title: The X-ray afterglow of GRB030329

abstract:
  We report on XMM-Newton and Rossi-XTE observations of the bright (fluence
$\sim$ 10$^{-4}$ erg cm$^{-2}$) and nearby (z=0.1685) Gamma-Ray Burst GRB030329
associated to SN2003dh. The first Rossi-XTE observation, 5 hours after the
burst, shows a flux decreasing with time as a power law with index 0.9$\pm$0.3.
Such a decay law is only marginally consistent with a further Rossi-XTE
measurement (at t-t$_{GRB}\sim$30 hr). Late time observations of this bright
afterglow at X-ray wavelengths have the advantage, compared to optical
observations, of not being affected by contributions from the supernova and
host galaxy. A first XMM-Newton observation, at t-t$_{GRB}\sim$37 days, shows a
flux of 4$\times10^{-14}$ erg cm$^{-2}$ s$^{-1}$ (0.2-10 keV). The spectrum is
a power law with photon index $\Gamma$=1.9 and absorption $<2.5\times10^{20}$
cm$^{-2}$, consistent with the Galactic value. A further XMM-Newton pointing at
t-t$_{GRB}\sim$61 days shows a flux fainter by a factor $\sim$2. The combined
Rossi-XTE and XMM-Newton measurements require a break at t$\sim$0.5 days in the
afterglow decay, with a power law index increasing from 0.9 to 1.9, similar to
what is observed in the early part of the optical afterglow. The extrapolation
of the XMM-Newton spectra to optical frequencies lies a factor of $\sim10$
below simultaneous measurements. This is likely due to the presence of
SN2003dh.


title:
The Effects of UV Continuum and Lyman alpha Radiation on the Chemical
  Equilibrium of T Tauri Disks

abstract:
  We show in this Letter that the spectral details of the FUV radiation fields
have a large impact on the chemistry of protoplanetary disks surrounding T
Tauri stars. We show that the strength of a realistic stellar FUV field is
significantly lower than typically assumed in chemical calculations and that
the radiation field is dominated by strong line emission, most notably Lyman
alpha radiation. The effects of the strong Lyman alpha emission on the chemical
equilibrium in protoplanetary disks has previously been unrecognized. We
discuss the impact of this radiation on molecular observations in the context
of a radiative transfer model that includes both direct attenuation and
scattering. In particular, Lyman alpha radiation will directly dissociate water
vapor and may contribute to the observed enhancements of CN/HCN in disks.


title: The Revised Flat Galaxy Catalogue

abstract:
  We present a new improved and completed version of the Flat Galaxy Catalogue
(FGC) named the Revised Flat Galaxy Catalogue (RFGC) containing 4236 thin
edge-on spiral galaxies and covering the whole sky. The Catalogue is intended
to study large-scale cosmic streamings as well as other problems of
observational cosmology. The dipole moment of distribution of the RFGC galaxies
(l = 273 degr; b =+19 degr) lies within statistical errors (+/-10 degr) in the
direction of the Local Group motion towards the Microwave Background Radiation
(MBR).


title: Copper and Zinc in Bulge-Like Stars

abstract:
  The star formation history of a given population remains imprinted in the
chemical distributions of the their individuals. The parallel study of stellar
abundances and nucleosynthesis helps to understand the production of the
elements inside stars and their evolution in the interestellar medium. In the
present paper copper and zinc abundances of a sample of bulge-like stars are
inferred and compared to samples of the solar vicinity. A disk-like
distribution of [Zn/Fe] is found for the bulge-like stars, while underabundant
[Cu/Fe] ratios relative to disk samples are determined.


title:
Constraining cosmological parameters using Sunyaev-Zel'dovich cluster
  surveys

abstract:
  We discuss how future cluster surveys can constrain cosmological parameters
with particular reference to the properties of the dark energy component
responsible for the observed acceleration of the universe by probing the
evolution of the surface density of clusters as a function of redshift. We
explain how the abundance of clusters selected using their Sunyaev-Zel'dovich
effect can be computed as a function of the observed flux and redshift taking
into account observational effects due to a finite beam-size. By constructing
an idealized set of simulated observations for a fiducial model, we forecast
the likely constraints that might be possible for a variety of proposed surveys
which are assumed to be flux limited. We find that Sunyaev-Zel'dovich cluster
surveys can provide vital complementary information to those expected from
surveys for supernovae. We analyse the impact of statistical and systematic
uncertainties and find that they only slightly limit our ability to constrain
the equation of state of the dark energy component.


title: Cosmological density perturbations from perturbed couplings

abstract:
  The density perturbations generated when the inflaton decay rate is perturbed
by a light scalar field $\chi$ are studied. By explicitly solving the
perturbation equations for the system of two scalar fields and radiation, we
show that even in low energy-scale inflation nearly scale-invariant spectra of
scalar perturbations with an amplitude set by observations are obtained through
the conversion of $\chi$ fluctuations into adiabatic density perturbations. We
demonstrate that the spectra depend on the average decay rate of the inflaton &
on the inflaton fluctuations. We then apply this new mechanism to string
cosmologies & generalized Einstein theories and discuss the conditions under
which scale-invariant spectra are possible.


title: Meeting the Optical Requirements of Large Focal-Plane Arrays

abstract:
  Technological advances will allow the placement of many Terahertz detectors
at the focal plane of a single telescope. For a telescope of a given diameter
and wavelength of operation, there is a limit to the number of usable detectors
imposed by diffraction and optical aberrations. These effects can be
ameliorated through an optical design where the magnification of the
telescope's secondary mirror is small and the detector package is therefore
located near the secondary mirror. A field mirror can be used to flatten the
image, and the focal reducer which matches the detector to the telescope can
also provide an image of the aperture for placement of filters and stops. A
design concept is presented for the South Pole Telescope which comprises a
10-meter diameter off-axis paraboloidal primary mirror, a Gregorian secondary
mirror, a tertiary chopper, dewar widow, Lyot stops, band-pass filter, and
space behind the focal plane for cryogenics. The telescope is bilaterally
symmetric, and all apertures are unblocked. The field of view is one degree in
diameter, so this telescope can feed an array of several tens of thousands of
detectors at Terahertz frequencies.


title:
Evidence of a high velocity ionised outflow in a second narrow line
  quasar PG0844+349

abstract:
  Following the discovery of X-ray absorption in a high velocity outflow from
the bright quasar PG1211+143 we have searched for similar features in XMM
archival data of a second (high accretion rate) quasar PG0844+349. Evidence is
found for absorption lines in both the EPIC and RGS spectra, whose
identification with resonance transitions in H-like Fe, S, and Ne implies an
origin in highly ionised matter with an outflow velocity of order ~0.2c. The
line equivalent widths require a line-of-sight column density of N_H ~ 4 x
10^23 cm^-2, at an ionisation parameter of log(xi) ~ 3.7. Assuming a radial
outflow being driven by radiation pressure from the inner accretion disc, as
suggested previously for PG1211+143, the flow is again likely to be optically
thick, in this case within ~ 25 Schwarzschild radii. We suggest that a high
velocity, highly ionised outflow is likely to be a significant component in the
mass and energy budgets of many AGN accreting at or above the Eddington rate.


title:
Survival of Trojan-Type Companions of Neptune During Primordial Planet
  Migration

abstract:
  We investigate the survivability of Trojan-type companions of Neptune during
primordial radial migration of the giant planets Jupiter, Saturn, Uranus, and
Neptune. Loss of Neptune Trojans during planetary migration is not a random
diffusion process. Rather, losses occur almost exclusively during discrete
episodes when Trojan particles are swept by secondary resonances associated
with mean-motion commensurabilities of Uranus with Neptune. The single greatest
episode of loss ejects nearly 75% of existing Neptune Trojans and occurs just
prior to Neptune reaching its final orbit.


title:
Search for Very High Energy Gamma Rays from an X-ray Selected Blazar
  Sample

abstract:
  In recent years, blazar surveys at radio and X-ray energies have greatly
increased our understanding of this type of active galaxy. The combination of
multi-wavelength data has shown that blazars follow a well defined sequence in
terms of their broad band spectral properties. Together with increasingly
detailed emission models, this information has provided not only tools with
which to identify potential sources of TeV emission but also predictions of
their gamma-ray flux. A list of such candidates has been used in this work to
investigate the best targets for TeV observations. Observations reported here
have resulted in upper limits which do not conflict with the latest model
predictions.


title: Discovery of a New Pulsar Wind Nebula in the Large Magellanic Cloud

abstract:
  We present new high-resolution radio and X-ray observations of the supernova
remnant (SNR) B0453-685 in the Large Magellanic Cloud, carried out with the
Australia Telescope Compact Array and the Chandra X-ray Observatory
respectively. Embedded in the SNR shell is a compact central nebula producing
both flat-spectrum polarized radio emission and non-thermal X-rays; we identify
this source as a pulsar wind nebula (PWN) powered by an unseen central neutron
star. We present a new approach by which the properties of a SNR and PWN can be
used to infer upper limits on the initial spin period and surface magnetic
field of the unseen pulsar, and conclude that this star was an initial rapid
rotator with current properties similar to those of the Vela pulsar. As is the
case for other similarly-aged sources, there is currently an interaction taking
place between the PWN and the SNR's reverse shock.


title:
Search for TeV Emission at the Location of Milagro Sky Survey Hot Spot
  Using the Whipple Gamma-Ray Telescope

abstract:
  A recent report from the Milagro collaboration included an all-sky map
created using one year of data from Milagro (peak sensitivity at 3-4 TeV for
Crab-like spectra). This map included an unidentified excess that was brighter
than the Crab and was the second brightest spot on the map. The hot spot was
within the error box of the EGRET unidentified source 3EG J0520+2556. No strong
and steady emission was detected by the Whipple telescope at, or in the
vicinity of, either position. The 95% confidence level flux upper limits from
Whipple observations at the locations of the Milagro hot spot and the EGRET
UnID position are 0.09 Crabs and 0.14 Crabs, respectively.


title: Very High Energy Observations of PSR B1823-13

abstract:
  To date three plerionic systems have been detected as emitters of very
energetic photons. As part of an ongoing study of pulsar systems at the Whipple
observatory, observations of the plerion PSR B1823-13 are being conducted.
Observations were made with the Whipple 10 m gamma-ray telescope utilizing the
high resolution, 490 pixel camera.


title: Whipple observations of 1ES1959+650: an Update

abstract:
  Strong flares of TeV gamma-ray emission up to a level of ~5 Crab were
detected by the Whipple 10 m atmospheric Cerenkov telescope from the BL
Lacertae object 1ES1959+650 during May - July 2002. We report here the results
of follow up observations during 2002 - 2003.


