title:
B and Be stars in the Magellanic Clouds: rotation, evolution and
  variability

abstract:
  Thanks to observations at the ESO VLT with the GIRAFFE multifibers
spectrograph, we have obtained spectra of 177 and 346 B-type stars in the Large
and Small Magellanic Clouds respectively. We have discovered 25 and 90 new Be
stars among the 47 and 131 Be stars observed in the LMC and SMC respectively.
We have determined the fundamental parameters of these stars and examined the
effect of the metallicity, star formation conditions and evolution on the
behaviour of the rotational velocities. We discovered that only the future
B-type stars with a strong rotational velocity in ZAMS will become a Be star.
We have also discovered short term variability in several SMC Be stars thanks
to a cross-correlation with the MACHO database.


title: The spectrum of the B[e] star BAL224

abstract:
  We present optical spectroscopy of the emission line star BAL 224 (V=17.3,
B-V=0.46). This star also named KWBBE 485, [MA93]906 is located at the
periphery of the young SMC cluster NGC 330; it is known as a photometric
variable with a possible period around 1 day (Balona 1992). Furthermore it was
reported as the optical counterpart of the prominent mid-infrared source (MIR1)
by Kucinskas et al. (2000), indicating the presence of a dust shell. The star
was included in a sample of B-type stars observed using the ESO VLT-FLAMES
facilities. The presence of emission lines such as Fe II,[Fe II], [S II] make
this object like a B[e] star. The H$ alpha$, H$ gamma$ and H$ delta$ lines show
an asymmetrical double-peaked emission profile suggesting the presence of an
accretion disk. Moreover the MACHO and OGLE light curves were analyzed; in
addition to a long-term variability ($ simeq$ 2300d), a short period very close
to 1 day has been detected using different methods, confirming the variability
previously reported by Balona (1992). Finally the nature of this object is
reconsidered.


title:
3-Dimensional Simulations of the Reorganization of a Quark Star's
  Magnetic Field as Induced by the Meissner Effect

abstract:
  In a previous paper (Ouyed et al. 2004) we presented a new model for soft
gamma-ray repeaters (SGR), based on the onset of colour superconductivity in
quark stars. In this model, the bursts result from the reorganization of the
exterior magnetic field following the formation of vortices that confine the
internal magnetic field (the \mz effect). Here we extend the model by
presenting full 3-dimensional simulations of the evolution of the inclined
exterior magnetic field immediately following vortex formation. The simulations
capture the violent reconnection events in the entangled surface magnetic field
as it evolves into a smooth, more stable, configuration which consists of a
dipole field aligned with the star's rotation axis. The total magnetic energy
dissipated in this process is found to be of the order of $10^{44}
\mathrm{erg}$ and, if it is emitted as synchrotron radiation, peaks typically
at $280 \mathrm{keV}$. The intensity decays temporally in a way resembling SGRs
and AXPs (anomalous X-ray pulsars), with a tail lasting from a few to a few
hundred times the rotation period of the star, depending on the initial
inclination between the rotation and dipole axis. One of the obvious
consequences of our model's final state (aligned rotator) is the suppression of
radio-emission in SGRs and AXPs following their bursting era. We suggest that
magnetar-like magnetic field strength alone cannot be responsible for the
properties of SGRs and AXPs, while a quark star entering the ``Meissner phase''
is compatible with the observational facts. We compare our model to
observations and highlight our predictions.


title: Comment on "On curvature coupling and quintessence fine-tuning"

abstract:
  In this comment, we show explicitly that the phenomenological model in which
the quintessence field depends linearly on the energy density of the spatial
curvature can provide acceleration for the universe, contrary to recent claims
it could not.


title:
Unveiling the thermal and magnetic map of neutron star surfaces though
  their X-ray emission: method and lightcurves analysis

abstract:
  Recent Chandra and XMM-Newton observations of a number of X-ray ``dim''
pulsating neutron stars revealed quite unexpected features in the emission from
these sources. Their soft thermal spectrum, believed to originate directly from
the star surface, shows evidence for a phase-varying absorption line at some
hundred eVs. The pulse modulation is relatively large (pulsed fractions in the
range ~12%-35%), the pulse shape is often non-sinusoidal, and the hard X-ray
color appears to be anti-correlated in phase with the total emission. Moreover,
the prototype of this class, RX J0720.4-3125, has been found to undergo rather
sensible changes both in its spectral and timing properties over a timescale of
a few years. All these new findings seem difficult to reconcile with the
standard picture of a cooling neutron star endowed with a purely dipolar
magnetic field, at least if surface emission is produced in an atmosphere on
top of the crust. In this paper we explore how a dipolar+quadrupolar
star-centered field influence the properties of the observed lightcurves. The
phase-resolved spectrum has been evaluated accounting for both radiative
transfer in a magnetized atmosphere and general relativistic ray-bending. We
computed over 78000 lightcurves varying the quadrupolar components and the
viewing geometry. A comparison of the data with our model indicate that higher
order multipoles are required to reproduce the observations.


title: Low-luminosity Active Galaxies and their Central Black Holes

abstract:
  Central black hole masses for 118 spiral galaxies representing morphological
stages S0/a through Sc and taken from the large spectroscopic survey of Ho,
Filippenko & Sargent (1997) are derived using 2MASS Ks data. Black hole (BH)
masses are found using a calibrated black-hole - Ks bulge luminosity relation,
while bulge luminosities are measured using GALFIT, a two-dimensional
bulge/disk decomposition routine.
  The BH masses are correlated against a variety of nuclear and host-galaxy
properties. Nuclear properties such as line width and line ratios show a very
high degree of correlation with BH mass. The excellent correlation with
line-width supports the view that the emission-line gas is in virial
equilibrium with either the BH or bulge potential. The very good emission-line
ratio correlations may indicate a change in ionizing continuum shape with BH
mass in the sense that more massive BHs generate harder spectra.
  Apart from the inclination-corrected rotational velocity, no excellent
correlations are found between BH mass and host-galaxy properties.
  Significant differences are found between the distributions of BH masses in
early-, mid- and later-type spiral galaxies in the sense that early-type
galaxies have preferentially larger central BHs. The line-width distributions
show a marked difference among the subsamples in the sense that earlier-type
galaxies have larger line widths. There are also clear differences in line
ratios between subsamples likely related to the level of ionization in the gas.
Finally, a Ks-band Simien & de Vaucouleurs diagram shows excellent agreement
with the original B-band relation.


title: Outflowing disk winds in B[e] Supergiants

abstract:
  The effects of rapid rotation and bi--stability upon the density contrast
between the equatorial and polar directions of a B[e] supergiant are
investigated. Based on a new slow solution for different high rotational
radiation--driven winds and the fact that bi--stability allows a change in the
line--force parameters ($\alpha$, $k$, and $\delta$), the equatorial densities
are about $10^2$--$10^3$ times higher than the polar ones. These values are in
qualitative agreement with the observations. This calculation also permits to
obtain the aperture angle of the disk.


title: A search for the most massive galaxies: Double Trouble?

abstract:
  We describe the results of a search for galaxies with large (> 350 km/s)
velocity dispersions. The largest systems we have found appear to be the
extremes of the early-type galaxy population: compared to other galaxies with
similar luminosities, they have the largest velocity dispersions and the
smallest sizes. However, they are not distant outliers from the Fundamental
Plane and mass-to-light scaling relations defined by the bulk of the early-type
galaxy population. They may host the most massive black holes in the Universe,
and their abundance and properties can be used to constrain galaxy formation
models. Clear outliers from the scaling relations tend to be objects in
superposition (angular separations smaller than 1 arcsec), evidence for which
comes sometimes from the spectra, sometimes from the images, and sometimes from
both. The statistical properties of the superposed pairs, e.g., the
distribution of pair separations and velocity dispersions, can be used to
provide useful information about the expected distribution of image
multiplicities, separations and flux ratios due to gravitational lensing by
multiple lenses, and may also constrain models of their interaction rates.


title:
Luminosity Functions and Star Formation Rates at z~6-10: Galaxy Buildup
  in the Reionization Age

abstract:
  HST ACS and NICMOS data are now of sufficient depth and areal coverage to
place strong constraints on the formation and evolution of galaxies during the
first 1-2 Gyrs of the universe. Of particular interest are galaxies at z~6
since they represent the earliest epoch accessible by current high-efficiency
optical instrumentation. To this end, we have constructed a sample of 506 z~6
objects from all the deepest wide-area HST data (UDF, UDF-Parallel, and GOODS
fields). They have been used to construct an optimal determination of the
rest-frame continuum UV LF at z~6. Our LF extends to over 3 magnitudes below
L*, fainter than has been done at z~3. Over the interval z~6 to z~3, we find
strong evidence for evolution in the UV LF. Though constraints on the faint-end
slope remain modest (and are consistent with no-evolution), the characteristic
luminosity appears to have approximately doubled over the interval z~6 to z~3,
consistent with hierarchical expectations. Remarkably, this shift to lower
luminosities extends to even higher redshifts. Using all deep J+H NICMOS
observations (800 orbits in total), we have been able to demonstrate that the
bright end of the LF (>0.3L*) is at least 5 times lower at z~10 than at z~4,
with a similar deficit being established from our recent detections and first
statistical sample of z~7-8 galaxies using our UDF NICMOS data. In these
proceedings, we discuss what is known about the UV LF and UV luminosity density
at z~6-10 from current data and its evolution relative to z~3. We also describe
several exciting prospects for advance in this area over the next year.


title: Jets in neutron star X-ray binaries: a comparison with black holes

abstract:
  (Abridged) We present a comprehensive study of the relation between radio and
X-ray emission in neutron star X-ray binaries, use this to infer the general
properties of the disc-jet coupling in such systems, and compare the results
quantitatively with those already established for black hole systems. There are
clear qualitative similarities between the two classes of object: hard states
below about 1% of the Eddington luminosity produce steady jets, while transient
jets are associated with outbursting and variable sources at the highest
luminosities. However, there are important quantitative differences: the
neutron stars are less radio-loud for a given X-ray luminosity (regardless of
mass corrections), and they do not appear to show the strong suppression of
radio emission in steady soft states which we observe in black hole systems.
Furthermore, in the hard states the correlation between radio and X-ray
luminosities of the neutron star systems is steeper than the relation observed
in black holes by about a factor of two. This result strongly suggests that the
X-ray emission in the black hole systems is radiatively inefficient, with an
approximate relation of the form L_X \propto \dot{m}^2, consistent with both
advection-dominated models and jet-dominated scenario. On the contrary the jet
power in both classes of object scales linearly with accretion rate. This
constitutes some of the first observational evidence for the radiatively
inefficient scaling of X-ray luminosity with accretion rate in accreting black
hole systems.


