title: Cosmology in the Very Local Universe - Why Flow Models Matter

abstract:
  While much of the focus of observational cosmology is on the high redshift
universe it is important not to neglect the very local universe as a source of
cosmological information. The inner profiles and number counts of low mass
halos have provided the biggest stumbling blocks so far for LCDM. These small
structures can only be seen nearby where the component of a galaxy's redshift
which is due to motions under gravity can be comparable to (or even larger
than) its cosmological redshift. We report on a new sample of Tully-Fisher
distances (the SFI++) which is being used in combination with publicly
available primary distances to model galaxy flows in and around the Local
Supercluster. This sample has ~10 times as many tracers as were used for the
current best model. Initially a parametric model including infall onto multiple
attractors will be used. Such models are not realistic representations of the
true velocity field, but provide useful first order corrections. We explore the
typical errors in distances from such a flow model and how they vary in
different regions of the local supercluster by fitting the same parametric
model to mock catalogs derived from a constrained simulation of the volume.


title: Cosmological constrains from X-ray AGN clustering and SNIa data

abstract:
  We put constraints on the main cosmological parameters of different spatially
flat cosmological models by combining the recent clustering results of
XMM-Newton soft (0.5-2 keV) X-ray sources, which have a redshift distribution
with median redshift $z\sim 1.2$, and SNIa data. Using a likelihood procedure
we find that the model which best reproduces the observational data and that is
consistent with stellar ages is the concordance $\Lambda$CDM model with:
$\Omega_{\rm m}\simeq 0.28$, $w\simeq -1$, $H_{\circ} \simeq 72$ km s$^{-1}$
Mpc$^{-1}$, $t_{\circ}\simeq 13.5$Gyr and has an X-ray AGN clustering evolution
which is constant in physical coordinates. For a different clustering evolution
model (constant in comoving coordinates) we find another viable model, although
less probable due to the smaller age of the Universe, with $\Omega_{\rm
m}\simeq 0.38$, $w\simeq -1.25$, $H_{\circ} \simeq 70$ km s$^{-1}$ Mpc$^{-1}$,
$t_{\circ}\simeq 12.9$Gyr.


title:
The Emergence of the Thick Disk in a CDM Universe II: Colors and
  Abundance Patterns

abstract:
  The recently emerging conviction that thick disks are prevalent in disk
galaxies, and their seemingly ubiquitous old ages, means that the formation of
the thick disk, perhaps more than any other component, holds the key to
unravelling the evolution of the Milky Way, and indeed all disk galaxies. In
Paper I, we proposed that the thick disk was formed in an epoch of gas rich
mergers, at high redshift. This hypothesis was based on comparing N-body/SPH
simulations to a variety of Galactic and extragalactic observations, including
stellar kinematics, ages and chemical properties.Here examine our thick disk
formation scenario in light of the most recent observations of extragalactic
thick disks. In agreement, our simulted thick disks are old and relatively
metal rich, with V-I colors that do not vary significantly with distance from
the plane. Further, we show that our proposal results in an enhancement of
alpha-elements in thick disk stars as compared with thin disk stars, consistent
with observations of the relevant populations of the Milky Way. We also find
that our scenario naturally leads to the formation of an old metal weak stellar
halo population with high alpha-element abundances.


title:
Low Frequency Radio Observations of X-ray Ghost Bubbles in Abell 2597: A
  History of Radio Activity in the Core

abstract:
  A previous analysis of the Chandra X-ray image of the center of the cooling
core cluster Abell 2597 showed two ``ghost holes'' in the X-ray emission to the
west and northeast of the central radio galaxy PKS 2322-123. Previous radio
observations did not detect any radio emission coming from the interior of the
X-ray holes. We present new low frequency radio observations of Abell 2597. At
330 MHz, radio emission extends into the interior of the western ghost bubble,
but not the northeast one. Our re-analysis of the archival Chandra data shows
evidence for an X-ray tunnel (elongated region of reduced X-ray emission)
extending from near the center of the cD out to the west ghost bubble. We also
detect a smaller X-ray hole to the northeast of the center of the cD and closer
than the outer ghost bubbles. Radio observations at 1.3 GHz show extensions to
the west along the X-ray tunnel toward the west ghost bubble, to the northeast
into the new X-ray hole, and to the northwest. All of these structures are much
larger than the two inner radio lobes seen previously at 8 GHz. The X-ray
tunnel suggests that the west ghost bubble is part of a continuous flow of
radio plasma out from the active galactic nucleus, rather than a detached
buoyant old radio lobe, and thus it may be an intermediate case between an
active radio galaxy and a buoyant lobe.


title: The Stellar Mass Evolution of Galaxies in the NICMOS Ultra Deep Field

abstract:
  We measure the build-up of the stellar mass of galaxies from z=6 to z=1.
Using 15 band multicolor imaging data in the NICMOS Ultra Deep Field we derive
photometric redshifts and masses for 796 galaxies down to H(AB)=26.5. The
derived evolution of the global stellar mass density of galaxies is consistent
with previous star formation rate density measurements over the observed range
of redshifts. Beyond the observed range, maintaining consistency between the
global stellar mass and the observed star formation rate suggests the epoch of
galaxy formation was z=16.


title:
Metric Tests for Curvature from Weak Lensing and Baryon Acoustic
  Oscillations

abstract:
  We describe a practical measurement of the curvature of the Universe which
relies purely on the properties of the Robertson-Walker metric rather than any
model for the dynamics or content of the Universe. The cross-correlation
between foreground mass and gravitational shear of background galaxies depends
upon the angular diameter distances d_A(z_l), d_A(z_s), and d_A(z_s,z_l) on the
degenerate triangle formed by observer, source, and lens. In a flat Universe,
d_A(z_l,z_s) = d_A(z_s)-d_A(z_l), but in curved Universes an additional term
$\propto\Omega_k$ alters the lensing observables even if d_A(z) is fixed. Weak
lensing data may be used to solve simultaneously for d_A and the curvature.
This method is completely insensitive to: the equation of state; amendments to
the General Relativity formulae for the deflection of light or the growth of
structure; or biases in the photometric redshift scale. There is however a
degeneracy among d_A, $\Omega_k$ and the galaxy bias factors, that can be
broken by using measurements of baryon acoustic oscillations with the same
imaging data. Ambitious weak-lensing + baryon-oscillation surveys would measure
$\Omega_k$ to an accuracy $\approx0.04 f_{\rm sky}^{-1/2} (\sigma_{\ln
z}/0.04)^{1/2}$, where $\sigma_{\ln z}$ is the photometric redshift error. We
also predict bounds on curvature and other parameters in the context of
specific dark-energy models, and compare to other analyses of the weak lensing
cross-correlation method. We find both curvature and parametric constraints to
be surprisingly insensitive to systematic shear calibration errors.


title: Speeding Up Cosmological Boltzmann Codes

abstract:
  We introduce a novel strategy for cosmological Boltzmann codes leading to an
increase in speed by a factor of \sim 30 for small scale Fourier modes. We
(re-)investigate the tight coupling approximation and obtain analytic formulae
reaching up to the octupoles of photon intensity and polarization. This leads
to accurate results reaching optimal precision, while still being simple.
Damping rapid oscillations of small scale modes at later times, we simplify the
integration of cosmological perturbations. We obtain analytic expressions for
the photon density contrast and velocity as well as an estimate of the
quadrupole from after last scattering until today. These analytic formulae hold
well during re-ionization and are in fact negligible for realistic cosmological
scenarios. However, they do extend the validity of our approach to models with
very large optical depth to the last scattering surface.


title: Investigation of the rapid magnetic field variability in gamma Equ

abstract:
  We investigated magnetic variability of the roAp star gamma Equ (HD 201601)
with high time resolution. Measurements of the stellar longitudinal magnetic
field B_e were performed with the hydrogen line polarimeter and the 6-m optical
telescope of Special Astrophysical Observatory on 20/21 August 1989. We
obtained a single 3-hour series of 1720 rapid B_e measurements for this star
with the average time resolution of 6.6 sec. The averaged value of <B_e> on
this night equals -750 \pm 22 G. Both the power spectrum and the amplitude
spectrum of the B_e time series essentially are flat. However, they show the
presence of a marginally significant magnetic period at P_B = 3.596 min. which
is real with the probability 67 %. The amplitude of the magnetic field
variations with this period equals 347 \pm 31 G. We did not detect variations
of B_e field in gamma Equ with the well-known photometric period, P_phot=12.44
min.


title:
TeV-PeV Neutrinos from Giant Flares of Magnetars and the Case of SGR
  1806-20

abstract:
  We estimate the high energy neutrino flux from the giant flare of SGR 1806-20
on December 27, 2004, which irradiated Earth with a gamma-ray flux ~10^4 times
larger than the most luminous gamma-ray bursts (GRBs) ever detected. The
Antarctic Cherenkov neutrino detector AMANDA was on-line during the flare, and
may either have detected high energy neutrinos for the first time from a cosmic
point source, or put constraints on the flare mechanism of magnetars. If TeV
neutrinos are detected, one would expect also detectable EeV cosmic rays and
possibly TeV gamma-ray emission in coincidence.


title:
A Variable Infrared Counterpart to the Soft Gamma-ray Repeater SGR
  1806-20

abstract:
  We present K'-band (2.12 micron) imaging observations of the SGR 1806-20
field taken during its very active phase in mid 2004, which reveal brightening
of sources within the Chandra X-ray error circle when compared with earlier
images obtained in 2002. One source brightened by more than a factor of 2, and
so we consider this to be the probable infrared counterpart for SGR 1806-20.
The other two sources are located in close proximity to the probable
counterpart and show marginal brightening, which may suggest that the
high-energy photons emitted from the SGR during its active phase have induced
dust sublimation or brightening of the unresolved background around the SGR.


title:
Detecting Intracluster Gas Motion in Galaxy Clusters: Mock Astro-E2
  Observations

abstract:
  We explore the detectability of bulk motions in the X-ray emitting
intracluster medium (ICM) using a catalog of 1,836 mock Astro-E2 observations
of simulated clusters of galaxies. We generate high resolution mock spectra for
two observing strategies: a four-pointing mosaic and a single central pointing.
Normalizing to 200 (400) photons in the iron K-alpha region for the mosaic
(central) study, we fit Poisson realizations of each simulated spectrum to a
velocity broadened isothermal plasma emission model. We confirm that the
velocity characteristics (mean and dispersion) returned by the spectral
fittings are unbiased measures of the emission-weighted values within the
observed region, with scatter 55 km/s. The maximum velocity difference between
mosaic element pairs $\Delta v_{\rm max}$ has ~ 6% likelihood of being
transonic ($\Delta v_{\rm max} \ge 0.5 c_s$), and the likelihood falls steeply,
$p \spropto (\Delta v_{\rm max}/c_s)^{-4}$, at high Mach number. The velocity
broadening parameter $\sigma_v$ from the central pointing fit exceeds the
thermal value in 49% of the cases, with again a $\sigma_v^{-4}$ tail at large
dispersion. We present as case studies the clusters that yield the strongest
signal for each observing strategy.


