title:
Investigation of the 2-body system with a rotating central body (e. g.
  earth-moon system) within the Projective Unified Field theory: the transfer
  of rotational angular momentum and energy from the central body to the
  orbital 2-body system, the tidal and the non-tidal influences (mechanical,
  general-relativistic Lense-Thirring effect and cosmological
  PUFT-contributions)

abstract:
  In this treatise the well-known 2-body problem with a rotating central body
is systematically reinvestigated on the basis of the Projective Unified Field
Theory (PUFT) under the following aspects (including the special case of the
Newton mechanics): First, equation of motion with abstract additional terms
being appropriate for the interpretation of the various effects under
discussion: tidal friction effect as well as non-tidal effects (e.g. rebound
effect as temporal variation of the moment of inertia of the rotating body,
general-relativistic Lense-Thirring effect, new scalaric effects of
cosmological origin, being an outcome of the scalarity phenomenon of matter
(PUFT). Second, numerical evaluation of the theory.
  Key words: two-body problem with rotating central body -- tidal and non-tidal
effects -- scalaric-cosmological influence of the expanding cosmos on the
2-body system.


title:
Multi-object spectroscopy of low redshift EIS clusters. III. Properties
  of optically selected clusters

abstract:
  We have carried out an investigation of the properties of low redshift EIS
clusters using both spectroscopy and imaging data. We present new redshifts for
738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the
``gap''-technique to search for significant overdensities in redshift space and
to identify groups/clusters of galaxies corresponding to the original EIS
matched filter cluster candidates. In this way we spectroscopically confirm 20
of the 21 cluster candidates with a matched-filter estimated redshift z_MF=0.2.
We have now obtained spectroscopic redshifts for 34 EIS cluster candidates with
z_MF=0.2 (see also Hansen et al., 2002; Olsen et al., 2003). Of those we
spectroscopically confirm 32 with redshifts ranging from z=0.064 to 0.283. We
find that: 1) the velocity dispersions of the systems range from
sigma_v<=130km/s to sigma_v=1200km/s, typical of galaxy groups to rich
clusters; 2) richnesses corresponding to Abell classes R<=1; and 3)
concentration indices ranging from C=0.2 to C=1.2. From the analysis of the
colours of the galaxy populations we find that 53% of the spectroscopically
confirmed systems have a ``significant'' red sequence. These systems are on
average richer and have higher velocity dispersions. We find that the colour of
the red sequence galaxies matches passive stellar evolution predictions.


title: A test for the universality of extinction curve shape

abstract:
  We present an analysis of 436 lines of sight with extinction data covering
wavelength range from near-infrared (NIR) to ultraviolet (UV). We use J, H, K
photometry from 2MASS database, the IR intrinsic colors from Wegner (1994), and
UV extinction data from Wegner (2002). We exclude 19 lines of sight (4%) from
the original sample because of suspected photometric problems. We derive total
to selective extinction ratios (R_V) based on the Cardelli, Clayton, and Mathis
(1989; CCM) law, which is typically used to fit the extinction data for both
diffuse and dense interstellar medium. We conclude that CCM law is able to fit
well most of the extinction curves in our sample (71%), and we present a
catalog of R_V and visual extinction (A_V) values for those cases. We divide
the remaining lines of sight with peculiar extinction into two groups according
to two main behaviors: a) the NIR or/and UV wavelength regions cannot be
reproduced by CCM formula (14% of the entire sample), b) the NIR and UV
extinction data taken separately are best fit by CCM laws with significantly
different values of R_V (10% of the entire sample). We present examples of such
curves. We caution that some peculiarities of the extinction curves may not be
intrinsic but simply caused by faulty data. The study of the intrinsically
peculiar cases could help us to learn about the physical processes that affect
dust in the interstellar medium, e.g., formation of mantles on the surface of
grains, evaporation, growing or shattering.


title:
The Konus-Wind and Helicon-Coronas-F detection of the giant $\gamma$-ray
  flare from the soft $\gamma$-ray repeater SGR 1806-20

abstract:
  The giant outburst from SGR 1806-20 was observed on 2004 December 27 by many
spacecraft. This extremely rare event exhibits a striking similarity to the two
giant outbursts thus far observed, on 1979 March 5 from SGR 0526-66 and 1998
August 27 from SGR 1900+14. All the three outbursts start with a short giant
radiation pulse followed by a weaker tail. The tail pulsates with the period of
neutron star rotation of $\sim$5--8 s, to decay finally in a few minutes. The
enormous intensity of the initial pulse proved to be far above the saturation
level of the gamma-ray detectors, with the result that the most valuable data
on the time structure and energy spectrum of the pulse is lost. At the time of
the December 27 outburst, a Russian spacecraft Coronas-F with a $\gamma$-ray
spectrometer aboard was occulted by the Earth and could not see the outburst.
It succeeded, however, in observing a weak reflected signal due to the
$\gamma$-rays Compton scattered by the Moon. This has been the first
observation of a cosmic gamma-ray flare reflected from a celestial body. Here
we report, that the detection of a weakened back-scattered initial pulse
combined with direct observations by the Konus $\gamma$-ray spectrometer on the
Wind spacecraft permitted us to reliably reconstruct the intensity, time
history, and energy spectra of the outburst.


title: The Chandra Deep Field South/GOODS survey. Optically faint X-ray sources

abstract:
  We provide important new constraints on the nature and redshift distribution
of optically faint (R>25) X-ray sources in the Chandra Deep Field South Survey.
We show that we can derive accurate photometric redshifts for the
spectroscopically unidentified sources thus maximizing the redshift
completeness for the whole X-ray sample. Our new redshift distribution for the
X-ray source population is in better agreement with that predicted by X-ray
background synthesis models; however, we still find an overdensity of low
redshift (z<1) sources. The optically faint sources are mainly X-ray absorbed
AGN, as determined from direct X-ray spectral analysis and other diagnostics.
Many of these optically faint sources have high (>10) X-ray-to-optical flux
ratios. We also find that ~71% of them are well fitted with the SED of an
early-type galaxy with <z_phot>~1.9 and the remaining 29% with irregular or
starburst galaxies mainly at z_phot>3. We estimate that 23% of the optically
faint sources are X-ray absorbed QSOs. The overall population of X-ray absorbed
QSOs contributes a ~15% fraction of the [2-10] keV X-ray Background (XRB)
whereas current XRB synthesis models predict a ~38% contribution.


title: X-rays from Cepheus A East and West

abstract:
  We report the discovery of X-rays from both components of Cepheus A, East and
West, with the XMM-Newton Observatory. HH 168 joins the ranks of other
energetic Herbig Haro objects that are sources of T~10^6 K X-ray emission. The
HH 168 effective temperature is T = 5.8 (+3.5,-2.3) x 10^6 K and its unabsorbed
luminosity is 1.1 x 10^29 erg s^-1, making it hotter and less luminous than
other representatives of its class. We also detect prominent X-ray emission
from the complex of compact radio sources believed to be the power sources for
Cep A. We call this source HWX and it is distinguished by its hard X-ray
spectrum, T = 1.2 (+1.2,-0.5) x 10^8 K, and complex spatial distribution. It
may arise from one or more protostars associated with the radio complex, the
outflows, or a combination of the two. We detect 102 X-rays sources; many
presumed to be pre-main sequence stars based upon the reddening of their
optical/IR counterparts.


title: CO emission from discs around isolated HAeBe and Vega-excess stars

abstract:
  We describe results from a survey for J=3-2 12CO emission from visible stars
with an infrared excess. The line is clearly detected in 21 objects, with
molecular gas (>10^-3 Jupiter masses) common in targets with infrared excesses
>0.01 (>56% of objects). Such high excesses indicate the presence of a disc of
opening angle >12 degrees; within this, the optically thick disc prevents CO
photodissociation. Two or three stars with associated CO have an excess <0.01,
implying a disc opening angle <1 degree. Most line profiles are double-peaked
or relatively broad. Model fits, assuming a Keplerian disc, indicate outer
radii, R_out, of ~20-300 au. As many as 5 discs have outer radii smaller than
the Solar System (50 au), and a further 4 have gas at radii <20 au. R_out is
independent of the stellar spectral type (from K through to B9), but is
correlated with total dust mass. R_out appears to decrease with time: discs
around stars of age 3-7 Myr have a mean radius of ~210 au, whereas discs of age
7-20 Myr are a factor of 3 smaller. The only bona fide debris disc with
detected CO is HD9672; this has a double peaked line profile and is the most
compact gas disc observed, with a modelled radius 17 au). A fit to HD141569
suggests the gas lies in two rings of radii 90 and 250 au, similar to the
scattered light structure. In both AB Aur and HD163296 the sizes of the
molecular and dust scattering discs are also similar, suggesting that the gas
and small dust grains are co-located.


title:
The Angstrom Project: a microlensing survey of the structure and
  composition of the bulge of the Andromeda galaxy

abstract:
  The Andromeda Galaxy Stellar Robotic Microlensing Project (The Angstrom
Project) aims to use stellar microlensing events to trace the structure and
composition of the inner regions of the Andromeda Galaxy (M31). We present
microlensing rate and timescale predictions and spatial distributions for
stellar and sub-stellar lens populations in combined disk and barred bulge
models of M31. We show that at least half of the stellar microlenses in and
around the bulge are expected to have characteristic durations between 1 and 10
days, rising to as much as 80% for brown-dwarf dominated mass functions. These
short-duration events are mostly missed by current microlensing surveys that
are looking for Macho candidates in the M31 dark matter halo. Our models
predict that an intensive monitoring survey programme such as Angstrom, which
will be able to detect events of durations upwards of a day, could detect
around 30 events per season within ~5 arcminutes of the M31 centre, due to
ordinary low-mass stars and remnants. This yield increases to more than 60
events for brown-dwarf dominated mass functions. The overall number of events
and their average duration are sensitive diagnostics of the bulge mass, in
particular the contribution of low-mass stars and brown dwarfs. The combination
of an inclined disk, an offset bar-like bulge, and differences in the bulge and
disk luminosity functions results in a four-way asymmetry in the number of
events expected in each quadrant defined by the M31 disk axes. The asymmetry is
sensitive to the bar prolongation, orientation and mass.


title: Surface Modes on Bursting Neutron Stars and X-ray Burst Oscillations

abstract:
  Accreting neutron stars (NSs) often show coherent modulations during type I
X-ray bursts, called burst oscillations. We consider whether a nonradial mode
can serve as an explanation for burst oscillations from those NSs which are not
magnetic. We find that a surface wave in the shallow burning layer transitions
into a crustal interface wave as the envelope cools, a new and previously
uninvestigated phenomenon. The surface modulations decrease dramatically as the
mode switches, explaining why burst oscillations often disappear before burst
cooling ceases. When we include rotational modifications, we find mode
frequencies and drifts consistent with those observed. The large NS spin
($\approx270-620 {\rm Hz}$) needed to make this match implies that accreting
NSs are spinning at frequencies $\approx4 {\rm Hz}$ above the burst
oscillation. Since the asymptotic frequency is set by the crustal interface
wave, the observed late time frequency drifts are a probe of the composition
and temperature of NS crusts. We compare our model with the observed drifts and
persistent luminosities of X-ray burst sources, and find that NSs with a higher
average accretion rate show smaller drifts, as we predict. Furthermore, the
drift sizes are consistent with crusts composed of iron-like nuclei, as
expected for the ashes of the He-rich bursts that are exhibited by these
objects.