title: X-ray Spectral States and High-Frequency QPOs in Black Hole Binaries

abstract:
  The high-frequency quasi-periodic oscillations in the X-ray emission of black
hole binaries and candidates are briefly examined with respect to the question
of X-ray states. We use the prescription of McClintock and Remillard (2005), in
which X-ray spectra and power density spectra are used to differentiate three
main states of active accretion: "thermal", "hard", and "steep power-law". For
the sources that exhibit pairs of HFQPOs with frequencies that scale in a 3:2
ratio, the QPO detections are associated with the steep power-law state.
Furthermore, there is a clear trend in which the oscillation at twice the
fundamental frequency is seen when the source has high X-ray luminosity, while
the QPO at three times the fundamental frequency is seen at lower luminosity.


title:
The role of absorption and reflection in the soft X-ray excess of Active
  Galactic Nuclei : 1. Preliminary results

abstract:
  The 2-10 keV continuum of AGN is well represented by a single power law,
generally attributed to a hot comptonizing medium, such as a corona above the
accretion disk. At smaller energies the continuum displays an excess with
respect to the extrapolation of this power law, called the ``soft X-ray
excess". Until now it was attributed, either to reflection of the hard X-ray
source by the accretion disk, or to the presence of an additional comptonizing
medium. An alternative solution proposed by Gierli\'nski & Done (2004) is that
a single power law represents correctly both the soft and the hard X-ray
emission, and the soft X-ray excess is an artefact due to the absorption of the
primary power law by a relativistic wind. We examine the advantages and
drawbacks of the reflection versus absorption models. We argue that in the
absorption hypothesis, the absorbing medium should be in total pressure
equilibrium, to constrain the spectral distribution which otherwise would be
too strongly variable in time and from one object to the other, as compared to
observations. We conclude that some X-ray spectra, in particular those with
strong soft X-ray excesses, can be modelled by absorption in the 0.3-10 keV
range. However, due to the lack of a complete grid of models and good data
extending above 10 keV, we are not able to conclude presently that all objects
can be accommodated with such models. These absorption models imply either
strong relativistic outflowing winds with mass rates of the order of the
Eddington value (or even larger), or quasi-spherical inhomogeneous accretion
flows. Only weak excesses can be modelled by reflection, unless the primary
continuum is not directly seen. Finally, a reflection model absorbed by a
modest relativistic wind could be the best solution to the problem.


title: Non-thermal high-energy emission from colliding winds of massive stars

abstract:
  Colliding winds of massive star binary systems are considered as potential
sites of non-thermal high-energy photon production. This is motivated merely by
the detection of synchrotron radio emission from the expected colliding wind
location. Here we investigate the properties of high-energy photon production
in colliding winds of long-period WR+OB-systems. We found that in the
dominating leptonic radiation process anisotropy and Klein-Nishina effects may
yield spectral and variability signatures in the gamma-ray domain at or above
the sensitivity of current or upcoming gamma-ray telescopes. Analytical
formulae for the steady-state particle spectra are derived assuming diffusive
particle acceleration out of a pool of thermal wind particles, and taking into
account adiabatic and all relevant radiative losses. For the first time we
include their advection/convection in the wind collision zone, and distinguish
two regions within this extended region: the acceleration region where spatial
diffusion is superior to convective/advective motion, and the convection region
defined by the convection time shorter than the diffusion time scale. The
calculation of the Inverse Compton radiation uses the full Klein-Nishina cross
section, and takes into account the anisotropic nature of the scattering
process. This leads to orbital flux variations by up to several orders of
magnitude which may, however, be blurred by the geometry of the system. The
calculations are applied to the typical WR+OB-systems WR 140 and WR 147 to
yield predictions of their expected spectral and temporal characteristica and
to evaluate chances to detect high-energy emission with the current and
upcoming gamma-ray experiments. (abridged)


title:
Conservative special relativistic radiative transfer for
  multidimensional astrophysical simulations: motivation and elaboration

abstract:
  Many astrophysical phenomena exhibit relativistic radiative flows. While
velocities in excess of $v \sim 0.1c$ can occur in these systems, it has been
common practice to approximate radiative transfer to $\cO(v/c)$. In the case of
neutrino transport in core-collapse supernovae, this approximation gives rise
to an inconsistency between the lepton number transfer and lab frame energy
transfer, which have different $\cO(v/c)$ limits. A solution used in
spherically symmetric $\cO(v/c)$ simulations has been to retain, for energy
accounting purposes, the $\cO(v^2/c^2)$ terms in the lab frame energy transfer
equation that arise from the $\cO(v/c)$ neutrino number transport equation.
Avoiding the proliferation of such ``extra'' $\cO(v^2/c^2)$ terms in the
absence of spherical symmetry motivates a special relativistic formalism, which
we exhibit in coordinates sufficiently general to encompass Cartesian,
spherical, and cylindrical coordinate systems.


title:
X-rays from the radio-quiet quasar PG 1407+265: relativistic jet or
  accretion disc emission?

abstract:
  We present two XMM-Newton observations of the luminous (L_x > 10^46 erg/s),
radio-quiet quasar, PG 1407+265, separated by eleven months. The data indicate
two distinct states: a highly variable, bright state (first epoch); and a
quiescent, low-flux one (second epoch). During the low-flux state the spectrum
is consistent with a single, unabsorbed power law. However, during the brighter
state a highly variable, steep component is statistically required.
Contemporaneous UV data from the Optical Monitor allow an estimate of the
optical-to-X-ray spectral index (alpha_ox), which appears typical of
radio-quiet quasars during the low-flux state, but extremely flat during the
high-flux state. The XMM-Newton data can be described as originating from a
combination of jet and accretion disc processes, in which the (relativistic)
X-ray jet only works intermittently. The scenario could help describe some of
the complexities seen in the broadband spectral energy distribution of PG
1407+265, such as weak high-ionisation emission lines, strong Fe II, unbeamed
continuum, and the weak radio emission relative to the optical.


title: The Long Term: Six-dimensional Core-collapse Supernova Models

abstract:
  The computational difficulty of six-dimensional neutrino radiation
hydrodynamics has spawned a variety of approximations, provoking a long history
of uncertainty in the core-collapse supernova explosion mechanism. Under the
auspices of the Terascale Supernova Initiative, we are honoring the physical
complexity of supernovae by meeting the computational challenge head-on,
undertaking the development of a new adaptive mesh refinement code for
self-gravitating, six-dimensional neutrino radiation magnetohydrodynamics. This
code--called {\em GenASiS}, for {\em Gen}eral {\em A}strophysical {\em
Si}mulation {\em S}ystem--is designed for modularity and extensibility of the
physics. Presently in use or under development are capabilities for Newtonian
self-gravity, Newtonian and special relativistic magnetohydrodynamics (with
`realistic' equation of state), and special relativistic energy- and
angle-dependent neutrino transport--including full treatment of the energy and
angle dependence of scattering and pair interactions.


title:
Implications of the DAMA/NaI and CDMS experiments for mirror matter-type
  dark matter

abstract:
  We re-analyse the implications of the DAMA/NaI experiment for mirror
matter-type dark matter, taking into account information from the energy
dependence of the DAMA annual modulation signal. This is combined with the null
results from the CDMS experiment, leading to fairly well defined allowed
regions of parameter space. The allowed regions of parameter space will be
probed in the near future by the DAMA/LIBRA, CDMS, and other experiments, which
should either exclude or confirm this explanation of the DAMA/NaI annual
modulation signal. In particular, we predict that the CDMS experiments should
find a positive signal around the threshold recoil energy region, E_R < 15 keV
in the near future.


title: Toward Five-dimensional Core-collapse Supernova Simulations

abstract:
  The computational difficulty of six-dimensional neutrino radiation
hydrodynamics has spawned a variety of approximations, provoking a long history
of uncertainty in the core-collapse supernova explosion mechanism. Under the
auspices of the Terascale Supernova Initiative, we are honoring the physical
complexity of supernovae by meeting the computational challenge head-on,
undertaking the development of a new adaptive mesh refinement code for
self-gravitating, six-dimensional neutrino radiation magnetohydrodynamics. This
code--called {\em GenASiS,} for {\em Gen}eral {\em A}strophysical {\em
Si}mulation {\em S}ystem--is designed for modularity and extensibility of the
physics. Presently in use or under development are capabilities for Newtonian
self-gravity, Newtonian and special relativistic magnetohydrodynamics (with
`realistic' equation of state), and special relativistic energy- and
angle-dependent neutrino transport--including full treatment of the energy and
angle dependence of scattering and pair interactions.


title:
A Method for Determining the Physical Properties of the Coldest Known
  Brown Dwarfs

abstract:
  We present a method for measuring the physical parameters of the coldest
T-type brown dwarfs using low resolution near infrared spectra. By comparing
H_2O- and H_2-sensitive spectral ratios between empirical data and theoretical
atmosphere models, and calibrating these ratios to measurements for the
well-characterized 2-5 Gyr companion brown dwarf Gliese 570D, we derive
estimates of the effective temperatures and surface gravities for 13 mid- and
late-type field T dwarfs. We also deduce the first quantitative estimate of
subsolar metallicity for the peculiar T dwarf 2MASS 0937+2931. Derived
temperatures are consistent with prior estimates based on parallax and
bolometric luminosity measurements, and examination of possible systematic
effects indicate that the results are robust. Two recently discovered late-type
T dwarfs, 2MASS 0939-2448 and 2MASS 1114-2618, both appear to be >50 K cooler
than the latest-type T dwarf, 2MASS 0415-0935, and are potentially the coldest
and least luminous brown dwarfs currently known. We find that, in general,
higher surface gravity T dwarfs have lower effective temperatures and
luminosities for a given spectral type, explaining previously observed scatter
in the Teff/spectral type relation for these objects. Masses, radii and ages
are estimated for the T dwarfs in our sample using the evolutionary models of
Burrows et al.; we also determine masses and radii independently for eight T
dwarfs with measured luminosities. These two determinations are largely
consistent, lending support to the validity of evolutionary models at late
ages. Our method is well suited to large samples of faint brown dwarfs, and can
ultimately be used to directly measure the substellar mass function and
formation history in the Galaxy.


title:
Examining the Seyfert - Starburst Connection with Arcsecond Resolution
  Radio Continuum Observations

abstract:
  We compare the arcsecond-scale circumnuclear radio continuum properties
between five Seyfert and five starburst galaxies, concentrating on the search
for any structures that could imply a spatial or causal connection between the
nuclear activity and a circumnuclear starburst ring. No evidence is found in
the radio emission for a link between the triggering or feeding of nuclear
activity and the properties of circumnuclear star formation. Conversely, there
is no clear evidence of nuclear outflows or jets triggering activity in the
circumnuclear rings of star formation. Interestingly, the difference in the
angle between the apparent orientation of the most elongated radio emission and
the orientation of the major axis of the galaxy is on average larger in
Seyferts than in starburst galaxies, and Seyferts appear to have a larger
physical size scale of the circumnuclear radio continuum emission. The
concentration, asymmetry, and clumpiness parameters of radio continuum emission
in Seyferts and starbursts are comparable, as are the radial profiles of radio
continuum and near-infrared line emission. The circumnuclear star formation and
supernova rates do not depend on the level of nuclear activity. The radio
emission usually traces the near-infrared Br-gamma and H2 1-0 S(1) line
emission on large spatial scales, but locally their distributions are
different, most likely because of the effects of varying local magnetic fields
and dust absorption and scattering.


