium Radioisotopes and Other Short-lived
  Radionuclides

abstract:
  Two explanations exist for the short-lived radionuclides present in the solar
system when the CAIs first formed. They originated either from the ejecta of a
supernova or by the in situ irradiation of nebular dust by energetic particles.
With a half-life of only 53 days, Beryllium-7 is then the key discriminant,
since it can be made only by irradiation. We calculate the yield of Be-7.
Within model uncertainties associated mainly with nuclear cross sections, we
obtain agreement with the experimental value. Moreover, if Be-7 and Be-10 have
the same origin, the irradiation time must be short. The x-wind model provides
a natural astrophysical setting that gives the requisite conditions. The
decoupling of the Al-26 and Be-10 observed in some rare CAIs receives a
quantitative explanation when rare gradual events are considered. Finally, we
show that the presence of supernova-produced Fe-60 in the solar accretion disk
does not necessarily mean that other short-lived radionuclides have a stellar
origin.


title: Local virial relation for self-gravitating system

abstract:
  We demonstrate that the quasi-equilibrium state in self-gravitating $N$-body
system after cold collapse are uniquely characterized by the local virial
relation using numerical simulations. Conversely assuming the constant local
virial ratio and Jeans equation for spherically steady state system, we
investigate the full solution space of the problem under the constant
anisotropy parameter and obtain some relevant solutions. Especially, the local
virial relation always provides a solution which has a power law density
profile in both the asymptotic regions $r\to 0$ and $\infty$. This type of
solutions observed commonly in many numerical simulations. Only the anisotropic
velocity dispersion controls this asymptotic behavior of density profile.


title: Pulsars and quark stars

abstract:
  Members of the family of pulsar-like stars are distinguished by their
different manifestations observed, i.e., radio pulsars, accretion-driven X-ray
pulsars, X-ray bursts, anomalous X-ray pulsars/soft gamma-ray repeaters,
compact center objects, and dim thermal neutron stars. Though one may
conventionally think that these stars are normal neutron stars, it is still an
open issue whether they are actually neutron stars or quark stars, as no
convincing work, either theoretical from first principles or observational, has
confirmed Baade-Zwicky's original idea that supernovae produce neutron stars.
After introducing briefly the history of pulsars and quark stars, the author
summarizes the recent achievements in his pulsar group, including quark matter
phenomenology at low temperature, starquakes of solid pulsars, low-mass quark
stars, and the pulsar magnetospheric activities.


title:
Virgo High-Resolution CO Survey :V. Circumnuclear Elliptical Ring in NGC
  4569

abstract:
  We present high-resolution ($1\farcs8$ -- $4\farcs5$) CO data of the Virgo
spiral galaxy NGC 4569, obtained using the Nobeyama Millimeter Array. We found
that the molecular gas is highly concentrated in the circumnuclear region with
two off-center peaks. A CO image with the highest angular resolution of
$2\farcs0 \times 1\farcs8$ shows that six blobs likely form a circumnuclear
elliptical ring (CER) with a semi-major axis radius of 720 pc. The CER shows a
strongly twisted velocity field, and the position--velocity (PV) diagram shows
significant forbidden velocity components. These kinetic features are
understood as being non-circular motion due to a bar-potential. We found that
the CER coincides with the H$\alpha$ bright central core and that the mass
ratio of the molecular gas to the dynamical mass is about 18%. These results
support a gaseous inflow scenario induced by a weak bar potential and
self-gravity of the gas.


title:
Reliability checks on the Indo-US Stellar Spectral Library using
  Artificial Neural Networks and Principal Component Analysis

abstract:
  The Indo-US coud\'{e} feed stellar spectral library (CFLIB) made available to
the astronomical community recently by Valdes et al. (2004) contains spectra of
1273 stars in the spectral region 3460 to 9464 \AA at a high resolution of 1
\AA FWHM and a wide range of spectral types. Cross-checking the reliability of
this database is an important and desirable exercise since a number of stars in
this database have no known spectral types and a considerable fraction of stars
has not so complete coverage in the full wavelength region of 3460-9464 \AA
resulting in gaps ranging from a few \AA to several tens of \AA. In this paper,
we use an automated classification scheme based on Artificial Neural Networks
(ANN) to classify all 1273 stars in the database. In addition, principal
component analysis (PCA) is carried out to reduce the dimensionality of the
data set before the spectra are classified by the ANN. Most importantly, we
have successfully demonstrated employment of a variation of the PCA technique
to restore the missing data in a sample of 300 stars out of the CFLIB.