title: Density scaling and anisotropy in supersonic MHD turbulence

abstract:
  We study the statistics of density for supersonic turbulence in a medium with
magnetic pressure larger than the gaseous pressure. This study is motivated by
molecular cloud research. Our simulations exhibit clumpy density structures,
which contrast increases with the Mach number. At 10 Machs densities of some
clumps are three orders of magnitude higher than the mean density. These clumps
give rise to flat and approximately isotropic density spectrum corresponding to
the random distribution of clumps in space. We claim that the clumps originate
from our random, isotropic turbulence driving. When the contribution from those
clumps is suppressed by studying logarithm of density, the density statistics
exhibit scale-dependent anisotropy consistent with the models where density
structures arise from shearing by Alfv\'en waves. It is noteworthy that
originally such models were advocated for the case of low-Mach, nearly
incompressible turbulence.


title:
A Fuzzy Logic Based Algorithm for Finding Astronomical Objects in
  Wide-Angle Frames

abstract:
  Accurate automatic identification of astronomical objects in an imperfect
world of non-linear wide-angle optics, imperfect optics, inaccurately pointed
telescopes, and defect-ridden cameras is not always a trivial first step. In
the past few years, this problem has been exacerbated by the rise of digital
imaging, providing vast digital streams of astronomical images and data. In the
modern age of increasing bandwidth, human identifications are many times
impracticably slow. In order to perform an automatic computer-based analysis of
astronomical frames, a quick and accurate identification of astronomical
objects is required. Such identification must follow a rigorous transformation
from topocentric celestial coordinates into image coordinates on a CCD frame.
This paper presents a fuzzy logic based algorithm that estimates needed
coordinate transformations in a practical setting. Using a training set of
reference stars, the algorithm statically builds a fuzzy logic model. At
runtime, the algorithm uses this model to associate stellar objects visible in
the frames to known-catalogued objects, and generates files that contain
photometry information of objects visible in the frame. Use of this algorithm
facilitates real-time monitoring of stars and bright transients, allowing
identifications and alerts to be issued more reliably. The algorithm is being
implemented by the Night Sky Live all-sky monitoring global network and has
shown itself significantly more reliable than the previously used non-fuzzy
logic algorithm.


title:
Cosmic 21-cm Delensing of Microwave Background Polarization and the
  Minimum Detectable Energy Scale of Inflation

abstract:
  The curl (B) modes of cosmic microwave background (CMB) polarization
anisotropies are a unique probe of the primordial background of inflationary
gravitational waves (IGWs). Unfortunately, the B-mode polarization anisotropies
generated by gravitational waves at recombination are confused with those
generated by the mixing of gradient-mode (E-mode) and B-mode polarization
anisotropies as CMB photons propagate through the Universe and are
gravitationally lensed. We describe here a method for delensing CMB
polarization anisotropies using observations of anisotropies in the cosmic
21-cm radiation emitted or absorbed by neutral hydrogen atoms at redshifts 10
to 200. While the detection of cosmic 21-cm anisotropies at high resolution is
challenging, a combined study with a relatively low-resolution (but
high-sensitivity) CMB polarization experiment could probe inflationary energy
scales well below the Grand Unified Theory (GUT) scale of 10^{16} GeV --
constraining models with energy scales below 10^{15} GeV (the detectable limit
derived from CMB observations alone). The ultimate theoretical limit to the
detectable inflationary energy scale via this method may be as low as 3 \times
10^{14} GeV.


title: Dip in UHECR spectrum as signature of proton interaction with CMB

abstract:
  Ultrahigh energy (UHE) extragalactic protons propagating through cosmic
microwave radiation (CMB) acquire the spectrum features in the form of the dip,
bump (pile-up protons) and the Greisen-Zatsepin-Kuzmin (GZK) cutoff. We have
performed the analysis of these features in terms of the modification factor.
This analysis is weakly model-dependent, especially in case of the dip. The
energy shape of the dip is confirmed by the Akeno-AGASA data with
$\chi^2=19.06$ for d.o.f. =17 with two free parameters used for comparison. The
agreement with HiRes data is also very good. This is the strong evidence that
UHE cosmic rays observed at energies $1\times 10^{18}$ eV - $4\times 10^{19}$
eV are extragalactic protons propagating through CMB. The dip is also present
in case of diffusive propagation in magnetic field.


title:
Radio Sources in Low-Luminosity Active Galactic Nuclei.IV. Radio
  Luminosity Function, Importance of Jet Power, and Radio Properties of the
  Complete Palomar Sample

abstract:
  We present the completed results of a high resolution radio imaging survey of
all (~200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the
Palomar Spectroscopic Sample. The high incidences of pc-scale radio nuclei,
with T(brightness) >=10^7 K, and sub-parsec jets argue for accreting black
holes in >=50% of all LINERs and low-luminosity Seyferts; there is no evidence
against all LLAGNs being mini-AGNs. The radio luminosity function (RLF) of
Palomar Sample LLAGNs and AGNs extends three orders of magnitude below, and is
continuous with, that of `classical' AGNs. We find marginal evidence for a
low-power turnover in the RLF; nevertheless LLAGNs are responsible for a
significant fraction of present day mass accretion. Adopting the jet model of
Falcke & Biermann, we show that the accretion energy output in LLAGNs is
dominated by the energy in the observed jets rather than the radiated
bolometric luminosity. The Palomar LLAGNs and AGNs follow the same scaling
between jet power and narrow line region (NLR) luminosity as the pc to kpc jets
in powerful radio galaxies. Eddington ratios of <= 10^{-1} - 10^{-5} are
implied in jet models of the radio emission. We find evidence that, in analogy
to Galactic black hole candidates, LINERs are in a `low/hard' state (gas poor
nuclei, low Eddington ratio, ability to launch collimated jets) while
low-luminosity Seyferts are in a `high' state (gas rich nuclei, higher
Eddington ratio, less likely to launch collimated jets). The jets are
energetically more significant than supernovae in the LLAGN host galaxies, and
are potentially able to deposit sufficient energy into the innermost parsecs to
significantly slow the gas supply to the accretion disk.


title:
Galaxy-galaxy-galaxy lensing: Third-order correlations between the
  galaxy and mass distributions in the Universe

abstract:
  Galaxy-galaxy lensing (GGL) measures the 2-point cross-correlation between
galaxies and mass in the Universe. In this work we seek to generalise this
effect by considering the third-order correlations between galaxies and mass:
galaxy-galaxy-galaxy lensing. Third-order correlations in the cosmic shear
field have recently been reported in the VIRMOS-DESCART and CTIO surveys. Such
data should also be ideal for measuring galaxy-galaxy-galaxy lensing. Indeed,
the effects of these higher-order correlations may have already been detected
in recent studies of galaxy-galaxy lensing. In this paper we lay out the basic
relations for third-order cross correlations and their projections and
introduce a new set of scale dependent third-order bias parameters. We define
three new observables: two galaxy-shear-shear correlation functions, $G_{\pm}$,
and a galaxy-galaxy-shear correlation, ${\cal G}$. We relate these to the
various projected cross-bispectra and give practical estimators for their
measurement. We note that the observational signature of these correlators is
simply the excess shear-shear correlation measured about foreground galaxies
(for $G_{\pm}$) and the average tangential shear around foreground galaxy pairs
(for $\cal G$). Finally we derive expressions for the third order aperture mass
statistics in terms of both the cross-bispectra and the real-space correlation
functions. (Abridged)


title: An HST Search for Supernovae Accompanying X-ray Flashes

abstract:
  We present the results from an Hubble Space Telescope/ACS search for
supernovae associated with X-ray flashes 020903, 040701, 040812 and 040916. We
find strong evidence that XRF 020903 (z=0.25) was associated with a SN
1998bw-like supernova and confirm this using optical spectroscopy at t ~ 25
days. We find no evidence, however, for SN 1998bw-like supernovae associated
with the other three events. In the case of XRF 040701 (z=0.21), we rule out
even a faint supernova similar to SN 2002ap, using template light-curves for
several local Type Ic supernovae. For the two cases in which the redshift is
not known, XRFs 040812 and 040916, we derive robust redshift limits assuming
they were accompanied by supernovae similar to SN 1998bw and compare these
limits with photometric redshift constraints provided by their host galaxies.
We supplement this analysis with results for three additional events (XRFs
011030, 020427 and 030723) and discuss the observed diversity of supernovae
associated with X-ray flashes and gamma-ray bursts. We conclude that XRF-SNe
exist, but can be significantly fainter than SN 1998bw, possibly consistent
with the observed spread in local Type Ibc supernovae.


title: Power of a Turbulent Pulsar

abstract:
  We speculate that stationary force-free pulsar magnetospheres are screw
unstable, and the spin-down power of real pulsars is carried by turbulent
Poynting jets. The turbulent jet entrains poloidal flux as it propagates away
from the star. Due to poloidal flux entrainment, poloidal field inside the jet
decreases at a slower rate than the dipole's $r^{-3}$, and the pulsar power
increases accordingly: $L\sim (\mu ^2\Omega^4/c^3)(\Omega R/c)^{-\alpha}$,
where $\mu$ is the magnetic dipole, $\Omega$ is the frequency, $R$ is the
neutron star radius, and $\alpha \lesssim 1$ is an index which depends on
spin-dipole angle. Our speculation is of interest because it seems to provide
the only possible explanation (without fine-tuning) of observed pulsar braking
indices.


title: GRB afterglows: deep Newtonian phase and its application

abstract:
  Gamma-ray burst afterglows have been observed for months or even years in a
few cases. It deserves noting that at such late stages, the remnants should
have entered the deep Newtonian phase, during which the majority of
shock-accelerated electrons will no longer be highly relativistic. To calculate
the afterglows, we must assume that the electrons obey a power-law distribution
according to their kinetic energy, not simply the Lorentz factor.


title: A Leading Logarithm Approximation for Inflationary Quantum Field Theory

abstract:
  During inflation explicit perturbative computations of quantum field theories
which contain massless, non-conformal fields exhibit secular effects that grow
as powers of the logarithm of the inflationary scale factor.
Starobinski\u{\i}'s technique of stochastic inflation not only reproduces the
leading infrared logarithms at each order in perturbation theory, it can
sometimes be summed to reveal what happens when inflation has proceeded so long
that the large logarithms overwhelm even very small coupling constants. It is
thus a cosmological analogue of what the renormalization group does for the
ultraviolet logarithms of quantum field theory, and generalizing this technique
to quantum gravity is a problem of great importance. There are two significant
differences between gravity and the scalar models for which stochastic
formulations have so far been given: derivative interactions and the presence
of constrained fields. We use explicit perturbative computations in two simple
scalar models to infer a set of rules for stochastically formulating theories
with these features.


