title:
Search for anisotropic light propagation as a function of laser beam
  alignment relative to the Earth's velocity vector

abstract:
  A laser diffraction experiment was conducted to study light propagation in
air. The experiment is easy to reproduce and it is based on simple optical
principles. Two optical sensors (segmented photo-diodes) are used for measuring
the position of diffracted light spots with a precision better than $0.1 \mu
m$. The goal is to look for signals of anisotropic light propagation as
function of the laser beam alignment to the Earth's motion (solar barycenter
motion) obtained by COBE. Two raster search techniques have been used. First, a
fixed laser beam in the laboratory frame that scans due to Earth's rotation.
Second, an active rotation of the laser beam on a turntable system. The results
obtained with both methods show that the course of the light rays are affected
by the motion of the Earth, and a predominant quantity of first order with a
$\Delta c/c=-\beta (1+2a)\cos \theta$ signature with $a=-0.4106\pm 0.0225$
describes well the experimental results. This result differs in a amount of 18%
from the Special Relativity Theory prediction and that supplies the value of
$a=-1/2$ (isotropy).


title:
Quark Deconfinement inside Compact Stars and Gamma Ray Bursts Inner
  Engine

abstract:
  The temporal structure of Gamma Ray Bursts can be interpreted assuming as a
inner engine a neutron star which undergoes a progressive compactification via
production of strangeness (hyperons and kaons) and quarks. We will propose a
tentative identification of various emission periods of the burst with specific
structural changes of the star. Each of these modifications of the composition
of the compact star takes place as a deflagration and not as a detonation, so
the energy released in the transition goes mainly into heat and not into a
mechanical wave. This is important in order to avoid an excessive baryonic
contamination of the region surrounding the compact star. In this way a
ultrarelativistic plasma of electron-positron pairs and of photons can be
obtained, powering the Gamma Ray Burst.


title: A Survey of 56 Mid-latitude EGRET Error Boxes for Radio Pulsars

abstract:
  We have conducted a radio pulsar survey of 56 unidentified gamma-ray sources
from the 3rd EGRET catalog which are at intermediate Galactic latitudes (5 deg.
< |b| < 73 deg.). For each source, four interleaved 35-minute pointings were
made with the 13-beam, 1400-MHz multibeam receiver on the Parkes 64-m radio
telescope. This covered the 95% error box of each source at a limiting
sensitivity of about 0.2 mJy to pulsed radio emission for periods P > 10 ms and
dispersion measures < 50 pc cm-3. Roughly half of the unidentified gamma-ray
sources at |b| > 5 deg. with no proposed active galactic nucleus counterpart
were covered in this survey. We detected nine isolated pulsars and four
recycled binary pulsars, with three from each class being new. Timing
observations suggest that only one of the pulsars has a spin-down luminosity
which is even marginally consistent with the inferred luminosity of its
coincident EGRET source. Our results suggest that population models, which
include the Gould belt as a component, overestimate the number of isolated
pulsars among the mid-latitude Galactic gamma-ray sources and that it is
unlikely that Gould belt pulsars make up the majority of these sources.
However, the possibility of steep pulsar radio spectra and the confusion of
terrestrial radio interference with long-period pulsars (P > 200 ms) having
very low dispersion measures (< 10 pc cm-3, expected for sources at a distance
of less than about 1 kpc) prevent us from strongly ruling out this hypothesis.
Our results also do not support the hypothesis that millisecond pulsars make up
the majority of these sources. Non-pulsar source classes should therefore be
further investigated as possible counterparts to the unidentified EGRET sources
at intermediate Galactic latitudes.


title:
The X-ray binary 2S0114+650=LSI+65 010:A slow pulsar or tidally-induced
  pulsations?

abstract:
  The X-ray source 2S0114+650=LSI+65 010 is a binary system containing a B-type
primary and a low mass companion believed to be a neutron star. The system has
three reported periodicities: the orbital period, P{orb}~11.6 d, X-ray flaring
with P{flare}~2.7 hr, and a "superorbital" X-ray periodicity P{super}~30.7 d.
The objective of this paper is to show that the puzzling periodicities in the
system may be explained in the context of scenarios in which tidal interactions
drive oscillations in the B-supergiant star. We calculate the solution of the
equations of motion for one layer of small surface elements distributed along
the equator of the star, as they respond to the forces due to gas pressure,
centrifugal, coriolis, viscous forces, and the gravitational forces of both
stars. This calculation provides variability timescales that can be compared
with the observations. In addition, we use observational data obtained at the
Observatorio Astron\'omico Nacional en San Pedro M\'artir (OAN/SPM) between
1993-2004 to determine which of the periodicities may be present in the optical
region. We suggest that the tidal oscillations lead to a structured stellar
wind which, when fed to the neutron star, produces the X-ray modulations. The
connection between the stellar oscillations and the modulation of the mass
ejection may lie in the shear energy dissipation generated by the tangential
motions that are produced by the tidal interaction, particularly in the tidal
bulge region. The tidal oscillation scenario weakens the case for 2S0114+650
containing a magnetar descendent.