title:
Measuring the Galaxy-Galaxy-Mass Three-point Correlation Function with
  Weak Gravitational Lensing

abstract:
  We discuss the galaxy-galaxy-mass three-point correlation function and show
how to measure it with weak gravitational lensing. The method entails choosing
a large of pairs of foreground lens galaxies and constructing a mean shear map
with respect to their axis, by averaging the ellipticities of background source
galaxies. An average mass map can be reconstructed from this shear map and this
will represent the average mass distribution around pairs of galaxies. We show
how this mass map is related to the projected galaxy-galaxy-mass three-point
correlation function. Using a large N-body dark matter simulation populated
with galaxies using the Halo Occupation Distribution (HOD) bias prescription,
we compute these correlation functions, mass maps, and shear maps. The
resultant mass maps are distinctly bimodal, tracing the galaxy centers and
remaining anisotropic up to scales much larger than the galaxy separation. At
larger scales, the shear is approximately tangential about the center of the
pair but with small azimuthal variation in amplitude. We estimate the
signal-to-noise ratio of the reconstructed mass maps for a survey of similar
depth to the Sloan Digital Sky Survey (SDSS) and conclude that the
galaxy-galaxy-mass three-point function should be measurable with the current
SDSS weak lensing data. Measurements of this three-point function, along with
galaxy-galaxy lensing and galaxy auto-correlation functions, will provide new
constraints on galaxy bias models. The anisotropic shear profile around close
pairs of galaxies is a prediction of cold dark matter models and may be
difficult to reconcile with alternative theories of gravity without dark
matter.


title:
A wide-field photometric study of the globular cluster system of NGC
  4636

abstract:
  We investigate the unusually rich cluster system of NGC4636 with wide-field
Washington photometry. The globular cluster luminosity function can be followed
roughly 1 mag beyond the turn-over magnitude. This corresponds to a distance
modulus of m-M=31.24+-0.17, 0.4 mag larger than the distance determined from
surface brightness fluctuations. The high specific frequency is confirmed, yet
the exact value remains uncertain because of the uncertain distance: it varies
between 5.6+-1.2 and 8.9+-1.2. The globular cluster system has a clearly
bimodal color distribution. The color peak positions show no radial dependence
and are in good agreement with the values found for other galaxies studied in
the same filter system. However, a luminosity dependence is found: brighter
clusters with an ``intermediate'' color exist. The clusters exhibit a shallow
radial distribution within 7'.Within the same radial interval, the galaxy light
has a distinctly steeper profile. Because of the difference in the cluster and
light distribution the specific frequency increases considerably with radius.
At 7' and 9' the density profiles of the red and blue clusters, respectively,
change strongly which indicates that we reach the outer rim of the cluster
system at approximately 11'. This feature is seen for the first time in a
globular cluster system. While the radial distribution of the cluster and field
populations are rather different, this is not true for the ellipticity of the
system: the elongation as well as the position angle of the cluster system
agree well with the galaxy light. We compare the radial distribution of
globular clusters with the light profiles for a sample of elliptical galaxies.
The difference observed in NGC 4636 is typical of an elliptical galaxy of this
luminosity.


title: High-redshift quasar host galaxies with adaptive optics

abstract:
  We present K band adaptive optics observations of three high-redshift (z ~
2.2) high-luminosity quasars, all of which were studied for the first time. We
also bserved several point spread function (PSF) calibrators,
non-simultaneously because of the small field of view. The significant temporal
PSF variations on timescales of minutes inhibited a straightforward scaled PSF
removal from the quasar images. Characterising the degree of PSF concentration
by the radii encircling 20% and 80% of the total flux, respectively, we found
that even under very different observing conditions the r_20 vs. r_80 relation
varied coherently between individual short exposure images, delineating a
well-defined relation for point sources. Placing the quasar images on this
relation, we see indications that all three objects were resolved. We designed
a procedure to estimate the significance of this result, and to estimate host
galaxy parameters, by reproducing the statistical distribution of the
individual short exposure images. We find in all three cases evidence for a
luminous host galaxy, with a mean absolute magnitude of M_R = -27.0 and scale
lengths around ~ 4-12 kpc. Together with a rough estimate of the central black
hole masses obtained from C_iv line widths, the location of the objects on the
bulge luminosity vs. black hole mass relation is not significantly dfferent
from the low-redshift regime, assuming only passive evolution of the host
galaxy. Corresponding Eddington luminosities are L_nuc/L_Edd ~ 0.1-0.6.


title:
Power spectrum and correlation function errors: Poisson vs. Gaussian
  shot noise

abstract:
  Poisson distributed shot noise is normally considered in the Gaussian limit
in cosmology. However, if the shot noise is large enough and the correlation
function/power spectrum conspires, the Gaussian approximation mis-estimates the
errors and their covariance significantly. The power spectrum, even for
initially Gaussian densities,acquires cross correlations which can be large,
while the change in the correlation function error matrix is diagonal except at
zero separation. Two and three dimensional power law correlation function and
power spectrum examples are given. These corrections appear to have a large
effect when applied to galaxy clusters, e.g. for SZ selected galaxy clusters in
2 dimensions. This can increase the error estimates for cosmological parameter
estimation and consequently affect survey strategies, as the corrections are
minimized for surveys which are deep and narrow rather than wide and shallow.
In addition, a rewriting of the error matrix for the power spectrum/correlation
function is given which eliminates most of the Bessel function dependence (in
two dimensions) and all of it (in three dimensions), which makes the
calculation of the error matrix more tractable. This applies even when the shot
noise is in the (usual) Gaussian limit.


title:
Pulling out Threads from the Cosmic Tapestry: Defining Filaments of
  Galaxies

abstract:
  Filaments of galaxies are the dominant feature of modern large scale redshift
surveys. They can account for up to perhaps half of the baryonic mass budget of
the Universe and their distribution and abundance can help constrain
cosmological models. However, there remains no single, definitive way in which
to detect, describe and define what filaments are and their extent. This work
examines a number of physically motivated, as well as statistical, methods that
can be used to define filaments and examines their relative merits.


title:
Gravitational Radiation from an Accreting Millisecond Pulsar with a
  Magnetically Confined Mountain

abstract:
  The amplitude of the gravitational radiation from an accreting neutron star
undergoing polar magnetic burial is calculated. During accretion, the magnetic
field of a neutron star is compressed into a narrow belt at the magnetic
equator by material spreading equatorward from the polar cap. In turn, the
compressed field confines the accreted material in a polar mountain which is
misaligned with the rotation axis in general, producing gravitational waves.
The equilibrium hydromagnetic structure of the polar mountain, and its
associated mass quadrupole moment, are computed as functions of the accreted
mass, M_a, by solving a Grad-Shafranov boundary value problem. The orientation-
and polarization-averaged gravitational wave strain, h_c ~ 6e-24 for a 0.6 kHz
source at 1 kpc with M_a > 10^-5 M_Sun, exceeds previous estimates that failed
to treat equatorward spreading and flux freezing self-consistently. It is
concluded that an accreting millisecond pulsar emits a persistent, sinusoidal
gravitational wave signal at levels detectable, in principle, by long baseline
interferometers after phase-coherent integration, provided that the polar
mountain is hydromagnetically stable. Magnetic burial also reduces the magnetic
dipole moment, mu, monotonically, implying a novel, observationally testable
scaling h_c(mu). The implications for the rotational evolution of (accreting)
X-ray and (isolated) radio millisecond pulsars are explored.


title:
Large-Amplitude, Pair-Creating Oscillations in Pulsar and Black Hole
  Magnetospheres

abstract:
  A time-dependent model for pair creation in a pulsar magnetosphere is
developed. It is argued that the parallel electric field that develops in a
charge-starved region (a gap) of a pulsar magnetosphere oscillates with large
amplitude. Electrons and positrons are accelerated periodically and the
amplitude of the oscillations is assumed large enough to cause creation of
upgoing and downgoing pairs at different phases of the oscillation. With a
charge-starved initial condition, we find that the oscillations result in
bursts of pair creation in which the pair density rises exponentially with
time. The pair density saturates at $N_\pm\simeq E_{0}^2/(8\pi
m_ec^2\Gamma_{\rm thr})$, where $E_0$ is the parallel electric field in the
charge-starved initial state, and $\Gamma_{\rm thr}$ is the Lorentz factor for
effec tive pair creation. The frequency of oscillations following the pair
creation burst is given roughly by $\omega_{\rm osc}=eE_0/(8m_ec\Gamma_{\rm
thr})$. A positive feedback keeps the system stable, such that the average pair
creation rate balances the loss rate due to pairs escaping the magnetosphere.


title: The cosmology of the nonsymmetric theory of gravitation

abstract:
  We show that during cosmological inflation the nonsymmetric metric tensor
theory of gravitation develops a spectrum which is potentially observable by
cosmic microwave background observations, and may be the most sensitive probe
of the scale of cosmic inflation.


title:
Strong dust processing in circumstellar discs around 6 RV Tauri stars.
  Are dusty RV Tauri stars all binaries?

abstract:
  We present extended Spectral Energy Distributions (SEDs) of seven classical
RV Tauri stars, using newly obtained submillimetre continuum measurements and
Geneva optical photometry supplemented with literature data. The broad-band
SEDs show a large IR excess with a black-body slope at long wavelengths in six
of the seven stars, R Sct being the noticeable exception. This long wavelength
slope is best explained assuming the presence of a dust component of large
grains in the circumstellar material. We show that the most likely distribution
of the circumstellar dust around the six systems is that the dust resides in a
disc. Moreover, very small outflow velocities are needed to explain the
presence of dust near the sublimation temperature and we speculate that the
discs are Keplerian. The structure and evolution of these compact discs are as
yet not understood but a likely prerequisite for their formation is that the
dusty RV Tauri stars are binaries.


title:
INTEGRAL observations of OAO 1657-415: gamma-ray tomography of a B
  supergiant

abstract:
  OAO 1657-415 is an accreting pulsar in an eclipsing binary system. We
analyzed the INTEGRAL core program observations of this object and obtained the
eclipse light curve in the soft gamma-ray band between 15 and 40 keV. We note
that the gamma rays from the pulsar allow to probe the density profile of the
outer layers of the B supergiant companion. We find that the density profile of
the outer layer can be described by a power law with the index
  $\alpha = 8.5$. We also note that the fit hints toward smaller inclinations
of the system within the allowed range 60-90 degrees.


