title: Rotating Core Collapse and Bipolar Supernova Explosions

abstract:
  We review some of the reasons for believing that the generic core-collapse
supernova is neutrino-driven, not MHD-jet driven. We include a discussion of
the possible role of rotation in supernova blast energetics and morphology, and
speculate on the origin of Cas A's and SN1987A's ejecta fields. Two "explosive"
phenomena may be associated with most core collapses, the neutrino-driven
supernova itself and an underenergetic jet-like ejection that follows. The
latter may be a magnetic wind that easily penetrates the debris created by the
much more energetic supernova. We predict that many core-collapse supernova
remnants should have sub-dominant jet-like features. In Cas A, we associate
this sub-dominant collimated wind with the "jet/counter-jet" structure
observed. We suggest that the actual Cas A explosion itself is at nearly right
angles to this jet, along a rotation axis that coincides with the bulk of the
ejecta, the iron lobes, and the putative direction of motion of the point
source. It may be that when rotation becomes sufficiently rapid that the
strong-neutrino-driven-supernova/weak-jet duality switches to a strong-MHD-jet
scenario that might be associated with hypernovae, and in some cases GRBs.
Finally, we present a calculation using a new 2D multi-group, flux-limited
radiation/hydrodynamics code we have recently developed for the simulation of
core-collapse supernovae. We discuss the rotation-induced anisotropy in the
neutrino radiation field, neutrino heating, and the neutrino flux vectors and
speculate on rotation's possible role in the supernova mechanism and in the
overall supernova phenomenon.


title:
Optical and Infrared Photometry of the Type Ia Supernovae 1991T, 1991bg,
  1999ek, 2001bt, 2001cn, 2001cz, and 2002bo

abstract:
  We present optical and/or infrared photometry of the Type Ia supernovae SN
1991T, SN 1991bg, SN 1999ek, SN 2001bt, SN 2001cn, SN 2001cz, and SN 2002bo.
All but one of these supernovae have decline rate parameters Delta m_15(B)
close to the median value of 1.1 for the whole class of Type Ia supernovae. The
addition of these supernovae to the relationship between the near-infrared
absolute magnitudes and Delta m_15(B) strengthens the previous relationships we
have found, in that the maximum light absolute magnitudes are essentially
independent of the decline rate parameter. (SN 1991bg, the prototype of the
subclass of fast declining Type Ia supernovae, is a special case.) The
dispersion in the Hubble diagram in JHK is only ~0.15 mag. The near-infrared
properties of Type Ia supernovae continue to be excellent measures of the
luminosity distances to the supernova host galaxies, due to the need for only
small corrections from the epoch of observation to maximum light, low
dispersion in absolute magnitudes at maximum light, and the minimal reddening
effects in the near-infrared.


title: Mass Segregation and Tidal Tails of the Globular Cluster NGC 7492

abstract:
  We present a wide field CCD photometric study of Galactic globular cluster
NGC 7492. The derived VR color-magnitude diagram extends down to about 3.5 mag
below the cluster main sequence turn-off. The field covers 42' X 42' about 3
times larger than the known tidal radius of this cluster. The sample of cluster
member candidates obtained by CMD-mask process has been used to construct
luminosity and mass functions and surface density map. NGC 7492 has a very flat
mass function with very little variation in the slope with the distance from
the cluster center. However, there is a clear evidence for the increase of the
slope of the mass function from inner to outer regions, indicating a mass
segregation of the cluster. The surface density map of NGC 7492 shows
extensions toward the Galactic anticenter (northeast) and northwest from the
cluster center. A comparison of luminosity function for stars in the tails with
that for stars within the tidal radius suggests that the extensions shown in
the surface density map could be a real feature. The overall shape of NGC 7492
is significantly flattened. If the flattened shape of the NGC 7492 is caused by
its rotation, Galactic tidal field must have given important influences, since
the initial rotation would have been almost completely removed by dynamical
relaxation.


title: Dark energy and CMB bispectrum

abstract:
  We consider the CMB bispectrum signal induced by structure formation through
the correlation between the Integrated Sachs-Wolfe and the weak lensing effect.
We investigate how the bispectrum knowledge can improve our knowledge of the
most important cosmological parameters, focusing on the dark energy ones.
Preliminary results suggest a consistent improvement on the estimation of dark
energy abundance and on dynamical properties of the equation of state.


title:
Radio Detection of Cosmic Ray Extensive Air Showers: present status of
  the CODALEMA experiment

abstract:
  Data acquisition and analysis for the CODALEMA experiment, in operation for
more than one year, has provided improved knowledge of the characteristics of
this new device. At the same time, an important effort has been made to develop
processing techniques for extracting transient signals from data containing
interference.


title: Systematic study of (g,n) reaction rates for Z>=78 isotopes

abstract:
  The (g,n) reaction rates of the isotopes 196,198,204-Hg and 204-Pb have been
determined using the photoactivation technique in an energy region relevant for
p process nucleosynthesis. The systematic study of the ground-state (g,n)
reaction rates on even-even nuclei in the mass region Z>=78 is complemented
with these experiments. The data are compared to rates predicted in the
framework of two statistical model approaches.


title:
A new photometric technique for the joint selection of star-forming and
  passive galaxies at 1.4<z<2.5

abstract:
  A simple two color selection based on B-, z-, and K- band photometry is
proposed for culling galaxies at 1.4<z<2.5 in K-selected samples and
classifying them as star-forming or passive systems. The method is calibrated
on the highly complete spectroscopic redshift database of the K20 survey,
verified with simulations and tested on other datasets. Requiring
BzK=(z-K)-(B-z)>-0.2 (AB) allows to select actively star-forming galaxies at
z>1.4, independently on their dust reddening. Instead, objects with BzK<-0.2
and (z-K)>2.5 (AB) colors include passively evolving galaxies at z>1.4, often
with spheroidal morphologies. Simple recipes to estimate the reddening, SFRs
and masses of BzK-selected galaxies are derived, and calibrated on K<20
galaxies. Based on their UV (reddening-corrected), X-ray and radio
luminosities, the BzK-selected star-forming galaxies with K<20 turn out to have
average SFR ~ 200 Msun yr^-1, and median reddening E(B-V)~0.4. Besides missing
the passively evolving galaxies, the UV selection appears to miss some relevant
fraction of the z~2 star-forming galaxies with K<20, and hence of the
(obscured) star-formation rate density at this redshift. The high SFRs and
masses add to other existing evidence that these z=2 star-forming galaxies may
be among the precursors of z=0 early-type galaxies. Theoretical models cannot
reproduce simultaneously the space density of both passively evolving and
highly star-forming galaxies at z=2. In view of Spitzer Space Telescope
observations, an analogous technique based on the RJL photometry is proposed to
complement the BzK selection and to identify massive galaxies at 2.5<z<4.0.
These color criteria should help in completing the census of the stellar mass
and of the star-formation rate density at high redshift (abridged).


title: Cosmological Phase Transitions

abstract:
  In this lecture at a school for condensed matter physicists, I begin with
basic concepts and tools for investigating phase transitions in quantum field
theory. The very different roles of global and gauge symmetries in phase
transitions will be elucidated. Among the important applications of the basic
theory the thermodynamics of the electroweak transition is treated in detail,
and the implications for baryogenesis will be discussed. The status of lattice
simulations of the transition from a high temperature quark-gluon plasma to
confined hadronic matter with spontaneously broken chiral symmetry is also
briefly reviewed. The various changes of the free energy density in
cosmological phase transitions reinforce the cosmological constant problem. In
the last part of the lecture I shall address this profound mystery of present
day physics.


title:
Search for Low-Mass Exoplanets by Gravitational Microlensing at High
  Magnification

abstract:
  Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE
2003-BLG-219 are presented for which the peak magnification was over 500, the
highest yet reported. Continuous observations around the peak enabled a
sensitive search for planets orbiting the lens star. No planets were detected.
Planets 1.3 times heavier than Earth were excluded from more than 50 % of the
projected annular region from approximately 2.3 to 3.6 astronomical units
surrounding the lens star, Uranus-mass planets from 0.9 to 8.7 astronomical
units, and planets 1.3 times heavier than Saturn from 0.2 to 60 astronomical
units. These are the largest regions of sensitivity yet achieved in searches
for extrasolar planets orbiting any star.


title: Anti-Hierarchical Growth of Supermassive Black Holes and QSO lifetimes

abstract:
  I present a new method to unveil the history of cosmic accretion and the
build-up of Supermassive Black Holes (SMBH) in the nuclei of galaxies, based on
observations of the evolving radio and (hard) X-ray luminosity functions of
AGN. The fundamental plane of black hole activity discovered by Merloni, Heinz
& Di Matteo (2003) is used as a mass and accretion rate estimator. I adopt the
local BH mass function as a boundary condition to integrate backwards in time
the continuity equation for the SMBH evolution, neglecting the role of mergers.
Under the most general assumption that accretion proceeds in a radiatively
efficient way above a certain rate, and in a radiatively inefficient way below,
the redshift evolution of the mass and accretion rate functions are calculated
self-consistently. The only tunable parameters are the accretion efficiency and
the critical ratio of the X-ray to Eddington luminosity at which the transition
between accretion modes takes place. The evolution of the BH mass function
between z=0 and z ~ 3 shows clear signs of an anti-hierarchical behaviour:
while the majority of the most massive objects (M > 10^9) were already in place
at z ~ 3, lower mass ones mainly grew at progressively lower redshift. As an
example, I will discuss the consequences of these results for the lifetimes of
accreting black holes.


title: An Expanded RXTE Survey of X-ray Variability in Seyfert 1 Galaxies

abstract:
  The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei
have been systematically analyzed to yield five homogeneous samples of 2-12 keV
light curves, probing hard X-ray variability on successively longer durations
from ~1 day to ~3.5 years. 2-10 keV variability on time scales of ~1 day, as
probed by ASCA, are included. All sources exhibit stronger X-ray variability
towards longer time scales, but the increase is greater for relatively higher
luminosity sources. Variability amplitudes are anti-correlated with X-ray
luminosity and black hole mass, but amplitudes saturate and become independent
of luminosity or black hole mass towards the longest time scales. The data are
consistent with the models of power spectral density (PSD) movement described
in Markowitz et al. (2003a) and McHardy et al. (2004), whereby Seyfert 1
galaxies' variability can be described by a single, universal PSD shape whose
break frequency scales with black hole mass. The best-fitting scaling relations
between variability time scale, black hole mass and X-ray luminosity imply an
average accretion rate of ~5% of the Eddington limit for the sample. Nearly all
sources exhibit stronger variability in the relatively soft 2-4 keV band
compared to the 7-12 keV band on all time scales. There are indications that
relatively less luminous or less massive sources exhibit a greater degree of
spectral variability for a given increase in overall flux.