title: Canonical Particle Acceleration in FRI Radio Galaxies

abstract:
  Matched resolution multi-frequency VLA observations of four radio galaxies
are used to derive the asymptotic low energy slope of the relativistic electron
distribution. Where available, low energy slopes are also determined for other
sources in the literature. They provide information on the acceleration physics
independent of radiative and other losses, which confuse measurements of the
synchrotron spectra in most radio, optical and X-ray studies. We find a narrow
range of inferred low energy electron energy slopes, n(E)=const*E^-2.1 for the
currently small sample of lower luminosity sources classified as FRI (not
classical doubles). This distribution is close to, but apparently inconsistent
with, the test particle limit of n(E)=const*E^-2.0 expected from strong
diffusive shock acceleration in the non-relativistic limit. Relativistic shocks
or those modified by the back-pressure of efficiently accelerated cosmic rays
are two alternatives to produce somewhat steeper spectra. We note for further
study the possiblity of acceleration through shocks, turbulence or shear in the
flaring/brightening regions in FRI jets as they move away from the nucleus.
Jets on pc scales and the collimated jets and hot spots of FRII (classical
double) sources would be governed by different acceleration sites and
mechanisms; they appear to show a much wider range of spectra than for FRI
sources.


title: RXTE observations of the dipping low-mass X-ray binary 4U 1624-49

abstract:
  We analyse ~ 360 ks of archival data from the Rossi X-Ray Timing Explorer
(RXTE) of the 21 hr orbital period dipping low-mass X-ray binary 4U 1624-49. We
find that outside the dips the tracks in the colour-colour and
hardness-intensity diagrams (CDs and HIDs) are reminiscent of those of atoll
sources in the middle and upper parts of the banana branch. The tracks show
secular shifts up to ~ 10%. We study the power spectrum of 4U 1624-49 as a
function of the position in the CD. This is the first time power spectra of
this source are presented. No quasi-periodic oscillations (QPOs) are found. The
power spectra are dominated by very low frequency noise (VLFN), characteristic
for atoll sources in the banana state, and band limited noise (BLN) which is
not reliably detected but may, uncharacteristically, strengthen and increase in
frequency with spectral hardness. The VLFN fits to a power law, which becomes
steeper when the source moves to the harder part of the CD. We conclude that 4U
1624-49 is an atoll source which in our observations is in the upper banana
branch. Combining this with the high (0.5-0.7 L_Edd) luminosity, the long-term
flux stability of the source as seen with the RXTE All-Sky Monitor (ASM), and
with the fact that it is an X-ray dip source, we conclude that 4U 1624-49 is
most likely a GX atoll source such as GX 3+1 and GX 9+9, but seen edge on.


title: Present and Future Prospects for GRB Standard Candles

abstract:
  Following our previous work, we conclude that a GRB standard candle
constructed from the Ghirlanda et al. power-law relation between the
geometry-corrected energy (E_gamma) and the peak of the rest-frame prompt burst
spectrum (E_p) is not yet cosmographically useful, despite holding some
potential advantages over SNe Ia. This is due largely to the small sample of
\~20 GRBs with the required measured redshifts, jet-breaks, and peak energies,
and to the strong sensitivity of the goodness-of-fit of the power-law to input
assumptions. The most important such finding concerns the sensitivity to the
generally unknown density (and density profile), of the circumburst medium.
Although the E_p-E_gamma relation is a highly significant correlation over many
cosmologies, until the sample expands to include many low-z events, it will be
most sensitive to Omega_M but essentially insensitive to Omega_Lambda and w,
with some hope of constraining dw/dt with high-z GRB data alone. The relation
clearly represents a significant improvement in the search for an empirical GRB
standard candle, but is further hindered by an unknown physical basis for the
relation, the lack of a low-z training set to calibrate the relation in a
cosmology-independent way, and several major potential systematic uncertainties
and selection effects. Until these concerns are addressed, a larger sample is
acquired, and attempts are made to marginalize or perform Monte Carlo
simulations over the unknown density distribution, we urge caution concerning
claims of the utility of GRBs for cosmography and especially the attempts to
combine GRBs with SNe Ia.


title:
A Gravitational Mechanism for the Acceleration of Ultrarelativistic
  Particles

abstract:
  Imagine a swarm of free particles near a point P outside a gravitating mass M
and a free reference particle at P that is on a radial escape trajectory away
from M. Relative to this reference particle and in a Fermi normal coordinate
system constructed along its worldline, the particles in the swarm that move
along the radial direction and are ultrarelativistic (that is, they have speeds
above c/sqrt(2)) decelerate toward this terminal speed. On the other hand, the
swarm particles that are ultrarelativistic and move in directions normal to the
radial (jet) directions accelerate to almost the speed of light by the
gravitational tidal force of the mass M. The implications of these effects as
well as the influence of the higher-order terms on the tidal acceleration
mechanism are investigated. The observational evidence in support of these
general relativistic effects is briefly discussed.


title: The Star Cluster Population in the Tidal Tails of NGC 6872

abstract:
  We present a photometric analysis of the rich star cluster population in the
tidal tails of NGC 6872. We find star clusters with ages between 1 - 100 Myr
distributed in the tidal tails, while the tails themselves have an age of less
than 150 Myr. Most of the young massive ($10^{4} \le M/M_{\odot} \le 10^{7}$)
clusters are found in the outer regions of the galactic disk or the tidal
tails. The mass distribution of the cluster population can be well described by
power-law of the form $N(m) \propto m^{-\alpha}$, where $\alpha = 1.85 \pm
0.11$, in very good agreement with other young cluster populations found in a
variety of different environments. We estimate the star formation rate for
three separate regions of the galaxy, and find that the eastern tail is forming
stars at $\sim 2$ times the rate of the western tail and $\sim 5$ times the
rate of the main body of the galaxy. By comparing our observations with
published N-body models of the fate of material in tidal tails in a galaxy
cluster potential, we see that many of these young clusters will be lost into
the intergalactic medium. We speculate that this mechanism may also be at work
in larger galaxy clusters such as Fornax, and suggest that the so-called
ultra-compact dwarf galaxies could be the most massive star clusters that have
formed in the tidal tails of an ancient galactic merger.


title:
Spectrophotometry of Sextans A and B: Chemical Abundances of HII Regions
  and Planetary Nebulae

abstract:
  We present the results of high quality long-slit spectroscopy of planetary
nebulae (PNe) and HII regions in the two dwarf irregular galaxies Sextans A and
B, which belong to a small group of galaxies just outside the Local Group. In
Sextans A we obtained the element abundances in its only known PN and in three
HII regions with the classical Te method. The oxygen abundances in these three
HII regions of Sextans A are all consistent within the individual rms
uncertainties, with the average 12+log(O/H) = 7.54+/-0.06. The oxygen abundance
of the PN in Sextans A is, however, significantly higher: 12+$\log$(O/H) =
8.02+/-0.05. This PN is even more enriched in nitrogen and helium, suggesting a
classification as a PN of Type I. In Sextans B we obtained spectra of one PN
and six HII regions. Element abundances with the Te method could be derived for
the PN and three of the HII regions. For two of these HII regions, which have a
separation of only ~70 pc in projection, the oxygen abundances do not differ
within the rms uncertainties, with a mean of 12+log(O/H) = 7.53+/-0.05. The
third HII region, which is about 0.6 kpc northeast from the former two, is
twice as metal-rich, with 12+log(O/H) = 7.84+/-0.05. This suggests considerable
inhomogeneity in the present-day metallicity distribution in Sextans B.
(Abridged)


title: What Is The Neon Abundance Of The Sun?

abstract:
  We have evolved a series of thirteen complete solar models that utilize
different assumed heavy element compositions. Models that are based upon the
heavy element abundances recently determined by Asplund, Grevesse, and Sauval
(2005) are inconsistent with helioseismological measurements. However, models
in which the neon abundance is increased by 0.4-0.5 dex to log N(Ne) = 8.29 +-
0.05 (on the scale in which log N(H) = 12) are consistent with the
helioseismological measurements even though the other heavy element abundances
are in agreement with the determinations of Asplund et al. (2005). These
results sharpen and strengthen an earlier study by Antia and Basu (2005). The
predicted solar neutrino fluxes are affected by the uncertainties in the
composition by less than their 1sigma theoretical uncertainties.


title:
Probing the largest scale structure in the universe with polarization
  map of galaxy clusters

abstract:
  We introduce a new formalism to describe the polarization signal of galaxy
clusters on the whole sky. We show that a sparsely sampled, half-sky map of the
cluster polarization signal at $z\sim 1$ would allow to better characterize the
very large scale density fluctuations. While the horizon length is smaller in
the past, two other competing effects significantly remove the contribution of
the small scale fluctuations from the quadrupole polarization pattern at $z\sim
1$. For the standard Lambda-CDM universe with vanishing tensor mode, the
quadrupole moment of the temperature anisotropy probed by WMAP is expected to
have a ~32% contribution from fluctuations on scales below 6.3h^{-1}Gpc. This
percentage would be reduced to ~2% level for the quadrupole moment of
polarization pattern at $z\sim 1$. A cluster polarization map at $z \sim 1$
would shed light on the potentially anomalous features of the largest scale
structure in the observable universe.


title: Merger Dynamics of the Pair of Galaxy Clusters -- A399 and A401

abstract:
  Convincing evidence of a past interaction between two rich clusters A399 and
A401 was recently found by the X-ray imaging observations. In this paper we
examine the structure and dynamics of this pair of galaxy clusters. A
mixture-modeling algorithm has been applied to obtain a robust partition into
two clusters, which allows us to discuss the virial mass and velocity
distribution for each cluster. Assuming that these two clusters follow a linear
orbit and they have once experienced a close encounter, we model the binary
cluster as a two-body system. As a result, four gravitationally bound solutions
are obtained. The recent X-ray observations seem to favor a scenario in which
the two clusters with a true separation of $5.4h^{-1}$ Mpc are currently
expanding at 583 km/s along the direction with a projection angle of 67.5
degree, and they will reach a maximum extent of $5.65h^{-1}$ Mpc in about
$1.0h^{-1}$ Gyr.