title: VHE Observations of BL Lacertae Objects: 1995-2000

abstract:
  The results of observations of 29 BL Lacertae objects taken with the Whipple
Observatory 10 m gamma-ray Telescope between 1995 and 2000 are presented.


title:
Observations of H1426+428 from 1999 to 2002 with The Whipple Observatory
  10 m Telescope

abstract:
  The BL Lacertae object H1426+428 is the most distant, confirmed source of TeV
gamma rays. At a redshift of 0.129, its detection at TeV energies has important
implications for estimating the density of the extragalactic infra-red
background radiation. H1426+428 was observed extensively during the 2001/2002
observing season with the Whipple 10 m gamma-ray telescope. The results of
these observations are presented here and are combined with the results of
previous observations made between 1999 and 2001 at Whipple.


title:
A Search for Pulsed TeV Gamma-Ray Emission from the Crab Pulsar using
  the Whipple High Resolution GRANITE III Camera

abstract:
  We present the results of a search for pulsed TeV emission from the Crab
pulsar using 97 hours of data recorded with the high-resolution GRANITE III
camera of the Whipple 10 m gamma-ray telescope.


title:
Search for a WIMP annihilation signature in the core of the globular
  cluster M15

abstract:
  The Whipple 10m Very High Energy gamma-ray telescope has been used to search
for indications of WIMP annihilation in the direction of the globular cluster
M15. The upper limits derived constrain the amount of super-symmetric dark
matter that may reside in globular clusters.


title: Observation of M87 with the Whipple 10m telescope

abstract:
  The Whipple 10-m telescope was used to observe M87 since 2000. No significant
gamma-ray signal was found and upper limits compared to the HEGRA detection
suggest the source may be variable. We found weak evidence for a correlation
with the X-ray activity in 2000-2001 but this tendency did not persist in
2002-2003.


title:
Intensive TeV Gamma-Ray and X-Ray Observations of the Blazar Mrk 421 in
  December 2002 and January 2003

abstract:
  We report on observations of Markarian 421 made with the Whipple 10m Cerenkov
telescope and the RXTE satellite during a multi-wavelength campaign in December
2002 and January 2003, initiated by a Whipple target of opportunity. The
observations revealed several flares with flux levels between 1 and 2 times the
flux of the Crab Nebula. We will discuss the temporal properties, including
evidence of X-ray/TeV gamma-ray flux correlation.


title:
Search for TeV annihilation radiation from supersymmetric dark matter in
  nearby galaxies

abstract:
  During the 2002-2003 observing season the Whipple 10m imaging atmospheric
Cerenkov telescope was used to search for dark matter annihilation radiation in
four nearby galaxies: M32, M33, Draco, and Ursa Minor. Scientific motivations
for this choice of targets are discussed as well as accumulated exposure. The
analysis results are to be reported in the conference presentation.


title:
Whipple Telescope Observations of Potential TeV Gamma-Ray Sources Found
  by the Tibet Air Shower Array

abstract:
  An all-sky survey performed with the Tibet Air Shower Array (Tibet AS) has
found a number of potential point sources of TeV gamma rays. If they are steady
sources, the implied Tibet AS fluxes should be visible with strong significance
to the Whipple 10-m gamma-ray telescope (E > 400 GeV) with only a short (5
hour) exposure. We have observed four candidate directions from the Tibet-II HD
dataset for ~5 hours each with the Whipple telescope. In addition, we observed
a new candidate direction from the Tibet-III Phase 1 dataset for 7.5 hours. We
have found no corresponding excesses at the flux levels implied, and we have
set upper limits for each candidate.


title: The DEEP2 Galaxy Redshift Survey: Clustering of Galaxies in Early Data

abstract:
  We measure the two-point correlation function xi(r) using a sample of 2219
galaxies in an area of 0.32 degrees^2 at z=0.7-1.35 from the first season of
the DEEP2 Galaxy Redshift Survey. We find that xi(r) can be approximated by a
power-law, xi(r)=(r/r_0)^-gamma, on scales 0.1-20 Mpc/h. In a sample with an
effective redshift of z_eff=0.82, for a Lcdm cosmology we find r_0=3.53 +/-0.81
Mpc/h (comoving) and gamma=1.66 +/-0.12, while in a higher-redshift sample with
z_eff=1.14 we find r_0=3.14 +/-0.72 Mpc/h and gamma=1.61 +/-0.11. We find that
red, absorption-dominated, passively-evolving galaxies have a larger clustering
scale length, r_0, and more prominent ``fingers of God'' than blue,
emission-line, actively star-forming galaxies. Intrinsically brighter galaxies
also cluster more strongly than fainter galaxies at z~1, with a significant
luminosity-bias seen for galaxies fainter than M*. Our results are suggestive
of evolution in the galaxy clustering within our survey volume and imply that
the DEEP2 galaxies, with a median brightness one magnitude fainter than M* have
an effective bias b=0.97 +/-0.13 if sigma_{8 DM}=1 today or b=1.20 +/-0.16 if
sigma_{8 DM}=0.8 today. Given the strong luminosity-dependence in the bias that
we measure at z~1, the galaxy bias at M* may be significantly greater. We note
that our star-forming sample at z~1 has very similar selection criteria as the
Lyman-break galaxies at z~3 and that our red, absorption-line sample displays a
clustering strength comparable to the expected clustering of the Lyman-break
galaxy descendants at z~1. Our results demonstrate that the clustering
properties in the galaxy distribution seen in the local Universe were largely
in place by z~1.


title:
The DEEP2 Galaxy Redshift Survey: Spectral classification of galaxies at
  z~1

abstract:
  We present a Principal Component Analysis (PCA)-based spectral
classification, eta, for the first 5600 galaxies observed in the DEEP2 Redshift
Survey. This parameter provides a very pronounced separation between absorption
and emission dominated galaxy spectra - corresponding to passively evolving and
actively star-forming galaxies in the survey respectively. In addition it is
shown that despite the high resolution of the observed spectra, this parameter
alone can be used to quite accurately reconstruct any given galaxy spectrum,
suggesting there are not many `degrees of freedom' in the observed spectra of
this galaxy population. It is argued that this form of classification, eta,
will be particularly valuable in making future comparisons between high and
low-redshift galaxy surveys for which very large spectroscopic samples are now
readily available, particularly when used in conjunction with high-resolution
spectral synthesis models which will be made public in the near future. We also
discuss the relative advantages of this approach to distant galaxy
classification compared to other methods such as colors and morphologies.
Finally, we compare the classification derived here with that adopted for the
2dF Galaxy Redshift Survey and in so doing show that the two systems are very
similar. This will be particularly useful in subsequent analyses when making
comparisons between results from each of these surveys to study evolution in
the galaxy populations and large-scale structure.


title: CMB Signatures of Extended Reionization

abstract:
  I comment on the challenges and opportunities presented by an extended period
of reionization.


title: Barred Galaxies at z > 0.7: NICMOS HDFN Observations

abstract:
  Previous optical studies found an unexpected deficit of bars at z > 0.7. To
investigate the effects of bandshifting, we have studied the fraction of barred
spirals in the NICMOS Deep Field North. At z > 0.7 we find at least four barred
spirals, doubling the number previously detected. The number of barred galaxies
is small because these (and previous) data lack adequate spatial resolution. A
typical 5 kpc bar at z > 0.7 is only marginally detectable for WFPC2 at
0.8microns; the NICMOS data have even lower resolution and can only find the
largest bars. The average size of the four bars seen at z > 0.7 is 12 kpc. The
fraction of such large bars (4/95) is higher than that seen in nearby spirals
(1/44); all known selection effects suggest that the observed fraction is a
lower limit. However, important caveats such as small numbers and difficulties
in defining comparable samples at high and low redshifts should be noted. We
conclude that there is no significant evidence for a decrease in the fraction
of barred spirals beyond z ~ 0.7.


title: The Large-Scale Polarization of the Microwave Foreground

abstract:
  Most of the useful information about inflationary gravitational waves and
reionization is on large angular scales where Galactic foreground contamination
is the worst, so a key challenge is to model, quantify and remove polarized
foregrounds. We use the Leiden radio surveys to quantify the polarized
synchrotron radiation at large angular scales, which is likely to be the most
challenging polarized contaminant for the WMAP satellite. We find that the
synchrotron E- and B-contributions are equal to within 10% from 408-820MHz with
a hint of E-domination at higher frequencies. We quantify Faraday Rotation &
Depolarization effects and show that they cause the synchrotron polarization
percentage to drop both towards lower frequencies and towards lower multipoles.


title: Theoretical Overview of Cosmic Microwave Background Anisotropy

abstract:
  The theoretical basis for the prediction of anisotropies in the cosmic
microwave background is very well developed. Very low amplitude density and
temperature perturbations produce small gravitational effects, leading to an
anisotropy that is a combination of temperature fluctuations at the surface of
last scattering and gravitational redshifts both at last scattering and along
the path to the observer. All of the primary anisotropy can be handled by
linear perturbation theory, which allows a very accurate calculation of the
predicted anisotropy from different models of the Universe.


title: TeV Observations of the Galactic Center

abstract:
  We present the results of 16 hours of ongoing observations of the galactic
center region (including Sagittarius A*) with the Whipple High Energy Gamma-Ray
Telescope. We apply a data analysis method optimized for large zenith angle
observations on an independent Crab Nebula data set. We discuss possible
systematic problems associated with observations of extended sources in the
galactic plane.


title: Measuring CMB Polarization with BOOMERANG

abstract:
  BOOMERANG is a balloon-borne telescope designed for long duration (LDB)
flights around Antarctica. The second LDB Flight of BOOMERANG took place in
January 2003. The primary goal of this flight was to measure the polarization
of the CMB. The receiver uses polarization sensitive bolometers at 145 GHz.
Polarizing grids provide polarization sensitivity at 245 and 345 GHz. We
describe the BOOMERANG telescope noting changes made for 2003 LDB flight, and
discuss some of the issues involved in the measurement of polarization with
bolometers. Lastly, we report on the 2003 flight and provide an estimate of the
expected results.


title:
On Gas-Drag Induced Rapid Migration of Solids in a Non-Uniform Solar
  Nebula

abstract:
  We study the motions of small solids, ranging from micron-sized dust grains
to meter-sized objects, in the vicinity of local pressure enhancements of a
gaseous nebula. Integrating numerically, we show that as a result of the
combined effect of gas drag and pressure gradients, solids tend to accumulate
at the locations where the pressure of the gas maximizes. The rate of migration
of solids varies with their sizes and densities and also with the physical
properties of the gas. The results of our numerical simulations indicate that
such migrations are most rapid for meter-sized objects. The applicability of
the results to the enhancement of the collision and coagulation of solids and
also to the growth-rate of planetesimals is discussed.