title:
Radial velocities and membership of stars in the old, distant open
  cluster Berkeley 29

abstract:
  Multi slit spectroscopy at the Telescopio Nazionale Galileo was employed to
measure radial velocities for 20 stars in the direction of the old open cluster
Berkeley 29, the farthest known in our Galaxy. Membership information was
derived for stars along all the red giant branch, in particular near its tip,
and on the red clump. The sample of bona-fide cluster members was used to
revise the cluster distance to about 15 kpc, on the basis of an empirical
comparison with the red clump in open clusters with known distances. A
metallicity [Fe/H] = -0.74 +/- 0.18 was also estimated using the colours of
spectroscopically confirmed red giant stars.


title: Pulsar Slot Gaps and Unidentified EGRET Sources

abstract:
  A new picture of pulsar high-energy emission is proposed that is different
from both the traditional polar cap and outer gap models, but combines elements
of each. The slot gap model is based on electron acceleration along the edge of
the open field region from the neutron star surface to near the light cylinder.
Along the last open field line, the pair formation front rises to very high
altitude forming a slot gap, where the accelerating electric field is
unscreened by pairs. The resulting radiation features both hollow cones from
the lower-altitude pair cascades, seen at small viewing angles, as well as
caustic emission on the trailing-edge field lines at high altitude, seen from
both poles at large viewing angle. The combination of the small solid angle of
slot gap emission (<< 1 sr) with a high probability of viewing the emission
predicts that more gamma-ray pulsars could be detected at larger distances. In
this picture, many of the positional coincidences of radio pulsars with
unidentified EGRET sources become plausible as real associations, as the flux
predicted by the slot gap model for many of the pulsars would provide the
observed EGRET source flux. The expected probability of seeing radio-quiet
gamma-ray pulsars in this model will also be discussed.


title:
Are the WMAP angular magnification measurements consistent with an
  inhomogeneous critical density Universe?

abstract:
  The propagation of light through a Universe of (a) isothermal mass spheres
amidst (b) a homogeneous matter component, is considered. We demonstrate by an
analytical proof that as long as a small light bundle passes {\it through}
sufficient number of (a) at various impact parameters - a criterion of great
importance - its average convergence will exactly compensate the divergence
within (b). The net effect on the light is statistically the same as if all the
matter in (a) is `fully homogenized'. When applying the above ideas towards
understanding the angular size of the primary acoustic peaks of the microwave
background, however, caution is needed. The reason is that most (by mass) of
(a) are in galaxies - their full mass profiles are not sampled by passing light
- at least the inner 20 kpc regions of these systems are missed by the majority
of rays, while the rest of the rays would map back to unresolvable but
magnified, randomly located spots to compensate for the loss in angular size.
Therefore, a scanning pair of WMAP beams finds most frequently that the largest
temperature difference occurs when each beam is placed at diametrically
opposite points of the Dyer-Roeder collapsed sections. This is the {\it mode}
magnification, which corresponds to the acoustic {\it peaks}, and is less than
the mean (or the homogeneous pre-clumping angular size). Since space was seen
to be Euclidean without taking the said adjustment into account, the true
density of the Universe should be supercritical. Our analysis gives $\Omega_m
=$ 0.278 $\pm$ 0.040 and $\Omega_{\Lambda} =$ 0.782 $\pm$ 0.040.


title:
Why the astrophysical Black Hole Candidates may not be black holes at
  all

abstract:
  In a recent paper[1], it has been shown that, there cannot be any rotating
(Kerr) Black Hole (BH) with finite mass in order that the generic properties
associated with the symmetries of stationary axisymmetric Einstein equations
are obeyed, i.e, in order to have m\ge 0, we must have $a=0$. In other words,
all observed chargeless BHs with finite masses must be non-rotating
Schwarzschild BHs. Here, by comparing the invariant 4 volume associated with
original Kerr metric [2] with the Boyer-Lindquist version of the same [3], we
further find that, stationary axisymmetric {\em vacuum} Einstein solutions
actually correspond to m=0 in addition to a=0! This means that if the Kerr
solution is a unique one, the Schwarzschild BHs too correspond to only m=0 and
therefore the observed BH candidates (BHs) with m >0 are not BHs at all. This
is in agreement some detailed analysis of recent observations[4-7] which
suggest the the BHCs have strong intrinsic magnetic moment rather than any
Event Horizon. If one would derive the Boyer-Lindquist metric in a
straightforward manner by using the Backlund transformation, it would follow
that a= m sin phi, where phi is the azimuth angle. This relationship directly
confirms the result that for a supposed rotating BH, actually, both a=m=0.


title:
The tidally disturbed luminous compact blue galaxy Mkn 1087 and its
  surroundings

abstract:
  We present new broad-band optical and near-infrared CCD imaging together with
deep optical intermediate-resolution spectroscopy of Mkn 1087 and its
surrounding objects. We analyze the morphology and colors of the stellar
populations of the brightest objects, some of them star-formation areas, as
well as the kinematics, physical conditions and chemical composition of the
ionized gas associated with them. Mkn 1087 does not host an Active Galactic
Nucleus, but it could be a Luminous Compact Blue Galaxy. Although it was
classified as a suspected Wolf-Rayet galaxy, we do not detect the spectral
features of these sort of massive stars. Mkn 1087 shows morphological and
kinematical features that can be explained assuming that it is in interaction
with two nearby galaxies: the bright KPG 103a and a dwarf ($M_B\sim-18$)
star-forming companion. We argue that this dwarf companion is not a tidal
object but an external galaxy because of its low metallicity [12+log(O/H) =
8.24] with respect to the one derived for Mkn 1087 [12+log(O/H) = 8.57] and its
kinematics. Some of the non-stellar objects surrounding Mkn 1087 are connected
by bridges of matter with the main body, host star-formation events and show
similar abundances despite their different angular distances. These facts,
together their kinematics, suggest that they are tidal dwarf galaxies formed
from material stripped from Mkn 1087. A bright star-forming region at the south
of Mkn 1087 (knot #7) does not show indications of being a tidal galaxy or the
product of a merging process as suggested in previous works. We argue that Mkn
1087 and its surroundings should be considered a group of galaxies.


title: Excitation of Disk Oscillations by Warps: A Model of kHz QPOs

abstract:
  The amplification of disk oscillations resulting from non-linear resonant
couplings between the oscillations and a warp is examined. The disks are
geometrically thin and general relativistic with non-rotating central objects.
By using a Lagrangian formulation, a general stability criterion is derived.
The criterion is applied to horizontal and vertical resonances of g-mode
oscillations and to horizontal resonances of p-mode oscillations. The results
of analyses show that g-mode oscillations (including p-mode oscillations of
$n=0$) are amplified by horizontal resonances with the warp. Other modes of
oscillations with other resonances are all damped by resonances. The amplified
g-mode oscillations are located around the radius $4r_{\rm g}$, the radius of
the epicyclic frequency being maximum, i.e., $\kappa_{\rm max}$. The
frequencies of amplified oscillations are harmonics of $\kappa_{\rm max}$, and
well explain the 2 : 3 pairs of observed QPOs for reasonable masses (and spins)
of the central objects.


title:
Reconstructing the Primordial Spectrum with CMB Temperature and
  Polarization

abstract:
  We develop a new method to reconstruct the power spectrum of primordial
curvature perturbations, $P(k)$, by using both the temperature and polarization
spectra of the cosmic microwave background (CMB). We test this method using
several mock primordial spectra having non-trivial features including the one
with an oscillatory component, and find that the spectrum can be reconstructed
with a few percent accuracy by an iterative procedure in an ideal situation in
which there is no observational error in the CMB data. In particular, although
the previous ``cosmic inversion'' method, which used only the temperature
fluctuations, suffered from large numerical errors around some specific values
of $k$ that correspond to nodes in a transfer function, these errors are found
to disappear almost completely in the new method.


title:
The Interplanetary Network Supplement to the BATSE Catalogs of
  Untriggered Cosmic Gamma Ray Bursts

abstract:
  We present Interplanetary Network (IPN) detection and localization
information for 211 gamma-ray bursts (GRBs) observed as untriggered events by
the Burst and Transient Source Experiment (BATSE), and published in catalogs by
Kommers et al. (2001) and Stern et al. (2001). IPN confirmations have been
obtained by analyzing the data from 11 experiments. For any given burst
observed by BATSE and one other distant spacecraft, arrival time analysis (or
``triangulation'') results in an annulus of possible arrival directions whose
half-width varies between 14 arcseconds and 5.6 degrees, depending on the
intensity, time history, and arrival direction of the burst, as well as the
distance between the spacecraft. This annulus generally intersects the BATSE
error circle, resulting in a reduction of the area of up to a factor of ~650.
When three widely separated spacecraft observed a burst, the result is an error
box whose area is as much as 30000 times smaller than that of the BATSE error
circle.
  Because the IPN instruments are considerably less sensitive than BATSE, they
generally did not detect the weakest untriggered bursts, but did detect the
more intense ones which failed to trigger BATSE when the trigger was disabled.
In a few cases, we have been able to identify the probable origin of bursts as
soft gamma repeaters. The vast majority of the IPN-detected events, however,
are GRBs, and the confirmation of them validates many of the procedures
utilized to detect BATSE untriggered bursts.


title:
A Search for Dense Molecular Gas in High Redshift Infrared-Luminous
  Galaxies

abstract:
  We present a search for HCN emission from four high redshift far infrared
(IR) luminous galaxies. Current data and models suggest that these high $z$ IR
luminous galaxies represent a major starburst phase in the formation of
spheroidal galaxies, although many of the sources also host luminous active
galactic nuclei (AGN), such that a contribution to the dust heating by the AGN
cannot be precluded. HCN emission is a star formation indicator, tracing dense
molecular hydrogen gas within star-forming molecular clouds (n(H$_2$) $\sim
10^5$ cm$^{-3}$). HCN luminosity is linearly correlated with IR luminosity for
low redshift galaxies, unlike CO emission which can also trace gas at much
lower density. We report a marginal detection of HCN (1-0) emission from the
$z=2.5832$ QSO J1409+5628, with a velocity integrated line luminosity of
$L_{\rm HCN}'=6.7\pm2.2 \times10^{9}$ K km s$^{-1}$ pc$^2$, while we obtain
3$\sigma$ upper limits to the HCN luminosity of the $z=3.200$ QSO J0751+2716 of
$L_{\rm HCN}'=1.0\times10^{9}$ K km s$^{-1}$ pc$^2$, $L_{\rm
HCN}'=1.6\times10^{9}$ K km s$^{-1}$ pc$^2$ for the $z= 2.565$ starburst galaxy
J1401+0252, and $L_{\rm HCN}'=1.0\times10^{10}$ K km s$^{-1}$ pc$^2$ for the $z
= 6.42$ QSO J1148+5251. We compare the HCN data on these sources, plus three
other high-$z$ IR luminous galaxies, to observations of lower redshift
star-forming galaxies. The values of the HCN/far-IR luminosity ratios (or
limits) for all the high $z$ sources are within the scatter of the relationship
between HCN and far-IR emission for low $z$ star-forming galaxies (truncated).