title: Non Gaussianity of General Multiple-Field Inflationary Models

abstract:
  Using the "$\delta N$-formalism", We obtain the expression of the
non-Gaussianity of multiple-field inflationary models with the nontrivial
field-space metric. Further, we rewritten the result by using the slow-rolling
approximation.


title: Branchings in the gamma-process path revisited

abstract:
  The location of the (gamma,p)/(gamma,n) and (gamma,alpha)/(gamma,n) line at
gamma-process temperatures is discussed, using updated reaction rates based on
global Hauser-Feshbach calculations. The results can directly be compared to
classic gamma-process discussions. The nuclei exhibiting the largest
sensitivity to uncertainties in nuclear structure and reaction parameters are
specified and suggestions for experiments are made. Additionally, the impact of
employing two recent global alpha+nucleus potentials is discussed. It is found
that branchings at higher mass depend more sensitively on these potentials. The
case of 146Sm/144Sm production is addressed separately. Also in this case, the
more recent alpha+nucleus potentials seem to improve the issues concerning the
production of these Sm isotopes in massive stars. In conclusion it is found
that it is unlikely that the calculated underproduction of p nuclides in the
Mo-Ru region is due to nuclear physics deficiencies but that problems at higher
mass number may still be cured by improved nuclear input.


title:
Evidence for collisional depolarization in the MgH lines of the second
  solar spectrum

abstract:
  Analysis of the Hanle effect in solar molecular lines allows us to obtain
empirical information on hidden, mixed-polarity magnetic fields at
subresolution scales in the (granular) upflowing regions of the `quiet' solar
photosphere. Here we report that collisions seem to be very efficient in
depolarizing the rotational levels of MgH lines. This has the interesting
consequence that in the upflowing regions of the quiet solar photosphere the
strength of the hidden magnetic field cannot be sensibly larger than 10 G,
assuming the simplest case of a single valued microturbulent field that fills
the entire upflowing photospheric volume. Alternatively, an equally good
theoretical fit to the observed scattering polarization amplitudes can be
achieved by assuming that the rate of depolarizing collisions is an order of
magnitude smaller than in the previous collisionally dominated case, but then
the required strength of the hidden field in the upflowing regions turns out to
be unrealistically high. These constraints reinforce our previously obtained
conclusion that there is a vast amount of hidden magnetic energy and unsigned
magnetic flux localized in the (intergranular) downflowing regions of the quiet
solar photosphere.


title: A ZZ Ceti white dwarf in SDSS J133941.11+484727.5

abstract:
  We present time-resolved spectroscopy and photometry of the cataclysmic
variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in
the Sloan Digital Sky Survey Data Release 4. The orbital period determined from
radial velocity studies is 82.524(24)min, close to the observed period minimum.
The optical spectrum of SDSS1339 is dominated to 90% by emission from the white
dwarf. The spectrum can be successfully reproduced by a three-component model
(white dwarf, disc, secondary) with Twd=12500K for a fixed log g=8.0, d=170pc,
and a spectral type of the secondary later than M8. The mass transfer rate
corresponding to the optical luminosity of the accretion disc is very
low,~1.7x10^-13Msun/yr. Optical photometry reveals a coherent variability at
641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations
of the white dwarf. In addition, a long-period photometric variation with a
period of either 320min or 344min and an amplitude of 0.025mag is detected,
which bears no apparent relation with the orbital period of the system. Similar
long-period photometric signals have been found in the CVs
SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GW Lib and FS Aur, but so far
no working model for this behaviour is available.


title: Toy Stars in two dimensions

abstract:
  Toy Stars are gas masses where the compressibility is treated without
approximations but gravity is replaced by a force which, for any pair of
masses, is along their line of centres and proportional to their separation.
They provide an invaluable resource for testing the suitability of numerical
codes for astrophysical gas dynamics. In this paper we derive the equations for
both small amplitude oscillations and non linear solutions for rotating and
pulsating Toy Stars in two dimensions, and show that the solutions can be
reduced to a small number of ordinary differential equations. We compare the
accurate solutions of these equations with Smoothed Particle Hydrodynamics
(SPH) simulations. The two dimensional Toy Star solutions are found to provide
an excellent benchmark for SPH algorithms, highlighting many of the strengths
and also some weaknesses of the method.


title:
Gamma rays from the neutralino dark matter annihilations in the Milky
  Way substructures

abstract:
  High resolution simulations reveal that in the cold dark matter scenario the
structures form hierarchically and a large number of substructures survive in
the galactic halos. The substructures can be probed if they emit gamma rays via
dark matter annihilation. We calculated the gamma ray fluxes from the dark
matter annihilations in the substructures of our Galaxy within the frame of the
minimal supersymmetric extension of the standard model. The uncertainties of
the prediction from both the low energy supersymmetry and especially from the
density profiles of dark matter in the substructures are carefully
investigated. The cumulative number of substructures emitting gamma rays above
any given flux is calculated. Detectability of the gamma rays from the
substructures is discussed. We propose the viability to detect these signals
through the ground large field of view detectors.


title: Flux Measurement at 110 GeV of the Blazar Mrk 501 with CELESTE

abstract:
  The new analysis variable xi, shown to be powerful on the data taken with the
final configuration of CELESTE, has been applied to data taken with previous
detector configurations. First, the analysis is validated on Crab observations,
and then the cuts for the blazar Mrk 501 are optimized using Mrk 421 data since
the sources have similar declinations. Data from Mrk 501 was recorded in 2000
and 2001. The old analysis gave a 2.5 sigma excess. We obtain an excess of 2.9
sigma during this time and of 4.9 sigma during May and June 2000 that we
interpret as a gamma-ray signal from Mrk 501, for which we calculate a flux of
(6.9 +/- 2.2) * 10^{-7} photons m^{-2} s^{-1}. An upper limit from the other
data with no signal is determined.


title:
Comment on "Scalar-tensor gravity coupled to a global monopole and flat
  rotation curves" by Lee and Lee

abstract:
  The recent paper by Lee and Lee (2004) may strongly leave the impression that
astronomers have established that the rotation curves of spiral galaxies are
flat. We show that the old paradigm of Flat Rotation Curves lacks, today, any
observational support and following it at face value leads to intrinsically
flawed alternatives to the Standard Dark Matter Scenario. On the other side, we
claim that the rich systematics of spiral galaxy rotation curves, that reveals,
in the standard Newtonian Gravity framework, the phenomenon of dark matter, in
alternative scenarios, works as a unique benchmark.


title: Cosmic ray abundance measurements with the CAKE balloon experiment

abstract:
  We present the results from the CAKE (Cosmic Abundance below Knee Energy)
balloon experiment which uses nuclear track detectors. The final experiment
goal is the determination of the charge spectrum of CR nuclei with Z > 30 in
the primary cosmic radiation. The detector, which has a geometric acceptance of
\~ 1.7 m2 sr, was exposed in a trans-mediterranean stratospheric balloon
flight. Calibrations of the detectors used (CR39 and Lexan), scanning
strategies and algorithms for tracking particles in an automatic mode are
presented. The present status of the results is discussed


title:
Contribution of Compact Mass Transferring Systems to the Galactic
  Gravitational Wave Background

abstract:
  Compact object binaries, mostly double with dwarfs, are believed to be a
potential source of confusion-limited noise for the Laser Interferometer Space
Antenna (LISA). In a specific frequency range, this noise may rise above the
instrumental noise sources and hence hinder detection of other types of
signals, e.g. extreme mass ratio inspirals of stellar mass objects into
supermassive black holes. In most previous studies only detached populations of
compact object binaries have been considered. Here, we investigate the
influence of Galactic populations of compact mass transferring binaries on the
shape and strength of the LISA signal and compare our results with the signal
for detached binaries only. Our population synthesis includes all binary
systems containing two compact remnants. It is found that 99.5% of these
systems are double white dwarfs, and therefore we consider only binaries
consisting of two white dwarfs when calculating the LISA signal. We find that
the mass transferring binaries contributing to the confusion limited noise
dominate the population of LISA systems by number (60%), due to their long
lifetimes (few Gyrs). However, due to the very specific physical properties of
mass transferring systems, it is found that their contribution to the noise is
negligible at low frequencies and detached systems will set the magnitude of
the confusion-limited signal in this range. However, the mass transferring
systems begin to dominate the signal at higher frequencies (f>6 mHz). The
transition frequency at which the confusion limited regime becomes important is
found at 4 mHz. The addition of mass transferring systems tends to slightly
increase the transition frequency (from 3.5 to 4 mHz).


title:
Lensing Magnification and QSO-Galaxy Cross-Correlations: Observations,
  Theory and Simulations

abstract:
  We review observations and gravitational lensing theory related to the
magnification of background QSOs by intervening overdensities, and the induced
cross-correlation between sources and foreground galaxies. We pay special
attention to simulations, and present some preliminary results from high
resolution cluster simulations, which show the role of the halo core and
substructure on non-linear magnification. For massive clusters, deviations from
the weak gravitational lensing regime are significant on arcmin scales and
bellow. The accumulated knowledge in the field already shows that gravitational
lensing magnification is an important astrophysical and cosmological tool.


title:
Stellar Rotation in Young Clusters. II. Evolution of Stellar Rotation
  and Surface Helium Abundance

abstract:
  We derive the effective temperatures and gravities of 461 OB stars in 19
young clusters by fitting the H-gamma profile in their spectra. We use
synthetic model profiles for rotating stars to develop a method to estimate the
polar gravity for these stars, which we argue is a useful indicator of their
evolutionary status. We combine these results with projected rotational
velocity measurements obtained in a previous paper on these same open clusters.
We find that the more massive B-stars experience a spin down as predicted by
the theories for the evolution of rotating stars. Furthermore, we find that the
members of binary stars also experience a marked spin down with advanced
evolutionary state due to tidal interactions. We also derive non-LTE-corrected
helium abundances for most of the sample by fitting the He I 4026, 4387, 4471
lines. A large number of helium peculiar stars are found among cooler stars
with Teff < 23000 K. The analysis of the high mass stars (8.5 solar masses < M
< 16 solar masses) shows that the helium enrichment process progresses through
the main sequence (MS) phase and is greater among the faster rotators. This
discovery supports the theoretical claim that rotationally induced internal
mixing is the main cause of surface chemical anomalies that appear during the
MS phase. The lower mass stars appear to have slower rotation rates among the
low gravity objects, and they have a large proportion of helium peculiar stars.
We suggest that both properties are due to their youth. The low gravity stars
are probably pre-main sequence objects that will spin up as they contract.
These young objects very likely host a remnant magnetic field from their natal
cloud, and these strong fields sculpt out surface regions with unusual chemical
abundances.