title: Multiband optical monitoring of the blazars S5 0716+714 and BL Lacertae

abstract:
  We report results of multiband optical monitoring of two well known blazars,
S5 0716+714 and BL Lacertae, carried out in 1996 and 2000-01 with an aim to
study optical variations on time scales from minutes to hours and longer.The
light curves were derived relative to comparison stars present on the CCD
frames. Night to night flux variations of >0.1 mag were observed in S5 0716+714
during a campaign of ~2 weeks in 1996.A good correlation between the
lightcurves in different optical bands was found for both inter-night and
intra-night observations. Two prominent events of intra-night optical
variability were detected in S5 0716+714.Each of these rapidly varying segments
of the lightcurves trace an exponential flux profile whose rate of variation is
the same in both cases. Our long-term monitoring data of S5 0716+714 showed a
distinct flare around JD 2451875 which can be identified in the BVRI bands.This
flare coincides with the brightest phase recorded during 1994-2001 in the
long-term lightcurves reported by Raiteri et al.(2003). No evidence for the
bluer when brighter trend was noticed on inter-night and intra-night time
scales. On the other hand, our nearly simultaneous multiband observations of BL
Lacertae in October 2001 showed flux variations that were not achromatic. This
blazar was found to become bluer when brighter on intra-night time scales and
there is a hint of the same trend on inter-night time scales. Based on five
nights of observations during a week, BL Lacertae showed a peak night-to-night
variability of ~0.6 mag in B. Thus, we found that the present observations of
the two blazars, reveal a contrasting behaviour in terms of the dependence of
spectral hardening with increasing brightness, at least on intra-night, and
possibly also on inter-night, time scales.


title:
Ground-Based Gamma-Ray Astronomy at Energies Above 10 TeV: Searching for
  Galactic PeV Cosmic-Ray Accelerators

abstract:
  The origin of Galactic CRs up the knee energy remains unanswered and provides
strong motivation for the study of gamma-ray sources at energies above 10 TeV.
We discuss recent results from ground-based gamma-ray Cherenkov imaging systems
at these energies as well as future observational efforts in this direction.
The exciting results of H.E.S.S. give clues as to the nature of Galactic CR
accelerators, and suggest that there is a population of Galactic gamma-ray
sources with emission extending beyond 10 TeV. A dedicated system of Cherenkov
imaging telescopes optimised for higher energies appears to be a promising way
to study the multi-TeV gamma-ray sky.


title:
Filtration of atmospheric noise in narrow-field astrometry with very
  large telescopes

abstract:
  This paper presents a non-classic approach to narrow field astrometry that
offers a significant improvement over conventional techniques due to enhanced
reduction of atmospheric image motion. The method is based on two key elements:
apodization of the entrance pupil and the enhanced virtual symmetry of
reference stars. Symmetrization is implemented by setting special weights to
each reference star. Thus a reference field itself forms a virtual net filter
that effectively attenuates the image motion spectrum. Atmospheric positional
error was found to follow a power dependency ~ R^{K \mu /2} D^{-K/2+1/3} on
angular field size R and aperture D; here K is some optional even integer
2<=K<=sqrt{8N+1}-1 limited by a number N of reference stars, and \mu <= 1 is a
term dependent on K and the magnitude and sky star distribution in the field.
As compared to conventional techniques for which K=2, the improvement in
accuracy increases by some orders. Limitations to astrometric performance of
monopupil large ground-based telescopes are estimated. The total atmospheric
and photon noise for at a 10 m telescope at good 0.4" seeing was found to be,
depending on sky star density, 10 to 60 microarcsec per 10 min exposure in R
band. For a 100 m telescope and FWHM=0.1" (low-order adaptive optics
corrections) the potential accuracy is 0.2 to 2 microarcsec.