title: Generation of large scale magnetic fields at recombination epoch

abstract:
  It is argued that large scale cosmic magnetic field could be generated in the
primeval plasma slightly before hydrogen recombination. Non-zero vorticity,
necessary for that, might be created by the photon diffusion in the second
order in the temperature fluctuations. The resulting seed fields at galactic
scale would be only 4 orders of magnitude smaller than the observed ones and
with a mild galactic dynamo amplifying the seed fields by the factor $\sim
10^4$ an existence of coherent magnetic fields in galaxies may be explained.


title:
The effects of the Tidal Force on Shear Instabilities in the Dust Layer
  of the Solar Nebula

abstract:
  The linear analysis of the instability due to vertical shear in the dust
layer of the solar nebula is performed. The following assumptions are adopted
throughout this paper: (1) The self-gravity of the dust layer is neglected. (2)
One fluid model is adopted, where the dust aggregates have the same velocity
with the gas due to strong coupling by the drag force. (3) The gas is
incompressible.
  The calculations with both the Coriolis and the tidal forces show that the
tidal force has a stabilizing effect. The tidal force causes the radial shear
in the disk. This radial shear changes the wave number of the mode which is at
first unstable, and the mode is eventually stabilized. Thus the behavior of the
mode is divided into two stages: (1) the first growth of the unstable mode
which is similar to the results without the tidal force, and (2) the subsequent
stabilization due to an increase of the wave number by the radial shear. If the
midplane dust/gas density ratio is smaller than 2, the stabilization occurs
before the unstable mode grows largely. On the other hand, the mode grows
faster by one hundred orders of magnitude, if this ratio is larger than 20.
  Because the critical density of the gravitational instability is a few
hundreds times as large as the gas density, the hydrodynamic instability
investigated in this paper grows largely before the onset of the gravitational
instability. It is expected that the hydrodynamic instability develops
turbulence in the dust layer and the dust aggregates are stirred up to prevent
from settling further. The formation of planetesimals through the gravitational
instabilities is difficult to occur as long as the dust/gas surface density
ratio is equal to that for the solar abundance.


title: Two years of detecting DM objects - the Solar system members

abstract:
  With a probability >99% there are grounds to believe that our works on
detection of the Dark Electric Matter Objects (daemons), which were lauched in
1996, are crowned with success. The daemons are the relic elementary Planckian
black holes(m~30 microgramme) carrying stable electric charge of Ze=10e. During
the last two years, the detector made of two horizontal ZnS(Ag) screens of 1
m^2 area has been recording the correlated time-shifted scintillations
corresponding to flux 10^-5 m^-2 s^-1 of extraordinary penetrating
nuclear-active particles which moved both down and upward with velocity of only
\~5-30 km/s. The flux experiences seasonal variations with maxima supposedly
corresponding to the Earth transition through shadow and anti-shadow created by
the Sun in its motion relative the Galaxy disk daemon population. An
accumulation of negative daemons, which stimulate the proton decay in ~1
microsec, inside the Earth and the Sun is explaining a lot of previusly
non-understandable facts.


title: Non-spherical evolution of the line-driven wind instability

abstract:
  In this paper, we study the structure and stability of line driven winds
using numerical hydrodynamic simulations. We calculate the radiation force from
an explicit non-local solution of the radiation transfer equation, rather than
a Sobolev approximation, without restricting the flow to one-dimensional
symmetry. We find that the solutions which result have complex and highly
variable structures, including dense condensations which we compare to observed
variable absorption features in the spectra of early type stars.


title: Young close-by neutron stars: the Gould Belt vs. the Galactic disc

abstract:
  We present new population synthesis calculations of close young neutron
stars. In comparison with our previous investigation we use a different neutron
star mass spectrum and different initial spatial and velocity distributions.
The results confirm that most of ROSAT dim radioquiet isolated neutron stars
had their origin in the Gould Belt. Several tens of young neutron stars can be
identified in future in ROSAT data at low galactic latitudes and some of them
also can be EGRET unidentified sources.


title: A multiband study of Hercules A. II. Multifrequency VLA imaging

abstract:
  We have mapped the powerful radio galaxy Hercules A at six frequencies
spanning 1295 to 8440 MHz using the VLA in all four configurations. Here we
discuss the structure revealed in total intensity, spectral index,
polarization, and projected magnetic field. Our observations clearly reveal the
relation between the bright jets, radio source. The jets and rings form a
coherent structure with a dramatically flatter spectrum than the surrounding
lobes and bridge, strongly suggesting that they represent a recently renewed
outburst from the active nucleus. The spectrum of the lobes is also steeper
than in typical radio sources, and steepens further towards the centre. The
compact core is optically thin and also has a remarkably steep spectrum (alpha
\~ -1.2). There is some evidence that the old lobe material has been swept up
and compressed ahead of the new outburst. We interpret the dramatic asymmetry
in the bright structure, and more subtle differences between diffuse lobe
structures, in terms of relativistic beaming combined with front-to-back
light-travel delays which mean that we view the two lobes at different stages
of the outburst. After correcting for Faraday rotation the projected magnetic
field closely follows the edge of the lobes, the jets, and the rings; the field
pattern in the two lobes is broadly similar. We confirm a strong asymmetry in
depolarization and Faraday rotation, with the jet side the less depolarized and
the flatter spectrum, consistent with general correlations between these
asymmetries. The spectral index asymmetry is clearly present in the `old' lobe
material and so, at least in this case, is not due to beaming; but it can be
understood in terms of the light-travel delay.


title: The core/envelope symmetry in pulsating stars

abstract:
  We demonstrate that there is an inherent symmetry in the way high-overtone
stellar pulsations sample the core and the envelope, which can potentially lead
to an ambiguity in the asteroseismologically derived locations of internal
structures. We provide an intuitive example of the source of this symmetry by
analogy with a vibrating string. For the stellar case, we focus on the white
dwarf stars, establishing the practical consequences for high-order white dwarf
pulsations both analytically and numerically. In addition, we verify the effect
empirically by cross-fitting two different structural models, and we discuss
the consequences that this approximate symmetry may have for past and present
asteroseismological fits of the pulsating DBV, GD 358. Finally, we show how the
signatures of composition transition zones that are brought about by physically
distinct processes may be used to help alleviate this potential ambiguity in
our asteroseismological interpretation of the pulsation frequencies observed in
white dwarf stars.


title: The Secular Evolution of the Primordial Kuiper Belt

abstract:
  A model that computes the secular evolution of a gravitating disk-planet
system is developed. The disk is treated as a set of gravitating rings, with
the rings'/planets' time-evolution governed by the classical Laplace-Lagrange
solution for secular evolution but modified to account for the disk's finite
thickness h. This system's Lagrange planetary equations yield a particular
class of spiral wave solutions, usually denoted as apsidal density waves and
nodal bending waves. There are two varieties of apsidal waves:long waves and
short waves. Planets typically launch long density waves at the disk's nearer
edge or else at a secular resonance in the disk, and these waves ultimately
reflect downstream at a more distant disk edge or else at a Q-barrier in the
disk, whereupon they return as short density waves. Planets also launch nodal
bending waves, and these have the property that they can stall in the disk,
that is, their group velocity plummets to zero upon approaching a disk region
too thick to support the continued propagation of bending waves. The rings
model is used to compute the secular evolution of a Kuiper Belt having a
variety of masses, and it is shown that the early massive Belt was very
susceptible to the propagation of low-amplitude apsidal and nodal waves
launched by the giant planets.


title:
Angular Clustering with Photometric Redshifts in the Sloan Digital Sky
  Survey: Bimodality in the Clustering Properties of Galaxies

abstract:
  Understanding the clustering of galaxies has long been a goal of modern
observational cosmology. Utilizing our photometric redshift technique a volume
limited sample containing more than 2 million galaxies is constructed from the
SDSS galaxy catalog. In the largest such analysis to date, we study the angular
clustering as a function of luminosity and spectral type. Using Limber's
equation we calculate the clustering length for the full data set as
r0=5.77+/-0.10 Mpc/h. We find that r0 increases with luminosity by a factor of
1.6 over the sampled luminosity range, in agreement with previous redshift
surveys. We also find that both the clustering length and the slope of the
correlation function depend on the galaxy type. In particular, by splitting the
galaxies in four groups by their rest-frame type we find a bimodal behavior in
their clustering properties. Galaxies with spectral types similar to elliptical
galaxies have a correlation length of 6.59 +/- 0.17 Mpc/h and a slope of the
angular correlation function of 0.96 +/- 0.05 while blue galaxies have a
clustering length of 4.51 +/- 0.19 Mpc/h and a slope of 0.68 +/- 0.09. The two
intermediate color groups behave like their more extreme 'siblings', rather
than showing a gradual transition in slope. We discuss these correlations in
the context of current cosmological models for structure formation.


title:
SCUBA Polarization Measurements of the Magnetic Field Strengths in the
  L183, L1544, and L43 Prestellar Cores

abstract:
  We have mapped linearly polarized dust emission from L183 with the JCMT SCUBA
polarimeter and have analyzed these and our previously published data for the
prestellar cores L183, L1544, and L43 in order to estimate magnetic field
strengths in the plane of the sky, $B_{pos}$. The analysis used the
Chandrasekhar-Fermi technique, which relates the dispersion in polarization
position angles to $B_{pos}$. We have used these estimates of the field
strengths (neglecting the unmeasured line-of-sight component) to find the
mass-to-magnetic flux ratios $\lambda$ (in units of the critical ratio for
magnetic support). Results are $B_{pos} \approx 80$ $\mu$G and $\lambda \approx
2.6$ for L183, $B_{pos} \approx 140$ $\mu$G and $\lambda \approx 2.3$ for
L1544, and $B_{pos} \approx 160$ $\mu$G and $\lambda \approx 1.9$ for L43.
Hence, without correction for geometrical biases, for all three cores the
mass-to-flux ratios are supercritical by a factor of $\sim 2$, and magnetic
support cannot prevent collapse. However, a statistical mean correction for
geometrical bias may be up to a factor of three; this correction would reduce
the individual $\lambda$'s to $\lambda_{cor} \approx 0.9$, 0.8, and 0.6,
respectively; these values are approximately critical or slightly subcritical.
These data are consistent with models of star formation driven by ambipolar
diffusion in a weakly turbulent medium, but cannot rule out models of star
formation driven by turbulence.


title:
Strong Gravitational Lensing and Localization of Merging Massive Black
  Hole Binaries with LISA

abstract:
  We study how the angular resolution of LISA for merging massive black-hole
binaries would be improved if we observe multiple gravitational wave ``images''
due to strong gravitational lensing. The correlation between fitting parameters
is reduced by the additional information of the second image which
significantly reduces the error box on the sky. This improvement would be very
helpful for identifying the host galaxy of a binary. The angular resolution
expected with multiple detectors is also discussed.