title:
INTEGRAL spectroscopy of the accreting millisecond pulsar XTE J1807-294
  in outburst

abstract:
  The fourth transient accreting millisecond pulsar XTE J1807-294 was observed
during its February/March 2003 outburst by INTEGRAL, partly simultaneously with
the XMM-Newton and RXTE satellites. We present here the first study of the
0.5-200 keV broad-band spectra of the source. On February 28, the source
spectrum was consistent with thermal Comptonization by electrons of temperature
\~40 keV, considerably larger than the value (~10 keV) previously derived from
the low energy XMM-Newton data alone. The source is detected by INTEGRAL up to
200 keV with a luminosity in the energy band (0.1-200) keV of 1.3 x 10E37 erg/s
(assuming a distance of 8 kpc). 22 days later the luminosity dropped to 3.6 x
10E36 erg/s. A re-analysis of XMM-Newton data yields the orbital Doppler
variations of the pulse period and refines the previous ephemeris. For this
source having shortest orbital period of any known binary radio or X-ray
millisecond pulsar, we constrain the companion mass Mc < 0.022 Msun, assuming
minimum mass transfer driven by gravitational radiation. Only evolved dwarfs
with a C/O composition are consistent with the Roche lobe and gravitational
radiation constraints, while He dwarfs require an unlikely low inclination.


title:
The Connection between Ultraviolet and X-ray Outflows in AGN: the case
  of PDS 456

abstract:
  High-velocity outflows from AGN are a well-known phenomena in terms of the
Broad Absorption Lines seen in the UV/optical. More recently, similar, possibly
related, outflows have been reported in the X-ray. The most extreme example is
seen in the nearby, luminous QSO PDS 456, which displays a massive, high
velocity (50000 km s-1), high-ionization X-ray outflow of 10 solar masses yr-1.
Here we present the UV spectrum of PDS 456 as observed by the Hubble Space
Telescope. We find the UV spectrum is also extreme, displaying very broad
emission-lines, with CIV 1549 blueshifted by 5000 km s-1 and a broad Ly-alpha
absorption trough blueshifted by 14000-24000 km s-1. No strong, broad
high-ionization absorption features are seen. We interpret the combined UV and
X-ray spectrum of PDS 456 as the signature of a decelerating, cooling outflow,
which may be driven by radiation and/or magnetic field. This outflow may be the
source of some of the broad emission and absorption-line gas.


title: A Possible Hidden Population of Spherical Planetary Nebulae

abstract:
  We argue that relative to non-spherical planetary nebulae (PNs), spherical
PNs are about an order of magnitude less likely to be detected, at distances of
several kiloparsecs. Noting the structure similarity of halos around
non-spherical PNs to that of observed spherical PNs, we assume that most
unobserved spherical PNs are also similar in structure to the spherical halos
around non-spherical PNs. The fraction of non-spherical PNs with detected
spherical halos around them, taken from a recent study, leads us to the claim
of a large (relative to that of non-spherical PNs) hidden population of
spherical PNs in the visible band. Building a toy model for the luminosity
evolution of PNs, we show that the claimed detection fraction of spherical PNs
based on halos around non-spherical PNs, is compatible with observational
sensitivities. We use this result to update earlier studies on the different PN
shaping routes in the binary model. We estimate that ~30% of all PNs are
spherical, namely, their progenitors did not interact with any binary
companion. This fraction is to be compared with the ~3% fraction of observed
spherical PNs among all observed PNs. From all PNs, ~15% owe their moderate
elliptical shape to the interaction of their progenitors with planets, while
\~55% of all PNs owe their elliptical or bipolar shapes to the interaction of
their progenitors with stellar companions.


title: Power Spectra in V-band and Halpha of Nine Irregular Galaxies

abstract:
  Fourier transform power spectra of major axis cuts in V and Halpha images
were made for a sample of 9 irregular galaxies. These power spectra reveal
structure over a wide range of scales. For 6 of the galaxies the power spectrum
slopes at intermediate scales (1-400 pc) in the V-band images range from -1.3
to -1.5. The similarity of slopes suggests that the same processes are
structuring these systems. These slopes are slightly shallower than what is
observed in other galaxies in HI, molecular emission, dust extinction, and
optical light. Three of the galaxies have flat power spectra like noise from
the sky; these three galaxies are relatively indistinct in the direct images.
The power spectrum slope for Halpha steepens with increasing star formation
rate, ranging from a shallow value comparable to the noise at low rates to a
steep value with a slope of -1.5 at high rates. This change reflects the
increasing areal filling factor of Halpha emission with increasing star
formation rate, and an apparently universal slope inside the Halpha regions
that is comparable to that for Kolmogorov turbulence. The power spectrum of HI
in one galaxy has a steeper power law, with a slope of -2.9. The fact that the
power laws of star formation are about the same for dwarf galaxies and giant
spiral galaxies suggests the microscopic processes are the same, independent of
spiral density waves and galaxy size.


title: A new approach to the Sachs-Wolfe effect

abstract:
  We present a new approach to the Sachs-Wolfe effect, which is based on the
dynamics of photons in a space and time varying gravitational field. We
consider the influence of plasma dispersion effects on photon propagation, and
establish the limits of validity of the usual results of the standard
cosmological approach, for the large scale temperature anisotropies of the
cosmic microwave background. New dynamical contributions to the integrated
Sachs-Wolfe effect are also discussed.


title: The cool atmospheres of the binary brown dwarf eps Indi B

abstract:
  We have imaged $\epsilon$ Indi B, the closest brown dwarf binary known, with
VISIR at the VLT in three narrow-band mid-infrared bandpasses located around
8.6$\mu$m, 10.5$\mu$m and 11.3$\mu$m. We are able to spatially resolve both
components, and determine accurate mid-infrared photometry for both components
independently. In particular, our VISIR observations probe the NH$_3$ feature
in the atmospheres of the cooler and warmer brown dwarfs. For the first time,
we can disentangle the contributions of the two components, and find that % our
photometry of $\epsilon$ IndiBb is in good agreement with recent ``cloud-free''
atmosphere models having an effective temperature of $T_\mathrm{eff}=800$ K.
With an assumed age of 1 Gyr for the $\epsilon$ Indi system, component Ba
agrees more with $T_\mathrm{eff} \approx 1100$ K rather than with
$T_\mathrm{eff}=1200$ K, as suggested by SPITZER spectroscopic observations of
the combined $\epsilon$ Indi B system (Roellig et al., 2004). Even higher
effective temperatures appear inconsistent with our absolute photometry, as
they would imply an unphysical small size of the brown dwarf $\epsilon$ IndiBa.


title: Habitable Zones in the Universe

abstract:
  Habitability varies dramatically with location and time in the universe. This
was recognized centuries ago, but it was only in the last few decades that
astronomers began to systematize the study of habitability. The introduction of
the concept of the habitable zone was key to progress in this area. The
habitable zone concept was first applied to the space around a star, now called
the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable
zones have been proposed. We review the historical development of the concept
of habitable zones and the present state of the research. We also suggest ways
to make progress on each of the habitable zones and to unify them into a single
concept encompassing the entire universe.


title:
Mass estimates from stellar proper motions: The mass of $\omega$
  Centauri

abstract:
  A projected mass estimator and a maximum likelihood estimator are developed
to best determine the mass of stellar clusters from proper motion data. Both
methods effectively account and correct for errors in the velocities, and
provide an unbiased and robust estimate of the cluster mass. Using an extensive
proper motion study of $\omega$ Centauri by van Leeuwen et al. (2000), we
estimate the mass of $\omega$ Centauri using these two different methods to be
$2.8 \times 10^{6} M_{\odot} \left[d/5.1 kpc\right]^{3}$. Within this modeling
context, the statistical error is $3\%$ and the systematic error is $4\%$.


title: Emission From Rotation-Powered Pulsars: Is It All Relative?

abstract:
  Thirty-five years after the discovery of rotation-powered pulsars, we still
do not understand the fundamentals of their pulsed emission at any wavelength.
Even detailed pulse profiles cannot identify the location of the emission in a
magnetosphere that extends from the neutron star surface to near the light
cylinder. Compounding the problem are effects of strong gravity at low
altitudes and plasma moving at relativistic speeds in the outer magnetosphere.
I will discuss the role of special and general relativistic effects on pulsar
emission, from inertial frame-dragging near the stellar surface to aberration,
time-of-flight and retardation of the magnetic field near the light cylinder.
Understanding how these effects determine what we observe at different
wavelengths is critical to unraveling the emission physics.


title:
X-ray Lighthouses of the High-Redshift Universe. II. Further Snapshot
  Observations of the Most Luminous z>4 Quasars with Chandra

abstract:
  We report on Chandra observations of a sample of 11 optically luminous
(Mb<-28.5) quasars at z=3.96-4.55 selected from the Palomar Digital Sky Survey
and the Automatic Plate Measuring Facility Survey. These are among the most
luminous z>4 quasars known and hence represent ideal witnesses of the end of
the "dark age ''. Nine quasars are detected by Chandra, with ~2-57 counts in
the observed 0.5-8 keV band. These detections increase the number of X-ray
detected AGN at z>4 to ~90; overall, Chandra has detected ~85% of the
high-redshift quasars observed with snapshot (few kilosecond) observations. PSS
1506+5220, one of the two X-ray undetected quasars, displays a number of
notable features in its rest-frame ultraviolet spectrum, the most prominent
being broad, deep SiIV and CIV absorption lines. The average optical-to-X-ray
spectral index for the present sample (<alpha_ox>=-1.88+/-0.05) is steeper than
that typically found for z>4 quasars but consistent with the expected value
from the known dependence of this spectral index on quasar luminosity.
  We present joint X-ray spectral fitting for a sample of 48 radio-quiet
quasars in the redshift range 3.99-6.28 for which Chandra observations are
available. The X-ray spectrum (~870 counts) is well parameterized by a power
law with Gamma=1.93+0.10/-0.09 in the rest-frame ~2-40 keV band, and a tight
upper limit of N_H~5x10^21 cm^-2 is obtained on any average intrinsic X-ray
absorption. There is no indication of any significant evolution in the X-ray
properties of quasars between redshifts zero and six, suggesting that the
physical processes of accretion onto massive black holes have not changed over
the bulk of cosmic time.