title: Adaptive Optics Concept For Multi-Objects 3D Spectroscopy on ELTs

abstract:
  In this paper, we present a first comparison of different Adaptive Optics
(AO) concepts to reach a given scientific specification for 3D spectroscopy on
Extremely Large Telescope (ELT). We consider that a range of 30%-50% of
Ensquarred Energy (EE) in H band (1.65um) and in an aperture size from 25 to
100mas is representative of the scientific requirements. From these preliminary
choices, different kinds of AO concepts are investigated : Ground Layer
Adaptive Optics (GLAO), Multi-Object AO (MOAO) and Laser Guide Stars AO (LGS).
Using Fourier based simulations we study the performance of these AO systems
depending on the telescope diameter.


title: Optical Photometry of Type II-P Supernova 2004dj in NGC 2403

abstract:
  We present photometric data of the type II-P supernova (SN) 2004dj in NGC
2403. The multicolor light curves cover the SN from $\sim$ 60 to 200 days after
explosion, and are measured with a set of intermediate-band filters that have
the advantage of tracing the strength variations of some spectral features. The
light curves show a flat evolution in the middle of the plateau phase, then
decline exponentially at the late times, with a rate of 0.10$\pm$0.03 mag (10
days)$^{-1}$ in most of the filters. In the nebular phase, the spectral energy
distribution (SED) of SN 2004dj shows a steady increase in the flux near 6600
\AA and 8500 \AA, which may correspond to the emission lines of H$\alpha$ and
Ca II near-IR triplet, respectively. The photometric behavior suggests that SN
2004dj is a normal SN II-P. Compared with the light curves of another typical
SN II-P 1999em, we estimate the explosion date to be June 10$\pm$21 UT, 2004
(JD 2453167$\pm$21) for SN 2004dj. We also estimate the ejected nickel mass
during the explosion to be $M(^{56}\rm{Ni})$ = 0.023 $\pm$ 0.005 $M_{\odot}$
from two different methods, which is typical for a SN II-P. We derive the
explosion energy $E \approx 0.75^{+0.56}_{-0.38}\times10^{51}$ erg, the ejecta
mass $M \approx 10.0^{+7.4}_{-5.2}$ $M_{\odot}$, and the initial radius $R
\approx 282^{+253}_{-122}$ $R_{\odot}$ for the presupernova star of SN 2004dj,
which are consistent with other typical SNe II-P.


title: Spherical Accretion in Nearby Weakly Active Galaxies

abstract:
  We consider the sample of weakly active galaxies situated in 'Local Universe'
collected in the paper of Pellegrini (2005) with inferred accretion
efficiencies from $10^{-2}$ to $10^{-7}$.
  We apply a model of spherically symmetrical Bondi accretion for given
parameters ($M_{BH}$,$T_{\infty}$,$\rho_{\infty}$,) taken from observation. We
calculate spectra emitted by the gas accreting onto its central objects using
Monte Carlo method including synchrotron and bremsstrahlung photons as seed
photons. We compare our results with observed nuclear X-ray luminosities
$L_{X,nuc}$ (0.3-10 keV) of the sample. Model is also tested for different
external medium parameters ($\rho_{\infty}$ and $T_{\infty}$) and different
free parameters of the model. Our model is able to explain most of the observed
nuclear luminosities $L_X$ under an assumption that half of the compresion
energy is transfered directly to the electrons.


title:
The effect of heat conduction on the interaction of disk and corona
  around black holes

abstract:
  Heat conduction plays an important role in the balance between heating and
cooling in many astrophysical objects, e.g. cooling flows in clusters of
galaxies. Here we investigate the effect of heat conduction on the interaction
between a cool disk and a hot corona around black holes. Using the
one-radial-zone approximation, we study the vertical structure of the disk
corona and derive evaporation and coronal mass flow rates for various reduced
thermal conductivities. We find lower evaporation rates and a shift in the
evaporation maxima to smaller radii. This implies that the spectral state
transition occurs at a lower mass flow rate and a disk truncation closer to the
black hole. Reductions of thermal conductivity are thought to be magnetically
caused and might vary from object to object by a different configuration of the
magnetic fields.