title:
On the Presence of Thermal SZ Induced Signal in the First Year WMAP
  Temperature Maps

abstract:
  Using available optical and X-ray catalogues of clusters and superclusters of
galaxies, we build templates of tSZ emission as they should be detected by the
WMAP experiment. We compute the cross-correlation of our templates with WMAP
temperature maps, and interpret our results separately for clusters and for
superclusters of galaxies. For clusters of galaxies, we claim 2-5 $\sigma$
detections in our templates built from BCS Ebeling et al. (1998), NORAS
(Boehringer et al. 2000) and de Grandi et al. (1999) catalogues. In these
templates, the typical cluster temperature decrements in WMAP maps are around
15-35 $\mu$K in the RJ range (no beam deconvolution applied). Several tests
probing the possible influence of foregrounds in our analyses demonstrate that
our results are robust against galactic contamination. On supercluster scales,
we detect a diffuse component in the V & W WMAP bands which cannot be generated
by superclusters in our catalogues (Einasto et al. 1994, 1997), and which is
not present in the clean map of Tegmark, de Oliveira-Costa & Hamilton (2003).
Using this clean map, our analyses yield, for Einasto's supercluster
catalogues, the following upper limit for the comptonization parameter
associated to supercluster scales: $y_{SC} < 2.18 \time s 10^{-8}$ at the 95%
confidence limit.


title:
Investigating the Sloan Digital Sky Survey Cataclysmic Variable SSDS
  J132723.39+652854.2

abstract:
  Photometric and spectroscopic observations reveal the Sloan Digital Sky
Survey cataclysmic variable SDSS J132723.39+652854.2 to be a likely SW Sex star
with an orbital period of P = 3.28 hours. The Sloan Digital Sky Survey spectrum
shows strong HeI, HeII and Balmer emission lines. Time resolved spectra
acquired at Apache Point Observatory reveal absorption-line structure within
the emission lines near phase 0.5. Photometric data obtained at Manastash Ridge
Observatory using Harris V and B filters reveal a high inclination system (i =
80 degrees) with deep (~ 2 mag.) eclipses. The orbital period and the spectral
variations favor an SW Sex interpretation.


title:
COMPASS: An Instrument for Measuring the Polarization of the CMB on
  Intermediate Angular Scales

abstract:
  COMPASS is an on-axis 2.6 meter telescope coupled to a correlation
polarimeter. The entire instrument was built specifically for CMB polarization
studies. Careful attention was given to receiver and optics design, stability
of the pointing platform, avoidance of systematic offsets, and development of
data analysis techniques. Here we describe the experiment, its strengths and
weaknesses, and the various things we have learned that may benefit future
efforts to measure the polarization of the CMB.


title: The Short Rotation Period of Nereid

abstract:
  We determine the period, p = 11.52 \pm 0.14 h, and a light curve peak-to-peak
amplitude, a = 0.029 \pm 0.003 magnitudes, of the Neptunian irregular satellite
Nereid. If the light curve variation is due to albedo variations across the
surface, rather than solely to the shape of Nereid variations, the rotation
period would be a factor of two shorter. In either case, such a rotation period
and light curve amplitude, together with Nereid's orbital period, p=360.14
days, imply that Nereid is almost certainly in a regular rotation state, rather
than the chaotic rotation state suggested by Schaefer and Schaefer (1988,2000)
and Dobrovolskis (1995).
  Assuming that Nereid is perfectly spherical, the albedo variation is 3%
across the observed surface. Assuming a uniform geometric albedo, the observed
cross sectional area varies by 3%. We caution that the lightcurve found in this
paper only sets limits on the combination of albedo and physical irregularity
and that we cannot determine the orientation of Nereid's spin axis from our
data.


title: The CAPMAP Instrument and its First Season

abstract:
  I describe here the new CAPMAP (Cosmic Anisotropy Polarization MAPer)
instrument, which performed its first season of observing between February and
April 2003 from the Crawford Hill 7-meter antenna in NJ. CAPMAP is based on the
design for the PIQUE instrument, but has better sensitivity and superior
angular resolution.


title: Separating E from B

abstract:
  In a microwave background polarization map that covers only part of the sky,
it is impossible to separate the E and B components perfectly. This difficulty
in general makes it more difficult to detect the B component in a data set. Any
polarization map can be separated in a unique way into "pure E," "pure B," and
"ambiguous" components. Power that resides in the pure E (B) component is
guaranteed to be produced by E (B) modes, but there is no way to tell whether
the ambiguous component comes from E or B modes. A polarization map can be
separated into the three components either by finding an orthonormal basis for
each component, or directly in real space by using Green functions or other
methods.


title: Entropy perturbations in quartessence Chaplygin models

abstract:
  We show that entropy perturbations can eliminate instabilities and
oscillations, in the mass power spectrum of the quartessence Chaplygin models.
Our results enlarge the current parameter space of models compatible with large
scale structure and cosmic microwave background (CMB) observations.


title:
Variable NaI Absorption toward rho Leo : Biased Neutral Formation in the
  Diffuse Interstellar Medium?

abstract:
  We present multi-epoch KPNO Coude Feed observations of interstellar NaI and
CaII absorption toward the bright star rho Leo. Comparisons of the NaI profiles
observed over a period of 8 years reveal significant temporal variations in the
NaI column in at least one component, implying that there is ``structure'' at
scales of order of the proper motion (~12 AU). Archival HST Goddard High
Resolution Spectrograph observations of the CI fine-structure excitation in the
variable component suggest that the density is <20 cm-3, significantly lower
than the densities inferred in past HI 21 cm and NaI studies. We suggest that
the bulk of the trace neutral species are in the density peaks within an
interstellar cloud. The patchy distribution of these species naturally gives
rise to the large fluctuations seen on scales of 10--1,000 AU in past temporal
and binary studies. This picture predicts that the scales over which
fluctuations will be observed vary as a function of the ionization rate of a
species.


title: Non-Gaussianities in models with a varying inflaton decay rate

abstract:
  We consider the expected level of primordial non-Gaussianities in models in
which density perturbations are produced by spatial fluctuations in the decay
rate of the inflaton. We consider both the non-Gaussianities resulting from the
self-couplings of the field that controls the decay rate as well as from the
non-linear relation between field and curvature perturbations. We show that in
these scenario non-Gaussianities are of the "local" form, that is well
described be the ansatz R =Rg + f_{NL} (Rg^2 - <Rg^2>). This is a consequence
of the fact that they were created when modes were already outside the horizon.
We show that f_{NL} is naturally of order a few in these models, much larger
than what is expected in the standard one field models of inflation (f_{NL}\sim
10^{-2}) and possibly accessible to observations.


title:
A study of the appearance of tau neutrinos from a gamma ray burst by
  detecting their horizontal electromagnetic showers

abstract:
  We explore the possibilty of detecting horizontal electromagnetic showers of
tau neutrinos from individual gamma ray bursts, in large scale detectors like
  HiRes and Telescope Array. We study the role of the parameters of a gamma ray
burst in determining the expected number of tau events from that burst. The
horizontal beam of tau leptons produce visible signals in the atmosphere. We
find that there is a slim chance of observing tau lepton appearances from GRBs
with Telescope Array. The number of signals is strongly dependent on the
Lorentz factor $\Gamma$, redshift $z$ of a GRB, energy emitted in muon
neutrinos and antineutrinos $E_{\nu,HE}$ and also on some other parameters of a
GRB. It is possible to understand neutrino oscillations in astrophysical
neutrinos and the mechanism or model of neutrino production inside a GRB by
detection or non detection of tau lepton signals from it.


title:
X-ray Modeling of Very Young Early Type Stars in the Orion Trapezium:
  Signatures of Magnetically Confined Plasmas and Evolutionary Implications

abstract:
  We analyzed high resolution X-ray spectra in the wavelength range of 1.5 --
25 A of three of its X-ray brightest members obtained with the High Energy
Transmission Grating Spectrometer (HETGS) on-board the Chandra X-ray
Observatory. The DEM derived from over 80 emission lines in the spectrum of
Theta Ori C indicates three peaks located at 7.9 MK, 25 MK, and 66 MK. The
emission measure varies over the 15.4 day wind period of the star. For the two
phases observed, the low temperature emission remains stable, while the high
temperature emission shows significant differences. The line widths seem to
show a similar bifurcation, where we resolve some of the soft X-ray lines with
velocities up to 850 km/s, whereas the bulk of the lines remain unresolved.
None of the lines are resolved for Theta Ori A and E. The high temperature
emissivity contributes to most of the total X-ray flux in all stars. The bulk
of the X-ray emission cannot be produced by shock instabilities in a radiation
driven wind and are likely the result of magnetic confinement in all three
stars. The fact that all stars appear to be magnetic and are near zero age on
the main sequence also raises the issue whether the Orion stars are simply
different or whether young massive stars enter the main sequence carrying
significant magnetic fields.


title: Negative heat capacity and non-extensive kinetic theory

abstract:
  The negative nature of the heat capacity $C_V$ of thermodynamically isolated
self-gravitating systems is rediscussed in the framework of a non-extensive
kinetic theory. It is found that the dependence of $C_V$ on the non-extensive
parameter $q$ gives rise to a negative branch with the critical value
corresponding to $q = 5/3$ ($C_V\to - \infty$).


title: The Ku-band Polarization Identifier

abstract:
  The Ku-band Polarization Identifier (KUPID) will integrate a very low noise
12-18 GHz, correlation polarimeter onto the Crawford Hill seven meter,
millimeter-wave antenna. The primary components of the polarimeter will be
built at the University of Miami and other key components, including the
microwave horn and data acquisition system will be built at the University of
Chicago and Princeton University. This project will measure the Q and U Stokes
parameters in regions near the north celestial pole, in regions of low galactic
contamination, and in regions near the galactic plane. The KUPID survey
experiment makes use of many of the techniques employed in the Princeton IQU
Experiment (PIQUE) that was developed by the members of this collaboration to
detect CMB polarization at shorter wavelengths. The KUPID experiment will be
constructed in parallel and on the same timescale as the CAPMAP experiment (see
Barkats, this volume) which is the follow-on experiment to PIQUE. KUPID will
observe on the Crawford Hill antenna from late spring until early autumn, while
CAPMAP will observe during the lower water vapor months of late autumn until
early spring.


title: Is the Pre-WMAP CMB Data Self-consistent?