title:
Vegetation's Red Edge: A Possible Spectroscopic Biosignature of
  Extraterrestrial Plants

abstract:
  Earth's deciduous plants have a sharp order-of-magnitude increase in leaf
reflectance between approximately 700 and 750 nm wavelength. This strong
reflectance of Earth's vegetation suggests that surface biosignatures with
sharp spectral features might be detectable in the spectrum of scattered light
from a spatially unresolved extrasolar terrestrial planet. We assess the
potential of Earth's step-function-like spectroscopic feature, referred to as
the "red edge", as a tool for astrobiology. We review the basic characteristics
and physical origin of the red edge and summarize its use in astronomy: early
spectroscopic efforts to search for vegetation on Mars and recent reports of
detection of the red edge in the spectrum of Earthshine (i.e., the spatially
integrated scattered light spectrum of Earth). We present Earthshine
observations from Apache Point Observatory to emphasize that time variability
is key to detecting weak surface biosignatures such as the vegetation red edge.
We briefly discuss the evolutionary advantages of vegetation's red edge
reflectance, and speculate that while extraterrestrial "light harvesting
organisms" have no compelling reason to display the exact same red edge feature
as terrestrial vegetation, they might have similar spectroscopic features at
different wavelengths than terrestrial vegetation. This implies that future
terrestrial-planet-characterizing space missions should obtain data that allow
time-varying, sharp spectral features at unknown wavelengths to be identified.
We caution that some mineral reflectance edges are similar in slope and
strength to vegetation's red edge (albeit at different wavelengths); if an
extrasolar planet reflectance edge is detected care must be taken with its
interpretation.


title: Further Wolf-Rayet stars in the starburst cluster Westerlund 1

abstract:
  We present new low and intermediate-resolution spectroscopic observations of
the Wolf Rayet (WR) star population in the massive starburst cluster Westerlund
1. Finding charts are presented for five new WRs - four WNL and one WCL -
raising the current total of known WRs in the cluster to 19. We also present
new spectra and correct identifications for the majority of the 14 WR stars
previously known, notably confirming the presence of two WNVL stars. Finally we
briefly discuss the massive star population of Westerlund 1 in comparison to
other massive young galactic clusters.


title: Tuning into UHE Neutrinos in Antarctica - The ANITA Experiment

abstract:
  The Antarctic Impulsive Transient Antenna (ANITA) experiment is being
developed to search for ultra-high-energy (UHE) neutrino interactions
($>3\times10^{18}$ eV) in the Antarctic ice cap. A neutrino interaction in the
ice will produce a radio pulse by the means of the Askaryan effect. The large
radio transparency of ice allows for such a pulse to be recorded by a cluster
of balloon-borne antennas. The details of the ANITA instrument, now in a
construction phase, and the science we hope to achieve is discussed. In order
to prepare for the main mission, we have flown ANITA-lite during the 2003/04
austral season. ANITA-lite consisted of two quad-ridge horn antennas and a
prototype RF (radio frequency) triggering and recording system. Here we present
the results of an impulsive RF background survey of Antarctica, as well as
proof-of-principle gain, tracking, and timing calibrations conducted by
observing solar radio emissions and calibration radio-pulses. A preliminary UHE
neutrino flux limit based on ANITA-lite data is also presented.


title: Quasi-Periodic Oscillations in Relativistic Tori

abstract:
  Motivated by recent interesting work on p-mode oscillations in axisymmetric
hydrodynamic black-hole tori by Rezzolla, Zanotti, and collaborators, I explore
the robustness of these oscillations by means of two and three-dimensional
relativistic hydrodynamic and MHD simulations. The primary purpose of this
investigation is to determine how the amplitudes of these oscillations are
affected by the presence of known instabilities of black-hole tori, including
the Papaloizou-Pringle instability (PPI) and the magneto-rotational instability
(MRI). Both instabilities drive accretion at rates above those considered in
Rezzolla's work. The increased accretion can allow wave energy to leak out of
the torus into the hole. Furthermore, with the MRI, the presence of turbulence,
which is absent in the hydrodynamic simulations, can lead to turbulent damping
(or excitation) of modes. The current numerical results are preliminary, but
suggest that the PPI and MRI both significantly damp acoustic oscillations in
tori.


title: Ice Age Epochs and the Sun's Path Through the Galaxy

abstract:
  We present a calculation of the Sun's motion through the Milky Way Galaxy
over the last 500 million years. The integration is based upon estimates of the
Sun's current position and speed from measurements with Hipparcos and upon a
realistic model for the Galactic gravitational potential. We estimate the times
of the Sun's past spiral arm crossings for a range in assumed values of the
spiral pattern angular speed. We find that for a difference between the mean
solar and pattern speed of Omega_Sun - Omega_p = 11.9 +/- 0.7 km/s/kpc the Sun
has traversed four spiral arms at times that appear to correspond well with
long duration cold periods on Earth. This supports the idea that extended
exposure to the higher cosmic ray flux associated with spiral arms can lead to
increased cloud cover and long ice age epochs on Earth.


title:
Relativistic solutions to the problem of jets with time-dependent
  injection velocities

abstract:
  We present a ballistic description of the propagation of the working surface
of a relativistic jet. Using simple laws of conservation of mass and linear
momentum at the working surface, we obtain a full description of the jet flow
parametrised by the initial velocity and mass injection. This analysis will
soon be applied to particular cases of time-dependent injection of mass and
velocity into the jet.


title: The Relationship between Class I and Class II Methanol Masers

abstract:
  The Australia Telescope National Facility Mopra millimetre telescope has been
used to search for 95.1-GHz class I methanol masers towards sixty-two 6.6-GHz
class II methanol masers. A total of twenty-six 95.1-GHz masers were detected,
eighteen of these being new discoveries. Combining the results of this search
with observations reported in the literature, a near complete sample of
sixty-six 6.6-GHz class II methanol masers has been searched in the 95.1-GHz
transition, with detections towards 38 per cent (twenty-five detections ; not
all of the sources studied in this paper qualify for the complete sample, and
some of the sources in the sample were not observed in the present
observations). There is no evidence of an anti-correlation between either the
velocity range, or peak flux density of the class I and II transitions,
contrary to suggestions from previous studies. The majority of class I methanol
maser sources have a velocity range that partially overlaps with the class II
maser transitions. The presence of a class I methanol maser associated with a
class II maser source is not correlated with the presence (or absence) of
main-line OH or water masers. Investigations of the properties of the infrared
emission associated with the maser sources shows no significant difference
between those class II methanol masers with an associated class I maser and
those without. This may be consistent with the hypothesis that the objects
responsible for driving class I methanol masers are generally not those that
produce main-line OH, water or class II methanol masers.


title: X-ray synchrotron emission from supernova remnants

abstract:
  X-ray synchrotron emission tells us of the highest energy reached by
accelerated electrons. In a few supernova remnants (SN 1006, G347.3-0.5) this
is the dominant form of X-ray radiation, but in most it is superposed to the
dominant thermal emission. Thanks to the spectro-imaging capability of Chandra
and XMM-Newton, X-ray synchrotron emission has now been unambiguously detected
in most young supernova remnants (Cas A, Tycho, Kepler). It arises in a very
thin shell (a few arcsecs) at the blast wave. The thinness of that shell (much
broader in the radio domain) implies that the high energy electrons cool down
very fast behind the shock. The magnetic field that one deduces from that
constraint is more than 100 muG behind the shock.


title:
Discovery of a Fifth Image of the Large Separation Gravitationally
  Lensed Quasar SDSS J1004+4112

abstract:
  We report the discovery of a fifth image in the large separation lensed
quasar system SDSS J1004+4112. A faint point source located 0.2'' from the
center of the brightest galaxy in the lensing cluster is detected in images
taken with the Advanced Camera for Surveys (ACS) and the Near Infrared Camera
and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope. The flux
ratio between the point source and the brightest lensed component in the ACS
image is similar to that in the NICMOS image. The location and brightness of
the point source are consistent with lens model predictions for a lensed image.
We therefore conclude that the point source is likely to be a fifth image of
the source quasar. In addition, the NICMOS image reveals the lensed host galaxy
of the source quasar, which can strongly constrain the structure of the lensing
critical curves and thereby the mass distribution of the lensing cluster.


title: Evidence for Supernova light in all Gamma-Ray Burst afterglows

abstract:
  We present an update of our systematic analysis of all Gamma-Ray Burst (GRB)
afterglow data, now published through the end of 2004, in an attempt to detect
the predicted supernova light component. We fit the observed photometric light
curves as the sum of an afterglow, an underlying host galaxy, and a supernova
component. The latter is modeled using published UBVRI light curves of SN
1998bw as a template. The total sample of afterglows with established redshifts
contains now 29 bursts (GRB 970228 - GRB 041006). For 13 of them a weak
supernova excess (scaled to SN 1998bw) was found. In agreement with our earlier
result (Zeh et al. 2004) we find that also in the updated sample all bursts
with redshift < 0.7 show a supernova excess in their afterglow light curves.
The general lack of a detection of a supernova component at larger redshifts
can be explained with selection effects. These results strongly support our
previous conclusion based on all afterglow data of the years 1997 to 2002 that
in fact all afterglows of long-duration GRBs contain light from an associated
supernova.


title:
The WEBT campaign to observe AO 0235+16 in the 2003-2004 observing
  season

abstract:
  A multiwavelength campaign on the BL Lac object AO 0235+16 has been organized
by the WEBT collaboration during the observing seasons 2003-2004 and 2004-2005.
Here we report on the results of the first season, which saw the participation
of 24 optical and near-IR telescopes and 4 radio telescopes, as well as the
first XMM-Newton pointing, which occurred on January 18-19, 2004. Unpublished
data from previous epochs were also collected. In the optical and near-IR the
source has been very active in the last 3 years, though rather faint most of
the time, with noticeable variations of more than a mag in a few days. In
contrast, in the radio bands it appears "quiescent" since early 2000. The X-ray
spectra obtained by the three EPIC detectors are well fitted by a power law
with extra-absorption at z=0.524. No significant variation of the X-ray flux
occurred during the pointing. In contrast, contemporaneous dense radio
monitoring with the 100 m telescope at Effelsberg shows a ~2-3% flux decrease
in 6-7 hours, which, if intrinsic, would imply a brightness temperature well
above the Compton limit. We construct the broad-band spectral energy
distribution of January 18-19, 2004 with simultaneous radio data from
Effelsberg, optical data from the Nordic Optical Telescope, optical-UV data
from the Optical Monitor onboard XMM-Newton, and X-ray data by the EPIC
instruments. Particular care was taken to correct data for extinction due to
both the Milky Way and the z=0.524 absorber. The resulting SED suggests the
existence of a bump in the UV spectral region.


title: PNe in the dwarf galaxy NGC 6822: Detection of new candidates

abstract:
  We have discovered 13 new candidate Planetary Nebulae (PNe) in the dwarf
irregular galaxy NGC 6822, increasing its total number to 17 objects. Our
sample of candidate PNe is complete down to 3.5 mag below the brightest PN.