title:
Ages, Metallicities, and [alpha/Fe] ratios of globular clusters in NGC
  147, NGC 185, and NGC 205

abstract:
  We present measurements of ages, metallicities, and [alpha/Fe] ratios for 16
globular clusters (GC) in NGC 147, NGC 185, and NGC 205 and of the central
regions of the diffuse galaxy light in NGC 185, and NGC 205. Our results are
based on spectra obtained with the SCORPIO multi-slit spectrograph at the 6-m
telescope of the Russian Academy of Sciences. We include in our analysis
high-quality HST/WFPC2 photometry of individual stars in the studied GCs to
investigate the influence of their horizontal branch (HB) morphology on the
spectroscopic analysis. All our sample GCs appear to be old (T>8 Gyr) and
metal-poor ([Z/H] <~ -1.1), except for the globular clusters Hubble V in NGC
205 (T=1.2+/-0.6 Gyr, [Z/H]=-0.6+/-0.2), Hubble VI in NGC 205 (T=4+/-2 Gyr,
[Z/H]=-0.8+/-0.2), and FJJVII in NGC 185 (T=7+/-3 Gyr, [Z/H]=-0.8+/-0.2). The
majority of our GC sample has solar [alpha/Fe] enhancements in contrast to the
halo population of GCs in M31 and the Milky Way. The HB morphologies for our
sample GCs follow the same behavior with metallicity as younger halo Galactic
globular clusters. We show that it is unlikely that they bias our spectroscopic
age estimates based on Balmer absorption line indices. Spectroscopic ages and
metallicities of the central regions in NGC 205 and NGC 185 coincide with those
obtained from color-magnitude diagrams. The central field stellar populations
in these galaxies have approximately the same age as their most central GCs
(Hubble V in NGC 205 and FJJIII in NGC 185), but are more metal-rich than the
central globular clusters.


title: Molecular dark matter in galaxies

abstract:
  Clouds containing molecular dark matter in quantities relevant for star
formation may exist in minihaloes of the type of cold dark matter included in
many cosmological simulations or in the regions of some galaxies extending far
beyond their currently known boundaries. We have systematically explored
parameter space to identify conditions under which plane-parallel clouds
contain sufficient column densities of molecular dark matter that they could be
reservoirs for future star formation. Such clouds would be undetected or at
least appear by current observational criteria to be uninteresting from the
perspective of star formation. We use a time-dependent PDR code to produce
theoretical models of the chemistry and emission arising in clouds for our
chosen region of parameter space. We then select a subset of model clouds with
levels of emission that are low enough to be undetectable or at least
overlooked by current surveys. The existence of significant column densities of
cold molecular dark matter requires that the background radiation field be
several or more orders of magnitude weaker than that in the solar
neighbourhood. Lower turbulent velocities and cosmic ray induced ionization
rates than typically associated with molecular material within a kpc of the Sun
are also required for the molecular matter to be dark. We find that there is a
large region within the parameter space that results in clouds that might
contain a significant mass of molecular gas whilst remaining effectively
undetectable or at least not particularly noticeable in surveys. We note
briefly conditions under which molecular dark matter may contain a dynamically
interesting mass.


title:
The Stellar Population of Stripped Cluster Spiral NGC 4522: A Local
  Analog to K+A Galaxies?

abstract:
  We present observations of the stripped Virgo Cluster spiral NGC 4522, a
clear, nearby example of a galaxy currently undergoing ISM-ICM stripping.
Utilizing SparsePak integral field spectroscopy on the WIYN 3.5m telescope and
GALEX UV photometry, we present an analysis of the outer disk (r > 3 kpc)
stellar population of this galaxy, beyond the HI and Halpha truncation radius.
We find that the star formation in the gas-stripped outer disk ceased very
recently, ~100 Myr ago, in agreement with previous claims that this galaxy is
currently being stripped. At the time of this stripping, data and models
suggest that the galaxy experienced a modest starburst. The stripping is
occurring in a region of the cluster well outside the cluster core, likely
because this galaxy is experiencing extreme conditions from a dynamic ICM due
to an ongoing sub-cluster merger. The outer disk has a spectrum of a K+A
galaxy, traditionally observed in high-redshift cluster galaxies. In the case
of NGC 4522, a K+A spectrum is formed by simple stripping of the interstellar
gas by the hot intracluster medium. These data show K+A spectra can be created
by cluster processes and that these processes likely extend beyond the cluster
core.