title:
Particle Energies and Filling Fractions of Radio Bubbles in Cluster
  Cores

abstract:
  Using Chandra images of cluster cores with clear radio bubbles, we have
determined k, which is the ratio of the total particle energy to that of the
electrons radiating between 10 MHz and 10 GHz. Radiative and dynamical
constraints on the bubbles indicate that the ratio of the energy factor, k, to
the volume filling factor, f, lies within the range 1 < k/f < 1000. Assuming
pressure equilibrium between the radio-emitting plasma and the surrounding
X-ray gas, none of the lobes have equipartition between relativistic particles
and magnetic field. There is no evidence for any dependence of the upper limit
of the k/f ratio on any physical parameter of the cluster or the radio source.
The distribution of the upper limit on k/f appears to be bimodal, the value for
some clusters being ~3 and for the others ~300. We show that this is may due to
the composition of the jet which forms the bubbles, the variation in the volume
filling fraction or variation in the amount of re-acceleration occurring in the
bubble.


title: Orbital Phase Spectroscopy of GX 301--2 with RXTE-PCA

abstract:
  We have investigated the orbital phase dependence of the X-ray spectrum of
the High Mass X-ray Binary pulsar GX 301--2. Here we present the results from a
spectral analysis of two sets of observations of GX 301--2 with the Rossi X-ray
Timing Explorer (RXTE). Of particular interest are the variations of the
absorption column density and the iron line flux along with other parameters of
the spectral model with the orbital phase. We found that the X-ray spectrum can
almost always be fitted with a partial covering absorption model. We have
detected enhanced absorption near the periastron. However, the column density
variation with orbital phase is not smooth, as is expected in a smooth stellar
wind model. We discuss the results of the column density variation in the light
of the two proposed models for GX 301-2, an equatorial disk emanating from the
companion star Wray 977 and a gas stream following the neutron star. We also
found that the iron K_alpha and K_beta line fluxes have peaks near the
periastron and are well correlated with the continuum hard X-ray flux. The line
equivalent width shows an interesting pattern with the column density,
reasonably constant for low values of the column density and increasing rapidly
beyond a certain value.


title: The Molecular and Dust Envelope of HD 56126

abstract:
  We present millimeter interferometry images of the CO J=1-0 line emission
arising in the circumstellar envelope of HD 56126 (a.k.a. IRAS 07134+1005),
which is one of the best studied 21-micron proto-planetary nebulae (PPNs). The
CO emission extends from 1.2" to 7" in radius from the central star and appears
consistent with a simple expanding envelope, as expected for a post-AGB star.
We quantitatively model the molecular envelope using a radiative transfer code
that we have modified for detached shells. Our best fit model reveals that two
sequential winds created the circumstellar envelope of HD 56126: an AGB wind
that lasted 6500 years with a mass-loss rate of 5.1x10^{-6} M_odot yr^{-1} and
a more intense superwind that lasted 840 years with a mass-loss rate of
3x10^{-5} M_odot yr^{-1} and that ended the star's life on the AGB 1240 years
ago. The total mass of this envelope is 0.059 M_odot which indicates a lower
limit progenitor mass for the system of 0.66 M_odot, quite reasonable for this
low-metallicity star which probably resides in the thick disk of the Galaxy.
Comparison with images of the dust emission reveal a similar structure with the
gas in the inner regions. Using 2-DUST, we model the dust emission of this
source so that the model is consistent with the CO emission model and find an
average gas-to-dust mass ratio of 75.


title:
Clusters of galaxies in the microwave band: influence of the motion of
  the Solar System

abstract:
  In this work we consider the changes of the SZ cluster brightness, flux and
number counts induced by the motion of the Solar System with respect to the
frame defined by the cosmic microwave background (CMB). These changes are
connected with the Doppler effect and aberration and exhibit a strong spectral
and spatial dependence. The correction to the SZ cluster brightness and flux
has an amplitude and spectral dependence, which is similar to the first order
cluster peculiar velocity correction to the thermal SZ effect. Due to the
change in the received cluster CMB flux the motion of the Solar System induces
a dipolar asymmetry in the observed number of clusters above a given flux
level. Similar effects were discussed for $\gamma$-ray bursts and radio
galaxies, but here, due to the very peculiar frequency-dependence of the
thermal SZ effect, the number of observed clusters in one direction of the sky
can be both, decreased or increased depending on the frequency band. A
detection of this asymmetry should be possible using future full sky CMB
experiments with mJy sensitivities.


title: Evolving dark energy equation of state and CMB/LSS cross-correlation

abstract:
  CMB power spectra and the SNIa luminosity-redshift curves have difficulty
distinguishing between models with the same average value of the dark energy
equation of state. We propose using the cross-correlation of the CMB
temperature anisotropy with large scale structure to help break this
degeneracy.


title: The Unique Eclipsing System KH 15D: New Photometric Data

abstract:
  We present results of the photometric observations of the young eclipsing
binary KH 15D obtained during the two observational seasons of 2002-2004 years.
A comparison of our data with those by Hamilton et al. (2001) and Herbst et al.
(2002) reveals an existence of the long-term photometrical brightness trend:
during 5 years a system brightness in the I band decreased by about one stellar
magnitude. It is also shown that a systematic change of the eclipse parameters
found by Herbst et al. (2002) is continuing up to now. The shape of the light
curve did not change essentially and is characterized with a small brightening
in the central part of the eclipses. The results obtained are discussed in the
context of the current models of KH 15D.


title: HST observations of nuclear stellar disks

abstract:
  We present observations of four nearby early-type galaxies with previously
known nuclear stellar disks using two instruments on-board the Hubble Space
Telescope. We observed NGC4128, NGC4612, and NGC5308 with the Wide Field
Planetary Camera 2, and the same three galaxies, plus NGC4570, with the Space
Telescope Imaging Spectrograph. We have detected a red nucleus in NGC4128, a
blue nucleus in NGC4621, and a blue disk in NGC5308. Additionally, we have
discovered a blue disk-like feature with position angle ~15 degrees from the
major axis in NGC4621. In NGC5308 there is evidence for a blue region along the
minor axis. We discovered a blue transient on the images of NGC4128 at position
0.14" west and 0.32" north from the nucleus. The extracted kinematic profiles
belong to two groups: fast (NGC4570 and NGC5308) and kinematically disturbed
rotators (NGC4128 and NGC4621). We report the discovery of a kinematically
decoupled core in NGC4128. Galaxies have mostly old (10-14 Gyr) stellar
populations with large spread in metallicities (sub- to super-solar). We
discuss the possible formation scenarios, including bar-driven secular
evolution and the influence of mergers, which can explain the observed color
and kinematic features.


title: Black-hole ejecta by frame-dragging along the axis of rotation

abstract:
  An energy $E=\omega J$ is derived for gravitational spin-orbit coupling by
frame-dragging $\omega$ acting on angular momentum $J$. This interaction
defines a no-boundary mechanism for linear acceleration of magnetized matter
along the axis of rotation of black holes. We explain GRB030329/SN2003dh by
centered nucleation of a high-mass black hole with rapid rotation, producing
baryon-poor ejecta by gravitational spin-orbit coupling. The duration of the
burst is attributed to spin-down in the emission of gravitational-waves by a
surrounding non-axisymmetric torus.


title: Sunyaev Zel'dovich polarization simulation

abstract:
  Compton scattering of Cosmic Microwave Background (CMB) photons on galaxy
cluster electrons produces a linear polarization, which contains some
information on the local quadrupole at the cluster location. We use N-body
simulations to create, for the first time, maps of this polarization signal. We
then look at the different properties of the polarization with respect to the
cluster position and redshift.


title:
Quasars as bubbles of dark matter: evidence for axion and tachyon matter
  in the Universe

abstract:
  Growing amount of data show evidence for statistical and apparent physical
association between low-redshift galaxies and high-redshift quasi-stellar
objects, suggesting noncosmological origin of their redshift and failure of
classical quasar explanation. Here we find an analytical solution of Einstein
equations describing bubbles made from axions with periodic interaction
potential. Such particles are currently considered as one of the leading dark
matter candidate. The bubble interior has equal gravitational potential and,
hence, photons emitted from the interior possess identical gravitational
redshift. The redshift depends on the bubble mass and can have any value
between zero and infinity. Quantum pressure supports the bubble against
collapse and yields states stable on the scale of the Universe age. Our results
explain the observed quantization of quasar redshift and suggest that
intrinsically faint point-like quasars associated with nearby galaxies (a few %
of known objects) are axionic bubbles with masses 10^8-10^9 M_{Sun} and radii
10^3-10^4 R_{Sun}. They are born in active galaxies and ejected into
surrounding space. Properties of such quasars unambiguously indicate presence
of axion dark matter in the Universe and yield the axion mass m=0.4-3 meV,
which fits in the open axion mass window constrained by astrophysical and
cosmological arguments. We also found that tachyons, another dark matter
candidate, can form objects with galactic size, negligible mass and any value
of the gravitational redshift. Such finding combined with quasar observations
suggests that bright quasars 3C 48, 3C 273 and 3C 279 are nuclei of forming
nearby small galaxies embedded into tachyonic clots and possess pure
gravitational redshift.


title: HI and Galaxy Formation in Loose Groups

abstract:
  Models of hierarchical galaxy formation predict that large numbers of
low-mass, dark matter halos remain around galaxies today. These models predict
an order of magnitude more halos than observed stellar satellites in the Local
Group. One possible solution to this discrepancy is that the high-velocity
clouds (HVCs) around the Milky Way may be associated with the excess dark
matter halos and be the gaseous remnants of the galaxy formation process. If
this is the case, then analogs to the HVCs should be visible in other groups.
In this paper, we review the observations of HI clouds lacking stars around
other galaxies and in groups and present early results from our HI survey of
loose groups analogous to the Local Group and its implications for the nature
of HVCs and galaxy formation.


title:
A photometrically and kinematically distinct core in the Sextans dwarf
  spheroidal galaxy

abstract:
  We present the line of sight radial velocity dispersion profile of the
Sextans dwarf spheroidal galaxy (dSph), based on a sample of 88 stars extending
to about 1 degree (about 1.5 kpc). Like the Draco and Ursa Minor dSphs, Sextans
shows some evidence of a fall-off in the velocity dispersion at large projected
radii, with significance p=0.96. Surprisingly, the dispersion at the very
centre of Sextans is close to zero (with significance p=0.96). We present
evidence which suggests that this latter change in the stellar kinematics
coincides with changes in the stellar populations within the dSph. We discuss
possible scenarios which could lead to a kinematically and photometrically
distinct population at the centre of Sextans.