title: Lopsided spiral galaxies: evidence for gas accretion

abstract:
  We quantify the degree of lopsidedness for a sample of 149 galaxies observed
in the near-infrared from the OSUBGS sample, and try to explain the physical
origin for the observed disk lopsidedness. We confirm previous studies, but now
for a larger sample, that a large fraction of galaxies show significant
lopsidedness in their stellar disks, measured as the Fourier amplitude of the
m=1 component, normalised to the average or m=0 component, in the surface
density. Late-type galaxies are found to be more lopsided, while the presence
of m=2 spiral arms and bars is correlated. The m=1 amplitude is found to be
uncorrelated with the tidal forces acting on a galaxy via nearby companions.
Numerical simulations are carried out to study the generation of m=1 via
different processes: galaxy tidal encounters, galaxy mergers, and external gas
accretion and subsequent star formation. The simulations show that galaxy
interactions and mergers can trigger strong lopsidedness, but do not explain
several independent statistical properties of observed galaxies. To explain all
the observational results, it is required that a large fraction of lopsidedness
results from cosmological accretion of gas on galactic disks, which can create
strongly lopsided disks when this accretion is asymmetrical enough.


title: Astrophysical Observations: Lensing and Eclipsing Einstein's Theories

abstract:
  Albert Einstein postulated the equivalence of energy and mass, developed the
theory of special relativity, explained the photoelectric effect, and described
Brownian motion in five papers, all published in 1905, 100 years ago. With
these papers, Einstein provided the framework for understanding modern
astrophysical phenomena. Conversely, astrophysical observations provide one of
the most effective means for testing Einstein's theories. Here, I review
astrophysical advances precipitated by Einstein's insights, including
gravitational redshifts, gravitational lensing, gravitational waves, the
Lense-Thirring effect, and modern cosmology. A complete understanding of
cosmology, from the earliest moments to the ultimate fate of the universe, will
require developments in physics beyond Einstein, to a unified theory of gravity
and quantum physics.


title: Particle Acceleration in Relativistic Flows

abstract:
  A property common to several different astrophysical sources of high-energy
gamma-rays is the presence of bulk motion at relativistic speed. The intrinsic
spectra of the nonthermal radiating particles also show interesting
similarities, with a pronounced hardening towards lower energies. This suggests
two distinct acceleration mechanisms could be at work in these sources. At high
energies, the stochastic first-order Fermi process at shocks seems to provide a
reasonable explanation. I will briefly review the status of this mechanism
before discussing the possibility that, at lower energies, non-stochastic
acceleration in the induced electric field of a relativistic current sheet
plays a role.


title:
Upper limits on CO 4.7 micron emission from disks around five Herbig
  Ae/Be stars

abstract:
  We present the results of medium-resolution spectroscopy of five nearby
Herbig Ae/Be stars at 4.7 micron: UX Ori, HD 34282, HD 50138, V380 Ori, HK Ori.
The goal was to search for CO fundamental ro-vibrational emission. None of the
targets show CO features, either in absorption nor in emission. We derive a
5sigma upper limit of < 10^-12 cm^-2 to the column density of hot CO (T ~ 1500
K) in the sources. These upper limits are considerably lower than the values of
Herbig Ae/Be stars for which warm and hot CO emission has been reported.The
non-detection of CO v=1-0 emission in these five targets suggest that Herbig
Ae/Be stars are not a homogeneous group with respect to the structure of the
gaseous disk and/or the amount of CO in the inner 50 AU of their disks.


title:
Non-thermal X-rays, a high abundance ridge and fossil bubbles in the
  core of the Perseus cluster of galaxies

abstract:
  Using a deep Chandra observation of the Perseus cluster of galaxies, we find
a high-abundance shell 250 arcsec (93 kpc) from the central nucleus. This ridge
lies at the edge of the Perseus radio mini-halo. In addition we identify two
Halpha filaments pointing towards this shell. We hypothesise that this ridge is
the edge of a fossil radio bubble, formed by entrained enriched material lifted
from the core of the cluster. There is a temperature jump outside the shell,
but the pressure is continuous indicating a cold front. A non-thermal component
is mapped over the core of the cluster with a morphology similar to the
mini-halo. Its total luminosity is 4.8x10^43 erg/s, extending in radius to ~75
kpc. Assuming the non-thermal emission is the result of inverse Compton
scattering of the CMB and infrared emission from NGC 1275, we map the magnetic
field over the core of the cluster.


title: An Overview of the Performance of the Chandra X-Ray Observatory

abstract:
  The Chandra X-ray Observatory is the X-ray component of NASA's Great
Observatory Program which includes the recently launched Spitzer Infrared
Telescope, the Hubble Space Telescope (HST) for observations in the visible,
and the Compton Gamma-Ray Observatory (CGRO) which, after providing years of
useful data has reentered the atmosphere. All these facilities provide, or
provided, scientific data to the international astronomical community in
response to peer-reviewed proposals for their use. The Chandra X-ray
Observatory was the result of the efforts of many academic, commercial, and
government organizations primarily in the United States but also in Europe.
NASA's Marshall Space Flight Center (MSFC) manages the Project and provides
Project Science; Northrop Grumman Space Technology (NGST -- formerly TRW)
served as prime contractor responsible for providing the spacecraft, the
telescope, and assembling and testing the Observatory; and the Smithsonian
Astrophysical Observatory (SAO) provides technical support and is responsible
for ground operations including the Chandra X-ray Center (CXC). Telescope and
instrument teams at SAO, the Massachusetts Institute of Technology (MIT), the
Pennsylvania State University (PSU), the Space Research Institute of the
Netherlands (SRON), the Max-Planck Institut fur extraterrestrische Physik
(MPE), and the University of Kiel also provide technical support to the Chandra
Project. We present here a detailed description of the hardware, its on-orbit
performance, and a brief overview of some of the remarkable discoveries that
illustrate that performance.


title: HST/ACS Lyman alpha imaging of the nearby starburst ESO338-IG04

abstract:
  ESO338-IG04 is a well known, local, luminous Blue Compact Galaxy. It has a
complex morphology and contains a central young starburst with compact young
star clusters. The galaxy was imaged using HST/ACS in the Lyman alpha line and
continuum. Using the Starburst99 synthetic spectra and other imaging data from
HST/WFPC2 we developed a technique that allows us to make the first
photometrically valid continuum subtraction for the LYa line. Our results are
in qualitative agreement with the models of LYa escape being regulated by
kinematical properties of the interstellar medium. The line-only image shows
LYa in both emission and absorption. Notably, emission is seen from central
bright young clusters and is in spatial agreement with the features present in
a longslit spectrum taken with HST/STIS. Diffuse LYa emission regions are seen
surrounding the central starburst where photons escape after one or more
resonant scatterings in HI. These regions dominate the total LYa output.
Photometry reveals a total LYa flux of 194 x 10^-14 erg/s/cm^2. Inside an
artificial aperture matching that of the IUE satelite, we measure a LYa flux
and equivalent width consistent with previous studies using the IUE. Analysis
of parameter dependencies show our technique to be largely parameter
independent, producing LYa maps indistinguishable from one another by eye and
with fluxes consistent with one another to better than 50%. By comparison of
LYa fluxes with Ha fluxes of a previous study, we estimate that each observed
LYa photon has undergone ~2 additional scatterings. We see that LYa line
closely correlate with other tracers of kinematics.


title: Detection of Neutrinos from Supernovae in Nearby Galaxies

abstract:
  While existing detectors would see a burst of many neutrinos from a Milky Way
supernova, the supernova rate is only a few per century. As an alternative, we
propose the detection of ~ 1 neutrino per supernova from galaxies within 10
Mpc, in which there were at least 9 core-collapse supernovae since 2002. With a
future 1-Mton scale detector, this could be a faster method for measuring the
supernova neutrino spectrum, which is essential for calibrating numerical
models and predicting the redshifted diffuse spectrum from distant supernovae.
It would also allow a > 10^4 times more precise trigger time than optical data
alone for high-energy neutrinos and gravitational waves.


title:
Galactic Wind Shells and High Redshift Radio Galaxies On the Nature of
  Associated Absorbers

abstract:
  A jet is simulated on the background of a galactic wind headed by a radiative
bow shock. The wind shell, which is due to the radiative bow shock, is
effectively destroyed by the impact of the jet cocoon, thanks to
Rayleigh-Taylor instabilities. Associated strong HI absorption, and possibly
also molecular emission, in high redshift radio galaxies which is observed
preferentially in the smaller ones may be explained by that model, which is an
improvement of an earlier radiative bow shock model. The model requires
temperatures of $\approx 10^6$ K in the proto-clusters hosting these objects,
and may be tested by high resolution spectroscopy of the Ly$\alpha$ line. The
simulations show that -- before destruction -- the jet cocoon fills the wind
shell entirely for a considerable time with intact absorption system.
Therefore, radio imaging of sources smaller than the critical size should
reveal the round central bubbles, if the model is correct.


title: Evolving Disks in Cold Dark Matter Cosmology

abstract:
  Despite having entered the era of "precision cosmology," the formation of
galaxies within the favored CDM cosmological paradigm remains problematic. By
relating our N-body/smooth particle hydro-dynamical simulation to an extensive
range of Galactic and extragalactic observations, we shed light on the
formation and evolution of the Milky Way and other late type galaxies. In light
of recent observations of the stellar populations of extragalactic thick disks,
we examine the proposal that the thick disk formed in a high redshift period
characterized by gas rich merging. We show such a scenario to be consistent
with color observations. We then follow the evolution of structural parameters
of the subsequently formed disk galaxy, from redshift ~1 to the present.
Consistent with observation, little evolution in the ratio of scale-height to
scale-length is found in our simulated galaxy, despite its somewhat chaotic
origins. The simulated galaxy in this report forms part of a larger study of a
suite of galaxies, with which these issues are to be studied in detail.


title: Supernova 1954J (Variable 12) in NGC 2403 Unmasked

abstract:
  We have confirmed that the precursor star of the unusual Supernova 1954J
(also known as Variable 12) in NGC 2403 survived what appears to have been a
super-outburst, similar to the 1843 Great Eruption of eta Carinae in the
Galaxy. The apparent survivor has changed little in brightness and color over
the last eight years, and a Keck spectrum reveals characteristics broadly
similar to those of eta Car. This is further suggested by our identification of
the actual outburst-surviving star in high-resolution images obtained with the
Advanced Camera for Surveys on the Hubble Space Telescope. We reveal this
``supernova impostor'' as a highly luminous (M_V^0 ~ -8.0 mag), very massive
(M_initial >~ 25 Msun) eruptive star, now surrounded by a dusty (A_V ~ 4 mag)
nebula, similar to eta Car's famous Homunculus.


title: Do Black Holes Produce Phantom Energy?

abstract:
  We conjecture that black holes, whether accreting matter or not, can also
lose mass to phantom energy production. Such a process can be made plausible in
theories that allow for non-local connections between short and long wavelength
modes. If true, observational data should show an exchange of energy from
matter to phantom at some cosmic epoch, and we discuss a simple model. Some
remarks on an appropriate quantum gravity theory and related issues are also
presented.