abstract:
  Although individual observational groups vigorously test their data sets for
systematic errors, the pre-WMAP CMB observational data set has not yet been
collectively tested. Under the assumption that the concordance model is the
correct model, we have explored residuals of the observational data with
respect to this model to see if any patterns emerge that can be identified with
systematic errors. We found no significant trends associated with frequency,
frequency channels, calibration source, pointing uncertainty, instrument type,
platform and altitude. We did find some evidence at the ~ 1 to ~ 2 sigma level
for trends associated with angular scale (l range) and absolute galactic
latitude. The slope of the trend in galactic latitude is consistent with low
level galactic contamination. The residuals with respect to l may indicate that
the concordance model used here needs slight modification. See Griffiths &
Lineweaver (2003) for more detail.


title:
Warping of Accretion Disks with Magnetically Driven Outflows: A Possible
  Origin for Jet Precession

abstract:
  Current theoretical models for the outflows/jets from AGN, X-ray binaries and
young stellar objects involve large-scale magnetic fields threading an
underlying accretion disk. We suggest that such a disk is subjected to warping
instability and retrograde precession driven by magnetic torques associated
with the outflow. The growth timescale for the disk warp and the precession
period are of order the radial infall time of the disk. These effects may be
relevant to jet precession and other variabilities observed in many systems.


title: Modulational instabilities in neutrino--anti-neutrino interactions

abstract:
  We analyze the collective behavior of neutrinos and antineutrinos in a dense
background. Using the Wigner transform technique, it is shown that the
interaction can be modelled by a coupled system of nonlinear Vlasov-like
equations. From these equations, we derive a dispersion relation for
neutrino-antineutrino interactions on a general background. The dispersion
relation admits a novel modulational instability. The results are examined,
together with a numerical example, and we discuss the induced density
inhomogeneities using parameters relevant to the early Universe.


title:
Non coeval young multiple systems? On the pairing of protostars and T
  Tauri stars

abstract:
  We summarize here the observed properties of ``infrared companions'' to T
Tauri stars and argue that their observational properties are identical to
those of Class I sources. They may therefore be embedded protostars in a much
earlier evolutionary phase than T Tauri stars, in which case these multiple
systems are significantly non-coeval as opposed to the majority of young binary
systems. They would have formed through a different mechanism than core
fragmentation. The only distinction between IRCs and Class I sources is that
they lie within a few tens of AU of a T Tauri star, and so they cannot be at
the center of a vast optically thick envelope as is believed to be the case for
protostars. We discuss whether systems with an IRC are really candidates for
non-coeval multiple systems.


title:
Tests of Statistical Significance and Background Estimation in Gamma Ray
  Air Shower Experiments

abstract:
  In this paper we discuss several methods of significance calculation and
point out the limits of their applicability. We then introduce a self
consistent scheme for source detection and discuss some of its properties. The
method allows incorporating background anisotropies by vetoing existing small
scale regions on the sky and compensating for known large scale anisotropies.
By giving an example using Milagro gamma ray observatory we demonstrate how the
method can be employed to relax the detector stability assumption. Two
practical implementations of the method are discussed. The method is universal
and can be used with any large field-of-view detector, where the object of
investigation, steady or transient, point or extended, traverses its field of
view.


title: Variation of cosmic ray injection across supernova shocks

abstract:
  The injection rate of suprathermal protons into the diffusive shock
acceleration process should vary strongly over the surface of supernova remnant
shocks. These variations and the absolute value of the injection rate are
investigated. In the simplest case, like for SN 1006, the shock can be
approximated as being spherical in a uniform large-scale magnetic field. The
injection rate depends strongly on the shock obliquity and diminishes as the
angle between the ambient field and the shock normal increases. Therefore
efficient particle injection, which leads to conversion of a significant
fraction of the kinetic energy at a shock surface element, arises only in
relatively small regions near the "poles", reducing the overall CR production.
The sizes of these regions depend strongly on the random background field and
the Alfven wave turbulence generated due to CR streaming instability. For the
cases of SN 1006 and Tycho's SNR they correspond to about 20, and for Cas A to
between 10 and 20 percent of the entire shock surface. In first approximation,
the CR production rate, calculated under the assumption of spherical symmetry,
has therefore to be renormalized by this factor, while the shock as such
remains roughly spherical.


title: New Classes of Cosmic Energy and Primordial Black-Hole Formation

abstract:
  It has recently been suggested that the formation of horizon-size primordial
black hole (PBH) from pre-existing density fluctuations is effective during the
cosmic QCD phase transition.
  In this Letter we discuss the dependence of PBH formation on effective
relativistic degrees of freedom, $g_{\rm eff}$ during the cosmic QCD phase
transition.
  Our finding is important in the light of recent cosmological arguments of
several new classes of cosmic energy that appear from universal neutrino
degeneracy, quintessential inflation, and dark radiation in brane world
cosmology. Extra-energy component from the standard value in these new
cosmological theories is represented as an effective radiation in terms of
$g_{\rm eff}$. We conclude that the PBH formation during QCD phase transition
becomes more efficient if negative extra-component of the cosmic energy is
allowed because of the increase of the duration of the QCD phase transition,
which leads to smaller mass scale of PBHs. This suggests larger probability of
finding more PBHs if the dark radiation exists as allowed in the brane world
cosmology.


title: Gravitational Thomas Precession and the Perihelion Advance of Mercury

abstract:
  Gravitational Thomas Precession (GTP) is the name given to Thomas Precession
when the acceleration is caused by a gravitational force field. The GTP gives a
negative contribution of 7.163 arcsec/century for the anomalous perihelion
advance of Mercury's orbit. This effect seems to be of some concern for the
General Relativity.


title:
Spectroscopy, Photometry and Micro-arcsec Astrometry of Binaries with
  the GAIA Space Mission and with the RAVE Experiment

abstract:
  GAIA astrometric mission of ESA will be very efficient in discovering binary
and multiple stars with any orbital period, from minutes to millions of years.
Main parameters of the revised mission design are presented. Next we estimate
the fraction of binary stars discovered by means of astrometry, photometry and
on-board spectroscopy. Finally we summarize observations that confirm the
ability to measure physical parameters like masses, radii and spectroscopic
distance from GAIA data alone. GAIA will fly only in 2010, but the Radial
velocity experiment (RAVE) has started this year. We show that its
spectroscopic observations have the capacity to discover a large fraction of so
far unknown binary systems.


title: Decaying Cold Dark Matter and the Evolution of the Cluster Abundance

abstract:
  The cluster abundance and its redshift evolution are known to be a powerful
tool to constrain the amplitude of mass fluctuations \sigma_8 and the mass
density parameter \Omega_m0. We study the impact of the finite decay rate of
cold dark matter particles on the cluster abundances. On the basis of spherical
model in decaying cold dark matter universe, we calculate the mass function of
clusters and compare it with observed cluster abundance. We find the decay of
cold dark matter particles significantly changes the evolution of the cluster
abundance. In particular, we point out that the lifetime of dark matter
particles comparable to the age of the universe lowers the ratio of the local
cluster abundance to the high-redshift cluster abundance and can account for
the observed evolution of the cluster abundance quite well. The strong
dependence of the cluster abundance on the decay rate of dark matter suggests
that distant cluster surveys may offer clues to the nature of dark matter.


title: The inner properties of late-type galaxies

abstract:
  I review some recent results on the inner properties of disk galaxies, and
highlight some issues that require either observational or theoretical
clarification and that are important for constructing a consistent picture of
the formation of the local disk galaxy population.


title: A CCD Time-Series Photometer

abstract:
  We describe a high speed time-series CCD photometer for the prime focus of
the 82-in (2.1 m) telescope at McDonald Observatory, and summarize the
observational results we have obtained since it was placed into regular use in
February, 2002. We compare this instrument with the three-channel time-series
photometers we have previously used in the asteroseismological study of
pulsating white dwarf stars, which used photomultiplier tubes (PMT) as the
detectors. We find the CCD instrument is about 9 times more sensitive than the
PMT instruments used on the same telescope for the same exposure time. We can
therefore find and measure variable white dwarf stars some 2.4 magnitudes
fainter than before, significantly increasing the number of such objects
available for study.


title:
A New Empirical Model for the Structural Analysis of Early-type Galaxies
  and a Critical Review of the Nuker Model

abstract:
  The Nuker law was designed to match the inner few (~3-10) arcseconds of
predominantly nearby (< 30 Mpc) early-type galaxy light-profiles; it was never
intended to describe an entire profile. The Sersic model, on the other hand,
was developed to fit the entire profile; however, due to the presence of
partially depleted galaxy cores, the Sersic model cannot always describe the
very inner region. We have therefore developed a new empirical model consisting
of an inner power-law, a transition region, and an outer Sersic model to
connect the inner and outer structure of elliptical galaxies. Moreover, the
stability of the Nuker model parameters are investigated. Surprisingly, none
are found to be stable quantities; all are shown to vary systematically with a
profile's fitted radial extent, and often by more than 100%. Considering
elliptical galaxies spanning a range of 7.5 magnitudes, the central stellar
density of the underlying host galaxy is observed to increase with galaxy
luminosity until the onset of core formation, detected only in the brightest
elliptical galaxies. We suggest that the so-called ``power-law'' galaxies may
actually be described by the Sersic model over their entire radial range.


title:
Optical Flash of GRB 990123: constraints on the physical parameter of
  the reverse shock

abstract:
  The optical flash accompanying GRB 990123 is believed to be powered by the
reverse shock of a thin shell. With the best fitted physical parameters for GRB
990123 (Panaitescu & Kumar 2001) and the assumption that the parameters in the
optical flash are the same as those in the afterglow, we show that: 1) the
shell is thick but not thin, and we have provided the light curve for the thick
shell case which coincides with the observation; 2) the theoretical peak flux
of the optical flash accounts for only 3\times10^{-4} of the observed. In order
to compensate this divergency, the physical parameters the electron energy
ration and the magnetic ratio $\epsilon_e$, $\epsilon_B$ should be 0.61, 0.39
respectively, which are much different from those in the late afterglow.


title: VY Scl-Type Star V504 Cen

abstract:
  V504 Cen was classified as a possible R CrB-type star. Although this object
has been spectroscopically confirmed to be a cataclysmic variable, no detailed
study has been yet published. We show, from long-term visual observations and
ASAS-3 public CCD data, that the light variation of V504 Cen is that of a
typical VY Scl-type cataclysmic variable. This report for the first time
presents a light curve and description of this overlooked rare bright VY
Scl-type object.


title:
A class of compact dwarf galaxies from disruptive processes in galaxy
  clusters

abstract:
  Dwarf galaxies have attracted increased attention in recent years, because of
their susceptibility to galaxy transformation processes within rich galaxy
clusters. Direct evidence for these processes, however, has been difficult to
obtain, with a small number of diffuse light trails and intra-cluster stars
being the only signs of galaxy disruption. Furthermore, our current knowledge
of dwarf galaxy populations may be very incomplete, because traditional galaxy
surveys are insensitive to extremely diffuse or compact galaxies. Aware of
these concerns, we recently undertook an all-object survey of the Fornax galaxy
cluster. This revealed a new population of compact members, overlooked in
previous conventional surveys. Here we demonstrate that these 'ultra-compact'
dwarf galaxies are structurally and dynamically distinct from both globular
star clusters and known types of dwarf galaxy, and thus represent a new class
of dwarf galaxy. Our data are consistent with the interpretation that these are
the remnant nuclei of disrupted dwarf galaxies, making them an easily observed
tracer of galaxy disruption.