title:
Gravitational Collapse and Equilibrium Conditions of a Toroidal Vortex
  with Thermal Pressure

abstract:
  We found equilibrium conditions for a self-gravitating toroidal vortex by
taking into account thermal pressure. These conditions are shown to
significantly differ from those for a disk and a sphere. The evolution of a
thin vortex turns it into a compact vortex that loses mechanical stability for
low masses at a polytropic index $\gamma < 4/3$ but retains stability for
sufficiently high masses and densities determined by the velocity circulation
in the vortex.


title: Self-Regulated AGN Heating in Elliptical Galaxies

abstract:
  We study the effect of active galactic nuclei (AGN) heating on the
chemodynamical evolution of elliptical galaxies and their X-ray and optical
properties using high-resolution Lambda-dominated cold dark matter cosmological
simulations. Our model considers an AGN as being ``active'' when a convergent
gas inflow condition exists within a galaxy's nucleus; otherwise, the AGN is
assumed to remain dormant. This induces a self-regulated activity for the AGN,
the result of which leads to a stable hot corona and the suppression of
significant late-time star formation - characteristics not encountered in
traditional chemodynamical models of ellipticals. These properties of our AGN
heating model leads to a system consistent with both the X-ray and optical
properties of comparable elliptical galaxies.


title:
Astrophysical Lasers Operating in optical Fe II Lines Lines in Stellar
  Ejecta of Eta Carinae

abstract:
  After the discovery of space masers based on OH radicals (Weaver et al, 1965)
and H2O (Cheung et al, 1969) such microwave lasers have been found to work in
more than 100 molecular species (Elitzur, 1992; Townes, 1997), as well as in
highly excited H atoms (Strelnitski et al,1996). In the IR region (10 microns),
the effect of stimulated emission of radiation in the CO2 molecule has been
discovered in the Martian and Venus' atmospheres (Betz et al, 1976; Mumma et
al, 1981). We report here on the discovery of laser action in the range 0.9-2
micr. in several spectral lines of Fe II, which are associated with transitions
from "pseudo-metastable" states populated by spontaneous transitions from
Ly-alpha pumped Fe II levels. The intense Ly-alpha radiation is formed in the
HII region of gas condensations close to the star Eta Carinae. The laser
transitions form together with spontaneous transitions closed radiative cycles,
one of which includes the extremely bright 2507/09 A lines. Closed radiative
cycles, together with an accidental mixing of energy levels, may provide an
explanation of the abnormal intensities of these UV non-lasing lines. Using the
complicated energy level diagram of Fe II we present those peculiar features,
which are essential for the inverted population and laser effect: the pumping,
the level mixing, and the "bottle neck" for spontaneous decay. The laser action
is a new indicator of non-equilibrium and spatially non-homogeneous physical
conditions as well as a high brightness temperature of Ly-alpha in ejecta from
eruptive stars. Such conditions are very difficult to probe by existing
methods, and we propose some future experiments. The fact, that the lasing
near-IR lines appear in the spectrum with about the same inten- sity as
non-lasing lines is discussed and compared with the situation in masers.


title:
Hydrodynamical simulations of the jet in the symbiotic star MWC 560 I.
  Structure, emission and synthetic absorption line profiles

abstract:
  We performed hydrodynamical simulations with and without radiative cooling of
jet models with parameters representative for the symbiotic system MWC 560. For
symbiotic systems we have to perform jet simulations of a pulsed underdense jet
in a high density ambient medium. We present the jet structure resulting from
our simulations and calculate emission plots which account for expected
radiative processes. In addition, our calculations provide expansion velocities
for the jet bow shock, the density and temperature structure in the jet, and
the propagation and evolution of the jet pulses.
  In MWC 560 the jet axis is parallel to the line of sight so that the
outflowing jet gas can be seen as blue shifted, variable absorption lines in
the continuum of the underlying jet source. Based on our simulations we
calculate and discuss synthetic absorption profiles.
  Based on a detailed comparison between model spectra and observations we
discuss our hydrodynamical calculations for a pulsed jet in MWC 560 and suggest
improvements for future models.


title: Testing for double inflation with WMAP

abstract:
  With the WMAP data we can now begin to test realistic models of inflation
involving multiple scalar fields. These naturally lead to correlated adiabatic
and isocurvature (entropy) perturbations with a running spectral index. We
present the first full (9 parameter) likelihood analysis of double inflation
with WMAP data and find that despite the extra freedom, supersymmetric hybrid
potentials are strongly constrained with less than 7% correlated isocurvature
component allowed when standard priors are imposed on the cosomological
parameters. As a result we also find that Akaike & Bayesian model selection
criteria rather strongly prefer single-field inflation, just as equivalent
analysis prefers a cosmological constant over dynamical dark energy in the late
universe. It appears that simplicity is the best guide to our universe.


title:
Dynamical state and star formation properties of the merging galaxy
  cluster Abell 3921

abstract:
  We present the results of a new spectroscopic and photometric survey of the
central region of the galaxy cluster A3921 (z=0.094). We detect the presence of
two dominant clumps of galaxies: a main cluster centred on the BCG (A3921-A),
and a NW sub-cluster (A3921-B) hosting the second brightest cluster galaxy. The
distorted morphology of the two sub-clusters suggests that they are
interacting, while the velocity distribution of 104 confirmed cluster members
does not reveal strong signatures of merging. By applying a two-body dynamical
formalism to the two sub-clusters of A3921, and by comparing our optical
results to the X-ray analysis of A3921 based on XMM observations (Belsole et
al. 2004), we conclude that A3921-B is probably tangentially traversing the
main cluster along a SW/NE direction. Our estimate of the star formation
properties of the cluster members reveals substantial fractions of both
emission-line (~13%) and post-star-forming objects (k+a's,~16%). A lack of
bright k+a's with respect to higher redshift clusters is observed, while the
fraction of k+a's increases towards fainter magnitudes. The spatial and
velocity distributions of k+a's galaxies, their red colours and their moderate
Balmer absorption lines suggest that their presence is difficult to relate to
the on-going merging event. Star forming galaxies, which are mostly
concentrated in A3921-B and between the two sub-clusters, share neither the
same kinematics, nor the same projected distribution of the passive cluster
members. Their spectral properties may be at least partly realted to the
ongoing merger.


title: Dynamics of the Universe with global rotation

abstract:
  We analyze dynamics of the FRW models with global rotation in terms of
dynamical system methods. We reduce dynamics of these models to the FRW models
with some fictitious fluid which scales like radiation matter. This fluid
mimics dynamically effects of global rotation. The significance of the global
rotation of the Universe for the resolution of the acceleration and horizon
problems in cosmology is investigated. It is found that dynamics of the
Universe can be reduced to the two-dimensional Hamiltonian dynamical system.
Then the construction of the Hamiltonian allows for full classification of
evolution paths. On the phase portraits we find the domains of cosmic
acceleration for the globally rotating universe as well as the trajectories for
which the horizon problem is solved. We show that the FRW models with global
rotation are structurally stable. This proves that the universe acceleration is
due to the global rotation. It is also shown how global rotation gives a
natural explanation of the empirical relation between angular momentum for
clusters and superclusters of galaxies. The relation $J \sim M^2$ is obtained
as a consequence of self similarity invariance of the dynamics of the FRW model
with global rotation. In derivation of this relation we use the Lie group of
symmetry analysis of differential equation.


title:
Spectroscopic Properties of Void Galaxies in the Sloan Digital Sky
  Survey

abstract:
  We study the spectroscopic properties of a sample of 10^3 void galaxies from
the Sloan Digital Sky Survey (SDSS) and compare these with the properties of
galaxies in higher density regions (wall galaxies). This sample of void
galaxies covers the range of absolute magnitude from M_r=-13.5 to M_r=-22.5 in
regions with density contrast delta < -0.6. In this paper we compare the
equivalent widths of Halpha, [OII], [NII], Hbeta, and [OIII] of void and wall
galaxies of similar luminosities and find that void galaxies have larger
values, indicating that they are still forming stars at a high rate. A
comparison of the Balmer break, as measured by the parameter Dn(4000), reveals
that void galaxies have younger stellar populations than wall galaxies. Using
standard techniques, we estimate Halpha and [OII] star formation rates of the
void and wall galaxies and along with estimates of the stellar masses, we
compute specific star formation rates. In most cases, we find that void
galaxies have similar SFRs to wall galaxies but they are fainter and smaller
mass. This means that, consistent with the EWs, void galaxies have higher
specific star formation rates than wall galaxies.


title: The impact of thermal gas in AGN jets on the low-frequency emission

abstract:
  We study the effect of non-relativistic, thermal matter in the jets of active
galaxies (AGN) on the low-frequency non-thermal emission and the variability
thereof. In matter-dominated jets, sizable quantities of gas should exist, in
particular in the compression zones near the collision fronts that are an
implicit ingredient of Fermi-type particle acceleration scenarios.
Non-relativistic thermal gas in AGN jets noticably contributes to the optical
depth at radio to infrared frequencies, and much less to the emission, with an
efficiency that is strongly temperature-dependent. The observable flux of
low-frequency emission is thus modulated by the temperature evolution of the
thermal gas, and it can therefore display very complicated variability. For a
particular particle energisation scenario we calculate the temperature
evolution of the thermal plasma as well as the radiation transport of
low-frequency emission, and thus derive simulated light curves at different
frequencies and their typical correlation properties.


title: Grad-Shafranov Approach To Axisymmetric Stationary Flows In Astrophysics

abstract:
  My lecture is devoted to the analytical results available for a large class
of axisymmetric stationary flows in the vicinity of compact astrophysical
objects. First, the most general case is formulated corresponding to the
axisymmetric stationary MHD flow in the Kerr metric. Then, I discuss the
hydrodynamical version of the Grad-Shafranov equation. Although not so
well-known as the full MHD one, it allows us to clarify the nontrivial
structure of the Grad-Shafranov approach as well as to discuss the simplest
version of the 3+1-split language -- the most convenient one for the
description of ideal flows in the vicinity of rotating black holes. Finally, I
consider several examples that demonstrate how this approach can be used to
obtain the quantitative description of the real transonic flows in the vicinity
of rotating and moving black holes.


title:
Fermion Scattering off a CP-violating Bubble Wall in the Background of a
  Uniform Magnetic Field

abstract:
  In the scenario of the electroweak baryogenesis we consider the dynamics of
fermions with a spatially varying mass in presence of a CP-violating bubble
wall and a uniform magnetic field perpendicular to the wall. The relevant
quantity for baryogenesis, $R_{R \to L} - R_{L \to R}$, is studied ($R_{R \to
L}$ and $R_{L \to R}$ being the reflection coefficients for right-handed and
left-handed chiral fermions, respectively).