title:
Towards a deterministic model of planetary formation. III. Mass
  distribution of short-period planets around stars of various masses

abstract:
  The origin of a recently discovered close-in Neptune-mass planet around GJ436
poses a challenge to the current theories of planet formation. Based on the
sequential accretion hypothesis and the standard theory of gap formation and
orbital migration, we show that around M dwarf stars, close-in Neptune-mass
ice-giant planets may be relatively common, while close-in Jupiter-mass
gas-giant planets are relatively rare. The mass distribution of close-in
planets generally has two peaks at about Neptune mass and Jupiter mass. The
lower-mass peak takes the maximum frequency for M dwarfs. Around more massive
solar-type stars (G dwarfs), the higher-mass peak is much more pronounced.
These are because planets tend to undergo type II migration after fully
accreting gas around G dwarfs while they tend to migrate faster than gas
accretion around M stars. Close-in Neptune-mass planets may also exist around G
dwarfs, though they tend to be mostly composed of silicates and iron cores and
their frequency is expected to be much smaller than that of Neptune-mass
planets around M dwarfs and that of gas giants around G dwarfs. We also show
that the conditions for planets' migration due to their tidal interaction with
the disk and the stellar-mass dependence in the disk-mass distribution can be
calibrated by the mass distribution of short-period planets around host stars
with various masses.


title:
A search for Warm-Hot Intergalactic Medium features in the X-ray spectra
  of Mkn 421 with the XMM-Newton RGS

abstract:
  We present the high-resolution X-ray spectra of Mkn 421 obtained in November
2003 with the RGS aboard the XMM-Newton satellite. This Target of Opportunity
observation was triggered because the source was in a high state of activity in
the X-ray band. These data are compared with three archival RGS observations of
the same source performed in November and December 2002 and one in June 2003.
We searched for the presence of absorption features due to warm-hot
intergalactic medium (WHIM). We identify various spectral features, most of
which are of instrumental origin. With the sensitivity provided by our spectra
we were able to identify only two lines of astronomical origin, namely features
at 23.5 A, probably due to interstellar neutral oxygen absorption, and at 21.6
A, which corresponds to a zero-redshift OVII K_alpha transition. For the
latter, we derive an upper limit to the gas temperature, which is consistent
with WHIM, of a few times 10^5 K, if the gas density has a value of n_e > 10^-5
cm^-3.


title:
Long-term optical photometric monitoring of the quasar SDSS
  J153259.96-003944.1

abstract:
  We report optical Cousins R and I band monitoring observations of the high
redshift (z = 4.67) QSO SDSS J153259.96-003944.1 that does not show detectable
emission lines in its optical spectrum. We show this object varies with a
maximum amplitude of ~0.4 mag during a year and three months of monitoring.
Combined with two other epochs of photometric data available in the literature,
we show the object has gradually faded by ~0.9 mag during the period June 1998
- April 2001. A linear least squares fit to all available observations gives a
slope of ~0.35 mag/yr which translates to ~1.9 mag/yr in the rest frame of the
quasar. Such a variability is higher than that typically seen in QSOs but
consistent with that of BL Lacs, suggesting that the optical continuum is
Doppler boosted. Alternatively, within photometric errors, the observed
lightcurve is also consistent with the object going through a microlensing
event. Photoionization model calculations show the mass of the Broad Line
Region to be few tens of solar mass similar to that of low luminosity Seyfert
galaxies, but about orders of magnitude less than that of luminous quasars.
Further frequent photometric/spectroscopic monitoring is needed to support or
refute the different alternatives discussed here on the nature of SDSS
J153259.96-003944.1.


title:
Observational evidence for the presence of PAHs in distant Luminous
  Infrared Galaxies using ISO and Spitzer

abstract:
  We present ISOCAM 15 micron and MIPS 24 micron photometry of a sample of 16
distant Luminous Infrared Galaxies (LIRGs) characterized by a median luminosity
L(IR) 2x10^11 Lsol and redshift z = 0.7 (distributed from z = 0.1 to 1.2).
While some sources display 24/15 micron flux ratios also consistent with a
featureless continuum dominating their mid-infrared (MIR) spectral energy
distributions (SEDs), the presence of prominent emission features such as the
Polycyclic Aromatic Hydrocarbons is clearly required to explain the observed
colors for more than half of the sample. As a result, a general good agreement
is observed between the data and predictions from the local starburst-dominated
SEDs that have been used so far to constrain IR galaxy evolution. This is
consistent with the star-forming nature of LIRGs derived from previous works,
even though our approach cannot rule out the dominance of an AGN in some cases.
Our study also supports the possibility of tracing the total IR luminosity of
distant galaxies (up to z ~ 1) from their MIR emission.


title: Magnetic Fields, Accretion, and the Central Engine of Gamma-Ray Bursts

abstract:
  I briefly review magnetic effects in accretion physics, and then go on to
discuss a possible central engine for gamma-ray bursts. A rotating black hole
immersed in a non-axisymmetric magnetic field experiences a torque trying to
align spin and field. I suggest that gamma-ray burst hosts may provide
conditions where this effect allows rapid extraction of a significant fraction
of the hole's rotational energy. I argue that much of the electromagnetic
emission is in two narrow beams parallel and antiparallel to the asymptotic
field direction. This picture suggests that only a mass 10^-5 Msun is expelled
in a relativistic outflow, as required by the fireball picture.


title:
The imprint of cosmological hydrogen recombination lines on the power
  spectrum of the CMB

abstract:
  We explore the imprint of the cosmological hydrogen recombination lines on
the power spectrum of the cosmic microwave background (CMB). In particular, we
focus our analysis in the three strongest lines for the Balmer, Paschen and
Brackett series of hydrogen. We expect changes in the angular power spectrum
due to these lines on the level of $0.3 \mu K$ for the H$\alpha$ line, being
maximum at small angular scales ($\ell \approx 870$). The morphology of the
signal is very rich. It leads to relatively narrow spectral features ($\Delta
\nu / \nu \sim 10^{-1}$), with several regions in the power spectrum showing a
characteristic change of sign of the effect as we probe different redshifts or
different multipoles by measuring the power spectrum at different frequencies.
It also has a very peculiar dependence on the multipole scale, connected with
the details of the transfer function at the epoch of scattering. In order to
compute the optical depths for these transitions, we have evolved numerically
the populations of the levels of the hydrogen atom during recombination,
treating simultaneously the evolution of helium. For the hydrogen atom, we
follow each angular momentum state separately, up to the level n=10.
Foregrounds and other frequency dependent contaminants, as Rayleigh scattering,
may be a important limitation for these measurements, although the peculiar
frequency and angular dependences of the effect which we are discussing might
permit to separate it. Detection of this signal using future narrow-band
spectral observations can give information about the details of how the cosmic
recombination proceeds, and how Silk damping operates during recombination.


title:
Probing the dark matter profile of hot clusters and the M-T relation
  with XMM-Newton

abstract:
  We present results based on XMM-Newton observations of a small sample of hot
galaxy clusters. Making a full use of XMM-Newton's spectro-imaging
capabilities, we have extracted the radial temperature profile and gas density
profile, and with this information, calculated the total mass profile of each
cluster (under the assumption of hydrostatic equilibrium and spherical
symmetry). Comparing the individual scaled total mass profiles, we have probed
the Universality of rich cluster mass profiles over a wide range of radii (from
0.01 to 0.7 the virial radius). We have also tested the shape of cluster mass
profiles by comparing with the predicted profiles from numerical simulations of
hierarchical structure formation. We also derived the local mass-temperature
(M-T) scaling relation over a range of temperature going from 4 to 9 keV, that
we compare with theoretical predictions.


title:
Supermassive black hole mass measurements for NGC 1300 and NGC 2748
  based on HST emission-line gas kinematics

abstract:
  We present Space Telescope Imaging Spectrograph emission-line spectra of the
central regions of the spiral galaxies NGC 1300 and NGC 2748. From the derived
kinematics of the nuclear gas we have found evidence for central supermassive
black holes in both galaxies. The estimated mass of the black hole in NGC 1300
is 6.6 (+6.3, -3.2) x 10^7 solar masses and in NGC 2748 is 4.4 (+3.5, -3.6) x
10^7 solar masses (both at the 95% confidence level). These two black hole mass
estimates contribute to the poorly sampled low-mass end of the nuclear black
hole mass spectrum.


title: The Multipole Vectors of WMAP, and their frames and invariants

abstract:
  We investigate the Statistical Isotropy and Gaussianity of the CMB
fluctuations, using a set of multipole vector functions capable of separating
these two issues. In general a multipole is broken into a frame and $2\ell-3$
ordered invariants. The multipole frame is found to be suitably sensitive to
galactic cuts. We then apply our method to real WMAP datasets; a coadded masked
map, the Internal Linear Combinations map, and Wiener filtered and cleaned
maps. Taken as a whole, multipoles in the range $\ell=2-10$ or $\ell=2-20$ show
consistency with statistical isotropy, as proved by the Kolmogorov test applied
to the frame's Euler angles. This result in {\it not} inconsistent with
previous claims for a preferred direction in the sky for $\ell=2,...5$. The
multipole invariants also show overall consistency with Gaussianity apart from
a few anomalies of limited significance (98%), listed at the end of this paper.


title: A Chandra and XMM-Newton study of the wide-angle tail radio galaxy 3C465

abstract:
  We have observed the prototypical wide-angle tail radio galaxy 3C465 with
Chandra and XMM-Newton. X-ray emission is detected from the active nucleus and
the inner radio jet, as well as a small-scale, cool component of thermal
emission, a number of the individual galaxies of the host cluster (Abell 2634),
and the hotter thermal emission from the cluster itself. The X-ray detection of
the jet allows us to argue that synchrotron emission may be an important
mechanism in other well-collimated, fast jets, including those of classical
double radio sources. The bases of the radio plumes are not detected in the
X-ray, which supports the model in which these plumes are physically different
from the twin jets of lower-power radio galaxies. The plumes are in fact
spatially coincident with deficits of X-ray emission on large scales, which
argues that they contain little thermal material at the cluster temperature,
although the minimum pressures throughout the source are lower than the
external pressures estimated from the observed thermal emission. Our
observations confirm both spatially and spectrally that a component of dense,
cool gas with a short cooling time is associated with the central galaxy.
However, there is no evidence for the kind of discontinuity in external
properties that would be required in many models of the jet-plume transition in
WATs. Although the WAT jet-plume transition appears likely to be related to the
interface between this central cool component and the hotter intra-cluster
medium, the mechanism for WAT formation remains unclear. We revisit the
question of the bending of WAT plumes, and show that the plumes can be bent by
plausible bulk motions of the intra-cluster medium, or by motion of the host
galaxy with respect to the cluster, as long as the plumes are light.