title:
Hyades Oxygen Abundances from the Lambda 6300 [O I] Line: The
  Giant-Dwarf Discrepancy Revisited

abstract:
  We present the results of our abundance analysis of Fe, Ni, and O in high
S/N, high-resolution VLT/UVES and McDonald/2dcoude spectra of nine dwarfs and
three giants in the Hyades open cluster. The difference in Fe abundances
derived from Fe II and Fe I lines ([Fe II/H] - [Fe I/H]) and Ni I abundances
derived from moderately high-excitation (Chi ~ 4.20 eV) lines are found to
increase with decreasing T_eff for the dwarfs. Both of these findings are in
concordance with previous results of over-excitation/ionization in cool young
dwarfs. Oxygen abundances are derived from the Lambda 6300 [O I] line, with
careful attention given to the Ni I blend. The dwarf O abundances are in
star-to-star agreement within uncertainties, but the abundances of the three
coolest dwarfs (4573 < T_eff < 4834 K) evince an increase with decreasing
T_eff. Possible causes for the apparent trend are considered, including the
effects of over-dissociation of O-containing molecules. O abundances are
derived from the near-UV Lambda 3167 OH line in high-quality Keck/HIRES
spectra, and no such effects are found- indeed, the OH-based abundances show an
increase with decreasing T_eff, leaving the nature and reality of the cool
dwarf [O I]-based O trend uncertain. The mean relative O abundance of the six
warmest dwarfs (5075 < T_eff < 5978 K) is [O/H] = +0.14 +/- 0.02, and we find a
mean abundance of [O/H] = +0.08 +/- 0.02 for the giants. Thus, our updated
analysis of the Lambda 6300 [O I] line does not confirm the Hyades giant-dwarf
oxygen discrepancy initially reported by King & Hiltgen (1996), suggesting the
discrepancy was a consequence of analysis-related systematic errors....


title: Low energy antideuterons: shedding light on dark matter

abstract:
  Low energy antideuterons suffer a very low secondary and tertiary
astrophysical background, while they can be abundantly synthesized in dark
matter pair annihilations, therefore providing a privileged indirect dark
matter detection technique. The recent publication of the first upper limit on
the low energy antideuteron flux by the BESS collaboration, a new evaluation of
the standard astrophysical background, and remarkable progresses in the
development of a dedicated experiment, GAPS, motivate a new and accurate
analysis of the antideuteron flux expected in particle dark matter models. To
this extent, we consider here supersymmetric, universal extra-dimensions (UED)
Kaluza-Klein and warped extra-dimensional dark matter models, and assess both
the prospects for antideuteron detection as well as the various related sources
of uncertainties. The GAPS experiment, even in a preliminary balloon-borne
setup, will explore many supersymmetric configurations, and, eventually, in its
final space-borne configuration, will be sensitive to primary antideuterons
over the whole cosmologically allowed UED parameter space, providing a search
technique which is highly complementary with other direct and indirect dark
matter detection experiments.


title: Microlensing toward crowded fields: Theory and applications to M31

abstract:
  We present a comprehensive treatment of the pixel-lensing theory and apply it
to lensing experiments and their results toward M31. Using distribution
functions for the distances, velocities, masses, and luminosities of stars, we
derive lensing event rates as a function of the event observables. In contrast
to the microlensing regime, in the pixel-lensing regime (crowded or unresolved
sources) the observables are the maximum excess flux of the source above a
background and the full width at half-maximum (FWHM) time of the event. To
calculate lensing event distribution functions depending on these observables
for the specific case of M31, we use data from the literature to construct a
model of M31, reproducing consistently photometry, kinematics and stellar
population. We predict the halo- and self-lensing event rates for bulge and
disk stars in M31 and treat events with and without finite source signatures
separately. We use the M31 photon noise profile and obtain the event rates as a
function of position, field of view, and S/N threshold at maximum
magnification. We calculate the expected rates for WeCAPP and for a potential
Advanced Camera for Surveys (ACS) lensing campaign. The detection of two events
with a peak signal-to-noise ratio larger than 10 and a timescale larger than 1
day in the WeCAPP 2000/2001 data is in good agreement with our theoretical
calculations. We investigate the luminosity function of lensed stars for noise
characteristics of WeCAPP and ACS. For the pixel-lensing regime, we derive the
probability distribution for the lens masses in M31 as a function of the FWHM
timescale, flux excess and color, including the errors of these observables.


title:
Testing Models of the Individual and Cosmological Evolutions of Powerful
  Radio Galaxies

abstract:
  We seek to develop an essentially analytical model for the evolution of
Fanaroff-Riley Class II radio galaxies as they age individually and as their
numbers vary with cosmological epoch. Such modeling is required in order to
probe in more detail the impact of radio galaxies on the growth of structures
in the universe, which appears likely to have been quite significant at z > 1.
In this first paper of a series we compare three rather sophisticated
analytical models for the evolution of linear size and lobe power of FR II
radio galaxies, those of Kaiser, Dennett-Thorpe & Alexander (1997), Blundell,
Rawlings & Willott (1999), and Manolakou & Kirk (2002). We perform
multi-dimensional Monte Carlo simulations in order to compare the predictions
of each model for radio powers, sizes, redshifts and spectral indices with
data. The observational samples used here are the low frequency radio surveys,
3CRR, 6CE and 7CRS, which are flux-limited and complete. We search for and
describe the best parameters for each model, after doing statistical tests on
them. We find that no existing model can give acceptable fits to all the
properties of the surveys considered, although the Kaiser, Dennett-Thorpe &
Alexander (1997) model gives better overall results than do the Manolakou &
Kirk (2002) or Blundell, Rawlings & Willott (1999) models for most of the tests
we performed. We suggest ways in which these models may be improved.


title: High frequency QPOs: nonlinear oscillations in strong gravity

abstract:
  Some of the more promising ideas about the origin of the high frequency
variability (kHz QPOs) in the observed X-ray emissions of low-mass X-ray
binaries are contrasted with less promising ones.


title: Anisotropic k-essence cosmologies

abstract:
  We investigate a Bianchi type-I (BTI) cosmology with k essence and find the
set of models which dissipate the initial anisotropy. There are cosmological
models with extended tachyon fields and k essence having constant bariotropic
index. We obtain the conditions leading to a regular bounce of the average
geometry and the residual anisotropy on the bounce. For constant potential, we
develop purely kinetic k-essence models which are dust dominated in their early
stages, dissipate the initial anisotropy and end in a stable de Sitter
accelerated expansion scenario. We show that linear k field and polynomial
kinetic function models evolve asymptotically to Friedmann-Robertson-Walker
(FRW) cosmologies. The linear case is compatible with an asymptotic potential
interpolating between $V_l\propto \phi^{-\gamma_l}$, in the shear dominated
regime, and $V_l\propto\phi^{-2}$ at late time. In the polynomial case, the
general solution contains cosmological models with an oscillatory average
geometry. For linear k essence, we find the general solution in the BTI
cosmology when the k field is driven by an inverse square potential. This model
shares the same geometry than a quintessence field driven by an exponential
potential.


title:
Expected coalescence rates of NS-NS binaries for laser beam
  interferometers

abstract:
  The coalescence rate of two neutron stars (NS) is revisited. For estimation
of the number of bound NS-NS and the probability of their coalescence in a
timescale $\tau$, the galactic star formation history, directly derived from
observations, and the evolution of massive stars are considered. The newly
established galactic merging rate is $(1.7\pm 1.0) \times 10^{-5} yr^{-1}$,
while the local merging rate, including the contribution of elliptical
galaxies, is about a factor of two higher, $3.4 \times 10^{-5} yr^{-1}$. Using
the present data basis on galaxy distribution in the local universe and the
expected sensitivity of the first generation of laser beam interferometers, we
estimate that one event should occur every 125 years for LIGO and one event
each 148 years for VIRGO. The situation is considerably improved for
advanced-LIGO since we predict that 6 events per year should be detected
whereas for a recently proposed VIRGO new configuration, the event rate might
increase up to 3 events every two years.


title:
Mass Along the Line of Sight to the Gravitational Lens B1608+656: Galaxy
  Groups and Implications for H_0

abstract:
  We report the discovery of four groups of galaxies along the line of sight to
the B1608+656 gravitational lens system. One group is at the redshift of the
primary lensing galaxy (z = 0.631) and appears to have a low mass, with eight
spectroscopically-confirmed members and an estimated velocity dispersion of
150+/-60 km/s. The three other groups are in the foreground of the lens. These
groups contain ~10 confirmed members each, and are located at redshifts of
0.265, 0.426, and 0.520. Two of the three additional groups are centered
roughly on the lens system, while the third is centered ~1 arcminute south of
the lens. We find that each group provides an external convergence (kappa_ext)
of ~0.005--0.060, depending on the assumptions made in calculating the
convergence. For lens systems where no additional observables that can break
the mass-sheet degeneracy exist, the determination of H_0 will be biased high
by a factor of (1-kappa_ext)^{-1} if the external convergence is not properly
included in the model. For the B1608+656 system, the stellar velocity
dispersion of the lensing galaxy has been measured, thus breaking the
mass-sheet degeneracy due to the group that is physically associated with the
lens. The effect of the other groups along the line of sight can be folded into
the overall uncertainties due to large-scale structure (LSS) along the line of
sight. Because the B1608+656 system appears to lie along an overdense line of
sight, the LSS will cause the measurement of H_0 to be biased high for this
system. The systematic bias introduced by LSS could be 5% or greater.
(Abridged)


title:
Distribution of Damped Lyman-alpha Absorbers in a Lambda Cold Dark
  Matter Universe

abstract:
  We present the results of a numerical study of a galactic wind model and its
implications on the properties of damped Lyman-alpha absorbers (DLAs) using
cosmological hydrodynamic simulations. We vary both the wind strength and the
internal parameters of the the wind model in a series of cosmological SPH
simulations that include radiative cooling and heating by a UV background, star
formation, and feedback from supernovae and galactic winds. To test our
simulations, we examine the DLA `rate-of-incidence' as a function of halo mass,
galaxy apparent magnitude, and impact parameter. We find that the statistical
distribution of DLAs does not depend on the exact values of internal numerical
parameters that control the decoupling of hydrodynamic forces when the gas is
ejected from starforming regions. The DLA rate-of-incidence in our simulations
at z=3 is dominated by the faint galaxies with apparent magnitude R_AB < 25.5.
However, interestingly in a `strong wind' run, the differential distribution of
DLA sight-lines is peaked at Mhalo = 10^{12} Msun/h (R_AB~27), and the mean DLA
halo mass is Mmean=10^{12.4} Msun/h (R_AB ~ 26). These mass-scales are much
larger than those if we ignore winds, because galactic wind feedback suppresses
the DLA cross section in low-mass halos and increases the relative contribution
to the DLA incidence from more massive halos. The DLAs in our simulations are
more compact than the present-day disk galaxies, and the impact parameter
distribution is very narrow unless we limit the search for the host galaxy to
only bright LBGs. The comoving number density of DLAs is higher than that of
LBGs down to R_AB=30 mag if the physical radius of each DLA is smaller than 5
kpc/h_70. We discuss conflicts between current simulations and observations,
and potential problems with simulations based on the CDM model.