title: Similarity solutions for radiation in time-dependent relativistic flows

abstract:
  Exact analytic solutions are derived for radiation in time-dependent
relativistic flows. The flows are spherically-symmetric homologous explosions
or implosions of matter with a grey extinction coefficient. The solutions are
suitable for testing numerical transfer codes, and this is illustrated for a
fully relativistic Monte Carlo code.


title:
An HST STIS Observation of VW Hydri at the Exact FUV Onset of an
  Outburst

abstract:
  We present an analysis of HST STIS data of VW Hyi acquired ~ 14 days after a
superoutburst. At the time of the observation the system appears to be going
into outburst with the longest wavelengths increasing in flux by a factor of 5,
while the shortest wavelengths increase by only a factor of 2. Using the
distance of 65 pc, a system inclination angle of 60 degrees and a white dwarf
mass of 0.86 solar mass, we carried out model fits involving a white dwarf by
itself, an optically thisck accretion disk by itself, a composite model using
an optically thick accretion disk and a white dwarf, a two-temperature white
dwarf model with a cooler more slowly rotating photosphere and a hotter,
rapidly rotating accretion belt and a composite model involving a white dwarf
and a rapidly rotating cooler disk ring heated up to a ``low'' temperature of
\~13-14,000K. This component of temperature stays fairly constant throughout
the HST observations while the area of the disk ring increases by a factor of
12. We see evidence of a delay in the UV emission consistent with the outburst
beginning outside of a disk truncation radius.


title: DAzLE: The Dark Ages z (redshift) Lyman-alpha Explorer

abstract:
  DAzLE is an near infrared narrowband differential imager being built by the
Institute of Astronomy, Cambridge, in collaboration with the Anglo-Australian
observatory. It is a special purpose instrument designed with a sole aim; the
detection of redshifted Lyman-alpha emission from star forming galaxies at z>7.
DAzLE will use pairs of high resolution (R=1000) narrowband filters to exploit
low background `windows' in the near infrared sky emission spectrum. This will
enable it to reach sensitivities of ~2E-21 W/m^2, thereby allowing the
detection of z>7 galaxies with star formation rates as low as a few solar
masses per year. The design of the instrument, and in particular the crucial
narrowband filters, are presented. The predicted performance of DAzLE,
including the sensitivity, volume coverage and expected number counts, is
discussed. The current status of the DAzLE project, and its projected timeline,
are also presented.


title: Harmonic projection and multipole Vectors

abstract:
  We show that the multipole vector decomposition, recently introduced by Copi
et al., is a consequence of Sylvester's theorem, and corresponds to the
Maxwell's representation. Analyzing it in terms of harmonic polynomials, we
show that this decomposition results in fact from the application of the
harmonic projection operator and its inverse. We derive the coefficients of the
usual harmonic decomposition from the multipole vectors. We answer to '' an
open question '', first raised by Copi et al., and reported by Katz and Weeks,
by showing that the decomposition resulting from their corollary is unstable.
We propose however a new decomposition which is stable. We generalize these
results to complex functions and polynomials.


title:
Archival light curves from the Bamberg Sky Patrol - CFOctantis,
  1964-1976

abstract:
  We use the archive of the Bamberg Sky Patrol to obtain light curves of the
active K subgiant CF Octantis for the interval 1964-1976. Digitised images of
the field near CF Oct were obtained with a flat-bed scanner. Aperture
photometry was performed of photo-positives of these images. Using a
transformation to second order in plate magnitude, and first order in B-V, for
9 field stars for each plate, the B magnitudes of CF Octantis were obtained for
just over 350 plates. The estimated precision of an individual determination of
the B magnitude of CF Oct is 0.05 mag. Analysis of the resulting data reveals
the known 20 d rotational variation of this star, and shows the evolution of
the light curves from year to year. We obtain light curves with good phase
coverage for 1964 to 1969 inclusive, partial light curves for 1970 and 1976,
and a few data points from 1971. The amplitude of variation ranges from ~0.2 to
\~0.4 mag. There is evidence that the characteristic rotation period of the
star in the 1960s was slightly less than that measured from photoelectric
photometry in the 1980s.


title:
The Composition of the Sagittarius Dwarf Spheroidal Galaxy and
  Implications for Nucleosynthesis and Chemical Evolution

abstract:
  We outline the results of a study of the chemical composition of 14 stars in
the Sagittarius dwarf spheroidal galaxy (Sgr dSph). For the Sgr dSph stars with
[Fe/H]>-1 the abundances are highly unusual, showing a striking enhancement in
heavy s-process elements, increasing with [Fe/H], deficiencies of the alpha-
elements (O, Si, Ca, and Ti), deficiencies of Al and Na, and deficiencies of
the iron-peak elements Mn and Cu. Our abundances suggest that the composition
of the metal-rich Sgr dSph stars is dominated by the ejecta of an old,
metal-poor population, including products of AGB stars and type Ia supernovae
(SN). We suggest two scenarios to explain the observations: Prolonged chemical
evolution in a galaxy experiencing significant mass-loss, and chemical
enrichment in a system with a large burst of star-formation, followed by a
quiescent period of many Gry. The Galactic globular cluster Omega Cen, and the
Fornax dwarf galaxy show similar abundance patterns, which suggests that those
systems evolved similar to the Sgr dSph.


title: Galactic Metallicity Gradients Derived from a Sample of OB Stars

abstract:
  The distribution of stellar abundances along the Galactic disk is an
important constraint for models of chemical evolution and Galaxy formation. In
this study we derive radial gradients of C, N, O, Mg, Al, Si, as well as S,
from abundance determinations in young OB stars. Our database is composed of a
sample of 69 members of 25 open clusters, OB associations and H II regions with
Galactocentric distances between 4.7 and 13.2 kpc. An important feature of this
abundance database is the fact that the abundances were derived
self-consistently in non-LTE using a homogeneous set of stellar parameters.
Such an uniform analysis is expected to reduce the magnitude of random errors,
as well as the influence of systematics in the gradients defined by the
abundance and Galactocentric distance. The metallicity gradients obtained in
this study are, in general, flatter than the results from previous recent
abundance studies of early-type stars. The slopes are found to be between
-0.031 (for oxygen) and $-0.052 dex kpc^{-1}$ (for magnesium). The gradients
obtained for the studied elements are quite similar and if averaged, they can
be represented by a single slope of $-0.042 \pm 0.007 dex kpc^{-1}$. This value
is generally consistent with an overall flattening of the radial gradients with
time.


title:
Multipixel characterization of imaging CZT detectors for hard X-ray
  imaging and spectroscopy

abstract:
  We report our in-depth study of Cd-Zn-Te (CZT) crystals to determine an
optimum pixel and guard band configuration for Hard X-ray imaging and
spectroscopy. We tested 20x20x5mm crystals with 8x8 pixels on a 2.46mm pitch.
We have studied different types of cathode / anode contacts and different pixel
pad sizes. We present the measurements of leakage current as well as spectral
response for each pixel. Our I-V measurement setup is custom designed to allow
automated measurements of the I-V curves sequentially for all 64 pixels,
whereas the radiation properties measurement setup allows for interchangeable
crystals with the same XAIM3.2 ASIC readout from IDEAS. We have tested multiple
crystals of each type, and each crystal in different positions to measure the
variation between individual crystals and variation among the ASIC channels. We
also compare the same crystals with and without a grounded guard band deposited
on the crystal side walls vs. a floating guard band and compare results to
simulations. This study was carried out to find the optimum CZT crystal
configuration for prototype detectors for the proposed Black-Hole Finder
mission, EXIST.


title:
Galaxy Groups Associated with Gravitational Lenses and H_0 from
  B1608+656

abstract:
  Compact groups of galaxies recently have been discovered in association with
several strong gravitational lens systems. These groups provide additional
convergence to the lensing potential and thus affect the value of H_0 derived
from the systems. Lens system time delays are now being measured with
uncertainties of only a few percent or better. Additionally, vast improvements
are being made in incorporating observational constraints such as Einstein ring
structures and stellar velocity dispersions into the lens models. These
advances are reducing the uncertainties on H_0 to levels at which the the
effects of associated galaxy groups may contribute significantly to the overall
error budget. We describe a dedicated multiwavelength program, using Keck, HST,
and Chandra, to find such groups and measure their properties. We present, as a
case study, results obtained from observations of the CLASS lens system
B1608+656 and discuss the implications for the value of H_0 derived from this
system.


title:
The Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman
  Hole-Northwest: The X-ray Catalog

abstract:
  We present the X-ray catalog and basic results from our Chandra Large Area
Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. Our 9
ACIS-I fields cover a contiguous solid angle of ~0.4 sq. deg. and reach fluxes
of 5E-16 cgs (0.4-2 keV) and 3E-15 cgs (2-8keV). Our survey bridges the gap
between ultradeep pencil-beam surveys, such as the Chandra Deep Fields (CDFs),
and shallower, large area surveys, allowing a better probe of the X-ray sources
that contribute most of the 2-10 keV cosmic X-ray background (CXB). We find a
total of 525 X-ray point sources and 4 extended sources. At ~10E-14 cgs 2-8
keV, our number counts are significantly higher than those of several
non-contiguous, large area surveys. On the other hand, the integrated flux from
the CLASXS field, combined with ASCA and Chandra ultradeep surveys, is
consistent with results from other large area surveys, within the variance of
the CXB. Spectral evolution is seen in the hardening of the sources at fluxes
below 1E-14 cgs Above 4E1-14 cgs(0.4-8 keV), ~60 of the sources are variable.
Four extended sources in CLASXS is consistent with the previously measured
LogN-LogS of galaxy clusters. We report the discovery of a gravitational
lensing arc associated with one of these sources. (Abridged)


title:
An Optical Catalog of the Chandra Large Area Synoptic X-ray Survey
  Sources

abstract:
  We present photometric and spectroscopic observations of the X-ray sources
detected in the wide-area, moderately deep Chandra Large Area Synoptic X-ray
Survey of the Lockman Hole-Northwest field. We have B, V, R, I, and z'
photometry for 521 (99%) of the 525 sources in the X-ray catalog and
spectroscopic redshifts for 271 (52%), including 20 stars. We do not find
evidence for redshift groupings of the X-ray sources, like those found in the
Chandra Deep Field surveys, because of the larger solid angle covered by this
survey. We separate the X-ray sources by optical spectral type and examine the
colors, apparent and absolute magnitudes, and redshift distributions for the
broad-line and non-broad-line active galactic nuclei. Combining our wide-area
survey with other Chandra and XMM-Newton hard X-ray surveys, we find a definite
lack of luminous, high accretion rate sources at z<1, consistent with previous
observations that showed that supermassive black hole growth is dominated at
low redshifts by sources with low accretion rates.


title:
Ambipolar-Diffusion Timescale, Star-Formation Timescale, and the Ages of
  Molecular Clouds: Is There a Discrepancy?