title:
The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m
  Program -- Twenty New Members of the RECONS 10 Parsec Sample

abstract:
  Astrometric measurements for 25 red dwarf systems are presented, including
the first definitive trigonometric parallaxes for 20 systems within 10 pc of
the Sun, the horizon of the RECONS sample. The three nearest systems that had
no previous trigonometric parallaxes (other than perhaps rough preliminary
efforts) are SO 0253+1652 (3.84 +/- 0.04 pc, the 23rd nearest system), SCR
1845-6357 AB (3.85 +/- 0.02 pc, 24th), and LHS 1723 (5.32 +/- 0.04 pc, 56th).
In total, seven of the systems reported here rank among the nearest 100 stellar
systems. Supporting photometric and spectroscopic observations have been made
to provide full characterization of the systems, including complete VRIJHK
photometry and spectral types. A study of the variability of 27 targets reveals
six obvious variable stars, including GJ 1207, for which we observed a flare
event in the V band that caused it to brighten by 1.7 mag.
  Improved parallaxes for GJ 54 AB and GJ 1061, both important members of the
10 pc sample, are also reported. Definitive parallaxes for GJ 1001 A, GJ 633,
and GJ 2130 ABC, all of which have been reported to be within 10 pc, indicate
that they are beyond 10 pc. From the analysis of systems with (previously) high
trigonometric parallax errors, we conclude that parallaxes with errors in
excess of 10 mas are insufficiently reliable for inclusion in the RECONS
sample. The cumulative total of new additions to the 10 pc sample since 2000 is
now 34 systems -- 28 by the RECONS team and six by other groups. This total
represents a net increase of 16% in the number of stellar systems reliably
known to be nearer than 10 pc.


title: Aspects of Neutrino Production in Supernovae

abstract:
  I discuss neutrino production in supernovae (SNe) and the detection of both
Galactic core collapse events and the diffuse extra-galactic MeV neutrino
background expected from the integrated history of star formation. In
particular, I consider what processes might affect our expectations for both. I
focus on ``rapid'' rotation, defined as leading to millisecond initial neutron
star spin periods. Rotation affects the neutrino luminosity, the average
neutrino energy, the duration of the Kelvin-Helmholtz cooling epoch, and the
ratios of luminosities and average energies between neutrino species; it can
strongly suppresses the anti-electron as well as mu, anti-mu, tau, and anti-tau
neutrino fluxes relative to those for the electron neutrinos. As a result,
depending on the prevalence of rapid rotation in SN progenitors through cosmic
time, this may affect predictions for the MeV neutrino background and the
history of nucleosynthetic enrichment. I emphasize connections between the MeV
neutrino background and tracers of the star formation rate density at high
redshift in other neutrino and photon wavebands.


title:
Correlation between Flux and Spectral Index during Flares in Sagittarius
  A*

abstract:
  Flares in Sagittarius A* are produced by hot plasmas within a few
Schwarzschild radii of the supermassive black hole at the Galactic center. The
recent detection of a correlation between the spectral index and flux during a
near infrared (NIR) flare provides a means to conduct detailed investigations
of the plasma heating and radiation processes. We study the evolution of the
electron distribution function under the influence of a turbulent magnetic
field in a hot collisionless plasma. The magnetic field, presumably generated
through instabilities in the accretion flow, can both heat the plasma via
resonant wave-particle coupling and cool the electrons via radiation. The
electron distribution can generally be approximated as relativistic Maxwellian.
To account for the observed correlation, we find that the magnetic field needs
to be anti-correlated with the electron ''temperature''. NIR and X-ray light
curves are produced for a cooling and a heating phase. The model predicts
simultaneous flare activity in the NIR and X-ray bands, which can be compared
with observations. These results can be applied to MHD simulations to study the
radiative characteristics of collisionless plasmas, especially accretion flows
in low-luminosity AGNs.