title:
Constraining the Emission Properties of TeV Blazar H1426+428 by the
  Synchrotron-Self-Compton Model

abstract:
  H1426+428 is one of blazars that are observed by $\gamma$-rays in the TeV
region. Because TeV $\gamma$-rays from distant sources are subject to
attenuation by the extragalactic background light (EBL) via electron-positron
pair production, the intrinsic spectrum of the TeV $\gamma$-rays should be
inferred by using the models of radiation processes and EBL spectrum. We set
constraints on the physical condition of H1426+428 with the
synchrotron-self-Compton model applying several EBL models. We find that the
emission region of H1426+428 is moving toward us with the bulk Lorentz factor
of $\sim 20$ and that its magnetic field strength is $\sim 0.1$ G. These
properties are similar to other TeV blazars such as Mrk 421 and Mrk 501.
However, the ratio of the energy density of nonthermal electrons to that of the
magnetic fields is about 190 and fairly larger than those of Mrk 421 and Mrk
501, which are about 5 -- 20. It is also found that the intensity of EBL in the
middle and near infrared wavelengths should be low, i.e., the intensity at 10
$\mu$m is about 1 nW m$^{-2}$ sr$^{-1}$ to account for the observed TeV
$\gamma$-ray flux. Because the spectral data of H1426+428 in X-rays and
$\gamma$-rays used in our analysis were not obtained simultaneously, further
observations of TeV blazars are necessary to make the constraints on EBL more
stringent.


title: The Standard Cosmological Model

abstract:
  The Standard Model of Particle Physics (SMPP) is an enormously successful
description of high energy physics, driving ever more precise measurements to
find "physics beyond the standard model", as well as providing motivation for
developing more fundamental ideas that might explain the values of its
parameters. Simultaneously, a description of the entire 3-dimensional structure
of the present-day Universe is being built up painstakingly. Most of the
structure is stochastic in nature, being merely the result of the particular
realisation of the "initial conditions" within our observable Universe patch.
However, governing this structure is the Standard Model of Cosmology (SMC),
which appears to require only about a dozen parameters. Cosmologists are now
determining the values of these quantities with increasing precision in order
to search for "physics beyond the standard model", as well as trying to develop
an understanding of the more fundamental ideas which might explain the values
of its parameters. Although it is natural to see analogies between the two
Standard Models, some intrinsic differences also exist, which are discussed
here. Nevertheless, a truly fundamental theory will have to explain both the
SMPP and SMC, and this must include an appreciation of which elements are
deterministic and which are accidental. Considering different levels of
stochasticity within cosmology may make it easier to accept that physical
parameters in general might have a non-deterministic aspect.


title: Obscured AGN: clues from high-resolution imaging and spectroscopy

abstract:
  We present a sample of 8 Seyfert 2 galaxies observed by HST, Chandra and
XMM-Newton. All of the sources present soft X-ray emission which is coincident
in extension and overall morphology with the [OIII] emission. The spectral
analysis reveals that the soft X-ray emission of all the objects is likely to
be dominated by a photoionized gas. We tested with the code CLOUDY a simple
scenario where the same gas photoionized by the nuclear continuum produces both
the soft X-ray and the [OIII] emission. Solutions satisfying the observed ratio
between the two components exist, and require the density to decrease with
radius roughly like $r^{-2}$, similarly to what often found for the Narrow Line
Region.


title: VIMOS-VLT and Spitzer observations of a radio galaxy at z=2.5

abstract:
  We present: 1) a kinematic and morphological study of the giant Lya nebula
associated with the radio galaxy MRC2104-242 (z = 2.49) based on integral field
spectroscopic VIMOS data from VLT; 2) a photometric study of the host (proto?)
galaxy based on Spitzer Space Telescope data.
  The galaxy appears to be embedded in a giant (>120 kpc) gas reservoir that
surrounds it completely. The kinematic properties of the nebula suggest that it
is a rotating structure, which would imply a lower limit to the dynamical mass
of ~3 x 1e11 Msun. An alternate scenario is that the gas is infalling. Such a
process would be able to initiate and sustain significant central starburst
activity, although it is likely to contribute with less than 10% of the total
stellar mass of the galaxy.
  The near- to mid-IR spectral energy distribution of the radio galaxy suggests
the existence of a reddened, E(B-V)=0.4(+/-)0 .1$, evolved stellar population
of age >~ 1.8 Gyr and mass 5(+/-)2 x 1e11 Msun. The implied formation redshift
is z_f >~ 6. This stellar mass is similar to the stellar masses found for
massive early-type galaxies at z~2 in deep, near-infrared surveys.


title: The gaseous haloes of disc galaxies

abstract:
  The study of gas outside the plane of disc galaxies is crucial to
understanding the circulation of material within a galaxy and between galaxies
and the intergalactic environment. We present new HI observations of the
edge-on galaxy NGC891, which show an extended halo component lagging behind the
disc in rotation. We compare these results for NGC891 with other detections of
gaseous haloes. Finally, we present a dynamical model for the formation of
extra-planar gas.


title:
VLTI/AMBER and VLTI/MIDI spectro-interferometric observations of the
  B[e] supergiant CPD-57 2874

abstract:
  We present the first high spatial and spectral observations of the
circumstellar envelope (CSE) of a B[e] supergiant (CPD$-57 2874$), performed
with the Very Large Telescope Interferometer (VLTI). Spectra, visibilities, and
closure phase, were obtained using the beam-combiner instruments AMBER (near-IR
interferometry with three 8.3 m Unit Telescopes or UTs) and MIDI (mid-IR
interferometry with two UTs). The interferometric observations of the CSE are
well fitted by an elliptical Gaussian model with FWHM diameters varying
linearly with wavelength. Typical diameters measured are $\simeq1.8\times3.4$
mas or $\simeq4.5\times8.5$ AU (adopting a distance of 2.5 kpc) at
$2.2\micron$, and $\simeq12\times15$ mas or $\simeq30\times38$ AU at
$12\micron$. The size of the region emitting the Br$\gamma$ flux is
$\simeq2.8\times5.2$ mas or $\simeq7.0\times13.0$ AU. The major-axis position
angle of the elongated CSE in the mid-IR ($\simeq144\degr$) agrees well with
previous polarimetric data, hinting that the hot-dust emission originates in a
disk-like structure. In addition to the interferometric observations we also
present new optical ($UBVR_{c}I_{c}$) and near-IR ($JHKL$) broadband
photometric observations of CPD$-57 2874$. Our spectro-interferometric VLTI
observations and data analysis support the non-spherical CSE paradigm for B[e]
supergiants.


title:
The vicinity of the galactic supergiant B[e] star CPD -57 2874 from
  near- and mid-IR long baseline spectro-interferometry with the VLTI (AMBER
  and MIDI)

abstract:
  We present the first spectro-interferometric observations of the
circumstellar envelope (CSE) of a B[e] supergiant (CPD -57 2874), performed
with the Very Large Telescope Interferometer (VLTI) using the beam-combiner
instruments AMBER (near-IR interferometry with three 8.3 m Unit Telescopes or
UTs) and MIDI (mid-IR interferometry with two UTs). Our observations of the CSE
are well fitted by an elliptical Gaussian model with FWHM diameters varying
linearly with wavelength. Typical diameters measured are $\simeq1.8\times3.4$
mas or $\simeq4.5\times8.5$ AU (adopting a distance of 2.5 kpc) at
$2.2\micron$, and $\simeq12\times15$ mas or $\simeq30\times38$ AU at
$12\micron$. We show that a spherical dust model reproduces the SED but it
underestimates the MIDI visibilities, suggesting that a dense equatorial disk
is required to account for the compact dust-emitting region observed. Moreover,
the derived major-axis position angle in the mid-IR ($\simeq144\degr$) agrees
well with previous polarimetric data, hinting that the hot-dust emission
originates in a disk-like structure. Our results support the non-spherical CSE
paradigm for B[e] supergiants.


title:
Investigation of Diffuse Hard X-ray Emission from the Massive
  Star-Forming Region NGC 6334

abstract:
  Chandra ACIS-I data of the molecular cloud and HII region complex NGC 6334
were analyzed. The hard X-ray clumps detected with ASCA (Sekimoto et al. 2000)
were resolved into 792 point sources. After removing the point sources, an
extended X-ray emission component was detected over a 5x9 pc2 region, with the
0.5-8 keV absorption-corrected luminosity of 2x10^33 erg/s. The contribution
from faint point sources to this extended emission was estimated as at most ~20
%, suggesting that most of the emission is diffuse in nature. The X-ray
spectrum of the diffuse emission was observed to vary from place to place. In
tenuous molecular cloud regions with hydrogen column density of 0.5~1x10^22
cm-2, the spectrum can be represented by a thermal plasma model with
temperatures of several keV. The spectrum in dense cloud cores exhibits harder
continuum, together with higher absorption more than ~3x10^22 cm-2. In some of
such highly obscured regions, the spectrum show extremely hard continua
equivalent to a photon index of ~1, and favor non-thermal interpretation. These
results are discussed in the context of thermal and non-thermal emissions, both
powered by fast stellar winds from embedded young early-type stars through
shock transitions.


title: Echoes from Ancient Supernovae in the Large Magellanic Cloud

abstract:
  In principle, the light from historical supernovae could still be visible as
scattered-light echoes even centuries later. However, while echoes have been
discovered around some nearby extragalactic supernovae well after the
explosion, targeted searches have not recovered any echoes in the regions of
historical Galactic supernovae. The discovery of echoes can allow us to
pinpoint the supernova event both in position and age and, most importantly,
allow us to acquire spectra of the echo light to type the supernova centuries
after the direct light from the explosion first reached the Earth. Here we
report on the discovery of three faint new variable surface brightness
complexes with high apparent proper motion pointing back to well-defined
positions in the Large Magellanic Cloud (LMC). These positions correspond to
three of the six smallest (and likely youngest) previously catalogued supernova
remnants, and are believed to be due to thermonuclear (Type Ia) supernovae.
Using the distance and proper motions of these echo arcs, we estimate ages of
610 and 410 yr for the echoes #2 and #3.