title: A Systematic Search for Periodicities in RXTE/ASM Data

abstract:
  We present the results of a systematic search in 8.5 years of Rossi X-ray
Timing Explorer All-Sky Monitor data for evidence of periodicities. The search
was conducted by application of the Lomb-Scargle periodogram to the light
curves of each of 458 actually or potentially detected sources in each of four
energy bands (1.5-3 keV, 3-5 keV, 5-12 keV, and 1.5-12 keV). A whitening
technique was applied to the periodograms before evaluation of the statistical
significance of the powers. We discuss individual detections with focus on
relatively new findings.


title:
Temperature distribution in magnetized neutron star crusts. II. The
  effect of a strong toroidal component

abstract:
  We continue the study of the effects of a strong magnetic field on the
temperature distribution in the crust of a magnetized neutron star (NS) and its
impact on the observable surface temperature. Extending the approach initiated
in Geppert et al.(2004), we consider more complex and, hence, more realistic,
magnetic field structures but still restrict ourselves to axisymmetric
configurations. We put special emphasis on the heat blanketing effect of a
toroidal field component. We show that asymmetric temperature distributions can
occur and a crustal field consisting of dipolar poloidal and toroidal
components will cause one polar spot to be larger than the opposing one. These
two warm regions can be separated by an extended cold equatorial belt. We
present an internal magnetic field structure which can explain both the X-ray
and optical spectra of the isolated NS RXJ 1856-3754. We investigate the
effects of the resulting surface temperature profiles on the observable
lightcurve which an isolated thermally emitting NS would produce for different
field geometries. The lightcurves will be both qualitatively (deviations from
sinusoidal shape) and quantitatively (larger pulsed fraction for the same
observational geometry) different from those of a NS with an isothermal crust.
This opens the possibility to determine the interna} magnetic field strengths
and structures in NSs by modeling their X-ray lightcurves and spectra. The
striking similarities of our model calculations with the observed spectra and
pulse profiles of isolated thermally emitting NSs is an indication for the
existence of strong magnetic field components maintained by crustal currents.


title: The long period Intermediate Polar 1RXSJ154814.5-452845

abstract:
  We present the first time resolved medium resolution optical spectroscopy of
the recently identified peculiar Intermediate Polar (IP) 1RXSJ154814.5-452845,
which allows us to precisely determine the binary orbital period
(Porb=9.87+/-0.03hr) and the white dwarf spin period Pspin=693.01+/-0.06s).
This system is then the third just outside the purported 6-10hr IP orbital
period gap and the fifth of the small group of long period IPs, which has a
relatively high degree of asynchronism. From the presence of weak red
absorption features, we identify the secondary star with a spectral type
K2+/-2V, which appears to have evolved on the nuclear timescale. From the
orbital radial velocities of emission and the red absorption lines a mass ratio
q=0.65+/-0.12 is found. The masses of the components are estimated to be Mwd >=
0.5Msun and Msec=0.4-0.79Msun and the binary inclination 25deg < i <=58deg . A
distance between 540-840pc is estimated. At this distance, the presence of
peculiar absorption features surrounding Balmer emissions cannot be due to the
contribution of the white dwarf photosphere and their spin modulation suggests
an origin in the magnetically confined accretion flow. The white dwarf is also
not accreting at a particularly high rate (Mdot<5x10**16g/s), for its orbital
period. The spin-to-orbit period ratio Pspin/Porb=0.02 and the low mass
accretion rate suggest that this system is far from spin equilibrium. The
magnetic moment of the accreting white dwarf is found to be < 4.1x10**32
Gcm**3, indicating a low magnetic field system.


title: SNSPH: A Parallel 3-D Smoothed Particle Radiation Hydrodynamics Code

abstract:
  We provide a description of the SNSPH code--a parallel 3-dimensional
radiation hydrodynamics code implementing treecode gravity, smooth particle
hydrodynamics, and flux-limited diffusion transport schemes. We provide
descriptions of the physics and parallelization techniques for this code. We
present performance results on a suite of code tests (both standard and new),
showing the versatility of such a code, but focusing on what we believe are
important aspects of modeling core-collapse supernovae.