abstract:
  We re-examine critically the estimates of the duration of different phases of
star formation and the lifetimes of molecular clouds, based on the ages of
T-Tauri stars, age spreads of stars in clusters, and statistics of pre-stellar
cores. We show that all available observational data are consistent with
lifetimes of molecular clouds comparable to 10 Myr, as well as with the
predictions of the theory of self-initiated, ambipolar-diffusion--controlled
star formation. We conclude that there exists no observational support for
either "young" molecular clouds or "rapid" star formation.


title: Spectroscopic Properties of the z=4.5 Lyman-alpha Emitters

abstract:
  We present Keck/LRIS optical spectra of 17 Lya-emitting galaxies and one
Lyman break galaxy at z=4.5 discovered in the Large Area Lyman Alpha (LALA)
survey. The survey has identified a sample of ~350 candidate Lya-emitting
galaxies at z=4.5 in a search volume of 1.5 x 10^6 comoving Mpc^3. We targeted
25 candidates for spectroscopy; hence, the 18 confirmations presented herein
suggest a selection reliability of 72%. The large equivalent widths (median
W(rest)~80 A) but narrow physical widths (v < 500 km/s) of the Lya emission
lines, along with the lack of accompanying high-ionization state emission
lines, suggest that these galaxies are young systems powered by star formation
rather than by AGN activity. Theoretical models of galaxy formation in the
primordial Universe suggest that a small fraction of Lya-emitting galaxies at
z=4.5 may still be nascent, metal-free objects. Indeed, we find with 90%
confidence that 3 to 5 of the confirmed sources show W(rest) > 240 A, exceeding
the maximum Lya equivalent width predicted for normal stellar populations.
Nonetheless, we find no evidence for HeII 1640 emission in either individual or
composite spectra, indicating that though these galaxies are young, they are
not truly primitive, Population III objects.


title: Complex X-ray Absorption and the Fe Kalpha Profile in NGC 3516

abstract:
  We present data from simultaneous Chandra, XMM-Newton and BeppoSAX
observations of the Seyfert 1 galaxy NGC 3516, taken during 2001 April and Nov.
We have investigated the nature of the very flat observed X-ray spectrum.
Chandra grating data show the presence of X-ray absorption lines, revealing two
distinct components of the absorbing gas, one which is consistent with our
previous model of the UV/X-ray absorber while the other, which is outflowing at
a velocity of ~1100 km/s has a larger column density and is much more highly
ionized. The broad-band spectral characteristics of the X-ray continuum
observed with XMM during 2001 April, reveal the presence of a third layer of
absorption consisting of a very large column (~2.5 x 10E23 cm^-2) of highly
ionized gas with a covering fraction ~50%. This low covering fraction suggests
that the absorber lies within a few lt-days of the X-ray source and/or is
filamentary in structure. Interestingly, these absorbers are not in thermal
equilibrium with one another. The two new components are too highly ionized to
be radiatively accelerated, which we suggest is evidence for a hydromagnetic
origin for the outflow. Applying our model to the Nov dataset, we can account
for the spectral variability primarily by a drop in the ionization states of
the absorbers, as expected by the change in the continuum flux. When this
complex absorption is accounted for we find the underlying continuum to be
typical of Seyfert 1 galaxies. The spectral curvature attributed to the high
column absorber, in turn, reduces estimates of the flux and extent of any broad
Fe emission line from the accretion disk.


title:
Multi-wavelength observations of the Galactic black hole transient
  4U1543-47 during outburst decay: state transitions and jet contribution

abstract:
  Multiwavelength observations of Galactic black hole (GBH) transients during
the state transitions and in the low/hard state may provide detailed
information on the accretion structure of these systems. 4U1543-47 is a GBH
transient that was covered exceptionally well in X-ray and infrared (daily
observations) and reasonably well in optical and radio during its outburst
decay in 2002. When all the available information is gathered in the
intermediate and the low/hard state, 4U1543-47 makes an important contribution
to our understanding of state transitions and the role of outflows on the high
energy emission properties of black hole binaries. The evolution of the X-ray
spectral and temporal properties and the IR light curve place strong
constraints on different models for explaining the overall emission from
accreting black holes. The overall spectral energy distribution is consistent
with synchrotron origin for the optical and infrared emission, however, the
X-ray flux is above the power-law continuation of the optical and infrared
flux. The infrared light curve, the HEXTE light curve and the evolution of the
X-ray photon index indicate that the major source of hard X-rays cannot be
direct synchrotron radiation from an acceleration region in a jet for most of
the outburst decay.


title:
Extragalactic source counts in the 20-50 keV energy band from the deep
  observation of the Coma region by INTEGRAL/IBIS

abstract:
  We present the analysis of serendipitous sources in a deep, 500 ksec, hard
X-ray observation of the Coma cluster region with the IBIS instrument onboard
INTEGRAL. In addition to the Coma cluster, the final 20-50 keV image contains
12 serendipitous sources with statistical significance >4sigma. We use these
data (after correcting for expected number of false detections) to extend the
extragalactic source counts in the 20-50 keV energy band down to a limiting
flux of 1.0e-11 erg/s/cm^2 (~ 1mCrab). This is a more than a factor of 10
improvement in sensitivity compared to the previous results in this energy band
obtained with the HEAO-1 A4 instrument. The derived source counts are
consistent with the Euclidean relation, N(>f) ~ f**(-3/2). A large fraction of
identified serendipitous sources are low-redshift, z<0.02, AGNs, mostly of
Seyfert 1 type. The surface density of hard X-ray sources is 0.014 +- 0.005 per
square degree above a flux threshold of 1e-11 erg/s/cm^2. These sources
directly account for ~3% of the cosmic X-ray background in the 20-50 keV energy
band. Given the low redshift depth of our sample, we expect that similar
sources at higher redshifts account for a significant fraction of the hard
X-ray background. Our field covers only 3% of the sky; a systematic analysis of
other extragalactic INTEGRAL observations can produce much larger source
samples and is, therefore, critically important.


title: The Infrared Sky

abstract:
  The infrared sky from space is the sum of a cosmic signal from galaxies,
quasars, and perhaps more exotic sources; and foregrounds from the Milky Way
and from the Solar System. At a distance of 1 AU from the Sun, the foreground
from interplanetary dust is very bright between 5 and 100 microns, but ``very
bright'' is still several million times fainter than the background produced by
ground-based telescopes. In the near infrared 1-2.2 micron range the space
infrared sky is a thousand times fainter than the OH nightglow from the Earth's
atmosphere. As a result of these advantages, wide-field imaging from space in
the infrared can be an incredibly sensitive method to study the Universe.


title: Strong Gravitational Lensing with SKA

abstract:
  The advent of new observational facilities in the last two decades has
allowed the rapid discovery and high-resolution optical imaging of many strong
lens systems from galaxy to cluster scales, as well as their spectroscopic
follow-up. Radio telescopes have played the dominant role in the systematic
detection of dozens of new arcsec-scale lens systems. For the future, we expect
nothing less! The next major ground- and space-based facilities, especially the
Square Kilometer Array can discover tens of thousands of new lens systems in
large sky surveys. For optical imaging and spectroscopic follow-up a strong
synergy with planned optical facilities is needed. Here, we discuss the field
where strong gravitational lensing is expected to play the dominant role and
where SKA can have a major impact: The study of the internal mass structure and
evolution of galaxies and clusters to z~1. In addition, studies of more exotic
phenomena are contemplated. For example, milli- and microlensing can provide a
way to measure the mass-functions of stars and CDM substructure at cosmological
distances. All-sky radio monitoring will also rapidly develop the field of
time-domain lensing.


title: The Gould Belt, star formation, and the local interstellar medium

abstract:
  The history of the local medium, within a few hundred parsecs, is dominated
by the evolution of the Gould Belt. The event that triggered this star-forming
region and molded the gas distribution is still unknown. Its orientation and
extent are reasonably well determined and its expansion matches the space and
velocity distributions of many large HI and H2 clouds within half a kiloparsec.
The present rim coincides with most of the nearby OB associations, but their
mean velocity does not seem to be related to the Belt expansion. The Belt age
is uncertain by a factor of 2 because of the discrepancy found between the
dynamical timescale (20 to 30 Myr) and the stellar ages (30 to 60 Myr). The
stellar content is derived from kinematic studies for massive stars and from
X-ray observations for young solar-mass ones. Whether star formation is active
along the rim or spread over a larger fraction of the disc is debated. The Belt
flatness and its tilt remain very difficult to interpret. Various scenarii
involve the impact of a high-velocity cloud, a cascade of supernovae, the
dissolution of a rotating system, or the braking of a supercloud entering the
spiral arm. Because of the enhanced star formation, the Belt supernova rate
over the past few million years has been 3 to 4 times larger than the local
Galactic rate. The corresponding pulsars may be responsible for the population
of unknown gamma-ray sources associated with the Belt. The higher rate also
implies an enhanced cosmic-ray production locally.


title: The accretion history of the Universe with the SKA

abstract:
  In this paper we investigate how the Square Kilometre Array (SKA) can aid in
determining the evolutionary history of active galactic nuclei (AGN) from
redshifts z= 0 ->6. Given the vast collecting area of the SKA, it will be
sensitive to both `radio-loud' AGN and the much more abundant `radio-quiet'
AGN, namely the radio-quiet quasars and their `Type-II' counterparts, out to
the highest redshifts. Not only will the SKA detect these sources but it will
also often be able to measure their redshifts via the Hydrogen 21 cm line in
emission and/or absorption. We construct a complete radio luminosity function
(RLF) for AGN, combining the most recent determinations for powerful radio
sources with an estimate of the RLF for radio-quiet objects using the hard
X-ray luminosity function of Ueda et al., including both Type-I and Type-II
AGN. We use this complete RLF to determine the optimal design of the SKA for
investigating the accretion history of the Universe for which it is likely to
be a uniquely powerful instrument.


title:
Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic
  Ray Propagation

abstract:
  We discuss the influence of large scale cosmic magnetic fields on the
propagation of hadronic cosmic rays above 10^19 eV based on large scale
structure simulations. Our simulations suggest that rather substantial
deflection up to several tens of degrees at 10^20 eV are possible for nucleon
primaries. Further, spectra and composition of cosmic rays from individual
sources can depend on magnetic fields surrounding these sources in
intrinsically unpredictable ways. This is true even if deflection from such
individual sources is small. We conclude that the influence of large scale
cosmic magnetic fields on ultra-high energy cosmic ray propagation is currently
hard to quantify. We discuss possible reasons for discrepant results of
simulations by Dolag et al. which predict deflections of at most a few degrees
for nucleons. We finally point out that even in these latter simulations a
possible heavy component would in general suffer substantial deflection.