title:
G313.3+00.3: A New Planetary Nebula discovered by the Australia
  Telescope Compact Array and the Spitzer Space Telescope

abstract:
  We present a new planetary nebula, first identified in images from the
Australia Telescope Compact Array, although not recognized at that time. Recent
observations with the Spitzer Space Telescope during the GLIMPSE Legacy program
have rediscovered the object. The high-resolution radio and infrared images
enable the identification of the central star or its wind, the recognition of
the radio emission as thermal, and the probable presence of polycylic aromatic
hydrocarbons in and around the source. These lead to the conclusion that
G313.3+00.3 is a planetary nebula. This object is of particular interest
because it was discovered solely through radio and mid-infrared imaging,
without any optical (or near-infrared) confirmation, and acts as a proof of
concept for the discovery of many more highly extinguished planetary nebulae.
G313.3+00.3 is well-resolved by both the instruments with which it was
identified, and suffers extreme reddening due to its location in the
Scutum-Crux spiral arm.


title:
Near-Infrared echelle spectroscopy of Proto-Planetary Nebulae: probing
  the fast wind in H2

abstract:
  Echelle spectroscopy of H2, [FeII] and Br-gamma line emission from a very
young planetary nebula, IRAS 21282+5050, and from four proto-planetary nebulae,
IRAS 19343+2926 (M 1-92), IRAS 17150-3224 (AFGL 6815), IRAS 17423-1755 (Hen
3-1475), and IRAS 17441-2411 is presented. H2 line emission is detected in
discrete shock fronts in the lobes of each nebula, regardless of source
spectral type. In IRAS 17150-3224 we also uncover possible signs of rotation,
as would be expected if the H2 features were excited in a magneto-centrifugal
disk wind. [FeII] emission was detected in only one source, M 1-92. The H2 and
[FeII] observations of M 1-92, and the complex H2 profiles in IRAS 21282+5050,
are explained using the shock models of Smith and collaborators. J-type bow
models are adequate in each case, i.e. a strongly-magnetised wind is not
required. Finally, Br-gamma is detected in each of the five targets; in
absorption in the G-type PPN though in emission in the O and B-type sources.
Br-gamma emission is detected predominantly toward the near-IR continuum peak
in each PPN. Low peak velocities, though very broad profile widths, are
measured in each target. The emission must therefore derive from ionised
regions in a fast wind very close to the central star, or, in the late-type
sources, from absorption in an equatorial torus.


title: Neutrino Mass Limit from Galaxy Cluster Number Density Evolution

abstract:
  Measurements of the evolution with redshift of the number density of massive
galaxy clusters are used to constrain the energy density of massive neutrinos
and so the sum of neutrino masses $\sum m_\nu$. We consider a spatially-flat
cosmological model with cosmological constant, cold dark matter, baryonic
matter, and massive neutrinos. Accounting for the uncertainties in the
measurements of the relevant cosmological parameters we obtain a limit of $\sum
m_\nu$ $<$ 2.4 eV (95 % C.L.).


title:
CMB Polarimetry using Correlation Receivers with the PIQUE and CAPMAP
  Experiments

abstract:
  The Princeton IQU Experiment (PIQUE) and the Cosmic Anisotropy Polarization
MAPper (CAPMAP) are experiments designed to measure the polarization of the
Cosmic Microwave Background (CMB) on sub-degree scales in an area within 1
degree of the North Celestial Pole using heterodyne correlation polarimeters
and off-axis telescopes located in central New Jersey. PIQUE produced the
tightest limit on the CMB polarization prior to its detection by DASI, while
CAPMAP has recently detected polarization at l~1000. The experimental methods
and instrumentation for these two projects are described in detail with
emphasis on the particular challenges involved in measuring the tiny polarized
component of the CMB.


title: Forming a Primordial Star in a Relic HII Region

abstract:
  There has been considerable theoretical debate over whether photoionization
and supernova feedback from the first Population III stars facilitate or
suppress the formation of the next generation of stars. We present results from
an Eulerian adaptive mesh refinement simulation demonstrating the formation of
a primordial star within a region ionized by an earlier nearby star. Despite
the higher temperatures of the ionized gas and its flow out of the dark matter
potential wells, this second star formed within 23 million years of its
neighbor's death. The enhanced electron fraction within the HII region
catalyzes rapid molecular hydrogen formation that leads to faster cooling in
the subsequent star forming halos than in the first halos. This "second
generation" primordial protostar has a much lower accretion rate because,
unlike the first protostar, it forms in a rotationally supported disk of
approx. 10-100 solar masses. This is primarily due to the much higher angular
momentum of the halo in which the second star forms. In contrast to previously
published scenarios, such configurations may allow binaries or multiple systems
of lower mass stars to form. These first high resolution calculations offer
insight into the impact of feedback upon subsequent populations of stars and
clearly demonstrate how primordial chemistry promotes the formation of
subsequent generations of stars even in the presence of the entropy injected by
the first stars into the IGM.


title: The Vela Pulsar in the Ultraviolet

abstract:
  We describe time-tagged observations of the Vela pulsar (PSR B0833-45) with
the HST STIS MAMA-UV detectors. Using an optimal extraction technique, we
obtain a NUV light curve and crude FUV phase-resolved spectra. The pulse is
dominated by complex non-thermal emission at all phases. We obtain approximate
spectral indices for the brightest pulse components, relate these to pulsations
observed in other wavebands, and constrain the thermal surface emission from
the neutron star. An upper limit on the Rayleigh-Jeans component at UV pulse
minimum suggests a rather low mean surface temperature T_eff^\infty <4.6 x 10^5
(d_{300}/R_{14.2})^2 K. If confirmed by improved phase-resolved spectroscopy,
this observation has significant impact on our understanding of neutron star
interiors.


title: Collisionless Plasma Shocks. Field Generation and Particle Acceleration

abstract:
  Gamma ray bursts are among the most energetic events in the known universe. A
highly relativistic fireball is ejected. In most cases the burst itself is
followed by an afterglow, emitted under deceleration as the fireball plunges
through the circum-stellar media. To interpret the observations of the
afterglow emission, two physical aspects need to be understood: 1) The origin
and nature of the magnetic field in the fireball and 2) the particle velocity
distribution function behind the shock. Both are necessary in existing
afterglow models to account for what is believed to be synchrotron radiation.
To answer these questions, we need to understand the microphysics at play in
collisionless shocks. Using 3D particle-in-cell simulations we can gain insight
in the microphysical processes that take place in such shocks. We discuss the
results of such computer experiments. It is shown how a Weibel-like two-stream
plasma instability is able to create a strong transverse intermittent magnetic
field and points to a connected mechanism for in situ particle acceleration in
the shock region.


title:
High Angular Resolution Observations of the Collimated Jet Source
  Associated with a Massive Protostar in IRAS 16547-4247

abstract:
  A triple radio source recently detected in association with the luminous
infrared source IRAS 16547-4247 has been studied with high angular resolution
and high sensitivity with the Very Large Array at 3.6 and 2 cm. Our
observations confirm the interpretation that the central object is a thermal
radio jet, while the two outer lobes are most probably heavily obscured HH
objects. The thermal radio jet is resolved angularly for the first time and
found to align closely with the outer lobes. The opening angle of the thermal
jet is estimated to be $\sim 25^\circ$, confirming that collimated outflows can
also be present in massive protostars. The proper motions of the outer lobes
should be measurable over timescales of a few years. Several fainter sources
detected in the region are most probably associated with other stars in a young
cluster.


title: Is the `IR Coincidence' Just That?

abstract:
  (Abridged) Motch (1985) suggested that in the hard state of GX 339-4 the soft
X-ray power-law extrapolated backward in energy agrees with the IR flux. Corbel
& Fender (2002) showed that the hard state radio power-law extrapolated forward
in energy meets the extrapolated X-ray power-law at an IR break, which was
explicitly observed twice in GX 339-4. This `IR coincidence' has been cited as
further evidence that a jet might make a significant contribution to the X-rays
in hard state systems. We explore this hypothesis with a series of simultaneous
radio/X-ray observations of GX 339-4, taken during its 1997, 1999, and 2002
hard states. We fit these spectra, in detector space, with a simple, but
remarkably successful, doubly broken power-law that requires an IR spectral
break. For these observations, the break position and the integrated radio/IR
flux have stronger dependences upon the X-rays than the simplest jet
predictions. If one allows for a softening of the X-ray power law with
increasing flux, then the jet model agrees with the correlation. We also find
evidence that the radio/X-ray fcorrelation previously observed in GX 339-4
shows a `parallel track' for the 2002 hard state. The slope of the 2002
correlation is consistent with prior observations; however, the radio amplitude
is reduced. We then examine the correlation in Cyg X-1 through the use of radio
data, obtained with the Ryle radio telescope, and RXTE data, from the ASM and
pointed observations. We again find evidence of `parallel tracks', and here
they are associated with `failed transitions' to the soft state. We also find
that for Cyg X-1 the radio flux is more fundamentally correlated with the hard
X-ray flux.


title:
Possibility of Ultra High-Energy Cosmic Rays from the Giant Flare in SGR
  1806-20

abstract:
  On 2004 December 27, a giant flare from the soft gamma repeater 1806$-$20 was
observed. The radiation mechanism of the initial peak of the flare would be
controversial. In this letter we point out that very high-energy cosmic rays
would be produced in the case that the flare was caused by internal shocks, as
is usually considered for gamma-ray bursts. The highest energy of cosmic rays
can reach $10^{19}$ eV, if the Lorentz factor of the shocks is sufficiently
high. Future observations of cosmic rays will inform us about the mechanism of
the giant flare.


title: Hydrodynamical scaling laws for astrophysical jets

abstract:
  The idea of a unified model for all astrophysical jets has been considered
for some time now. We present here some hydrodynamical scaling laws relevant
for all type of astrophysical jets, analogous to those of Sams et al. (1996).
We use Buckingham's Pi theorem of dimensional analysis to obtain a family of
dimensional relations among the physical quantities associated with the jets.


title:
The Origin of Massive O-type Field Stars. Part II: Field O stars as
  runaways

abstract:
  In two papers we try to confirm that all Galactic high-mass stars are formed
in a cluster environment, by excluding that O-type stars found in the Galactic
field actually formed there. In de Wit et al. (2004) we presented deep K-band
imaging of 5 arcmin fields centred on 43 massive O-type field stars that
revealed that the large majority of these objects are single objects. In this
contribution we explore the possibility that the field O stars are dynamically
ejected from young clusters, by investigating their peculiar space velocity
distribution, their distance from the Galactic plane, and their spatial
vicinity to known young stellar clusters. We (re-)identify 22 field O-type
stars as candidate runaway OB-stars. The statistics show that ~4% of all O-type
stars with V < 8 can be considered as formed outside a cluster environment.
Most are spectroscopically single objects, some are visual binaries. The
derived percentage for O-type stars that form isolated in the field based on
our statistical analyses is in agreement with what is expected from
calculations adopting a universal cluster richness distribution with power
index of beta = 1.7, assuming that the cluster richness distribution is
continuous down to the smallest clusters containing one single star.