title: Cooling Evolution of Hybrid Stars

abstract:
  The cooling of compact isolated objects for different values of the
gravitational mass has been simulated for two alternative assumptions. One is
that the interior of the star is purely hadronic and second that the star can
have a rather large quark core. It has been shown that within a nonlocal chiral
quark model the critical density for a phase transition to color
superconducting quark matter under neutron star conditions can be low enough
for these phases to occur in compact star configurations with masses below 1.3
M_sun. For a realistic choice of parameters the equation of state (EoS) allows
for 2SC quark matter with a large quark gap ~ 100 MeV for u and d quarks of two
colors that coexists with normal quark matter within a mixed phase in the
hybrid star interior. We argue that, if in the hadronic phase the neutron
pairing gap in 3P_2 channel is larger than few keV and the phases with unpaired
quarks are allowed, the corresponding hybrid stars would cool too fast.
  Even in the case of the essentially suppressed 3P_2 neutron gap if free
quarks occur for M < 1.3 M_sun, as it follows from our EoS, one could not
appropriately describe the neutron star cooling data existing by today.
  It is suggested to discuss a "2SC+X" phase, as a possibility to have all
quarks paired in two-flavor quark matter under neutron star constraints, where
the X-gap is of the order of 10 keV - 1 MeV. Density independent gaps do not
allow to fit the cooling data. Only the presence of an X-gap that decreases
with increase of the density could allow to appropriately fit the data in a
similar compact star mass interval to that following from a purely hadronic
model.


title:
The first giant flare from SGR 1806-20: observations with the INTEGRAL
  SPI Anti-Coincidence Shield

abstract:
  A giant flare from the Soft Gamma-ray Repeater SGR 1806-20 has been detected
by several satellites on 2004 December 27. This tremendous outburst, the first
one observed from this source, was a hundred times more powerful than the two
previous giant flares from SGR 0525-66 and SGR 1900+14. We report the results
obtained for this event with the Anticoincidence Shield of the SPI spectrometer
on board the INTEGRAL satellite, which provides a high-statistics light curve
at E>~80 keV. The flare started with a very strong pulse, which saturated the
detector for ~0.7 s, and whose backscattered radiation from the Moon was
detected 2.8 s later. This was followed by a ~400 s long tail modulated at the
neutron star rotation period of 7.56 s. The tail fluence corresponds to an
energy in photons above 3 keV of 1.6x10^44 (d/15 kpc)^2 erg. This is of the
same order of the energy emitted in the pulsating tails of the two giant flares
seen from other soft repeaters, despite the hundredfold larger overall emitted
energy of the SGR 1806-20 giant flare. Long lasting (~1 hour) hard X-ray
emission, decaying in time as t^-0.85, and likely associated to the SGR 1806-20
giant flare afterglow has also been detected.


title: Non-gaussianity from the second-order cosmological perturbation

abstract:
  Several conserved and/or gauge invariant quantities described as the
second-order curvature perturbation have been given in the literature. We
revisit various scenarios for the generation of second-order non-gaussianity in
the primordial curvature perturbation \zeta, employing for the first time a
unified notation and focusing on the normalisation f_{NL} of the bispectrum.
When the classical curvature perturbation first appears a few Hubble times
after horizon exit, |f_{NL}| is much less than 1 and is, therefore, negligible.
Thereafter \zeta (and hence f_{NL}) is conserved as long as the pressure is a
unique function of energy density (adiabatic pressure). Non-adiabatic pressure
comes presumably only from the effect of fields, other than the one pointing
along the inflationary trajectory, which are light during inflation (`light
non-inflaton fields'). During single-component inflation f_{NL} is constant,
but multi-component inflation might generate |f_{NL}| \sim 1 or bigger.
Preheating can affect f_{NL} only in atypical scenarios where it involves light
non-inflaton fields. The curvaton scenario typically gives f_{NL} \ll -1 or
f_{NL} = +5/4. The inhomogeneous reheating scenario can give a wide range of
values for f_{NL}. Unless there is a detection, observation can eventually
provide a limit |f_{NL}| \lsim 1, at which level it will be crucial to
calculate the precise observational limit using second order theory.


title: Planar resonant periodic orbits in Kuiper belt dynamics

abstract:
  In the framework of the planar restricted three body problem we study a
considerable number of resonances associated to the Kuiper Belt dynamics and
located between 30 and 48 a.u. Our study is based on the computation of
resonant periodic orbits and their stability. Stable periodic orbits are
surrounded by regular librations in phase space and in such domains the capture
of trans-Neptunian object is possible. All the periodic orbits found are
symmetric and there is evidence for the existence of asymmetric ones only in
few cases. In the present work first, second and third order resonances are
under consideration. In the planar circular case we found that most of the
periodic orbits are stable. The families of periodic orbits are temporarily
interrupted by collisions but they continue up to relatively large values of
the Jacobi constant and highly eccentric regular motion exists for all cases.
In the elliptic problem and for a particular eccentricity value of the primary
bodies the periodic orbits are isolated. The corresponding families, where they
belong to, bifurcate from specific periodic orbits of the circular problem and
seem to continue up to the rectilinear problem. Both stable and unstable orbits
are obtained for each case. In the elliptic problem the unstable orbits found
are associated with narrow chaotic domains in phase space. The evolution of the
orbits, which are located in such chaotic domains, seems to be practically
regular and bounded for long time intervals.


title:
Weakly Nonlocal Hydrodynamics and the Origin of Viscosity in the
  Adhesion Model

abstract:
  We use the weakly nonlocal hydrodynamics approach to obtain a dynamical
equation for the peculiar velocity field in which the viscosity term is
physically motivated. Based on some properties of the Ginzburg-Landau equation
and the wave mechanics analog of hydrodynamics we find the nonlocal adhesion
approximation taking into account the internal structures of the Zeldovich
pancakes. If the internal structures correspond to significant mesoscopic
fluctuations, viscosity is probably driven by a stochastic force and dynamics
is given by the noisy Burgers equation.


title:
PMAS, the Potsdam Multi-Aperture Spectrophotometer. I. Design,
  Manufacture, and Performance

abstract:
  We describe the design, manufacture, commissioning, and performance of PMAS,
the Potsdam Multi-Aperture Spectrophotometer. PMAS is a dedicated integral
field spectrophotometer, optimized to cover the optical wavelength regime of
0.35--1um. It is based on the lens array -- fiber bundle principle of
operation. The instrument employs an all-refractive fiber spectrograph, built
with CaF2 optics, to provide good transmission and high image quality over the
entire nominal wavelength range. A set of user-selectable reflective gratings
provides low to medium spectral resolution in first order of approx. 1.5, 3.2,
and 7 A, depending on the groove density (1200, 600, 300 gr/mm). While the
standard integral field unit (IFU) uses a 16x16 element lens array, which
provides seeing-limited sampling in a relatively small field-of-view (FOV) in
one of three magnifications (8x8, 12x12, or 16x16 arcsec^2, respectively), a
recently retrofitted bare fiber bundle IFU (PPak) expands the FOV to a
hexagonal area with a footprint of 65x74 arcsec^2. Other special features
include a cryogenic CCD camera for field acquisition and guiding, a nod-shuffle
mode for beam switching and improved sky background subtraction, and a scanning
Fabry-Perot etalon in combination with the standard IFU (PYTHEAS mode). PMAS
was initially designed and built as an experimental traveling instrument with
optical interfaces to various telescopes (Calar Alto 3.5m, ESO-VLT, LBT). It is
offered as a common user instrument at Calar Alto under contract with MPIA
Heidelberg since 2002.


title:
Ab Initio Calculation of the Anomalous Acceleration of Pioneer 10 In
  Vacuo

abstract:
  The anomalous acceleration of Pioneer 10 is presented as a calculation using
a simple optical model. The model is based on the bending of background gravity
behind the Sun in the same way that light is bent by the Sun. Structures of
ponderable matter about the Solar system, neutron stars, and galaxies are
described. Viewable red and blue shiftings of light are predicted.


title: Thermal Evolution of a Pulsating Neutron Star

abstract:
  We have derived a set of equations to describe the thermal evolution of a
neutron star which undergoes small-amplitude radial pulsations. We have taken
into account, in the frame of the General Theory of Relativity, the pulsation
damping due to the bulk and shear viscosity and the accompanying heating of the
star. The neutrino emission of a pulsating non-superfluid star and its heating
due to the bulk viscosity are calculated assuming that both processes are
determined by the non-equilibrium modified Urca process. Analytical and
numerical solutions to the set of equations of the stellar evolution are
obtained for linear and strongly non-linear deviations from beta-equilibrium.
It is shown that a pulsating star may be heated to very high temperatures,
while the pulsations damp very slowly with time (a power law damping for
100-1000 years), as long as the damping is determined by the bulk viscosity.
The contribution of the shear viscosity to the damping becomes important in a
rather cool star with a low pulsation energy.


title:
On the existence of three-dimensional hydrostatic and magnetostatic
  equilibria of self-gravitating fluid bodies

abstract:
  (Abridged) We develop an analytical spectral method to solve the equations of
equilibrium for a self-gravitating, magnetized fluid body, under the only
hypotheses that (a) the equation of state is isothermal, (b) the configuration
is scale-free, and (c) the body is electrically neutral. All physical variables
are represented as series of scalar and vector spherical harmonics of degree l
and order m, and the equilibrium equations are reduced to a set of coupled
quadratic algebraic equations for the expansion coefficients of the density and
the magnetic vector potential. The method is general, and allows to recover
previously known hydrostatic and magnetostatic solutions possessing axial
symmetry. A linear perturbation analysis of the equations in spectral form show
that these basic axisymmetric states, considered as a continuos sequence with
the relative amount of magnetic support as control parameter, have in general
no neighboring nonaxisymmetric equilibria. This result lends credence to a
conjecture originally made by H. Grad and extends early results obtained by E.
Parker to the case of self-gravitating magnetized bodies. The only allowed
bifurcations of this sequence of axisymmetric equilibria are represented by
distortions with dipole-like angular dependence (l=1) that can be continued
into the nonlinear regime. These new configurations are either (i) azimuthally
asymmetric (m=+-1) or (ii) azimuthally symmetric but without reflection
symmetry with respect to the equatorial plane (m=0). To the extent that
interstellar clouds can be represented as isolated magnetostatic equilibria,
the results of this study suggest that the observed triaxial shapes of
molecular cloud cores can be interpreted in terms of weakly damped Alfven
oscillations about an equilibrium state.


title: On the anomalous red giant branch of the globular cluster Omega Cen

abstract:
  We present three different optical and near-infrared (NIR) data sets for
evolved stars in the Galactic Globular Cluster Omega Cen The comparison between
observations and homogeneous sets of stellar isochrones and Zero-Age Horizontal
Branches provides two reasonable fits. Both of them suggest that the so-called
anomalous branch has a metal-intermediate chemical composition (-1.1 < [Fe/H] <
-0.8) and is located ~500 pc beyond the bulk of Omega Cen stars. These findings
are mainly supported by the shape of the subgiant branch in four different
color-magnitude diagrams (CMDs). The most plausible fit requires a higher
reddening, E(B-V)=0.155 vs. 0.12, and suggests that the anomalous branch is
coeval, within empirical and theoretical uncertainties, to the bulk of Omega
Cen stellar populations. This result is supported by the identification of a
sample of faint horizontal branch stars that might be connected with the
anomalous branch. Circumstantial empirical evidence seems to suggest that the
stars in this branch form a clump of stars located beyond the cluster.