title:
The coronal structure of Speedy Mic - I: A densely packed prominence
  system beyond co-rotation

abstract:
  We present new observations of the prominence system on the K3 dwarf Speedy
Mic (BO Mic, HD 197890). Using an improved technique to track the absorption
features in H_alpha we find a very active prominence system with approximately
ten prominences on the observable hemisphere per rotation. From a total of 25
prominences we find an average axial distance of 2.85+/-0.54 R_* which is twice
the co-rotation radius above the stellar surface. We discuss the consequences
of these observations on the nature of the supporting magnetic structures. Two
consecutive nights, with complete phase coverage, combined with a further night
after a three night gap allow us to study the evolution of the prominence
system on two different timescales. Several of the prominences have
counterparts at similar phases on consecutive nights. During this interval many
prominences show evidence for evolution in their heights and phases of
observation. Five nights (13 rotation cycles) later we recover many prominences
at approximately the same phases. Whilst individual prominences change axial
distances or appear/re-appear from night-to-night the underlying prominence
supporting structures appear to be stable over as many as 13 stellar rotations.


title: Evidence for Fine Structure in the Chromospheric Umbral Oscillation

abstract:
  Novel spectro-polarimetric observations of the \ion{He}{1} multiplet are used
to explore the dynamics of the chromospheric oscillation above sunspot umbrae.
The results presented here provide strong evidence in support of the
two-component model proposed by Socas-Navarro and co-authors. According to this
model, the waves propagate only inside channels of sub-arcsecond width (the
``active'' component), whereas the rest of the umbra remains nearly at rest
(the ``quiet'' component). Although the observations support the fundamental
elements of that model, there is one particular aspect that is not compatible
with our data. We find that, contrary to the scenario as originally proposed,
the active component remains through the entire oscillation cycle and harbors
both the upflowing and the downflowing phase of the oscillation.


title:
Vertical Structure of Gas Pressure-Dominated Accretion Disks with Local
  Dissipation of Turbulence and Radiative Transport

abstract:
  (shortened) We calculate the vertical structure of a local patch of an
accretion disk in which heating by dissipation of MRI-driven MHD turbulence is
balanced by radiative cooling. Heating, radiative transport, and cooling are
computed self-consistently with the structure by solving the equations of
radiation MHD in the shearing-box approximation. Using a fully 3-d and
energy-conserving code, we compute the structure of this disk segment over a
span of more than five cooling times. After a brief relaxation period, a
statistically steady-state develops. Measuring height above the midplane in
units of the scale-height H predicted by a Shakura-Sunyaev model, we find that
the disk atmosphere stretches upward, with the photosphere rising to about 7H,
in contrast to the approximately 3H predicted by conventional analytic models.
This more extended structure, as well as fluctuations in the height of the
photosphere, may lead to departures from Planckian form in the emergent
spectra. Dissipation is distributed across the region within roughly 3H of the
midplane, but is very weak at greater altitudes. Because fluctuations in the
dissipation are particularly strong away from the midplane, the emergent
radiation flux can track dissipation fluctuations with a lag that is only
0.1--0.2 times the mean cooling time of the disk. Long timescale asymmetries in
the dissipation distribution can also cause significant asymmetry in the flux
emerging from the top and bottom surfaces of the disk. Radiative diffusion
dominates Poynting flux in the vertical energy flow throughout the disk.


title: Emission Line Properties of Seyfert 2 Nuclei

abstract:
  We present a study of the global properties of Joguet's sample of 65 Seyfert
2 galaxies. We use the population synthesis models of our Paper II to derive
`pure' emission-line spectra, and thus explore the statistical properties of
the nuclear nebular components and their relation to the stellar populations.
We find that the emission line clouds suffer substantially more extinction than
the starlight, and confirm the correlations between stellar and nebular
velocity dispersions and between emission line luminosity and velocity
dispersions. Nuclear luminosities correlate with stellar velocity dispersions.
Removing the contribution of young stars to the optical continuum produces a
tighter and steeper relation, $L \propto \sigma_\star^4$, consistent with the
Faber-Jackson law. Emission line ratios indicative of the gas excitation such
as [OIII]/H$\beta$ and [OIII]/[OII] are statistically smaller for Seyferts with
significant star-formation, implying that ionization by massive stars is
responsible for a substantial, and sometimes even a dominant, fraction of the
H$\beta$ and [OII] fluxes. We use our models to constrain the maximum fraction
of the ionizing power that can be generated by a hidden AGN. We correlate this
fraction with classical indicators of AGN photo-ionization: X-ray luminosity
and nebular excitation, but find no significant correlations. Thus, while there
is a strong contribution of starbursts to the excitation of the nuclear nebular
emission in low-luminosity Seyferts, the contribution of the hidden AGN remains
elusive even in hard X-rays. (abridged)


title: The Inner Caustics of Cold Dark Matter Halos

abstract:
  We prove that a flow of cold collisionless particles from all directions in
and out of a region necessarily forms a caustic. A corollary is that, in cold
dark matter cosmology, galactic halos have inner caustics in addition to the
more obvious outer caustics. The outer caustics are fold catastrophes located
on topological spheres surrounding the galaxy. To obtain the catastrophe
structure of the inner caustics, we simulate the infall of cold collisionless
particles in a fixed gravitational potential. The structure of inner caustics
depends on the angular momentum distribution of the infalling particles. We
confirm a previous result that the inner caustic is a "tricusp ring" when the
initial velocity field is dominated by net overall rotation. A tricusp ring is
a closed tube whose cross section is a section of an elliptic umbilic
catastrophe. However, tidal torque theory predicts that the initial velocity
field is irrotational. For irrotational initial velocity fields, we find the
inner caustic to have a tent-like structure which we describe in detail in
terms of the known catastrophes. We also show how the tent caustic transforms
into a tricusp ring when a rotational component is added to the initial
velocity field.


title: Simulation of quiet Sun waves in the Ca II infrared triplet

abstract:
  The Ca II infrared triplet around 8540 A is a good candidate for observing
chromospheric magnetism. We show results from combining a radiation
hydrodynamic simulation with a Stokes synthesis code. The simulation shows
interesting time-varying behavior of the Stokes V profiles as waves propagate
through the lines' formation regions. Disappearing and reappearing lobes in the
Stokes V profiles as well as profile asymmetries are closely related to the
atmospheric velocity gradients.


title:
Ruling the Universe: An Improved Method for Measuring H_0 with Galaxy
  Clusters

abstract: Withdrawn at the current time due to errors.


title: Blue Stragglers in Low-Luminosity Star Clusters

abstract:
  We examine the blue straggler populations of 13 low-luminosity (M_V_t >~
  -6) globular clusters and 2 old open clusters. These clusters test blue
straggler formation in environments intermediate between higher luminosity (and
usually higher density) clusters and the Galactic field. The anti-correlation
between the relative frequency of blue stragglers (F_BSS = N_BSS / N_HB) and
cluster luminosity continues to the lowest luminosity clusters, which have
frequencies meeting or exceeding that of field stars. In addition we find that
the anti-correlation between straggler frequency and central density disappears
for clusters with density less than about 300 L_V,sun pc^-3, although this
appears to be an artifact of the correlation between cluster luminosity and
central density. We argue on observational (wide, eccentric binaries containing
blue stragglers in M67, and the existence of very bright stragglers in most of
the clusters in our sample) and theoretical grounds that stellar collisions
still produce a significant fraction of the blue stragglers in low luminosity
star clusters due to the long-term survival of wide binaries.


title: Double Lobed Radio Quasars from the Sloan Digital Sky Survey

abstract:
  We have combined a sample of 44984 quasars, selected from the Sloan Digital
Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel
technique where the optical quasar position is matched to the complete radio
environment within 450", we are able to characterize the radio morphological
make-up of what is essentially an optically selected quasar sample, regardless
of whether the quasar (nucleus) itself has been detected in the radio. About
10% of the quasar population have radio cores brighter than 0.75 mJy at 1.4
GHz, and 1.7% have double lobed FR2-like radio morphologies. About 75% of the
FR2 sources have a radio core (> 0.75 mJy). A significant fraction (~40%) of
the FR2 quasars are bent by more than 10 degrees, indicating either
interactions of the radio plasma with the ICM or IGM. We found no evidence for
correlations with redshift among our FR2 quasars: radio lobe flux densities and
radio source diameters of the quasars have similar distributions at low (mean
0.77) and high (mean 2.09) redshifts. Using a smaller high reliability FR2
sample of 422 quasars and two comparison samples of radio-quiet and non-FR2
radio-loud quasars, matched in their redshift distributions, we constructed
composite optical spectra from the SDSS spectroscopic data. Based on these
spectra we can conclude that the FR2 quasars have stronger high-ionization
emission lines compared to both the radio quiet and non-FR2 radio loud sources.
This is consistent with the notion that the emission lines are brightened by
ongoing shock ionization of ambient gas in the quasar host as the radio source
expands.


title:
Dynamical Interactions of Planetary Systems in Dense Stellar
  Environments

abstract:
  We study dynamical interactions of star--planet binaries with other single
stars. We derive analytical cross sections for all possible outcomes, and
confirm them with numerical scattering experiments. We find that a wide mass
ratio in the binary introduces a region in parameter space that is inaccessible
to comparable-mass systems, in which the nature of the dynamical interaction is
fundamentally different from what has traditionally been considered in the
literature on binary scattering. We study the properties of the planetary
systems that result from the scattering interactions for all regions of
parameter space, paying particular attention to the location of the
"hard--soft" boundary. The structure of the parameter space turns out to be
significantly richer than a simple statement of the location of the
"hard--soft" boundary would imply. We consider the implications of our
findings, calculating characteristic lifetimes for planetary systems in dense
stellar environments, and applying the results to previous analytical studies,
as well as past and future observations. Recognizing that the system PSR
B1620-26 in the globular cluster M4 lies in the "new" region of parameter
space, we perform a detailed analysis quantifying the likelihood of different
scenarios in forming the system we see today.


title: Anomalous X-ray line ratios in the cTTS TW Hya

abstract:
  The cTTS TW Hya has been observed with high-resolution X-ray spectrometers.
Previously found high densities inferred from He-like f/i triplets strongly
suggested the detected X-ray emission to be dominated by an accretion shock.
Because of their radiation field dependence He-like f/i ratios do not provide
unambiguous density diagnostics. Here we present additional evidence for high
densities from ratios of Fe XVII lines. Key Fe XVII line ratios in TW Hya
deviate from theoretical expectations at low densities as well as from the same
measurements in a large sample of stellar coronae. However, a quantitative
assessment of densities is difficult because of atomic physics uncertainties.
In addition, estimates of low optical depth in line ratios sensitive to
resonance scattering effects also support a high-density emission scenario in
the X-ray emitting regions of cTTS.