title:
The Kyiv Meridian Axial Circle Catalogue of stars in fields with
  extragalactic radio sources

abstract:
  A catalogue of astrometric (positions, proper motions) and photometric (B, V,
R, r', J) data of stars in fields with ICRF objects has been compiled at the
Observatory of the National Academy of Sciences of Ukraine and the Kyiv
University Observatory. All fields are located in the declination zone from 0
to +30 degrees; the nominal field size is 46' (right ascension) x 24'
(declination). The observational basis of this work is 1100 CCD scans down to
V=17 mag which were obtained with the Kyiv meridian axial circle in 2001-2003.
The catalogue is presented in two versions. The version KMAC1-T contains 159
fields (104 796 stars) and was obtained with reduction to the Tycho2 catalogue.
For another 33 fields, due to a low sky density of Tycho2 stars, the reduction
was found to be unreliable. Transformation to the ICRF system in the second
version of the catalogue (KMAC1-CU) was performed using the UCAC2 and CMC13
catalogues as a reference; it contains 115 032 stars in 192 fields and is of
slightly better accuracy. The external accuracy of one catalogue position is
about 50-90 mas for V < 15 mag stars. The average error of photometry is better
than 0.1 mag for stars down to 16 mag.


title: On the binarity of Herbig Ae/Be stars

abstract:
  We present high resolution spectro-astrometry of a sample of 28 Herbig Ae/Be
and 3 F-type pre-main sequence stars. The spectro-astrometry is shown from both
empirical and simulated data to be capable of detecting binary companions that
are fainter by up to 6 magnitudes at separations larger than 0.1 arcsec. The
nine targets that were previously known to be a binary are all detected. In
addition, we report the discovery of 6 new binaries and present 5 further
possible binaries. The resulting binary fraction of 68+/-11 per cent is the
largest reported for any observed sample of Herbig Ae/Be stars, presumably
because of the exquisite sensitivity of spectro-astrometry for detecting binary
systems. The data hint that the binary frequency of the Herbig Be stars is
larger than for the Herbig Ae stars. The appendix presents model simulations to
assess the capabilities of spectro-astrometry and reinforces the empirical
findings. Two objects, HD 87643 and Z CMa, display evidence for asymmetric
outflows. Finally, the position angles of the binary systems have been compared
with available orientations of the circumprimary disc and these appear to be
co-planar. The alignment between the circumprimary discs and the binary systems
strongly suggests that the formation of binaries with intermediate mass
primaries is due to fragmentation as the alternative, stellar capture, does not
naturally predict aligned discs. The aligment extends to the most massive
B-type stars in our sample. This leads us to conclude that formation mechanisms
that do result in massive stars, but predict random angles beween the binaries
and the circumprimary disks, such as stellar collisions, are also ruled out for
the same reason.


title:
Mass distribution of highly flattened galaxies and modified Newtonian
  dynamics

abstract:
  Dynamics of spiral galaxies derived from a given surface mass density has
been derived earlier in a classic paper. We try to transform the singular
elliptic function in the integral into a compact integral with regular elliptic
function. Solvable models are also considered as expansion basis for RC data.
The result makes corresponding numerical evaluations easier and analytic
analysis possible. It is applied to the study of the dynamics of Newtonian
system and MOND as well. Careful treatment is shown to be important in dealing
with the cut-off of the input data.


title:
Muon production in extensive air showers and its relation to hadronic
  interactions

abstract:
  In this work, the relation between muon production in extensive air showers
and features of hadronic multiparticle production at low energies is studied.
Using CORSIKA, we determine typical energies and phase space regions of
secondary particles which are important for muon production in extensive air
showers and confront the results with existing fixed target measurements.
Furthermore possibilities to measure relevant quantities of hadron production
in existing and planned accelerator experiments are discussed.