title: Radio Photosphere and Mass-Loss Envelope of VY CMa

abstract:
  We have used the VLA to detect emission from the supergiant VY CMa at radio
wavelengths and have constructed 3000-4500 K isothermal outer atmospheres
constrained by the data. These models produce a radio photosphere at 1.5-2
R_ast. An extrapolation of the model can account for the observed total
mass-loss rate of the star. We also present mid-infrared imaging of the
supergiant that suggests warm dust is extended in the same direction as the
near-infrared reflection nebula around VY CMa. The origin of the asymmetries in
the outflow remains an unsolved problem.


title:
Dust Penetrated Arm Classes: Insights from rising and falling rotation
  curves

abstract:
  In the last decade, near-infrared imaging has highlighted the decoupling of
gaseous and old stellar disks: the morphologies of optical (Population I)
tracers compared to the old stellar disk morphology, can be radically
different. Galaxies which appear multi-armed and even flocculent in the optical
may show significant Grand-Design spirals in the near-infrared. Furthermore,
the optically determined Hubble classification scheme does not provide a sound
way of classifying dust-penetrated stellar disks: spiral arm pitch angles (when
measured in the near-infrared) do not correlate with Hubble type. The
dust--penetrated classification scheme of Block & Puerari provides an
alternative classification based on near-infrared morphology, and which is thus
more closely linked to the dominant stellar mass component. Here we present
near--infrared K band images of 14 galaxies, on which we have performed a
Fourier analysis of the spiral structure in order to determine their
near-infrared pitch angles and dust--penetrated arm classes. We have also used
the rotation curve data of Mathewson et al. to calculate the rates of shear in
the stellar disks of these galaxies. We find a correlation between
near-infrared pitch angle and rate of shear: galaxies with wide open arms (the
$\gamma$ class) are found to have rising rotation curves, while those with
falling rotation curves belong to the tightly wound $\alpha$ bin. The major
determinant of near-infrared spiral arm pitch angle is the distribution of
matter within the galaxy concerned. The correlation reported in this study
provides the physical basis underpinning spiral arm classes in the
dust-penetrated regime and underscores earlier spectroscopic findings by
Burstein and Rubin that Hubble type and mass distributions are unrelated.


title: Nuclear Astrophysics

abstract:
  Nuclear physics has a long and productive history of application to
astrophysics which continues today. Advances in the accuracy and breadth of
astrophysical data and theory drive the need for better experimental and
theoretical understanding of the underlying nuclear physics. This paper will
review some of the scenarios where nuclear physics plays an important role,
including Big Bang Nucleosynthesis, neutrino production by our sun,
nucleosynthesis in novae, the creation of elements heavier than iron, and
neutron stars. Big-bang nucleosynthesis is concerned with the formation of
elements with A <= 7 in the early Universe; the primary nuclear physics inputs
required are few-nucleon reaction cross sections. The nucleosynthesis of
heavier elements involves a variety of proton-, alpha-, neutron-, and
photon-induced reactions, coupled with radioactive decay. The advent of
radioactive ion beam facilities has opened an important new avenue for studying
these processes, as many involve radioactive species. Nuclear physics also
plays an important role in neutron stars: both the nuclear equation of state
and cooling processes involving neutrino emission play a very important role.
Recent developments and also the interplay between nuclear physics and
astrophysics will be highlighted.


title: An emergent universe from a loop

abstract:
  Closed, singularity-free, inflationary cosmological models have recently been
studied in the context of general relativity. Despite their appeal, these so
called emergent models suffer from a number of limitations. These include the
fact that they rely on an initial Einstein static state to describe the past
eternal phase of the universe. Given the instability of such a state within the
context of general relativity, this amounts to a very severe fine tuning. Also
in order to be able to study the dynamics of the universe within the context of
general relativity, they set the initial conditions for the universe in the
classical phase. Here we study the existence and stability of such models in
the context of Loop Quantum Cosmology and show that both these limitations can
be partially remedied, once semi-classical effects are taken into account. An
important consequence of these effects is to give rise to a static solution
(not present in GR), which dynamically is a centre equilibrium point and
located in the more natural semi-classical regime. This allows the construction
of emergent models in which the universe oscillates indefinitely about such an
initial static state. We construct an explicit emergent model of this type, in
which a non-singular past eternal oscillating universe enters a phase where the
symmetry of the oscillations is broken, leading to an emergent inflationary
epoch, while satisfying all observational and semi-classical constraints. We
also discuss emergent models in which the universe possesses both early- and
late-time accelerating phases.


title:
MIPS 70-micron Observations of the Spitzer Extragalactic First Look
  Survey

abstract:
  Early results from the 70-micron observations of the Spitzer Extragalactic
First Look Survey are presented. As a whole, about 90% of the population show
infrared colors that are consistent with the spectral energy distributions of
the local IRAS population of luminous infrared starbursts, while approximately
10% of the sample show warm infrared colors consistent with AGN activity. The
mean redshift for the population is z=0.2, and the mean total infrared
luminosity is about L(ir)= 2x10^{11} L(sun).


title: HST Observations of Heavy Elements in Metal-Poor Galactic Halo Stars

abstract:
  We present new abundance determinations of neutron-capture elements Ge, Zr,
Os, Ir, and Pt in a sample of 11 metal-poor (-3.1 <= [Fe/H] <= -1.6) Galactic
halo giant stars, based on Hubble Space Telescope UV and Keck I optical
high-resolution spectroscopy. The stellar sample is dominated by r-process-rich
stars such as the well-studied CS 22892-052 and bd+173248, but also includes
the r-process-poor, bright giant HD 122563. Our results demonstrate that
abundances of the 3rd r-process peak elements Os, Ir and Pt in these metal-poor
halo stars are very well-correlated among themselves, and with the abundances
of the canonical r-process element Eu (determined in other studies), thus
arguing for a common origin or site for r-process nucleosynthesis of heavier
(Z>56) elements. However, the large (and correlated) scatters of
[Eu,Os,Ir,Pt/Fe] suggests that the heaviest neutron-capture r-process elements
are not formed in all supernovae. In contrast, the Ge abundances of all program
stars track their Fe abundances, very well. An explosive process on iron-peak
nuclei (e.g., the alpha-rich freeze-out in supernovae), rather than neutron
capture, appears to have been the dominant synthesis mechanism for this element
at low metallicities -- Ge abundances seem completely uncorrelated with Eu.


title: The Sources of Intergalactic Metals

abstract:
  We study the clustering properties of metals in the intergalactic medium
(IGM) as traced by 619 CIV, 81 SiIV, N >= 10^12 cm^-2 and 316 MgII, and 82 FeII
N >= 10^11.5 cm^-2 absorption components in 19 high signal-to-noise (60-100 per
pixel), high resolution (R = 45000) quasar spectra. Over the redshift range
probed (1.5-3.0), CIV and SiIV trace each other closely and their line-of-sight
correlation functions exhibit a steep decline at large separations and a
flatter profile below ~ 150 km s^-1, with a large overall bias. These features
do not depend on column depth. Carrying out a detailed SPH simulation (2 X
320^3, 57 Mpc^3 comoving), we show that this behavior can not be reproduced by
models in which the IGM metallicity is constant or a local function of density.
However, the CIV correlation function is consistent with a model in which
metals are confined within bubbles with a typical radius Rs = 2 comoving Mpc
about sources of mass >= Ms = 10^12 solar masses at z=3. Our lower redshift
(0.5-2) measurements of the MgII and FeII correlation functions also uncover a
steep decline at large separations and a flatter profile at small separations,
but the clustering is even higher, and the turn-over is shifted to ~ 75 km
s^-1. Again these features do not change with column depth. We describe an
analytical bubble model for these species, which come from regions that are too
compact to be simulated numerically, deriving best-fit values of R_s ~ 2.4 Mpc
and M_s ~ 10^12 solar masses. Equally good fits to all four species are found
in a similarly biased high-redshift enrichment model in which metals are placed
within 2.4 comoving Mpc of 3 x 10^9 solar mass sources at z = 7.5.


title: Cosmic Shear of the Microwave Background: The Curl Diagnostic

abstract:
  Weak-lensing distortions of the cosmic-microwave-background (CMB) temperature
and polarization patterns can reveal important clues to the intervening
large-scale structure. The effect of lensing is to deflect the primary
temperature and polarization signal to slightly different locations on the sky.
Deflections due to density fluctuations, gradient-type for the gradient of the
projected gravitational potential, give a direct measure of the mass
distribution. Curl-type deflections can be induced by, for example, a
primordial background of gravitational waves from inflation or by second-order
effects related to lensing by density perturbations. Whereas gradient-type
deflections are expected to dominate, we show that curl-type deflections can
provide a useful test of systematics and serve to indicate the presence of
confusing secondary and foreground non-Gaussian signals.


title: Early structure in LCDM

abstract:
  We use a novel technique to simulate the growth of the most massive
progenitor of a protocluster region from redshift z~80, when its mass was about
10 Msun until the present day. Our nested sequence of N-body resimulations
allows us to study in detail the structure both of the dark matter object
itself and of its environment. Our effective resolution is optimal at redshifts
of 49, 29, 12, 5 and 0 when the dominant object has mass 1.2e5, 5e7, 2e10, 3e12
and 8e14 Msun/hrespectively, and contains ~1e6 simulation particles within its
virial radius. Extended Press-Schechter theory correctly predicts both this
rapid growth and the substantial overabundance of massive haloes we find at
early times in regions surrounding the dominant object. Although the
large-scale structure in these regions differs dramatically from a scaled
version of its present-day counterpart, the internal structure of the dominant
object is remarkably similar. Molecular hydrogen cooling could start as early
as z~49 in this object, while cooling by atomic hydrogen becomes effective at
z~39. If the first stars formed in haloes with virial temperature ~2000, their
comoving abundance by z=49 would be similar to that of dwarf galaxies today,
while their comoving correlation length would be ~2.5Mpc/h.


title: Discovery of an X-ray-Luminous Galaxy Cluster at z=1.4

abstract:
  We report the discovery of a massive, X-ray-luminous cluster of galaxies at
z=1.393, the most distant X-ray-selected cluster found to date. XMMU
J2235.3-2557 was serendipitously detected as an extended X-ray source in an
archival XMM-Newton observation of NGC 7314. VLT-FORS2 R and z band snapshot
imaging reveals an over-density of red galaxies in both angular and color
spaces. The galaxy enhancement is coincident in the sky with the X-ray
emission; the cluster red sequence at R-z ~ 2.1 identifies it as a
high-redshift candidate. Subsequent VLT-FORS2 multi-object spectroscopy
unambiguously confirms the presence of a massive cluster based on 12 concordant
redshifts in the interval 1.38<z<1.40. The preliminary cluster velocity
dispersion is 762+/-265 km/s. VLT-ISAAC Ks and J band images underscore the
rich distribution of red galaxies associated with the cluster. Based on a 45 ks
XMM-Newton observation, we find the cluster has an aperture-corrected,
unabsorbed X-ray flux of f_X = (3.6 +/- 0.3) x 10^{-14} erg/cm^2/s, a
rest-frame X-ray luminosity of L_X = (3.0 +/- 0.2) x 10^{44} h_70^{-2} erg/s
(0.5--2.0 keV), and a temperature of kT=6.0 (+2.5, -1.8) keV. Though XMMU
J2235.3-2557 is likely the first confirmed z>1 cluster found with XMM-Newton,
the relative ease and efficiency of discovery demonstrates that it should be
possible to build large samples of z>1 clusters through the joint use of X-ray
and large, ground-based telescopes.