title:
On the p-mode asymmetry between velocity and intensity from the GONG+
  data

abstract:
  We have analyzed the local acoustic spectra of small regions over the solar
surface at different locations from disk center to limb via the technique of
ring diagrams. It is found that the frequency shifts between velocity and
intensity is a function of location on the disk and is higher near the disk
center than those near the limb.


title: Solar cycle variation in GONG and MDI data: 1995-2002

abstract:
  Both GONG and MDI projects have measured {\it p}-mode frequencies of the Sun
for more than 7 years. Here we review what we have learnt from the temporal
variation of the oscillation frequencies and splitting coefficients.


title: Neutron-Rich Hydromagnetic Outflows in Gamma-Ray Burst Sources

abstract:
  We demonstrate that ``hot'' MHD outflows from neutron-rich black-hole debris
disks can significantly alleviate the baryon-loading problem in gamma-ray burst
(GRB) sources. We argue that the neutron-to-proton ratio in disk-fed outflows
might be as high as ~30 and show, with the help of an exact semianalytic
relativistic-MHD solution, that the neutrons can decouple at a Lorentz factor
gamma_d ~ 15 even as the protons continue to accelerate to Lorentz factor ~200
and end up acquiring ~30% of the injected energy. We clarify the crucial role
that the magnetic field plays in this process and prove that purely
hydrodynamic outflows must have gamma_d > a few hundreds. The motion of the
decoupled neutrons is not collinear with that of the decoupled protons, so, in
contrast to previous suggestions based on purely hydrodynamic models, the two
particle groups do not collide after decoupling. If the decoupled neutrons move
at an angle > 1/gamma_d = 3.8 degr (15/gamma_d) to the line of sight to the GRB
source, most of their emission after they decay into protons will remain
unobservable.


title: Galaxies in Southern Bright Star Fields I. Near-infrared imaging

abstract:
  As a prerequisite for cosmological studies using adaptive optics techniques,
we have begun to identify and characterize faint sources in the vicinity of
bright stars at high Galactic latitudes. The initial phase of this work has
been a program of K_s imaging conducted with SOFI at the ESO NTT. From
observations of 42 southern fields evenly divided between the spring and autumn
skies, we have identified 391 additional stars and 1589 galaxies lying at
separations 60" from candidate guide stars in the magnitude range 9.0 R 12.4.
When analyzed as a "discrete deep field" with 131 arcmin^2 area, our dataset
gives galaxy number counts that agree with those derived previously over the
range 16 K_s 20.5. This consistency indicates that in the aggregate, our fields
should be suitable for future statistical studies. We provide our source
catalogue as a resource for users of large telescopes in the southern
hemisphere.


title:
Using the Intensity Modulation Index to Test Pulsar Radio Emission
  Models

abstract:
  This letter explores the possibility of testing pulsar radio emission models
by observing pulse-to-pulse intensity modulation. It is shown that a
relationship between a pulsar's period, period derivative, and intensity
modulation is a natural consequence of at least one theoretical model of radio
pulsar emission. It is proposed that other models may also predict a similar
correlation. The exact form of the relationship will depend on the model in
question. Hence, observations of intensity modulation should be able to
determine the validity of the various emission models. In an attempt to search
for the predicted dependencies, the modulation properties of a set of 12
pulsars are studied. These data are suggestive, but they are unable to
differentiate between three possibilities for the emission process. Future
observations will be able to confirm these results and determine whether or not
specific emission models are viable.


title: Archeops' results on the Cosmic Microwave Background

abstract:
  Archeops is a balloon--borne experiment dedicated to the measurement of the
temperature anisotropies of the cosmic microwave background (CMB) from large
angular scales to about 10 arcminutes. A brief introduction to the CMB is given
below, followed by a description of the Archeops experiment. Archeops flew on
the 7th of February 2002 in the Arctic night from Kiruna (Sweden) to Russia.
The analysis of part of these data is described below with the results on the
$C_\ell$ spectrum, showing for the first time a continuous link between the
large scales and the first acoustic peak. We end up with constraints on the
cosmological parameters. We confirm the flatness of the Universe. And,
combining the Archeops data with other CMB experiments data and with the HST
measurement of $H_0$, we measure for the first time $\Omega_{\Lambda}$
independently of SuperNovae based results.


title:
Constraining Dark Energy Evolution with Gravitational Lensing by Large
  Scale Structures

abstract:
  We study the sensitivity of weak lensing by large scale structures to the
evolution of dark energy. We explore a 2-parameters model of dark energy
evolution, inspired by tracking quintessence models. To this end, we compute
the likelihood of a few representative models with varying and non varying
equation of states. Based on an earlier work, we show that the evolution of
dark energy has a much stronger impact on the non-linear structure growth than
on the angular diameter distance, which makes large scale structure
measurements a very efficient probe of this evolution. For the different
models, we investigate the dark energy parameters degeneracies with the mass
power spectrum shape Gamma, normalisation sigma_8, and with the matter mean
density Omega_M. This result is a strong motivation for performing large scale
structure simulations beyond the simple constant dark energy models, in order
to calibrate the non-linear regime accurately. Prospective for the Canada
France Hawaii Telescope Legacy Survey (CFHTLS) and Super-Novae Acceleration
Probe (SNAP) are given. These results complement nicely the cosmic microwave
background and Super-Novae constraints. Weak lensing is shown to be more
sensitive to a variation of the equation of state, whereas CMB and SNIa give
information on its constant part.


title: Models of Chemical Evolution

abstract:
  The basic principles underlying galactic chemical evolution and the most
important results of chemical evolution models are discussed. In particular,
the chemical evolution of the Milky Way galaxy, for which we possess the
majority of observational constraints, is described. Then, it is shown how
different star formation histories influence the chemical evolution of galaxies
of different morphological type. Finally, the role of abundances and abundance
ratios as cosmic clocks is emphasized and a comparison between model
predictions and abundance patterns in high redshift objects is used to infer
the nature and the age of these systems.


title:
Effects of correlated turbulent velocity fields on the formation of
  maser lines

abstract:
  The microturbulent approximation of turbulent motions is widely used in
radiative transfer calculations. Mainly motivated by its simple computational
application it is probably in many cases an oversimplified treatment of the
dynamical processes involved. This aspect is in particular important in the
analysis of maser lines, since the strong amplification of radiation leads to a
sensitive dependence of the radiation field on the overall velocity structure.
To demonstrate the influence of large scale motions on the formation of maser
lines we present a simple stochastic model which takes velocity correlations
into account. For a quantitative analysis of correlation effects, we generate
in a Monte Carlo simulation individual realizations of a turbulent velocity
field along a line of sight. Depending on the size of the velocity correlation
length we find huge deviations between the resulting random profiles in respect
of line shape, intensity and position of single spectral components. Finally,
we simulate the emission of extended maser sources. A qualitative comparison
with observed masers associated with star forming regions shows that our model
can reproduce the observed general spectral characteristics. We also
investigate shortly, how the spectra are effected when a systematic velocity
field (simulating expansion) is superposed on the fluctuations. Our results
convincingly demonstrate that hydrodynamical motions are of great importance
for the understanding of cosmic masers.


title: A deep Chandra observation of the Perseus cluster: shocks and ripples

abstract:
  We present preliminary results from a deep observation lasting almost 200 ks,
of the centre of the Perseus cluster of galaxies around NGC 1275. The X-ray
surface brightness of the intracluster gas beyond the inner 20 kpc, which
contains the inner radio bubbles, is very smooth apart from some low amplitude
quasi-periodic ripples. A clear density jump at a radius of 24 kpc to the NE,
about 10 kpc out from the bubble rim, appears to be due to a weak shock driven
by the northern radio bubble. A similar front may exist round both inner
bubbles but is masked elsewhere by rim emission from bright cooler gas. The
continuous blowing of bubbles by the central radio source, leading to the
propagation of weak shocks and viscously-dissipating sound waves seen as the
observed fronts and ripples, gives a rate of working which balances the
radiative cooling within the inner 50 kpc of the cluster core.


title: Chemical Evolution of Damped Lyman Alpha Systems

abstract:
  By means of detailed chemical evolution models for galaxies of different
morphological types (i.e. spirals, irregular/starburst galaxies and
ellipticals) we study the nature of Damped Lyman-Alpha systems. Our concern is
to infer which systems represent likely candidates for the DLA population and
which do not. By focusing on individual systems, we can derive some constraints
on both the nature of the associated galaxy and its age. Our results indicate
that, owing to their high metallicities and [alpha/Fe] ratios, big spheroids
represent unlikely DLA candidates whereas spirals (observed at different
galactocentric distances) and irregulars are ideal sites where DLA absorptions
can occur.


title:
Results of the ESO-SEST Key Programme on CO in the Magellanic Clouds X.
  CO emission from star formation regions in LMC and SMC

abstract:
  We present J=1-0 and J=2-1 12CO maps of several star-forming regions in both
the Large and the Small Magellanic Cloud, and briefly discuss their structure.
Many of the detected molecular clouds are relatively isolated and quite small
with dimensions of typically 20 pc. Some larger complexes have been detected,
but in all cases the extent of the molecular clouds sampled by CO emission is
significantly less than the extent of the ionized gas of the star-formation
region. Very little diffuse extended CO emission was seen; diffuse CO in
between or surrounding the detected discrete clouds is either very weak or
absent. The majority of all LMC lines of sight detected in 13CO has an isotopic
emission ratio I(12CO)/I(13CO) of about 10, i.e. twice higher than found in
Galactic star-forming complexes. At the lowest 12CO intensities, the spread of
isotopic emission ratios rapidly increases, low ratios representing relatively
dense and cold molecular gas and high ratios marking CO photo-dissociation at
cloud edges.


title:
The relationship between the optical Halpha filaments and the X-ray
  emission in the core of the Perseus cluster

abstract:
  NGC 1275 in the centre of the Perseus cluster of galaxies, Abell 426, is
surrounded by a spectacular filamentary Halpha nebula. Deep Chandra X-ray
imaging has revealed that the brighter outer filaments are also detected in
soft X-rays. This can be due to conduction and mixing of the cold gas in the
filaments with the hot, dense intracluster medium. We show the correspondence
of the filaments in both wavebands and draw attention to the relationship of
two prominent curved NW filaments to an outer, buoyant radio bubble seen as a
hole in the X-ray image. There is a strong resemblance in the shape of the hole
and the disposition of the filaments to the behaviour of a large air bubble
rising in water. If this is a correct analogy, then the flow is laminar and the
intracluster gas around this radio source is not turbulent. We obtain a limit
on the viscosity of this gas.