title: Presence of exotic matter in the Cooperstock and Tieu galaxy model

abstract:
  We analyze the presence of an additional singular thin disk in the recent
General Relativistic model of galactic gravitational field proposed by
Cooperstock and Tieu. The physical variables of the disk's energy-momentum
tensor are calculated. We show that the disk is made of exotic matter, either
cosmic strings or struts with negative energy density.


title:
Pulsar Magnetosphere: Variation Priciple, Singularities, Estimate of
  Power

abstract:
  We formulate variation principle for force-free magnetosphere of an inclined
pulsar: ${\cal E} +{\bf \Omega}\cdot {\bf M}$ ($\cal E$, ${\bf M}$ are
electromagnetic energy and angular momentum, ${\bf \Omega}$ is the angular
velocity of a star) is stationary under isotopological variations of magnetic
field and arbitrary variations of electric field. The variation principle gives
the reason for existence and proves local stability of current singular layers
along magnetic separatrices. Magnetic field lines of inclined pulsar
magnetosphere lie on magnetic surfaces, and do have magnetic separatrices.
  In the framework of the isotopological variation principle, inclined
magnetospheres are expected to be simple deformations of the axisymmetric
pulsar magnetosphere. A singular line should exist on the light cylinder, where
inner separatrix terminates and outer separatrix emanates. The electromagnetic
field should have an inverse square root singularity near the singular line
inside the inner magnetic separatrix.
  Large distance asymptotic solution is calculated, and used to estimate the
pulsar power, $L\approx c^{-3}\mu ^2\Omega^4$ for spin-dipole inclinations
$\lesssim 30^{\circ}$ .


title: An ultra-cool white dwarf serendipitously found with COMBO-17

abstract:
  We report the discovery of an ultra-cool white dwarf in the COMBO-17 survey.
So far, only seven objects have been discovered in this rare category of white
dwarfs, which are characterized by strong flux depression in the far-red and
near-infrared part of the spectrum, presumably due to collisionally induced
absorption (CIA). The new object COMBO-17 J114356.08-0144032 has very similar
colours to LHS 3250, which was the first of its kind to be recognized. However,
at R=21.5 it is the faintest and possibly most distant such object discovered
to date. It is the only such object in COMBO-17 at R<23; due to the small sky
coverage of 0.78 square degree this chance discovery can not provide any
constraints on the abundance of faint ultra-cool white dwarfs. We speculate on
the basis of the proper motion that this new object is probably a member of the
Galactic (thin) disk.


title:
GOLF - NG spectrometer, a space prototype for studying the dynamics of
  the deep solar interior

abstract:
  The GOLFNG (Global Oscillations at Low Frequency New Generation) instrument
is devoted to the search for solar gravity and acoustic modes, and also
chromospheric modes from space. This instrument which is a successor to
GOLF/SOHO will contribute to improve our knowledge of the dynamics of the solar
radiative zone. It is a 15 points resonant scattering spectrometer, working on
the D1 sodium line. A ground-based prototype is under construction to validate
the difficult issues. It will be installed at the Teide Observatory, on
Tenerife in 2006 to analyse the separation of the effects of the magnetic
turbulence of the line from the solar oscillations. We are prepared to put a
space version of this instrument including a capability of identification of
the modes, in orbit during the next decade. This instrument should be included
in the ILWS program as it offers a key to the improvement of our knowledge of
the solar core in combination with observations from SDO and PICARD. We hope to
determine the core rotation and magnetic field, through precise measurements of
oscillation mode frequency splittings. Understanding the magnetic field of the
radiative zone is important for progress in the study of solar activity
sources, an important player for the long-term Sun-Earth relationship.


title: Principal component analysis of the X-ray variability in NGC 7469

abstract:
  We apply Principal Component Analysis (PCA) to study the variability of the
X-ray continuum in the Seyfert 1 galaxy NGC 7469. The PCA technique is used to
separate out linear components contributing to variability between multiple
datasets; the technique is often used in analysis of optical spectra, but has
rarely been applied to AGN X-ray spectroscopy. Running a PCA algorithm on
0.3-10 keV EPIC data from a 150 ks XMM-Newton observation of NGC 7469, we
describe the spectral components extracted and evaluate the usefulness of the
PCA technique for understanding the X-ray continuum in AGN.


title:
High spatial resolution mapping of extinction in the SMC with the
  Swift-UVOT

abstract:
  The wide range of UV extinction properties in the Small Magellanic Cloud
(SMC) probably traces the effects of star formation on interstellar dust. The
Swift UVOT, with its three UV filters (centred at 1800, 2200 and 2500 A
respectively) and three optical filters, is an ideal instrument to map this
extinction. We present preliminary results of six-band photometry in a ~ 3.3
arcminute square field in the SMC. Fitting the resulting optical/UV spectral
distributions with a dust model, we estimate the depths of extinction for 53
stars and use this to map the distribution of dust in the observed field. We
briefly discuss the relevance of this study for star forming galaxies,
including the hosts of Gamma-Ray Bursts.


title:
The Globular Cluster System of the Virgo Dwarf Elliptical Galaxy VCC
  1087

abstract:
  We have analysed the globular cluster (GC) system of the nucleated dwarf
elliptical galaxy VCC 1087 in the Virgo cluster, based on Keck/LRIS
spectroscopy and archival HST/ACS imaging. We estimate VCC 1087 hosts a total
population of 77+/-19 GCs, which corresponds to a relatively high V-band
specific frequency of 5.8+/-1.4. The g-z color distribution of the GCs shows a
blue (metal-poor) peak with a tail of redder (metal-rich) clusters similar in
color to those seen in luminous ellipticals. Spectroscopy of a subsample of 12
GCs suggests that the GC system is old and coeval (~10 Gyr), with a fairly
broad metallicity distribution (-1.8<[m/H]<-0.8). In contrast, an integrated
spectrum of the underlying galaxy starlight reveals that its optical luminosity
is dominated by metal-rich, intermediate-aged stars. Radial velocities of the
GCs suggest rotation close to the major axis of the galaxy, and this rotation
is dynamically significant with (v/sigma)^* >1. A compilation of the kinematics
of the GC systems of 9 early-type galaxies shows surprising diversity in the
v/sigma parameter for GC systems. In this context, the GC system of VCC 1087
exhibits the most significant rotation to velocity dispersion signature.
Modeling the velocity dispersion profile of the GCs and galaxy stars suggest
fairly constant mass-to-light ratios of ~3 out to 6.5 kpc. The present
observations can entertain both baryonic and non-baryonic solutions, and GC
velocities at larger radii would be most valuable with regard to this issue. We
discuss the evolution of VCC 1087 in terms of the galaxy ``harassment''
scenario, and conclude that this galaxy may well be the remains of a faded,
tidally perturbed Sc spiral [abridged].


title: Tidal dwarf galaxies candidates in a sample of minor merger of galaxies

abstract:
  We present in this paper a list of candidates tidal dwarf galaxies selected
among a sample of 117 HII region observed in 11 minor mergers. The
classification of the HII regions was performed using the blue absolute
magnitude (M$_B$ $<$ -15), H$\alpha$ luminosity ($\cal L$$(H\alpha)$ $>$
10$^{39}$ erg s$^{-1}$) and the star formation rate ($SFR_{H\alpha}$ $>$ 0.4
M$_{\odot}$ y$^{-1}$) as parameters. The total number of UV photons, the number
of the star of each spectral type and the total stellar mass of the cluster
were computed for different models adopting Salpeter's IMF with $\alpha =
-2.65$ for the ionizing cluster. The ionizing cluster model which better
reproduce the observed properties are supermassive clusters with mass greater
than 10$^6 \leq M/M_{\odot} \leq 10^7$.


title:
Particle Diffusion and Acceleration by Shock Wave in Magnetized
  Filamentary Turbulence

abstract:
  We expand the off-resonant scattering theory for particle diffusion in
magnetized current filaments that can be typically compared to astrophysical
jets, including active galactic nucleus jets. In a high plasma beta region
where the directional bulk flow is a free-energy source for establishing
turbulent magnetic fields via current filamentation instabilities, a novel
version of quasi-linear theory to describe the diffusion of test particles is
proposed. The theory relies on the proviso that the injected energetic
particles are not trapped in the small-scale structure of magnetic fields
wrapping around and permeating a filament but deflected by the filaments, to
open a new regime of the energy hierarchy mediated by a transition compared to
the particle injection. The diffusion coefficient derived from a quasi-linear
type equation is applied to estimating the timescale for the stochastic
acceleration of particles by the shock wave propagating through the jet. The
generic scalings of the achievable highest energy of an accelerated ion and
electron, as well as of the characteristic time for conceivable energy
restrictions, are systematically presented. We also discuss a feasible method
of verifying the theoretical predictions. The strong, anisotropic turbulence
reflecting cosmic filaments might be the key to the problem of the acceleration
mechanism of the highest energy cosmic rays exceeding 100 EeV (10^{20} eV),
detected in recent air shower experiments.


title: Results from the adaptive optics coronagraph at the WHT

abstract:
  Described here is the design and commissioning of a coronagraph facility for
the 4.2 metre William Herschel Telescope (WHT) and its Nasmyth Adaptive Optics
system for Multi-purpose Instrumentation (NAOMI). The use of the NAOMI system
gives an improved image resolution of ~0.15 arcsecs at a wavelength of 2.2um.
This enables the Optimised Stellar Coronagraph for Adaptive optics (OSCA) to
suppress stellar light using smaller occulting masks and thus allows regions
closer to bright astronomical objects to be imaged. OSCA provides a selection
of 10 different occulting masks with sizes of 0.25 - 2.0 arcsecs in diameter,
including two with full greyscale Gaussian profiles. There is also a choice of
different sized and shaped Lyot stops (pupil plane masks). Computer simulations
of the different coronagraphic options with the NAOMI segmented mirror have
relevance for the next generation of highly segmented extremely large
telescopes.


title:
Constraints on changes in fundamental constants from a cosmologically
  distant OH absorber/emitter

abstract:
  We have detected the four 18cm OH lines from the $z \sim 0.765$ gravitational
lens toward PMN J0134-0931. The 1612 and 1720 MHz lines are in conjugate
absorption and emission, providing a laboratory to test the evolution of
fundamental constants over a large lookback time. We compare the HI and OH main
line absorption redshifts of the different components in the $z \sim 0.765$
absorber and the $z \sim 0.685$ lens toward B0218+357 to place stringent
constraints on changes in $F \equiv g_p [\alpha^2/\mu]^{1.57}$. We obtain
$[\Delta F/F] = (0.44 \pm 0.36^{\rm stat} \pm 1.0^{\rm syst}) \times 10^{-5}$,
consistent with no evolution over the redshift range $0 < z < 0.7$. The
measurements have a $2 \sigma$ sensitivity of $[\Delta \alpha/\alpha] < 6.7
\times 10^{-6}$ or $[\Delta \mu/\mu] < 1.4 \times 10^{-5}$ to fractional
changes in $\alpha$ and $\mu$ over a period of $\sim 6.5$ Gyr, half the age of
the Universe. These are among the most sensitive current constraints on changes
in $\mu$.