title:
Internal Shocks in the Magnetic Reconnection Jet in Solar Flares:
  Multiple Fast Shocks Created by the Secondary Tearing Instability

abstract:
  Space solar missions such as {\it Yohkoh} and {\it RHESSI} observe the hard
X- and gamma-ray emission from energetic electrons in impulsive solar flares.
Their energization mechanism, however, is unknown. In this paper, we suggest
that the internal shocks are created in the reconnection jet and that they are
possible sites of particle acceleration. We examine how magnetic reconnection
creates the multiple shocks by performing two-dimensional resistive
magnetohydrodynamic simulations. In this paper, we use a very small grid to
resolve the diffusion region. As a result, we find that the current sheet
becomes thin due to the tearing instability, and it collapses to a Sweet-Parker
sheet. The thin sheet becomes unstable to the secondary tearing instability.
Fast reconnection starts by the onset of anomalous resistivity immediately
after the secondary tearing instability. During the bursty, time-dependent
magnetic reconnection, the secondary tearing instability continues in the
diffusion region where the anomalous resistivity is enhanced. As a result, many
weak shocks are created in the reconnection jet. This situation produces
turbulent reconnection. We suggest that multiple fast shocks are created in the
jet and that the energetic electrons can be accelerated by these shocks.


title:
Can Dark Matter Annihilation Dominate the Extragalactic Gamma-Ray
  Background?

abstract:
  Annihilating dark matter (DM) has been discussed as a possible source of
gamma-rays from the galactic center (GC) and contributing to the extragalactic
gamma-ray background (EGB). Assuming universality of the density profile of DM
halos, we show that it is quite unlikely that DM annihilation is a main
constituent of EGB, without exceeding the observed gamma-ray flux from the GC.
This argument becomes stronger when we include enhancement of the density
profiles by supermassive black holes or baryon cooling. The presence of
substructure may loosen the constraint, but only if a very large cross section
as well as the rather flat profile are realized.


title: Relativistic SPH Calculations of Compact Binary Mergers

abstract:
  We review recent progress in understanding the hydrodynamics of compact
binary mergers using relativistic smoothed particle hydrodynamics (SPH) codes.
Recent results are discussed for both double neutron stars and black hole -
neutron star binaries. The gravitational wave signals from these mergers
contain a lot of information about the masses and radii of the stars and the
equation of state of the neutron star fluid. For black hole - neutron star
mergers, the final fate of the fluid and the gravitational wave emission depend
strongly on the mass ratio and the black hole spin.


title: Spitzer Mid-Infrared Imaging of Nearby Ultraluminous Infrared Galaxies

abstract:
  We have observed 14 nearby (z<0.16) Ultraluminous Infrared Galaxies (ULIRGs)
with Spitzer at 3.6-24 microns. The underlying host galaxies are well-detected,
in addition to the luminous nuclear cores. While the spatial resolution of
Spitzer is poor, the great sensitivity of the data reveals the underlying
galaxy merger remnant, and provides the first look at off-nuclear mid-infrared
activity.


title:
Soft X-ray and Ultraviolet Emission Relations in Optically Selected AGN
  Samples

abstract:
  Using a sample of 228 optically selected Active Galactic Nuclei (AGNs) in the
0.01-6.3 redshift range with a high fraction of X-ray detections (81-86%), we
study the relation between rest-frame UV and soft X-ray emission and its
evolution with cosmic time. The majority of the AGNs in our sample (155
objects) have been selected from the Sloan Digital Sky Survey (SDSS) in an
unbiased way, rendering the sample results representative of all SDSS AGNs. The
addition of two heterogeneous samples of 36 high-redshift and 37 low-redshift
AGNs further supports and extends our conclusions. We confirm that the X-ray
emission from AGNs is correlated with their UV emission, and that the ratio of
the monochromatic luminosity emitted at 2keV compared to 2500A decreases with
increasing luminosity (a_ox=-0.136 l_uv+2.616, where l_uv is in log units), but
does not change with cosmic time. These results apply to intrinsic AGN
emission, as we correct or control for the effects of the host galaxy, UV/X-ray
absorption, and any X-ray emission associated with radio emission in AGNs. We
investigate a variety of systematic errors and can thereby state with
confidence that (1) the a_ox-l_uv anti-correlation is real and not a result of
accumulated systematic errors and (2) any a_ox dependence on redshift is
negligible in comparison. We provide the best quantification of the a_ox-l_uv
relation to date for normal radio-quiet AGNs; this should be of utility for
researchers pursuing a variety of studies.


title:
Thermal and Fragmentation Properties of Star-forming Clouds in
  Low-metallicity Environments

abstract:
  The thermal and chemical evolution of star-forming clouds is studied for
different gas metallicities, Z, using the model of Omukai (2000), updated to
include deuterium chemistry and the effects of cosmic microwave background
(CMB) radiation. HD-line cooling dominates the thermal balance of clouds when Z
\~ 10^{-5}-10^{-3} Z_sun and density ~10^{5} cm^{-3}. Early on, CMB radiation
prevents the gas temperature to fall below T_CMB, although this hardly alters
the cloud thermal evolution in low-metallicity gas. From the derived
temperature evolution, we assess cloud/core fragmentation as a function of
metallicity from linear perturbation theory, which requires that the core
elongation E := (b-a)/a > E_NL ~ 1, where a (b) is the short (long) core axis
length. The fragment mass is given by the thermal Jeans mass at E = E_NL. Given
these assumptions and the initial (gaussian) distribution of E we compute the
fragment mass distribution as a function of metallicity. We find that: (i) For
Z=0, all fragments are very massive, > 10^{3}M_sun, consistently with previous
studies; (ii) for Z>10^{-6} Z_sun a few clumps go through an additional high
density (> 10^{10} cm^{-3}) fragmentation phase driven by dust-cooling, leading
to low-mass fragments; (iii) The mass fraction in low-mass fragments is
initially very small, but at Z ~ 10^{-5}Z_sun it becomes dominant and continues
to grow as Z is increased; (iv) as a result of the two fragmentation modes, a
bimodal mass distribution emerges in 0.01 < Z/Z_sun < 0.1. (v) For > 0.1Z_sun,
the two peaks merge into a singly-peaked mass function which might be regarded
as the precursor of the ordinary Salpeter-like IMF.


title:
Quasi-periodic oscillations: Resonant shear Alfv`en waves in neutron
  star magnetospheres

abstract:
  In this paper we propose a new model for quasi-periodic oscillations (QPOs)
based on oscillating magnetohydrodynamic modes in neutron star magnetospheres.
We argue that the interaction of the accretion disk with the magnetosphere can
excite resonant shear Alfv`en waves in a region of enhanced density gradients,
the region where accretion material flows along the magnetic field lines in the
magnetosphere. We demonstrate that depending on the distance of this region
from the star and the magnetic field strength, the frequency of the field line
resonance can range from several Hz (weaker field, farther from star), to
approximately kHz frequencies (stronger field, ~ 2-10 stellar radii from the
star). We show that such oscillations are able to significantly modulate inflow
of matter from the high density region toward the star's surface, and possibly
produce the observed X-ray spectrum. In addition, we show that the observed 2:3
frequency ratio of QPOs is a natural result of our model.


title: Neutrino Absorption: In the magnetic field of GRB In the Fireball Model

abstract:
  TeV or Super TeV neutrinos are expected to originate at the Gamma ray burster
(GRB) events in the universe. These neutrinos are expected to be produced from
the photo-meson interaction of the protons in the GRB environment. In the usual
picture, the protons in the GRB fireball undergo Fermi acceleration in the
ambient magnetic field of the GRB to very high energy. These protons then
interact with the MeV, KeV or meV photons and produce Delta particles, those
subsequently decay to produce very high energy neutrinos. In this note we focus
on the 100 TeV neutrinos produced in a GRB in the fireball model. We try to
estimate the production point of these multi TeV neutrinos from the center. The
strength of the Magnetic field there. Lastly but importantly modification in
the spectrum because of neutrino absorption in the ambient magnetic field. The
strength of the ambient magnetic field may change the neutrino spectrum.


title:
Parker Instability in a Self-Gravitating Magnetized Gas Disk: I. Linear
  Stability Analysis

abstract:
  To be a formation mechanism of such large-scale structures as giant molecular
clouds (GMCs) and HI superclouds, the classical Parker instability driven by
external gravity has to overcome three major obstacles: The convective motion
accompanying the instability generates thin sheets than large condensations.
The degree of density enhancement achieved by the instability is too low to
make dense interstellar clouds. The time and the length scales of the
instability are significantly longer and larger than the estimated formation
time and the observed mean separation of the GMCs, respectively. This paper
examines whether a replacement of the driving agent from the external to the
self gravity might remove these obstacles by activating the gravitational
instability in the Galactic ISM disk. The self gravity can suppress the
convective motions, and a cooperative action of the Jeans and the Parker
instabilities can remove all the obstacles confronting the classical version of
the Parker instability. The mass and mean separation of the structures
resulting from the odd-parity undular mode solution are shown to agree better
with the HI superclouds than with the GMCs. We briefly discuss how inclusions
of the external gravity and cosmic rays would modify behaviors of the
odd-parity undular mode solution.


title: Predicting the CMB power spectrum for binary polyhedral spaces

abstract:
  The COBE and the first-year WMAP data both find the CMB quadrupole and
octopole to be anomalously low. Here it is shown, that a finite,
multi-connected universe may explain this anomaly, supporting earlier analyses
[5][18]. A novel technique, pioneered by [16] is used to compute the spectrum
and its variance up to k=102. Based on the properties of the Lie group of
rotations of S^3 it is shown that the spectrum and its variance may be computed
solely from the matrix elements of the group-averaging operator, for each of
the manifolds S^3/I^*, S^3/O^* and S^3/T^*. Further, it is proved that the
spectrum of the CMB may be calculated solely from the radial function, due to
the symmetry properties of the Lie-algebra, which is rigorously proven. It is
shown, that if the topology of the universe is S^3/I^* the uncertainty on the
estimates for the total energy density of the universe may be reduced by an
order of magnitude. Finally, the paper highlights how the unavailability of an
explicit probability function for the observations, given the model, is a
challenge for Monte-Carlo simulations of the binary polyhedral spaces which has
to be addressed in future work.