title: The Hubble Constant from Gravitational Lens Time Delays

abstract:
  There are now 10 firm time delay measurements in gravitational lenses. The
physics of time delays is well understood, and the only important variable for
interpreting the time delays to determine H_0 is the mean surface mass density
<k> (in units of the critical density for gravitational lensing) of the lens
galaxy at the radius of the lensed images. More centrally concentrated mass
distributions with lower <k> predict higher Hubble constants, with H_0~1-<k> to
lowest order. While we cannot determine <k> directly given the available data
on the current time delay lenses, we find H_0=48+/-3 km/s/Mpc for the
isothermal (flat rotation curve) models, which are our best present estimate
for the mass distributions of the lens galaxies. Only if we eliminate the dark
matter halo of the lenses and use a constant mass-to-light ratio (M/L) model to
find H_0=71+/-3 km/s/Mpc is the result consistent with local estimates.
Measurements of time delays in better-constrained systems or observations to
obtain new constraints on the current systems provide a clear path to
eliminating the <k> degeneracy and making estimates of H_0 with smaller
uncertainties than are possible locally. Independent of the value of H_0, the
time delay lenses provide a new and unique probe of the dark matter
distributions of galaxies and clusters because they measure the total (light +
dark) matter surface density.


title:
The Optical Gravitational Lensing Experiment. Catalog of RR Lyrae Stars
  in the Large Magellanic Cloud

abstract:
  We present the catalog of RR Lyrae stars discovered in a 4.5 square degrees
area in the central parts of the Large Magellanic Cloud (LMC). Presented sample
contains 7612 objects, including 5455 fundamental mode pulsators (RRab), 1655
first-overtone (RRc), 272 second-overtone (RRe) and 230 double-mode RR Lyr
stars (RRd). Additionally we attach a list of several dozen other short-period
pulsating variables. The catalog data include astrometry, periods, BVI
photometry, amplitudes, and parameters of the Fourier decomposition of the
I-band light curve of each object.
  We present density map of RR Lyr stars in the observed fields which shows
that the variables are strongly concentrated toward the LMC center. The modal
values of the period distribution for RRab, RRc and RRe stars are 0.573, 0.339
and 0.276 days, respectively. The period-luminosity diagrams for BVI magnitudes
and for extinction insensitive index W_I are constructed. We provide the
logP-I, logP-V and logP-W_I relations for RRab, RRc and RRe stars. The mean
observed V-band magnitudes of RR Lyr stars in the LMC are 19.36 mag and 19.31
mag for ab and c types, respectively, while the extinction free values are
18.91 mag and 18.89 mag.
  We also found a large number of RR Lyr stars pulsating in two modes closely
spaced in the power spectrum. We discovered three stars which simultaneously
reveal RR Lyr-type and eclipsing-type variability. If any of these objects were
an eclipsing binary system containing RR Lyr star, then for the first time the
direct determination of the mass of RR Lyr variable would be possible.
  We also provide a list of six LMC star clusters which contain RR Lyr stars.
The richest cluster, NGC 1835, hosts 84 RR Lyr variables.


title: Intrinsic Redshifts in QSOs Near NGC 6212

abstract:
  The high number of QSOs around NGC 6212 allows a correlation analysis to be
carried out between their redshift distribution and the redshift distributions
predicted by intrinsic redshift models. We find no correlation between the QSO
redshift distribution and the intrinsic redshifts predicted by Karlsson's
log(1+z) = 0.089 relation. However, we find that the QSO redshift distribution
is correlated with the intrinsic redshifts predicted by the relation z_{iQ} =
0.62[N-0.1M_{N}], for N = 3. We also find evidence that the observed redshifts
of the QSOs contain a small cosmological redshift component similar to that of
NGC 6212. The same correlation analysis carried out on the distribution of 574
quasar redshifts discussed by Karlsson also gave a negative result for the
log(1+z)= 0.089 relation, and a positive result for the z_{iQ} intrinsic
redshifts.


title:
STIS spectroscopy of the emission line gas in the nuclei of nearby FR-I
  galaxies

abstract:
  We present the results of the analysis of a set of medium resolution spectra,
obtained by the Space Telescope Imaging Spectrograph on board the Hubble Space
Telescope, of the emission line gas present in the nuclei of a complete sample
of 21 nearby, early-type galaxies with radio jets (the UGC FR-I Sample). For
each galaxy nucleus we present spectroscopic data in the region of H-alpha and
the dervived kinematics.
  We find that in 67% of the nuclei the gas appears to be rotating and, with
one exception, the cases where rotation is not seen are either face on or have
complex central morphologies. We find that in 62% of the nuclei the fit to the
central spectrum is improved by the inclusion of a broad component. The broad
components have a mean velocity dispersion of 1349 +/- 345 km\s and are
redshifted from the narrow line components (assuming an origin in H-alpha) by
486 +/- 443 km\s.


title: Reionization and Structure Formation with ARCADE

abstract:
  Structure formation in the early universe is expected to produce a
cosmological background of free-free emission. The Absolute Radiometer for
Cosmology, Astrophysics, and Diffuse Emission (ARCADE) will measure the
spectrum of the cosmic microwave background at centimeter wavelengths to detect
this signature of structure formation. I describe the ARCADE instrument and the
cryogenic engineering required to achieve mK accuracy at such long wavelengths.


title: Redshift of the Einstein Ring in MG1549+305

abstract:
  A deep spectrum taken with the Echelle Spectrograph and Imager (ESI) at the
Keck II Telescope as part of the Lenses Structure and Dynamics (LSD) Survey
reveals the redshifts of the extremely red source of the radio Einstein Ring in
the gravitational lens system MG1549+305 ($z_{\rm s}=1.170\pm 0.001$) and an
intermediate redshift lensed spiral galaxy ($z_{\rm G2}=0.604\pm 0.001$). The
source redshift allows us to determine the mass of the SB0 lens galaxy enclosed
by the Einstein Radius ($R_{\rm E}=1\farcs15\pm0\farcs05$) $M_{\rm
E}$$\equiv$$M(<R_{\rm E}) = 8.4\pm0.7\times 10^{10} h_{65}^{-1}$ M$_\odot$.
This corresponds to a Singular Isothermal Ellipsoid (SIE) velocity dispersion
$\sigma_{\rm SIE}=214\pm5$ \kms, in good agreement with the measured stellar
velocity dispersion $\sigma=227\pm18$ \kms (Leh\'ar et al. 1996). The
mass-to-light ratio within the Einstein Radius ($\sim$1.4 effective radii) is
$10\pm1 h_{65}$ \mlu. This is only marginally larger than typical stellar
mass-to-light ratios of local early-type galaxies, indicating that dark matter
is not likely to be dominant inside the Einstein Radius.


title:
Cross-correlation Tomography: Measuring Dark Energy Evolution with Weak
  Lensing

abstract:
  A cross-correlation technique of lensing tomography is presented to measure
the evolution of dark energy in the universe. The variation of the weak lensing
shear with redshift around massive foreground objects like bright galaxies and
clusters depends solely on ratios of angular diameter distances. Use of the
massive foreground halos allow us to compare relatively high, linear shear
values in the same part of the sky, thus largely eliminating the dominant
source of systematic error in cosmological weak lensing measurements. The
statistic we use does not rely on knowledge of the foreground mass distribution
and is only shot-noise limited. We estimate the constraints that deep lensing
surveys with photometric redshifts can provide on the dark energy density
Omega, the equation of state parameter w and its redshift derivative w'. The
accuracies on w and w' are: sigma(w) ~ 0.02 fsky^{-1/2} and sigma(w') ~ 0.05
fsky^{-1/2}, where fsky is the fraction of sky covered by the survey and
sigma(Omega)=0.03 is assumed in the marginalization. Combining our
cross-correlation method with standard lensing tomography, which has
complementary degeneracies, will allow measurement of the dark energy
parameters with significantly better accuracy.


title: Varying Alpha in a More Realistic Universe

abstract:
  We study the space-time evolution of the fine structure constant, $\alpha$,
inside evolving spherical overdensities in a lambda-CDM Friedmann universe
using the spherical infall model. We show that its value inside virialised
regions will be significantly larger than in the low-density background
universe. The consideration of the inhomogeneous evolution of the universe is
therefore essential for a correct comparison of extragalactic and solar system
limits on, and observations of, possible time variation in $\alpha$ and other
constants. Time variation in $\alpha$ in the cosmological background can give
rise to no locally observable variations inside virialised overdensities like
the one in which we live, explaining the discrepancy between astrophysical and
geochemical observations.


title: WMAP Polarization Results

abstract:
  The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the full sky in
Stokes I, Q, and U parameters at frequencies 23, 33, 41, 61, and 94 GHz. We
detect correlations between the temperature and polarization maps significant
at more than 10 standard deviations. The correlations are inconsistent with
instrument noise and are significantly larger than the upper limits established
for potential systematic errors. Correlations on small angualr scales are
consistent with the the signal expected from adiabatic initial conditions. We
detect excess power on large angular scales consistent with an early epoch of
reionization. A model-independent fit to reionization optical depth yields
results consistent with the best-fit LCDM model, with best fit value tau = 0.17
+/- 0.04 at 68% confidence, including systematic and foreground uncertainties.


title:
Statistical properties of exoplanets. I. The period distribution:
  constraints for the migration scenario

abstract:
  Interesting emerging observational properties of the period-mass distribution
of extra-solar planets are discussed. New recent detections confirm the already
emphasized lack of massive planets (m_2sini>=2M_Jup) on short-period orbits
(P<=100 days). Furthermore, we point out i) a shortage of planets in the
10--100 day period range as well as ii) a lack of light planets
(m_2sini<=0.75M_Jup) on orbits with periods larger than ~100 days. The latter
feature is shown not to be due to small-number statistics with Monte-Carlo
simulations. These observational period-related characteristics are discussed
in the context of the migration process of exoplanets. They are found to be in
agreement with recent simulations of planet interactions with viscous disks.
The observed valley at a few tens of days in the period distribution is
interpreted as a transition region between two categories of planets that
suffered different migration scenarios. The lack of light planets on
longer-period orbits and the corresponding intriguing sharp limit in mass is
tentatively explained by the runaway migration process recently studied by
Masset & Papaloizou (2003). The observed properties also have implications for
the observation strategies of the on-going surveys and of future
higher-precision searches.