title: The double AGN in NGC 6240 revealed through 3-5 micron spectroscopy

abstract:
  We present 3-5 micron spectroscopy of the interacting system NGC 6240,
showing the presence of two active galactic nuclei. The brightest (southern)
nucleus shows up with a starburst-like emission, with a prominent 3.3 micron
emission feature. However, the presence of an AGN is revealed by the detection
of a broad Br alpha emission line, with a width of ~1,800 km/s. The spectrum of
the faintest (northern) nucleus shows typical AGN features, such as a steep
continuum and broad absorption features in the M-band. We discuss the physical
properties of the dusty absorbers/emitters, and show that in both nuclei the
AGN is dominant in the 3-5 micron band, but its contribution to the total
luminosity is small (a few percent of the starburst emission).


title: Techniques for compact source extraction on CMB maps

abstract:
  The detection of compact sources embedded in a background is a very common
problem in many fields of Astronomy. In these lecture notes we present a review
of different techniques developed for the detection and extraction of compact
sources, with a especial focus on their application to the field of the cosmic
microwave background radiation. In particular, we will consider the detection
of extragalactic point sources and the thermal and kinematic Sunyaev-Zeldovich
effects from clusters of galaxies.


title: Spectroscopic search for binaries among EHB stars in globular clusters

abstract:
  We performed a spectroscopic search for binaries among hot Horizontal Branch
stars in globular clusters. We present final results for a sample of 51 stars
in NGC6752, and preliminary results for the first 15 stars analyzed in M80. The
observed stars are distributed along all the HBs in the range 8000 < Teff <
32000 K, and have been observed during four nights. Radial velocity variations
have been measured with the cross-correlation technique. We carefully analyzed
the statistical and systematic errors associated with the measurements in order
to evaluate the statistical significance of the observed variations. No close
binary system has been detected, neither among cooler stars nor among the
sample of hot EHB stars (18 stars with Teff > 22000 K in NGC6752). The data
corrected for instrumental effects indicate that the radial velocity variations
are always below the 3sigma level of ~15 km/s. These results are in sharp
contrast with those found for field hot subdwarfs, and open new questions about
the formation of EHB stars in globular clusters, and possibly of the field
subdwarfs.


title: Radiatively Inefficient Accretion Flow in the Nucleus of NGC 1097

abstract:
  We present a model for the accretion flow around the supermassive black hole
in the LINER nucleus of NGC 1097 which fits the optical to X-ray spectral
energy distribution (SED). The X-ray segment of the SED is based on
observations with the Chandra X-Ray Observatory, which are reported here for
the first time. The inner part of the flow is modeled as a radiatively
inefficient accretion flow (RIAF) and the outer part as a standard thin disk.
The value of the transition radius (~225 Schwarzschild radii) between the RIAF
and outer thin disk was obtained from our previous fitting of the double-peaked
Balmer emission line profile, which originates in the thin disk. The black hole
mass was inferred from measurements of the stellar velocity dispersion in the
host galaxy. When these parameters are used in the accretion flow model, the
SED can be successfully reproduced, which shows that the line profile model and
the accretion flow model are consistent with each other. A small remaining
excess in the near-UV is accounted by the contribution of an obscured starburst
located within 9 pc from the nucleus, as we reported in an earlier paper. The
radio flux is consistent with synchrotron emission of a relativistic jet
modeled by means of the internal shock scenario. In an appendix we also analyze
the Chandra X-ray observations of the ~1 kpc circumnuclear star-forming ring
and of an ultraluminous compact X-ray source located outside the ring.


title: A Mid-Infrared Study of the Class 0 Cluster in LDN 1448

abstract:
  We present ground-based mid-infrared observations of Class 0 protostars in
LDN 1448. Of the five known protostars in this cloud, we detected two, L1448N:A
and L1448C, at 12.5, 17.9, 20.8, and 24.5 microns, and a third, L1448 IRS 2, at
24.5 microns. We present high-resolution images of the detected sources, and
photometry or upper limits for all five Class 0 sources in this cloud. With
these data, we are able to augment existing spectral energy distributions
(SEDs) for all five objects and place them on an evolutionary status diagram.