title: "4n multipole periodicity" of the Galaxy image in the WMAP data

abstract:
  We present a specific periodicity of the Galaxy images in the multipole
domain which can be used for separation of the cosmic microwave background
(CMB) signal from the Galaxy and foreground component.
  This method takes into consideration all the coefficients of the expansion of
the signal from the sky \Delta T(\Theta, \phi) into spherical harmonics and
dealing with combination of multipoles a_{l,m} and a_{l+\Delta,m} for each
multipole mode (\ell, -\ell \le m \le \ell) from the whole sky without galactic
cut, masks or any dissection of the whole sky into disjoint regions. For the
polar coordinate system we use particular values for \Delta=4n, n=1,2,... which
remove all bright point-like sources localized in the Galactic plane and strong
diffused component down to the CMB level. To illustrate that significant
correlations of the point like sources and foregrounds a_{l,m},a_{l+\Delta,m}
coefficients we apply this method to the WMAP Q,V and W bands in order to
remove these marks of Galaxy from the maps. We believe that our method would be
useful for separation of the CMB signal from different kind of "noises" in the
maps.


title: High-Energy pulse profile of the Transient X-ray Pulsar SAX J2103.5+4545

abstract:
  In two recent INTEGRAL papers, Lutovinov et al. (2003) and Blay et al. (2004)
report a timing and spectral analysis of the transient Be/X-ray pulsar SAX
J2103.5+4545 at high energies (5--200 keV). In this work we present for the
first time a study of the pulse profile at energies above 20 keV using INTEGRAL
data. The spin-pulse profile shows a prominent (with a duty cycle of 14%) and
broad (with a FWHM of ~ 51 s) peak and a secondary peak which becomes more
evident above 20 keV. The pulsed fraction increases with energy from ~ 45% at
5--40 keV to ~ 80% at 40--80 keV. The morphology of the pulse profile also
changes as a function of energy, consistent with variations in the spectral
components that are visible in the pulse phase resolved spectra. A study of the
double peaked profile shows that the difference in the two peaks can be modeled
by a different scattering fraction between the radiation from the two magnetic
poles.


title:
Cosmic Infrared Background: Resolved, Unresolved and Spitzer
  Contributions

abstract:
  The Cosmic Infrared Background (CIB) peaks in the Far-Infrared (FIR), and its
Spectral Energy Distribution (SED) is now well constrained. Thanks to recent
facilities and Spitzer, the populations contributing to the CIB are being
characterized: the dominant galaxy contributions to the FIR CIB are Luminous IR
galaxies (LIRGs) at 0.5<z<1.5 and, to the submm CIB, Ultra-LIRGs at z>2. These
populations of galaxies experience very high rates of evolution with redshift.
Because of confusion, the CIB is (and will remain in some domains) partially
resolved and its contributing galaxies SEDs are not well constrained. We
discuss all these aspects and show how confusion limits Spitzer observations,
and how to overcome it in order to study the unresolved part of the CIB.


title:
Reconstruction of the microlensing light curves of the Einstein Cross,
  QSO2237+0305: possible evidence of an accretion disk with a central hole

abstract:
  Recent OGLE (Optical Gravitational Lensing Experiment) and GLITP
(Gravitational Lens International Time Project) monitoring data for QSO
2237+0305 (Huchra et al.) have been analyzed through a newly optimized N-body
microlensing analysis method, the Local HAE Caustic Modeling (LOHCAM). This
method simultaneously solves for the size of the source and N-body HAE (High
Amplification Events) caustic shapes in the source plane and determines those
sizes only as a function of the projected transverse velocity of the source. By
applying this method to the light curves of the A & C lensed components in the
Einstein Cross, these data are accurately reconstructed for the first time.
  From these modeling studies, we report several interesting results: the
minimum number of microlenses required for possible caustic models, the
possible evidence of an accretion disk with a central hole at the heart of the
quasar, the size of the UV-continuum source, the masses of the microlenses
being directly responsible for the observed HAEs, the estimated mass range of a
super massive black hole (SMBH) in QSO 2237+0305 and finally some clues for the
direction of the source motion in the sky.


title:
COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses I. How
  to sample the light curves of gravitationally lensed quasars to measure
  accurate time delays

abstract:
  We use numerical simulations to test a broad range of plausible observational
strategies designed to measure the time delay between the images of
gravitationally lensed quasars. Artificial quasar light curves are created
along with Monte-Carlo simulations in order to determine the best temporal
sampling to adopt when monitoring the photometric variations of systems with
time delays between 5 and 120 days, i.e., always shorter than the visibility
window across the year. Few and realistic assumptions are necessary on the
quasar photometric variations (peak-to-peak amplitude and time-scale of the
variations) and on the accuracy of the individual photometric points. The
output of the simulations is the (statistical) relative error made on the time
delay measurement, as a function of 1- the object visibility over the year, 2-
the temporal sampling of the light curves and 3- the time delay. Also
investigated is the effect of long term microlensing variations which must be
below the 5 % level (either intrinsically or by subtraction) if the goal is to
measure time delays with an accuracy of 1-2 %. However, while microlensing
increases the random error on the time delay, it does not significantly
increase the systematic error, which is always a factor 5 to 10 smaller than
the random error. Finally, it is shown that, when the time delay is comparable
to the visibility window of the object, a logarithmic sampling can
significantly improve the time delay determination. All results are presented
in the form of compact plots to be used to optimize the observational strategy
of future monitoring programs.


title: The interaction of a jet-like pulse with a wind from a stellar companion

abstract:
  We present numerical simulations of the interaction between a collimated,
bipolar ``pulse'' ejected from a star and a continuous wind ejected from a
stellar companion. We explore the characteristics of the predicted H$\alpha$
intensity maps by varying selected input parameters. We find that the asymmetry
(in size and strength) between the two lobes of the proto-planetary nebula OH
231.8+4.2 is reproduced in this scenario if the wind ejected by the companion
star has a strong latitude dependence.


title: Nucleosynthetic signatures of the first stars

abstract:
  The chemically most primitive stars provide constraints on the nature of the
first stellar objects that formed in the Universe; elements other than
hydrogen, helium and traces of lithium within these objects were generated by
nucleosynthesis in the very first stars. The relative abundances of elements in
the surviving primitive stars reflect the masses of the first stars, because
the pathways of nucleosynthesis are quite sensitive to stellar masses. Several
models have been suggested to explain the origin of the abundance pattern of
the giant star HE 0107-5240, which hitherto exhibited the highest deficiency of
heavy elements known. Here we report the discovery of HE 1327-2326, a subgiant
or main-sequence star with an iron abundance about a factor of two lower than
that of HE 0107-5240. Both stars show extreme overabundances of carbon and
nitrogen with respect to iron, suggesting a similar origin of the abundance
patterns. The unexpectedly low Li and high Sr abundances of HE 1327-2326,
however, challenge existing theoretical understanding: none predicts the high
Sr abundance or provides a Li depletion mechanism consistent with data
available for the most metal-poor stars.


title: Flares observed with XMM-Newton and the VLA

abstract:
  We present lightcurves obtained in X-ray by the XMM-Newton EPIC cameras and
simultaneous radio lightcurves obtained with the VLA for five active M-type
flare stars. A number of flare events were observed, and by comparing radio
with X-ray data, we consider various possible flare mechanisms. In cases where
there seems to be a clear correlation between radio and X-ray activity, we use
an energy budget argument to show that the heating which leads to the X-ray
emission could be due to the same particles emitting in the radio. In cases
where there is radio activity without corresponding X-ray activity, we argue
that the radio emission is likely to arise from coherent processes involving
comparatively few particles. In one case, we are able to show from polarization
of the radio emission that this is almost certainly the case. Cases for which
X-ray activity is seen without corresponding radio activity are more difficult
to explain. We suggest that the heating particles may be accelerated to very
high energy, and the resulting synchrotron radio emission may be beamed in
directions other than the line of sight.


title:
Effects of Unstable Particles on Light-Element Abundances: Lithium
  versus Deuterium and He3

abstract:
  We reconsider the effects of unstable particles on the production and
destruction of the primordial light elements, with a view to reconciling the
high primordial Li7 abundance deduced from Big Bang Nucleosynthesis (BBN), as
implied by the baryon-to-photon ratio now inferred from the anisotropies of the
Cosmic Microwave Background (CMB), with the lower abundance of Li7 observed in
halo stars. The potential destruction of Li7 is strongly constrained by
observations of Deuterium (D), He3 and Li6. We identify ranges for the unstable
particle abundance and lifetime which would deplete Li7 while remaining
consistent with the abundance of Li6. However, in these regions either the D
abundance is unacceptably low or the ratio He3/D is unacceptably large. We
conclude that late particle decay is unable to explain both the discrepancy of
the calculated Li7 abundance and the observed Li7 plateau. In the context of
supersymmetric theories with neutralino or gravitino dark matter, we display
the corresponding light-element constraints on the model parameters.


title:
The X-ray Emissions from the M87 Jet: Diagnostics and Physical
  Interpretation

abstract:
  We reanalyze the deep Chandra observations of the M87 jet, first examined by
Wilson & Yang (2002). By employing an analysis chain that includes image
deconvolution, knots HST-1 and I are fully separated from adjacent emission. We
find slight but significant variations in the spectral shape, with values of
$\alpha_x$ ranging from $\sim 1.2-1.6$. We use VLA radio observations, as well
as HST imaging and polarimetry data, to examine the jet's broad-band spectrum
and inquire as to the nature of particle acceleration in the jet. As shown in
previous papers, a simple continuous injection model for synchrotron-emitting
knots, in which both the filling factor, $f_{acc}$, of regions within which
particles are accelerated and the energy spectrum of the injected particles are
constant, cannot account for the X-ray flux or spectrum. Instead, we propose
that $f_{acc}$ is a function of position and energy and find that in the inner
jet, $f_{acc} \propto E_\gamma^{-0.4 \pm 0.2} \propto E_e^{-0.2 \pm 0.1}$, and
in knots A and B, $f_{acc} \propto E_\gamma^{-0.7 \pm 0.2} \propto E_e^{-0.35
\pm 0.1}$, where $E_\gamma$ is the emitted photon energy and and $E_e$ is the
emitting electron energy. In this model, the index $p$ of the injected electron
energy spectrum ($n(E_{e}) \propto E_{e}^{-p}$) is $p=2.2$ at all locations in
the jet, as predicted by models of cosmic ray acceleration by ultrarelativistic
shocks. There is a strong correlation between the peaks of X-ray emission and
minima of optical percentage polarization, i.e., regions where the jet magnetic
field is not ordered. We suggest that the X-ray peaks coincide with shock waves
which accelerate the X-ray emitting electrons and cause changes in the
direction of the magnetic field; the polarization is thus small because of beam
averaging.