title:
Distributions of the Hardness Ratio of short and Long Gamma-Ray Bursts
  in Different Time Intervals within the First 2 Seconds

abstract:
  In the present paper, we investigated the distribution of hardness ratio (HR)
for short and long gamma-ray bursts (GRBs) in different time scales for the
first two seconds. After including and subtracting the background count, we
performed a Kolmogorov--Smirnov (K-S) test to the HR distributions of the two
classes of GRBs in each time interval. Our analysis shows that the
probabilities of the KS test to the distributions are very small, suggesting
that the two classes of bursts are unlikely to arise from the same HR
distributions, and indicating that they probably originate from the different
physical processes and central engine. In addition, we found that the hardness
ratio of short bursts within the time interval of 0$-$0.96 seconds changes
hard-to-soft, on the other hand long bursts do not. The two kinds of bursts
have different characteristics in the first 2 seconds which might be associated
with different physical mechanisms.


title: Spectroscopy of the type Ia supernova SN 2002er: days -11 to +215

abstract:
  We present an extensive set of optical spectroscopy of the nearby type Ia
supernova, SN 2002er, with 24 epochs spanning -11 to +34 days. Its spectral
evolution is fairly typical of a type Ia supernova although it suffers high
extinction. Nevertheless, there are differences in the spectral evolution when
compared to coeval spectra of other normal type Ia supernova with comparable
decline-rate parameters. Modelling of the photospheric phase spectra using a
homogeneous abundance distribution in the atmosphere provides a fair match to
the observations, but only by pushing the adopted distance and risetime close
to the observational limits. Future improvements here will require models with
a more realtistic stratified abundance distribution. From simple modelling of a
nebular spectrum obtained at +215d, we infer a 56Ni mass of 0.69Msun,
consistent with that derived from the light curve.


title:
Runaway core collapse and cluster survival: where are the parent
  clusters of ULXs?

abstract:
  Accreting intermediate-mass black holes (IMBHs) have been proposed as an
explanation for ultraluminous X-ray sources (ULXs). Runaway core collapse
inside a massive cluster is a possible mechanism for IMBH formation. But if so,
why are ULXs only rarely found associated with a cluster? We use a simple
analytical approximation to show that rapid core collapse can occur in two
physical regimes. For cluster masses ~ 10^6 M_sun, an IMBH may be formed if the
collapse timescale is <~ 3 Myr, as already well known; the parent cluster is
expected to survive. For cluster masses ~ 10^5 M_sun, an IMBH may result from a
core collapse on even shorter timescales (~ 0.5 Myr), when the protocluster is
still embedded in optically thick gas. Most clusters in this latter regime are
disrupted ``explosively'' as soon as the gas is ionized by the OB stars. We
speculate that this process may produce isolated ULXs with masses up to a few
10^2 M_sun, surrounded by a loose OB association, and perhaps by a nebula,
remnant of the expanding gas from the disrupted protocluster.


title: How is Binary Radio-Pulsars with Black Holes Population Rich?

abstract:
  Using "Scenario Machine" we have carried out population synthesis of radio
pulsar with black hole binaries (BH+Psr) in context of the most wide
assumptions about star mass loss during evolution, binary stars mass ratio
distribution, kick velocity and envelope mass lost during collapse. Our purpose
is to display that under any suppositional parameters of evolution scenario
BH+Psr population have to be abundant in Galaxy. It is shown that in the all
models including models evolved by Heger et al. (2002), Woosley et al. (2002),
Heger et al. (2003) expected number of the black holes paired with radio
pulsars is sufficient enough to discover such systems within the next few
years.


title:
Forward modeling of stellar coronae: from a 3D MHD model to synthetic
  EUV spectra

abstract:
  A forward model is described in which we synthesize spectra from an ab-initio
3D MHD simulation of an outer stellar atmosphere, where the coronal heating is
based on braiding of magnetic flux due to photospheric footpoint motions. We
discuss the validity of assumptions such as ionization equilibrium and
investigate the applicability of diagnostics like the differential emission
measure inversion. We find that the general appearance of the synthesized
corona is similar to the solar corona and that, on a statistical basis,
integral quantities such as average Doppler shifts or differential emission
measures are reproduced remarkably well. The persistent redshifts in the
transition region, which have puzzled theorists since their discovery, are
explained by this model as caused by the flows induced by the heating through
braiding of magnetic flux. While the model corona is only slowly evolving in
intensity, as is observed, the amount of structure and variability in Doppler
shift is very large. This emphasizes the need for fast coronal spectroscopy, as
the dynamical response of the corona to the heating process manifests itself in
a comparably slow evolving coronal intensity but rapid changes in Doppler
shift.


title:
Scattering of Gravitational Waves by the Weak Gravitational Fields of
  Lens Objects

abstract:
  We consider the scattering of the gravitational waves by the weak
gravitational fields of lens objects. We obtain the scattered gravitational
waveform by treating the gravitational potential of the lens to first order,
i.e. using the Born approximation. We find that the effect of scattering on the
waveform is roughly given by the Schwarzschild radius of the lens divided by
the wavelength of gravitational wave for a compact lens object. If the lenses
are smoothly distributed, the effect of scattering is of the order of the
convergence field $\kappa$ along the line of sight to the source. In the short
wavelength limit, the amplitude is magnified by $1+\kappa$, which is consistent
with the result in weak gravitational lensing.


title: Abundance Analyses of Field RV Tauri Stars, VI: An Extended Sample

abstract:
  An abundance analysis is presented and discussed for a sample of 14 RV Tauri
stars. The present abundance data and those from our previous papers and by
other workers are combined in an attempt to further understanding of the
dust-gas separation process which afflicts many RV Tauri variables. We propose
that a star's intrinsic (i.e., initial) metallicity is given by the
photospheric zinc abundance. Variables warmer that about 5000 K and with an
initial metallicity [Fe/H] $\geq$ $-$1 are affected by dust-gas separation.
Variables of all metallicities and cooler than about $T_{\rm eff} \simeq 5000$
K are unaffected by dust-gas separation. The RV Tauri variables show a spread
in their C abundances with the lower boundary of the points in the C versus Zn
plane falling close to the predicted trend for giants after the first
dredge-up. The upper boundary is inhabited by a few stars that are carbon-rich.
The O abundances in the mean follow the predicted trend from unevolved stars in
line with the expectation that photospheric O abundance is unaffected by the
first dredge-up. An evolutionary scenario involving mass loss by a first ascent
or early-AGB red giant, the primary star of a binary, is sketched.


title:
Analysis of medium resolution spectra by automated methods - application
  to M55 and omega Centauri

abstract:
  We have employed feedforward neural networks trained on synthetic spectra in
the range 3800 to 5600 AA with resolutions of 2-3 AA to determine metallicities
from spectra of about 1000 main-sequence turn-off, subgiant and red giant stars
in the globular clusters M55 and omega Cen. The overall metallicity accuracies
are of the order of 0.15 to 0.2 dex. In addition, we tested how well the
stellar parameters logg and Teff can be retrieved from such data without
additional colour or photometric information. We find overall uncertainties of
0.3 to 0.4 dex for logg and 140 to 190 K for Teff. In order to obtain some
measure of uncertainty for the determined values of [Fe/H], logg and Teff, we
applied the bootstrap method for the first time to neural networks for this
kind of parametrization problem. The distribution of metallicities for stars in
omega Cen clearly shows a large spread in agreement with the well known
multiple stellar populations in this cluster.


title: A new calibration of stellar parameters of Galactic O stars

abstract:
  We present new calibrations of stellar parameters of O stars at solar
metallicity taking non-LTE, wind, and line-blanketing effects into account.
Gravities and absolute visual magnitudes are derived from results of recent
spectroscopic analyses. Two types of effective temperature scales are derived:
one from a compilation based on recent spectroscopic studies of a sample of
massive stars - the ``observational scale'' - and the other from direct
interpolations on a grid of non-LTE spherically extended line-blanketed models
computed with the code CMFGEN (Hillier & Miller 1998) - the ``theoretical
scale''. These Teff scales are then further used together with the grid of
models to calibrate other parameters (bolometric correction, luminosity,
radius, spectroscopic mass and ionising fluxes) as a function of spectral type
and luminosity class. Compared to the earlier calibrations of Vacca et al.
(1996) the main results are: 1) the effective temperature scales are cooler by
2000 to 8000 K, the reduction being the largest for early supergiants; 2)
bolometric corrections are lower by 0.1 mag for a given temperature, and are
lower by 0.3 - 0.6 mag for a given spectral type; 3) luminosities are reduced
by 0.20 to 0.35 dex; 4) Lyman ionising fluxes are lower by 0.20 to 0.80 dex. We
provide calibration tables for each luminosity class and for both types of Teff
scales.


title:
An analytic approach to the late ISW effect in a Lambda dominated
  universe

abstract:
  The integrated Sachs-Wolfe (ISW) effect in a Lambda dominated universe can be
an important factor in the evolution of cosmic microwave background
fluctuations. With the inclusion of cosmological constant we present the
complete analytic solution of the covariant linear perturbations of the
Einstein equations in the Newtonian gauge, in the case of a spatially flat
(K=0), Friedman-Robertson-Walker (FRW) universe, filled with pressureless ideal
fluid. We use the analytic time dependence of the perturbation potentials to
derive the anisotropy power spectrum of the late ISW effect. We choose the
scale invariant Harrison-Zeldovich spectrum for obtaining the C_l momenta and
show the agreement of our results with earlier, numeric calculations.


title: TeV photons and Neutrinos from giant soft-gamma repeaters flares

abstract:
  During the last 35 years three giant flares were observed from so-called Soft
Gamma Repeaters (SGR's). They are assumed to be associated with star-quakes of
pulsars accelerating electrons and, possibly, protons to high energy in the
huge magnetic fields as inferred from the observations. Because of this and the
observation of non-thermal emission it has been speculated that they may be
cosmic ray accelerators producing gamma-rays up to TeV energies. Neutrino
telescopes, such as AMANDA and the ANTARES now under construction, could be
used as TeV-gamma detectors for very short emissions by measuring underground
muons produced in $\gamma$ showers. We estimate signal and background rates for
TeV photons from SGR giant flares in AMANDA, and we provide an estimate of the
gamma shower events that Milagro could detect.
  Moreover, we consider that, if hadrons are accelerated in these sources, high
energy neutrinos would be produced together with photons. These may be detected
in neutrino telescopes using neutrino-induced cascades and upgoing muons.
  We argue that the Antarctic Muon and Neutrino Detector Array AMANDA may have
observed the December 27, 2004 giant flare from the soft gamma-ray repeater SGR
1806-20 if the non-thermal component of the spectrum extends to TeV energies
(at present the actual data is subject to blind analysis). Rates should be
scaled by about two orders of magnitude in km3 detectors, such as IceCube,
making SGR flares sources of primary interest.