title:
The Growth of the Earliest Supermassive Black Holes and Their
  Contribution to Reionization

abstract:
  We discuss currently available observational constraints on the reionization
history of the intergalactic medium (IGM), and the extent to which accreting
black holes (BHs) can help explain these observations. We show new evidence,
based on the combined statistics of Lyman alpha and beta absorption in quasar
spectra, that the IGM contains a significant amount of neutral hydrogen, and is
experiencing rapid ionization around redshift z=6. However, we argue that
quasar BHs, even faint ones that are below the detection thresholds of existing
optical surveys, are unlikely to drive the evolution of the neutral fraction
around this epoch, because they would over-produce the present-day soft X-ray
background. On the other hand, the seeds of the quasar BHs around z=6 likely
appeared at much earlier epochs (around z=20), and produced hard ionizing
radiation by accretion. These early BHs are promising candidates to account for
the high redshift ionization (around z=15) implied by the recent cosmic
microwave anisotropy data from WMAP. Using a model for the growth of BHs by
accretion and mergers in a hierarchical cosmology, we suggest that the early
growth of quasars must include a super-Eddington growth phase, and that,
although not yet optically identified, the FIRST radio survey may have already
detected several thousand BHs at z>6 with Mbh>10^8 Msun.


title: The Origin and Evolution of Cosmic Magnetism

abstract:
  Magnetism is one of the four fundamental forces. However, the origin of
magnetic fields in stars, galaxies and clusters is an open problem in
astrophysics and fundamental physics. When and how were the first fields
generated? Are present-day magnetic fields a result of dynamo action, or do
they represent persistent primordial magnetism? What role do magnetic fields
play in turbulence, cosmic ray acceleration and galaxy formation? Here we
demonstrate how the Square Kilometer Array (SKA) can deliver new data which
will directly address these currently unanswered issues. Much of what we
present is based on an all-sky survey of rotation measures, in which Faraday
rotation towards >10^7 background sources will provide a dense grid for probing
magnetism in the Milky Way, in nearby galaxies, and in distant galaxies,
clusters and protogalaxies. Using these data, we can map out the evolution of
magnetised structures from redshifts z>3 to the present, can distinguish
between different origins for seed magnetic fields in galaxies, and can develop
a detailed model of the magnetic field geometry of the intergalactic medium and
of the overall Universe. With the unprecedented capabilities of the SKA, the
window to the Magnetic Universe can finally be opened.


title: Nuclear vs. Circumnuclear Activity

abstract:
  We have analyzed the frequency and properties of the nuclear activity in a
sample of galaxies with circumnuclear rings and spirals (CNRs). This sample was
compared with a control sample of galaxies with very similar global properties
but without circumnuclear rings. We discuss the relevance of the results in
regard to the AGN feeding processes and present the following results: (i)
bright companion galaxies seem not to be important for the appearance of CNRs,
which appear to be more related to intrinsic properties of the host galaxies or
to minor merger processes; (ii) the proportion of strong bars in galaxies with
an AGN and a CNR is somewhat higher than the expected ratio of strongly barred
AGN galaxies from the results of Ho and coworkers; (iii) the incidence of
Seyfert activity coeval with CNRs is clearly larger than the rate expected from
the morphological distribution of the host galaxies; (iv) the rate of Sy 2 to
Sy 1 type galaxies with CNRs is about three times larger than the expected
ratio for galaxies without CNRs and is opposite to that predicted by the
geometric paradigm of the classical unified model for AGNs, although it does
support the hypothesis that Sy 2 activity is linked to circumnuclear star
formation.


title: Weak lensing and gravity theories

abstract:
  We present the theory of weak gravitational lensing in cosmologies with
generalized gravity, described in the Lagrangian by a generic function
depending on the Ricci scalar and a non-minimally coupled scalar field. We work
out the generalized Poisson equations relating the dynamics of the fluctuating
components to the two gauge invariant scalar gravitational potentials, fixing
the new contributions from the modified background expansion and fluctuations.
We show how the lensing observables are affected by the cosmic expansion as
well as by the presence of the anisotropic stress, which is non-null at the
linear level both in scalar-tensor gravity and in theories where the
gravitational Lagrangian term features a non-minimal dependence on the Ricci
scalar. We derive the generalized expressions for the convergence power
spectrum, and illustrate phenomenologically the new effects in Extended
Quintessence scenarios, where the scalar field coupled to gravity plays the
role of the dark energy.


title: Pseudobulges in Barred S0 Galaxies

abstract:
  We present preliminary results from an ongoing study of the bulges of S0
galaxies. We show that in a subsample of 14 barred S0 galaxies, fully half the
photometrically defined bulges show kinematic signatures of "pseudobulges" --
that is, their kinematics are dominated by rotation. In four of these galaxies,
we identify at least two subcomponents in the photometric bulge region:
flatter, disk or bar components, assocated with disklike kinematics; and
rounder "inner bulges,'' which appear to be hotter systems more like classical
bulges.


title: Pulsar Wind Nebulae in EGRET Error Boxes

abstract:
  A remarkable number of pulsar wind nebulae (PWN) are coincident with EGRET
gamma-ray sources. X-ray and radio imaging studies of unidentified EGRET
sources have resulted in the discovery of at least 6 new pulsar wind nebulae
(PWN). Stationary PWN (SPWN) appear to be associated with steady EGRET sources
with hard spectra, typical for gamma-ray pulsars. Their toroidal morphologies
can help determine the geometry of the pulsar which is useful for constraining
models of pulsed gamma-ray emission. Rapidly moving PWN (RPWN) with more
cometary morphologies seem to be associated with variable EGRET sources in
regions where the ambient medium is dense compared to what is typical for the
ISM.


title:
Molecular Line Observations of Carbon-Chain-Producing Regions L1495B and
  L1521B

abstract:
  We present the first comprehensive study on physical and chemical properties
of quiescent starless cores L1495B and L1521B, which are known to be rich in
carbon-chain molecules like the cyanopolyyne peak of TMC-1 and L1521E. We have
detected radio spectral lines of various carbon-chain molecules such as CCS,
C$_{3}$S, C$_{4}$H, HC$_{3}$N, and HC$_{5}$N. On the other hand, the NH$_{3}$
lines are weak and the N$_{2}$H$^{+}$ lines are not detected. According to our
mapping observations of the HC$_{3}$N, CCS, and C$_{3}$S lines, the dense cores
in L1495B and L1521B are compact with the radius of 0.063 and 0.044 pc,
respectively, and have a simple elliptical structure. The distributions of CCS
seem to be different from those of well-studied starless cores, L1498 and
L1544, where the distribution of CCS shows a shell-like structure. Since the
H$^{13}$CO$^{+}$, HN$^{13}$C, and C$^{34}$S lines are detected in L1495B and
L1521B, the densities of these cores are high enough to excite the NH$_{3}$ and
N$_{2}$H$^{+}$ lines. Therefore, the abundances of NH$_{3}$ and N$_{2}$H$^{+}$
relative to carbon-chain molecules are apparently deficient, as observed in
L1521E. We found that longer carbon-chain molecules such as HC$_{5}$N and
C$_{4}$H are more abundant in TMC-1 than L1495B and L1521B, while those of
sulfur-bearing molecules such as C$^{34}$S, CCS, and C$_{3}$S are comparable.
Both distributions and abundances of the observed molecules of L1495B and
L1521B are quite similar to those of L1521E, strongly suggesting that L1495B
and L1521B is in a very early stage of physical and chemical evolution.


title: Inflation parameters from Gauss-Bonnet braneworld

abstract:
  We calculate the spectral index and tensor-to-scalar ratio for patch
inflation arisen from the Gauss-Bonnet braneworld scenario. The patch
cosmological models consist of Gauss-Bonnet (GB), Randall-Sundrum (RS), and 4D
general relativistic (GR) cases. In order to compare with the observation data,
we perform leading-order calculations for all patch models by choosing
large-field, small-field, and hybrid potentials. We show that the large-field
potentials are sensitive to a given patch model, while the small-field and
hybrid potentials are insensitive to a given patch model. It is easier to
discriminates between quadratic potential and quartic potential in the GB model
rather than RS and GR models. Irrespective of patch models, it turns out that
the small-field potentials are the promising models in view of the observation.


title: A Hot Saturn Planet Orbiting HD 88133, from the N2K Consortium

abstract:
  The N2K consortium is carrying out a distributed observing campaign with the
Keck, Magellan and Subaru telescopes, as well as the automatic photometric
telescopes of Fairborn Observatory, in order to search for short-period gas
giant planets around metal-rich stars. We have established a reservoir of more
than 14,000 main sequence and subgiant stars, closer than 110 pc, brighter than
V=10.5 and with $0.4 < B-V < 1.2$. Because the fraction of stars with planets
is a sensitive function of stellar metallicity, a broadband photometric
calibration has been developed to identify a subset of 2000 stars with [Fe/H]
$> 0.1$ dex for this survey. We outline the strategy and report the detection
of a planet orbiting the metal-rich G5IV star HD 88133 with a period of 3.41
days, semi-velocity amplitude, K=35.7 \mse and \msini = 0.29 \mjupe.
Photometric observations reveal that HD 88133 is constant on the 3.415-day
radial velocity period to a limit of 0.0005 mag. Despite a transit probability
of 15.6%, our photometry rules out the shallow transits predicted by the large
stellar radius.


title: Large scale diffuse light in the Coma cluster: a multi-scale approach

abstract:
  We have obtained wide field images of the Coma cluster in the B, V, R and I
bands with the CFH12K camera at CFHT. In order to search for large scale
diffuse emission, we have applied to these images an iterative multi scale
wavelet analysis and reconstruction technique which allowed to model all the
sources (stars and galaxies) and subtract them from the original images. We
found various concentrations of diffuse emission present in the central zone
around the central galaxies NGC4874 and NGC4889. We characterize the positions,
sizes and colors of these concentrations. Some sources do not seem to have
strong star formation, while another one probably exhibits spiral-like color.
One possible origin for the star forming diffuse emission sources is that in
the region of the two main galaxies NGC4874 and NGC4889 spiral galaxies have
recently been disrupted and star formation is still active in the dispersed
material. We also use the characteristics of the sources of diffuse emission to
trace the cluster dynamics. A scenario in which the group around NGC 4874 is
moving north is consistent with our data.


title:
Chiral Symmetry Breaking in Presence of Strong Quantizing Magnetic
  Fields- A Nambu-Jona-Lasino Model with Semi-Classical Approximation

abstract:
  The breaking of chiral symmetry of light quarks at zero temperature in
presence of strong quantizing magnetic field is studied using
Nambu-Jona-Lasinio (NJL) model with Thomas-Fermi type semi-classical formalism.
It is found that the dynamically generated light quark mass can never become
zero if the Landau levels are populated and increases with the increase of
magnetic field strength.