title: Untwisting the Tornado: X-ray Imaging and Spectroscopy of G357.7-0.1

abstract:
  We report on the detection of X-ray emission from the unusual Galactic radio
source G357.7-0.1 (the "Tornado"). Observations made with the Chandra X-ray
Observatory demonstrate the presence of up to three sources of X-ray emission
from the Tornado: a relatively bright region of dimensions 2'x1' coincident
with and interior to the brightest radio emission at the "head" of the Tornado,
plus two fainter extended regions possibly associated with the Tornado's
"tail". No X-ray point sources associated with the Tornado are seen down to a
3-sigma luminosity (0.5-10 keV) of 1e33 ergs/s, for a distance to the system of
12 kpc. The spectrum of the brightest region of X-rays is consistent with a
heavily absorbed (N_H ~ 1e23 cm^-2) thermal plasma of temperature kT ~ 0.6 keV;
an absorbed power law can also fit the data, but implies an extremely steep
photon index. From these data we tentatively conclude that the Tornado is a
supernova remnant (SNR), although we are unable to rule out the possibility
that the Tornado is powered either by outflows from an X-ray binary or by the
relativistic wind of an unseen pulsar. Within the SNR interpretation, the head
of the Tornado is a limb-brightened radio shell containing centrally-filled
thermal X-rays and which is interacting with a molecular cloud. We therefore
propose that the Tornado is a "mixed morphology" supernova remnant. The unusual
tail component of the Tornado remains unexplained in this interpretation, but
might result from expansion of the SNR into an elongated progenitor wind
bubble.


title: Semi-Analytical Analysis of Helium Synthesis in Brane Cosmology

abstract:
  The problem of primordial nucleosynthesis of helium in brane cosmology is
studied using a semi-analytical method, where the Fermi-Dirac statistic is
ignored. This semi-analytical method agrees with a more complete numerical
calculation with a precision of order of 10% or better. The quadratic term for
the matter density is the only source considered in the modified Einstein
equations predicted by the brane configuration. This hypothesis is justified a
posteriori. An agreement between theoretical and observational values for the
helium abundance is obtained if the fundamental mass scale in five dimensions
is of the order of $M \sim 5\times10^3 GeV$.


title:
A comparison of cosmological Boltzmann codes: are we ready for high
  precision cosmology?

abstract:
  We compare three independent, cosmological linear perturbation theory codes
to asses the level of agreement between them and to improve upon it by
investigating the sources of discrepancy. By eliminating the major sources of
numerical instability the final level of agreement between the codes was
improved by an order of magnitude. The relative error is now below 0.1% for the
dark matter power spectrum. For the cosmic microwave background anisotropies
the agreement is below the sampling variance up to l=3000, with close to 0.1%
accuracy reached over most of this range of scales. The same level of agreement
is also achieved for the polarization spectrum and the temperature-polarization
cross-spectrum. Linear perturbation theory codes are thus well prepared for the
present and upcoming high precision cosmological observations.


title: Redshifting Rings of Power

abstract:
  The cosmic microwave background (CMB) has provided a precise template for
features in the linear power spectrum: the matter-radiation turnover, sound
horizon drop, and acoustic oscillations. In a two dimensional power spectrum in
redshift and angular space, the features appear as distorted rings, and yield
simultaneous, purely geometric, measures of the Hubble parameter H(z) and
angular diameter distance D_A(z) via an absolute version of the
Alcock-Paczynski test. Employing a simple Fisher matrix tool, we explore how
future surveys can exploit these rings of power for dark energy studies. High-z
CMB determinations of H and D_A are best complemented at moderate to low
redshift (z < 0.5) with a population of objects that are at least as abundant
as clusters of galaxies. We find that a sample similar to that of the ongoing
SDSS Luminous Red Galaxy (LRG) survey can achieve statistical errors at the ~5%
level for D_A(z) and H(z) in several redshift bins. This, in turn, implies
errors of sigma(w)=0.03-0.05 for a constant dark energy equation of state in a
flat universe. Deep galaxy cluster surveys such as the planned South Pole
Telescope (SPT) survey, can extend this test out to z~1 or as far as redshift
followup is available. We find that the expected constraints are at the
sigma(w)=0.04-0.08 level, comparable to galaxies and complementary in redshift
coverage.


title: Circulating Subbeam Systems and the Physics of Pulsar Emission

abstract:
  The purpose of this paper is to suggest how detailed single-pulse
observations of ``slow'' radio pulsars may be utilized to construct an
empirical model for their emission. It links the observational synthesis
developed in a series of papers by Rankin starting in the 1980s to the more
recent empirical feedback model of Wright (2003a) by regarding the entire
pulsar magnetosphere as a non-steady, non-linear interactive system with a
natural built-in delay. It is argued that the enhanced role of the outer gap in
such a system indicates an evolutionary link to younger pulsars, in which this
region is thought to be highly active, and that pulsar magnetospheres should no
longer be seen as being ``driven'' by events on the neutron star's polar cap,
but as having more in common with planetary magnetospheres and auroral
phenomena.


title: Quiescent and coherent cores from gravoturbulent fragmentation

abstract:
  [abridged] We investigate the velocity structure of protostellar cores that
result from non-magnetic numerical models of the gravoturbulent fragmentation
of molecular cloud material. A large fraction of the cores analyzed are
``quiescent'', and more than half are identified as ``coherent''. The fact that
dynamically evolving cores in highly supersonic turbulent flows can be
quiescent may be understood because cores lie at the stagnation points of
convergent turbulent flows, where compression is at a maximum, and relative
velocity differences are at a minimum. The coherence may be due to an
observational effect related to the length and concentration of the material
contributing to the line. The velocity dispersion of the our cores often has
its local maximum at small offsets from the column density maximum, suggesting
that the core is the dense region behind a shock. Such a configuration is often
found in observations of molecular cloud cores, and argues in favor of the
gravoturbulent scenario of stellar birth as it is not expected in
star-formation models based on magnetic mediation. Cores with collapsed objects
tend to be near equipartition between their gravitational and kinetic energies,
while cores without collapsed objects tend to be gravitationally unbound,
suggesting that gravitational collapse occurs immediately after gravity becomes
dominant. Finally, cores in simulations driven at large scales are more
frequently quiescent and coherent, and have more realistic ratios of $M_{\rm
vir}/M$, supporting the notion that molecular cloud turbulence is driven at
large scales.


title: Oscillations in Arcturus from WIRE photometry

abstract:
  Observations of the red giant Arcturus (Alpha Boo) obtained with the star
tracker on the Wide Field Infrared Explorer (WIRE) satellite during a baseline
of 19 successive days in 2000 July-August are analysed. The amplitude spectrum
has a significant excess of power at low-frequencies. The highest peak is at
about 4.1 micro-Hz (2.8 d), which is in agreement with previous ground-based
radial velocity studies. The variability of Arcturus can be explained by sound
waves, but it is not clear whether these are coherent p-mode oscillations or a
single mode with a short life-time.


title:
X-ray observations of the compact central object in supernova remnant
  G347.3-0.5

abstract:
  We present Chandra, XMM-Newton and RXTE observations of 1WGA J1713.4-3949, a
compact source at the center of the galactic supernova remnant (SNR)
G347.3-0.5. The X-ray spectrum of the source is well-fitted by the sum of a
blackbody component with a temperature of about 0.4 keV plus a power law
component with photon index about 4. We found no pulsations down to 4% in the
0.01-0.16 Hz range and down to 25% in the 0.01-128 Hz range. This source
resembles other compact central objects (CCOs) in SNRs, and we suggest that
1WGA J1713.4-3949 is the associated neutron star for G347.3--0.5. We also
measured the properties of the adjacent radio pulsar PSR J1713-3945 with a 392
ms period and show that it is not associated with 1WGA J1713.4-3949 nor, most
probably, with SNR G347.3-0.5 as well.


title: COBE Observations of the Cosmic Infrared Background

abstract:
  The Diffuse InfraRed Background Experiment on COBE measured the total
infrared signal seen from space at a distance of 1 astronomical unit from the
Sun. Using time variations as the Earth orbits the Sun, it is possible to
remove most of the foreground signal produced by the interplanetary dust cloud
[zodiacal light]. By correlating the DIRBE signal with the column density of
atomic hydrogen measured using the 21 cm line, it is possible to remove most of
the foreground signal produced by interstellar dust, although one must still be
concerned by dust associated with H_2 (molecular gas) and H II (the warm
ionized medium). DIRBE was not able to determine the CIRB in the 5-60 micron
wavelength range, but did detect both a far infrared background and a near
infrared background. The far infrared background has an integrated intensity of
about 34 nW/m^2/sr, while the near infrared and optical extragalactic
background has about 59 nW/m^2/sr. The Far InfraRed Absolute Spectrophotometer
(FIRAS) on COBE has been used to constrain the long wavelength tail of the far
infrared background but a wide range of intensities at 850 microns are
compatible with the FIRAS data. Thus the fraction of the CIRB produced by SCUBA
sources has large uncertainties in both the numerator and the denominator.


title: Observations of rotationally resolved C3 in translucent sight lines

abstract:
  The rotationally resolved spectrum of the A ^1Pi_u <- X ^1Sigma^+_g 000-000
transition of C3, centered at 4051.6A, has been observed along 10 translucent
lines of sight. To interpret these spectra, a new method for the determination
of column densities and analysis of excitation profiles involving the
simulation and fitting of observed spectra has been developed. The populations
of lower rotational levels (J<14) in C3 are best fit by thermal distributions
that are consistent with the kinetic temperatures determined from the
excitation profile of C2. Just as in the case of C2, higher rotational levels
(J>14) of C3 show increased nonthermal population distributions in clouds which
have been determined to have total gas densities below ~500 cm-3.


title:
First Fringe Detection with VERA's Dual-Beam System and its Phase
  Referencing Capability

abstract:
  We present the results of first dual-beam observations with VERA (VLBI
Exploration of Radio Astrometry). The first dual-beam observations of a pair of
H2O maser sources W49N and OH43.8-0.1 have been carried out on 2002 May 29 and
July 23, and fringes of H2O maser lines at 22 GHz have been successfully
detected. While the residual fringe phases of both sources show rapid
variations over 360 degree due to the atmospheric fluctuation, the differential
phase between the two sources remains constant for 1 hour with r.m.s. of 8
degree, demonstrating that the atmospheric phase fluctuation is removed
effectively by the dual-beam phase referencing. The analysis based on Allan
standard deviation reveals that the differential phase is mostly dominated by
white phase noise, and the coherence function calculated from the differential
phase shows that after phase referencing the fringe visibility can be
integrated for arbitrarily long time. These results demonstrate VERA's high
capability of phase referencing, indicating that VERA is a promising tool for
phase referencing VLBI astrometry at 10 microarcsec level accuracy.