title: Cosmology with massive neutrinos coupled to dark energy

abstract:
  Cosmological consequences of a coupling between massive neutrinos and dark
energy are investigated. In such models, the neutrino mass is a function of a
scalar field, which plays the role of dark energy. The background evolution, as
well as the evolution of cosmological perturbations is discussed. We find that
mass-varying neutrinos can leave a significant imprint on the anisotropies in
the cosmic microwave background radiation and even lead to a reduction of power
on large angular scales.


title: Ongoing Space Physics - Astrophysics Connections

abstract:
  I review several ongoing connections between space physics and astrophysics:
a) Measurements of energetic particle spectra have confirmed theoretical
prediction of the highest energy to which shocks can accelerate particles, and
this has direct bearing on the origin of the highest energy cosmic rays. b)
Mass ejection in solar flares may help us understand photon ejection in the
giant flares of magnetar outbursts. c) Measurements of electron heat fluxes in
the solar wind can help us understand whether heat flux in tenuous
astrophysical plasma is in accordance with the classical Spitzer-Harm formula
or whether it is reduced well below this value by plasma instabilities.


title: Extreme X-ray spectral variability in the Seyfert 2 Galaxy NGC 1365

abstract:
  We present multiple Chandra and XMM-Newton observations of the type 1.8
Seyfert Galaxy NGC 1365, which shows the most dramatic X-ray spectral changes
observed so far in an AGN: the source switched from reflection dominated to
transmission dominated and back in just 6 weeks. During this time the soft
thermal component, arising from a ~1 kpc region around the center, remained
constant. The reflection component is constant at all timescales, and its high
flux relative to the primary component implies the presence of thick gas
covering a large fraction of the solid angle. The presence of this gas, and the
fast variability time scale, suggest that the Compton-thick to Compton thin
change is due to variation in the line-of-sight absorber, rather than to
extreme intrinsic emission variability. We discuss a structure of the
circumnuclear absorber/reflector which can explain the observed X-ray spectral
and temporal properties.


title: INTEGRAL observations of SS433: Results of coordinated campaign

abstract:
  Results of simultaneous INTEGRAL and optical observations of galactic
microquasar SS433 in May 2003 and INTEGRAL/RXTE observations in March 2004 are
presented. Persistent precessional variability with a maximum to minimum
uneclipsed hard X-ray flux ratio of \sim 4 is discovered. The 18-60 keV X-ray
eclipse is found to be in phase with optical and near infrared eclipses. The
orbital eclipse observed by INTEGRAL in May 2003 is at least two times deeper
and apparently wider than in soft X-ray band. The broadband X-ray spectrum
2-100 keV simultaneously detected by RXTE/INTEGRAL in March 2004 can be
described by bremsstrahlung emission from optically thin thermal plasma with
kT\sim 30 keV. The optical spectroscopy with the 6-m SAO BTA telescope
confirmed the optical companion to be an A5-A7 supergiant. For the first time,
spectorscopic indications of a strong heating effect in the optical star
atmosphere are found. The measurements of absorption lines which are presumably
formed in the non-illuminated side of the supergiant yield its radial velocity
semi-amplitude K_v=132\pm 9 km/s. The analysis of the observed hard X-ray light
curve and the eclipse duration, combined with spectroscopically found optical
star radial velocity corrected for the strong heating effect, allows us to
model SS433 as a massive X-ray binary. Assuming that the hard X-ray source in
SS433 is eclipsed by the donor star that exactly fills its Roche lobe, the
masses of the optical and compact components in SS433 are suggested to be
M_v\approx 30 M_\odot and M_x\approx 9M_\odot, respectively. This provides
further evidence that SS433 is a massive binary system with supercritical
accretion onto a black hole.


title:
Measurements of Coherent Cherenkov Radiation in Rock Salt: Implications
  for GZK Neutrino Underground Detector

abstract:
  This paper has been withdrawn by the author, due to a misunderstanding about
publication.


title: TeV gamma rays from the Galactic Center

abstract:
  The recent detection of TeV gamma-radiation from the direction of the
Galactic Center within several arc-minutes around Sgr A* is the first
model-independent evidence of existence of high energy particle accelerator(s)
in the central 10 pc region of our Galaxy. This is an extraordinary site that
harbours many remarkable objects with the compact radio source Sgr A* - a
hypothetical super-massive black hole (SMBH) - in the dynamical center of the
Galaxy. Here we explore the possible direct and indirect links of the reported
TeV emission to the SMBH. We show that at least three $\gamma$-ray production
scenarios that take place close to the event horizon of the SMBH can explain
the reported TeV fluxes. An alternative (or additional) channel of TeV
radiation is related to the run-away protons accelerated in Sgr A*.
Quasi-continuous injection of relativistic protons into the surrounding dense
gas environment initiates detectable high energy gamma-ray emission. The
absolute flux and the energy spectrum of this radiation component strongly
depend on the history of particle injection and the character of diffusion of
protons during the last 10^5 years. For a reasonable combination of a few model
parameters, one can explain the detected gamma-ray flux solely by this diffuse
component.


title: Modelling of the fast rotating delta Scuti star Altair

abstract:
  We present an asteroseismic study of the fast rotating star HD187642
(Altair), recently discovered to be a delta Scuti pulsator. We have computed
models taking into account rotation for increasing rotational velocities. We
investigate the relation between the fundamental radial mode and the first
overtone in the framework of Petersen diagrams. The effects of rotation on such
diagrams, which become important at rotational velocities above 150 km/s, as
well as the domain of validity of our seismic tools are discussed. We also
investigate the radial and non-radial modes in order to constrain models
fitting the five most dominant observed oscillation modes.


title: Radiation in the process of the formation of voids

abstract:
  This paper aims to investigate the influence of inhomogeneous radiation in
void formation. Since the process of void formation is non-linear, a fully
relativistic model, which simulates the evolution of voids from the moment of
the last scattering until the present instant, is presented. It is found that
in order to obtain a model of a void which evolves from $\delta_0 = - 10^{-5}$
at the last scattering moment to the present day $\delta = - 0.94$, the
existence of radiation must be taken into account. The ratio of radiation
energy density to matter energy density in CDM models at the moment of last
scattering is 1/5. This paper proves that such a value of radiation energy
density cannot be neglected and influences the first stages of void evolution.
Namely, it is important to the process of structure formation and hence
significantly influences the dynamics of the Universe in the first millions of
years after the last scattering.
  From the fact that the evolution of voids proceeds differently in various
cosmological background models we use the process of void formation to put some
limits on values of cosmological parameters. We find that the model with
$\Omega_{mat} \approx 0.3$ fits the observational data best.


title:
Fireballs from Quark Stars in the CFL Phase: Application to Gamma Ray
  Bursters

abstract:
  Recent studies of photon-generation mechanisms in the color-superconducting
Color-Flavor Locked (CFL) phase of dense quark matter have found gamma-ray
emissivities in excess of ~ 10^{50} erg cm^{-3} s^{-1} for temperatures in the
10-30 MeV range. We suggest that this property can trigger gamma-ray bursts
(GRBs) and associated fireballs at the surface of hypothetical hot (newly born)
quark stars with an energy release of up to 10^{48}-10^{50} erg within a
fraction of a millisecond. If surrounded by an accretion disk following its
formation, the star's bursting activity can last from tens of milliseconds to
hundreds of seconds releasing up to 10^{52} erg in total energy. We discuss
typical features of observed GRBs within our model and explain how quark stars
in the CFL phase might constitute natural candidates for corresponding inner
engines.


title: Energy composition of the Universe: time-independent internal symmetry

abstract:
  The energy composition of the Universe, as emerged from the Type Ia supernova
observations and the WMAP data, looks preposterously complex, -- but only at
the first glance. In fact, its structure proves to be simple and regular. An
analysis in terms of the Friedmann integral enables to recognize a remarkably
simple time-independent covariant robust recipe of the cosmic mix: the
numerical values of the Friedmann integral for vacuum, dark matter, baryons and
radiation are approximately identical. The identity may be treated as a
symmetry relation that unifies cosmic energies into a regular set, a quartet,
with the Friedmann integral as its common genuine time-independent physical
parameter. Such cosmic internal (non-geometrical) symmetry exists whenever
cosmic energies themselves exist in nature. It is most natural for a finite
Universe suggested by the WMAP data. A link to fundamental theory may be found
under the assumption about a special significance of the electroweak energy
scale in both particle physics and cosmology. A freeze-out model developed on
this basis demonstrates that the physical nature of new symmetry might be due
to the interplay between electroweak physics and gravity at the cosmic age of a
few picoseconds. The big `hierarchy number' of particle physics represents the
interplay in the model. This number quantifies the Friedmann integral and gives
also a measure to some other basic cosmological figures and phenomena
associated with new symmetry. In this way, cosmic internal symmetry provides a
common ground for better understanding of old and recent problems that
otherwise seem unrelated; the coincidence of the observed cosmic densities, the
flatness of the co-moving space, the initial perturbations and their amplitude,
the cosmic entropy are among them.


title:
Outflowing disk formation in B[e] supergiants due to rotation and
  bi--stability in radiation driven winds

abstract:
  The effects of rapid rotation and bi-stability upon the density contrast
between the equatorial and polar directions of a B[e] supergiant are
re-investigated. Based upon a new slow solution for different high rotational
radiation driven winds (Cur\'e 2004) and the fact that bi--stability allows a
change in the line--force parameters ($\alpha$, $k$, and $\delta$), the
equatorial densities are about $10^2$--$10^4$ times higher than the polar ones.
These values are in qualitative agreement with the observations.


title: The Lyth Bound Revisited

abstract:
  We investigate the Lyth relationship between the tensor-scalar ratio, r, and
the variation of the inflaton field, Delta phi, over the course of inflation.
For inflationary models that produce at least 55 e-folds of inflation, there is
a correlation between r and Delta phi as anticipated by Lyth, but the scatter
around the relationship is huge. However, for inflationary models that satisfy
current observational constraints on the scalar spectral index and its first
derivative, the Lyth relationship is much tighter. In particular, any
inflationary model with r > 10^-3 must have Delta phi > m_pl. Large field
variations are therefore required if a tensor mode signal is to be detected in
any foreseeable cosmic microwave background (CMB) polarization experiment.