title:
Absolute measurement of the unresolved cosmic X-ray background in the
  0.5-8 keV band with Chandra

abstract:
  We present the absolute measurement of the unresolved 0.5-8 keV cosmic X-ray
background (CXB) in the Chandra Deep Fields (CDFs) North and South, the longest
observations with Chandra (2 Ms and 1 Ms, respectively). We measure the
unresolved CXB intensity by extracting spectra of the sky, removing all point
and extended sources detected in the CDF. To model and subtract the
instrumental background, we use observations obtained with ACIS in stowed
position, not exposed to the sky. The unresolved signal in the 0.5-1 keV band
is dominated by diffuse Galactic and local thermal-like emission. In the 1-8
keV band, the unresolved spectrum is adequately described by a power law with a
photon index 1.5. We find unresolved CXB intensities of (1.04+/-0.14)x10^-12
ergs cm^-2 s^-1 deg^-2 for the 1-2 keV band and (3.4+/-1.7)x10^-12 ergs cm^-2
s^-1 deg^-2 for the 2-8 keV band. Our detected unresolved intensities in these
bands significantly exceed the expected flux from sources below the CDF
detection limits, if one extrapolates the logN/logS curve to zero flux. Thus
these background intensities imply either a genuine diffuse component, or a
steepening of the logN/logS curve at low fluxes, most significantly for
energies <2 keV. Adding the unresolved intensity to the total contribution from
sources detected in these fields and wider-field surveys, we obtain a total
intensity of the extragalactic CXB of (4.6+/-0.3)x10^-12 ergs cm^-2 s^-1 deg^-2
for 1-2 keV and (1.7+/-0.2)x10^-11 ergs cm^-2 s^-1 deg^-2 for 2-8 keV. These
totals correspond to a CXB power law normalization (for photon index 1.4) of
10.9 photons cm^-2 s^-1 keV^-1 sr^-1 at 1 keV. This corresponds to resolved
fracations of 77+/-3% and 80+/-8% for 1-2 and 2-8 keV, respectively.


title: The Oxygen Abundance of HE 1327-2326

abstract:
  From a newly obtained VLT/UVES spectrum we have determined the oxygen
abundance of HE 1327-2326, the most iron-poor star known to date. UV-OH lines
yield a 1D LTE abundance of [O/Fe]_OH = 3.7 (subgiant case) and [O/Fe]_OH = 3.4
(dwarf case). Using a correction of -1.0 dex to account for 3D effects on OH
line formation, the abundances are lowered to [O/Fe] = 2.8 and [O/Fe] = 2.5,
respectively, which we adopt. Without 3D corrections, the UV-OH based abundance
would be in disagreement with the upper limits derived from the OI triplet
lines: [O/Fe]_trip < 2.8 (subgiant) and [O/Fe]_trip < 3.0 (dwarf). We also
correct the previously determined carbon and nitrogen abundances for 3D
effects. Knowledge of the O abundance of HE 1327-2326 has implications for the
interpretation of its abundance pattern. A large O abundance is in accordance
with HE 1327-2326 being an early Population II star which formed from material
chemically enriched by a first generation supernova. Our derived abundances,
however, do not exclude other possibilities such as a Population III scenario.


title:
Integrated optics for astronomical interferometry - VI. Coupling the
  light of the VLTI in K band

abstract:
  Our objective is to prove that integrated optics (IO) is not only a good
concept for astronomical interferometry but also a working technique with high
performance. We used the commissioning data obtained with the dedicated K-band
integrated optics two-telescope beam combiner which now replaces the fiber
coupler MONA in the VLTI/VINCI instrument. We characterize the behaviour of
this IO device and compare its properties to other single mode beam combiner
like the previously used MONA fiber coupler. The IO combiner provides a high
optical throughput, a contrast of 89% with a night-to-night stability of a few
percent. Even if a dispersive phase is present, we show that it does not bias
the measured Fourier visibility estimate. An upper limit of 0.005 for the
cross-talk between linear polarization states has been measured. We take
advantage of the intrinsic contrast stability to test a new astronomical
prodecure for calibrating diameters of simple stars by simultaneously fitting
the instrumental contrast and the apparent stellar diameters. This method
reaches an accuracy with diameter errors of the order of previous ones but
without the need of an already known calibrator. These results are an important
step of integrated optics and paves the road to incoming imaging interferometer
projects.