title: In Search of Circumstellar Disks Around Young Massive Stars

abstract:
  We present 7 mm, 1.3 cm and 3.6 cm continuum observations made with the Very
Large Array toward a sample of ten luminous IRAS sources that are believed to
be regions of massive star formation. We detect compact 7 mm emission in four
of these objects: IRAS 18089-1732(1), IRAS 18182-1433, IRAS 18264-1152 and IRAS
18308-0841 and for the first time find that these IRAS sources are associated
with double or triple radio sources separated by a few arcseconds. We discuss
the characteristics of these sources based mostly on their spectral indices and
find that their nature is diverse. Some features indicate that the 7 mm
emission is dominated by dust from disks or envelopes. Toward other components
the 7 mm emission appears to be dominated by free-free radiation, both from
ionized outflows or from optically thick H II regions. Furthermore, there is
evidence of synchrotron contamination in some of these sources. Finally, we
found that the sources associated with ionized outflows, or thermal jets are
correlated with CH$_3$OH masers.
  The precise determination of the nature of these objects requires additional
multifrequency observations at high angular resolution. The 3.6 cm continuum
observations also revealed seven UCHII regions in the vicinity of the sources
IRAS 18089-1732(1) and two more in the source IRAS 18182-1433. We show that the
small photoionized nebulae of these UCHII regions are produced by early B-type
stars.


title:
Large-scale Filamentary Structure around the Protocluster at Redshift
  z=3.1

abstract:
  We report the discovery of a large-scale coherent filamentary structure of
Lyman alpha emitters in a redshift space at z=3.1. We carried out spectroscopic
observations to map the three dimensional structure of the belt-like feature of
the Lyman alpha emitters discovered by our previous narrow-band imaging
observations centered on the protocluster at z=3.1. The feature was found to
consist of at least three physical filaments connecting with each other. The
result is in qualitative agreement with the prediction of the 'biased'
galaxy-formation theories that galaxies preferentially formed in large-scale
filamentary or sheet-like mass overdensities in the early Universe. We also
found that the two known giant Lyman alpha emission-line nebulae showing high
star-formation activities are located near the intersection of these filaments,
which presumably evolves into a massive cluster of galaxies in the local
Universe. This may suggest that massive galaxy formation occurs at the
characteristic place in the surrounding large-scale structure at high redshift.


title:
On possible manifestation of feedback coupling between geometry and
  matter in a phenomenon of an accelerating expansion of the Universe

abstract:
  It is shown that an accelerating expansion of the present-day Universe
extracted from observed luminosity of the type Ia supernovae can be explained
by quantum theory which takes into account feedback coupling between geometry
and matter (like in Mach's principle). At the same time an accelerating
expansion of the Universe is explained by the influence of small negative
cosmological constant. A comparison with the model with positive cosmological
constant (dark energy) which also has obtained its theoretical grounds in a
structure of the developed formalism is made. Parameters of the Universe in the
states with large quantum numbers are calculated.


title: The 2003/2004 superoutburst of SDSS J013701.06-091234.9

abstract:
  We report on time-resolved photometry of the superoutburst of an SU UMa-type
dwarf nova, SDSS J013701.06-091234.9 in 2003 December-2004 January. The
obtained light curves definitely show superhumps with a period of 0.056686 (12)
d, which is one of the shortest superhump periods among those of SU UMa-type
dwarf novae ever observed. Considering quiescent photometric studies, we
estimated the fractional superhump excess to be 0.024. Spectroscopic
observations by Szkody et al. (2003) provided evidence for TiO bands despite
the short orbital period, implying that the system has a luminous secondary
star. We draw a color-color diagram of SU UMa-type dwarf novae in quiescence
using 2MASS archives, revealing that the location of this star in the
color-color diagram is deviated from the general trend. The distance to the
system was roughly estimated to be 300${\pm}$80 pc, using the empirical
period-absolute magnitude relation and based on the proper motion.


title:
The footprint of large scale cosmic structure on the ultra-high energy
  cosmic ray distribution

abstract:
  Current experiments collecting high statistics in ultra-high energy cosmic
rays (UHECRs) are opening a new window on the universe. In this work we discuss
a large scale structure model for the UHECR origin which evaluates the expected
anisotropy in the UHECR arrival distribution starting from a given astronomical
catalogue of the local universe. The model takes into account the main
selection effects in the catalogue and the UHECR propagation effects. By
applying this method to the IRAS PSCz catalogue, we derive the minimum
statistics needed to significatively reject the hypothesis that UHECRs trace
the baryonic distribution in the universe, in particular providing a forecast
for the Auger experiment.


title: The WHAT Project

abstract:
  We describe WHAT, a small-aperture short focal length automated telescope
with an 8.2 deg X 8.2 deg field of view, located at the Wise Observatory. The
system is aimed at searching for transiting extrasolar planets and variable
stars. Preliminary results of 3892 exposures of a single field are presented,
where the telescope achieved already a precision of a few mmag for the
brightest objects. Additional information can be found at
http://wise-obs.tau.ac.il/~what .


title:
Phase-resolved spectroscopy of the helium dwarf nova 'SN 2003aw' in
  quiescence

abstract:
  High time resolution spectroscopic observations of the ultra-compact helium
dwarf nova 'SN 2003aw' in its quiescent state at V=20.5 reveal its orbital
period at 2027.8 +/- 0.5 seconds or 33.80 minutes. Together with the
photometric 'superhump' period of 2041.5 +/- 0.5 seconds, this implies a mass
ratio q of 0.036. We compare both the average and time-resolved spectra of 'SN
2003aw' and SDSS J124058.03-015919.2. Both show a DB white dwarf spectrum plus
an optically thin, helium-dominated accretion disc. 'SN 2003aw' distinguishes
itself from the SDSS source by its strong calcium H & K emission lines,
suggesting higher abundances of heavy metals than the SDSS source. The silicon
and iron emission lines observed in the SDSS source are about twice as strong
in 'SN 2003aw'. The peculiar 'double bright spot' accretion disc feature seen
in the SDSS source is also present in time-resolved spectra of 'SN 2003aw',
albeit much weaker.


title:
The SCUBA Local Universe Galaxy Survey - III. Dust along the Hubble
  sequence

abstract:
  We present new results from the SCUBA Local Universe Galaxy Survey (SLUGS),
the first large systematic submillimetre survey of the local Universe. Since
our initial survey of a sample of 104 IRAS-selected galaxies we have now
completed a survey of a sample of 81 optically-selected galaxies, observed with
the SCUBA camera on the James Clerk Maxwell Telescope. Since SCUBA is sensitive
to the 90% of dust too cold to radiate significantly in the IRAS bands our new
sample represents the first unbiased survey of dust in galaxies along the whole
length of the Hubble sequence. We find little change in the properties of dust
in galaxies along the Hubble sequence and detected 6 out of 11 elliptical
galaxies. As in our earlier work on IRAS galaxies we find that the IRAS and
submm fluxes are well-fitted by a two-component dust model with dust emissivity
index beta=2. The major difference from our earlier work is that we find the
ratio of the mass of cold dust to the mass of warm dust is much higher for our
optically-selected galaxies and can reach values of ~1000. Comparison of the
results for the IRAS- and optically-selected samples shows that there is a
population of galaxies containing a large proportion of cold dust that is
unrepresented in the IRAS sample. We derive local submm luminosity and dust
mass functions, both directly from our optically-selected SLUGS sample, and by
extrapolation from the IRAS PSCz survey using the method of Serjeant &
Harrison, and find excellent agreement between the two. We find them to be
well-fitted by Schechter functions except at the highest luminosities. We find
that as a consequence of the omission of cold galaxies from the IRAS sample the
luminosity function presented in our earlier work is too low by a factor of 2.


title: Hadronic processes within collective stellar winds

abstract:
  Recently, we have proposed that the interaction between relativistic protons
resulting from Fermi first order acceleration in the superbubble of a stellar
OB association or in other nearby accelerator and ions residing in single
stellar winds of massive stars could lead to TeV sources without strong
counterparts at lower energies. Here we refine this analysis in several
directions. We study collective wind configurations produced by a number of
massive stars, and obtain densities and expansion velocities of the stellar
wind gas that is to be target of hadronic interactions. We study the expected
$\gamma$-ray emission from these regions, considering in an approximate way the
effect of cosmic ray modulation. We compute secondary particle production
(electrons from knock-on interactions and electrons and positrons from charged
pion decay), and solve the loss equation with ionization, synchrotron,
bremsstrahlung, inverse Compton, and expansion losses. We provide examples
where configurations can produce sources for GLAST satellite, and the
MAGIC/HESS/VERITAS telescopes in non-uniform ways, i.e., with or without the
corresponding counterparts. We show that in all cases we studied no EGRET
source is expected. Finally, we comment on HESS J1303-631 and on Cygnus OB 2
and Westerlund 1 as two associations where this scenario could be tested.


title: An INTEGRAL Hard X-ray Survey of the Large Magellanic Cloud

abstract:
  Two observation campaigns performed in 2003 and 2004 with the INTEGRAL
satellite have provided the first sensitive survey of the Large Magellanic
Cloud with an imaging instrument in the hard X-ray range (15 keV - 10 MeV). The
high energy flux and long term variability of the black hole candidate LMC X-1
was measured for the first time without the contamination of the nearby (~25')
young pulsar PSR B0540-69. We studied the accreting pulsar LMC X-4,
constraining the size of the hard X-ray emitting region (<~3E10 cm) from the
analysis of its eclipses, and measuring its spin period (13.497+/-0.005 s) in
the 20-40 keV band. LMC X-3 was not detected, being in a soft state during the
first observation and possibly in an extremely low state in the second one.
Thanks to the large field of view of the IBIS instrument, we could study also
other sources falling serendipitously in the observed sky region around the
LMC: the Galactic low mass X-ray binary EXO 0748-676, the accreting pulsar SMC
X-1 in the Small Magellanic Cloud, and the Active Galactic Nucleus IRAS
04575--7537. In addition we discovered five new hard X-ray sources, two of
which most likely belong to the LMC.


title: On the accretion of phantom energy onto wormholes

abstract:
  By using a properly generalized accretion formalism it is argued that the
accretion of phantom energy onto a wormhole does not make the size of the
wormhole throat to comovingly scale with the scale factor of the universe, but
instead induces an increase of that size so big that the wormhole can engulf
the universe itself before it reaches the big rip singularity, at least
relative to an asymptotic observer.