title:
Mid-IR emission of galaxies in the Virgo cluster and in the Coma
  supercluster.IV. The nature of the dust heating sources

abstract:
  We study the relationship between the mid-IR (5-18 $\mu$m) emission of
late-type galaxies and various other star formation tracers in order to
investigate the nature of the dust heating sources in this spectral domain. The
analysis is carried out using a sample of 123 normal, late-type, nearby
galaxies with available data at several frequencies. The mid-IR luminosity
(normalized to the H-band luminosity) correlates better with the far-IR
luminosity than with more direct tracers of the young stellar population such
as the H$\alpha$ and the UV luminosity. The comparison of resolved images
reveals a remarkable similarity in the H$\alpha$ and mid-IR morphologies, with
prominent HII regions at both frequencies. The mid-IR images, however, show in
addition a diffuse emission not associated with HII regions nor with the
diffuse H$\alpha$ emission. This evidence indicates that the stellar population
responsible for the heating of dust emitting in the mid-IR is similar to that
heating big grains emitting in the far-IR, including relatively evolved stars
responsible for the non-ionizing radiation. The scatter in the mid-IR vs.
H$\alpha$, UV and far-IR luminosity relation is mostly due to metallicity
effects, with metal-poor objects having a lower mid-IR emission per unit star
formation rate than metal-rich galaxies. Our analysis indicates that the mid-IR
luminosity is not an optimal star formation tracer in normal, late-type
galaxies.


title: A quantum gravitational model of redshifts

abstract:
  The main features of an alternative model of redshifts are described here.
The model is based on conjectures about an existence of the graviton background
with the Planckian spectrum and a super-strong character of quantum
gravitational interaction. This model is connected with the assumed quantum
mechanism of gravity. A behavior of two theoretical functions of a redshift $z$
in this model - the geometrical distance $r(z)$ and the luminosity distance
$D_{L}(z)$ - and an existence of two different cosmological horizons for any
observer are discussed.


title: An L0 dwarf companion in the brown dwarf desert, at 30 AU

abstract:
  We present the discovery of an L0 companion to the nearby M1.5 dwarf G
239-25, at a projected distance of 31 AU. It is the faintest companion
discovered so far in our adaptive optics survey of all known M dwarfs within 12
pc, and it lies at the stellar/substellar limit. Given the assumed age of the
primary star, the companion is likely an extremely low mass star. The long
orbital period of G 239-25 AB ($\approx 100$ years) precludes a direct mass
determination, but the relatively wide angular separation will allow detailed
analyses of its near infrared and visible spectra.


title: The ASTRA Spectrophotometer: A July 2004 Progress Report

abstract:
  A cross-dispersed spectrophotometer with CCD detector and its automated 0.5-m
telescope at the Fairborn Observatory, now under construction, should begin
observations in 6 to 9 months. The Citadel ASTRA Telescope will be able to
observe Vega the primary standard, make rapid measurements of the naked-eye
stars, use 10 minutes per hour to obtain photometric measurements of the
nightly extinction, and obtain high quality observations of V=10.5 mag. stars
in an hour. The approximate wavelength range is 3300-9000A with a resolution of
14A in first and 7A in second order. Filter photometric magnitudes and indices
will be calibrated in part for use as quality checks.
  Science observations for major projects such as comparisons with model
atmospheres codes and for exploratory investigations should also begin in the
first year. The ASTRA team realizes to deal with this potential data flood that
they will need help to make the best scientific uses of the data. Thus they are
interested in discussing possible collaborations. In less than a year of normal
observing, all isolated stars in the Bright Star Catalog that can be observed
can have their fluxes well measured. Some A Star related applications are
discussed.


title: Massive Star Populations in Wolf-Rayet Galaxies

abstract:
  We analyze longslit spectral observations of fourteen Wolf-Rayet galaxies
from the sample of Schaerer, Contini & Pindao (1999). All 14 galaxies show
broad Wolf-Rayet emission in the blue region of the spectrum, consisting of a
blend of NIII4640, CIII4650, CIV4658, and HeII4686 emission lines, which is a
spectral characteristic of WN stars. Broad CIV5808 emission, termed the red
bump, is detected in 9 galaxies and CIII5996 is detected in 6 galaxies. These
emission features are due to WC stars. We derive the numbers of late WN and
early WC stars from the luminosity of the blue and red bumps, respectively. The
number of O stars is estimated from the luminosity of the Hbeta emission line,
after subtracting the contribution of WR stars. The Schaerer & Vacca 1998
(hereafter SV98) models predict that the number of WR stars relative to O
stars, N_WR/N_O, increases with metallicity. For low metallicity galaxies, the
results agree with predictions of evolutionary synthesis models for galaxies
with a burst of star formation, and indicates an IMF slope -2 < Gamma < -2.35
in the low metallicity regime. For high metallicity galaxies our observations
suggest a Salpeter IMF (Gamma = -2.35) and an extended short burst. The main
possible sources of error are the adopted luminosities for single WCE and WNL
stars. We also report, for the first time, NGC 450 as a galaxy with WR
characteristics.


title:
A Near-Infrared (JHK) Survey of the Vicinity of the HII region NGC 7538:
  Evidence for a Young Embedded Cluster

abstract:
  We describe the results of two near infrared (K-band) imaging surveys and a
three color (JHK) survey of the vicinity of NGC 7538. The limiting magnitudes
are K ~ 16.5 and K ~ 17.5 mag for the K-band surveys and K ~ 15 mag for the JHK
survey. We identify more than 2000 and 9000 near-infrared (NIR) sources on the
images of the two K-band surveys and 786 NIR sources in the JHK survey. From
color-color diagrams, we derive a reddening law for background stars and
identify 238 stars with NIR excesses. Contour maps indicate a high density peak
coincident with a concentration of stars with NIR excesses. We identify this
peak as a young, embedded cluster and confirm this result with the K-band
luminosity function, color histograms, and color-magnitude diagrams. The center
of the cluster is at RA = 23:13:39.34, DEC = 61:29:18.9. The cluster radius is
$\sim$ 3' ~ 2.5 pc for an adopted distance, d ~ 2.8 kpc. For d = 2.8 kpc, and
reddening, E_{J-K} = 0.55 mag, the slope of the logarithmic K-band luminosity
function (KLF) of the cluster, s ~ 0.32 +- 0.03, agrees well with previous
results for L1630 (s = 0.34) and M17 (s = 0.26).


title:
Lithium and its isotopic ratio 6Li/7Li in the atmospheres of some
  sharp-lined roAp star

abstract:
  The lines of lithium at 6708 A, and 6103 A, are analyzed in high resolution
spectra of some sharp-lined and slowly rotating roAp stars. Three spectral
synthesis codes - STARSP, ZEEMAN2 and SYNTHM were used. New lines of the rare
earth elements from the DREAM database, and lines calculated on the basis of
the NIST energy levels were included. Magnetic splitting and other line
broadening processes were taken into account. Enhanced abundances of lithium in
the atmospheres of the stars studied are obtained for both the lithium lines.
High estimates of 6Li/7Li ratio (0.2 -- 0.5) for the studied star can be
explained by Galactic Cosmic Ray (GCR) production through the spallation
reactions and the preservation of the original $^6$Li and $^7$Li by the strong
magnetic fields.


title: IR spectroscopy of pre-cataclysmic binaries

abstract:
  We have taken near-infrared (JHK) spectroscopic data of a sample of pre-CVs,
in order to examine them for signatures of nuclear evolution. Here we present
preliminary results for the three systems BPM 71214, RR Cae, and RE 1016-053.


title: Mapping Tidal Streams around Galactic Globular Clusters

abstract:
  The surroundings of globular clusters in the outer halo are one of the best
places to look for the remnants of ancient dwarf satellites. The classical
Searle & Zinn (1978) scenario of the formation of the Milky Way, in which the
halo globular clusters formed in larger dwarf galaxies, can nowadays be
considered the local manifestation of the hierarchical galaxy formation. It is
now well known that some Galactic globular clusters are actually associated
with the tidal stellar stream resulting from the accretion of dwarf satellites,
thereby confirming that this process plays an important role in the building of
the Milky Way globular cluster system. Furthermore, several recent studies have
suggested that the two most luminous Galactic globular clusters (M54,
associated with Sagittarius and Omega Centauri) might be the nuclei of dwarf
galaxies. Extending previous suggestions, van den Bergh (2000) has argued that
the ``young'' globulars located in the outer halo might be the nuclei of
extinct dwarf galaxies and suggests that a search for evidence of this may
prove worthwhile. If these clusters formed within larger stellar systems, we
would expect to find them surrounded by a stellar population that should be
revealed by deep photometry over a wide field. In this paper, we present the
first (most interesting) preliminary results from a long term project designed
to search for tidal debris around remote halo globular clusters, debris that
may be the vestiges of the larger systems in which these clusters formed.


title:
Determining cosmological parameters from X-ray measurements of strong
  lensing clusters

abstract:
  We discuss a new method which is potentially capable of constraining
cosmological parameters using observations of giant luminous arcs in rich X-ray
clusters of galaxies. The mass profile and the mass normalization of the lenses
are determined from X-ray measurements. The method also allows to probe the
amount and equation of state of the dark energy in the universe. The analysis
of a preliminary sample of 6 luminous, relatively relaxed clusters of galaxies
strongly favours an accelerating expansion of the universe. Under the
assumption that the dark energy is in the form of a cosmological constant, the
data provide an estimate of $ \Omega_\Lambda = 1.1$ with a statistical error of
$\pm 0.2$. Including the constraint of a flat universe and an equation of state
for the dark energy $w_X \geq -1$, we obtain $\Omega_M = 0.10 \pm 0.10$ and
$w_X = -0.84 \pm 0.14$. Relaxing the prior on $w_X$, we find that the null
energy condition is satisfied at the 3-$\sigma$ confidence level.


title:
Oscillations of magnetic stars: II. Axisymmetric toroidal and
  non-axisymmetric shear Alfven modes in a spherical shell

abstract:
  We carry out numerical and mathematical investigations of shear Alfven waves
inside of a spherical shell filled with an incompressible conducting fluid, and
bathed in a strong dipolar magnetic field. We focus on axisymmetric toroidal
and non-axisymmetric modes, in continuation of a previous work by Rincon &
Rieutord (2003, A&A, 398, 663). Analytical expressions are obtained for
toroidal eigenmodes and their corresponding frequencies at low diffusivities.
These oscillations behave like magnetic shear layers, in which the magnetic
poles play a key role, and hence become singular when diffusivities vanish. It
is also demonstrated that non-axisymmetric modes are split into two categories,
namely poloidal or toroidal types, following similar asymptotic behaviours as
their axisymmetric counterparts when the diffusivities become arbitrarily
small.


title: Has DAMA Detected Self-Interacting Dark Matter?

abstract:
  We consider a model in which dark matter consists of a large self-interacting
component (SIDM particles) and a small component with strong interactions with
baryons (SIMPs). We show that the DAMA annual modulation signal can be caused
by SIDM particles interacting with SIMPs trapped in iodine nuclei in the
DAMA/NaI detector.