title: Numerical Study on GRB-Jet Formation in Collapsars

abstract:
  Two-dimensional magnetohydrodynamic simulations are performed using the
ZEUS-2D code to investigate the dynamics of a collapsar that generates a GRB
jet, taking account of realistic equation of state, neutrino cooling and
heating processes, magnetic fields, and gravitational force from the central
black hole and self gravity. It is found that neutrino heating processes are
not so efficient to launch a jet in this study. It is also found that a jet is
launched mainly by B_\phi fields that are amplified by the winding-up effect.
However, since the ratio of total energy relative to the rest mass energy in
the jet is not so high as several hundred, we conclude that the jets seen in
this study are not be a GRB jet. This result suggests that general relativistic
effects, which are not included in this study, will be important to generate a
GRB jet. Also, the accretion disk with magnetic fields may still play an
important role to launch a GRB jet, although a simulation for much longer
physical time (\sim 10-100 s) is required to confirm this effect. It is shown
that considerable amount of 56Ni is synthesized in the accretion disk. Thus
there will be a possibility for the accretion disk to supply sufficient amount
of 56Ni required to explain the luminosity of a hypernova. Also, it is shown
that neutron-rich matter due to electron captures with high entropy per baryon
is ejected along the polar axis. Moreover, it is found that the electron
fraction becomes larger than 0.5 around the polar axis near the black hole by
\nu_e capture at the region. Thus there will be a possibility that r-process
and r/p-process nucleosynthesis occur at these regions. Finally, much neutrons
will be ejected from the jet, which suggests that signals from the neutron
decays may be observed as the delayed bump of afterglow or gamma-rays.


title:
Interpreting Spectral Energy Distributions from Young Stellar Objects.
  I. A grid of 200,000 YSO model SEDs

abstract:
  We present a grid of radiation transfer models of axisymmetric young stellar
objects (YSOs), covering a wide range of stellar masses (from 0.1Msun to
50Msun) and evolutionary stages (from the early envelope infall stage to the
late disk-only stage). The grid consists of 20,000 YSO models, with spectral
energy distributions (SEDs) and polarization spectra computed at ten viewing
angles for each model, resulting in a total of 200,000 SEDs. [...]. These
models are publicly available on a dedicated WWW server:
http://www.astro.wisc.edu/protostars/ . In this paper we summarize the main
features of our models, as well as the range of parameters explored. [...]. We
examine the dependence of the spectral indices of the model SEDs on envelope
accretion rate and disk mass. In addition, we show variations of spectral
indices with stellar temperature, disk inner radius, and disk flaring power for
a subset of disk-only models. We also examine how changing the wavelength range
of data used to calculate spectral indices affects their values. We show sample
color-color plots of the entire grid as well as simulated clusters at various
distances with typical {\it Spitzer Space Telescope} sensitivities. We find
that young embedded sources generally occupy a large region of color-color
space due to inclination and stellar temperature effects. Disk sources occupy a
smaller region of color-color space, but overlap substantially with the region
occupied by embedded sources, especially in the near- and mid-IR. We identify
regions in color-color space where our models indicate that only sources at a
given evolutionary stage should lie. [...].


title:
The Influence of Atmospheric Dynamics on the Infrared Spectra and Light
  Curves of Hot Jupiters

abstract:
  We explore the infrared spectrum of a three-dimensional dynamical model of
planet HD209458b as a function of orbital phase. The dynamical model predicts
day-side atmospheric pressure-temperature profiles that are much more
isothermal at pressures less than 1 bar than one-dimensional
radiative-convective models have found. The resulting day-side thermal spectra
are very similar to a blackbody, and only weak water absorption features are
seen at short wavelengths. The dayside emission is consequently in
significantly better agreement with ground-based and space-based secondary
eclipse data than any previous models, which predict strong flux peaks and deep
absorption features. At other orbital phases, absorption due to carbon monoxide
and methane is also predicted. We compute the spectra under two treatments of
atmospheric chemistry: one uses the predictions of equilibrium chemistry, and
the other uses non-equilibrium chemistry, which ties the timescales of methane
and carbon monoxide chemistry to dynamical timescales. As a function of orbital
phase, we predict planet-to-star flux ratios for standard infrared bands and
all Spitzer Space Telescope bands. In Spitzer bands, we predict 2-fold to
15-fold variation in planetary flux as a function of orbital phase with
equilibrium chemistry, and 2-fold to 4-fold variation with non-equilibrium
chemistry. Variation is generally more pronounced in bands from 3-10 $\mu$m
than at longer wavelengths. The orbital phase of maximum thermal emission in
infrared bands is 15--45 orbital degrees before the time of secondary eclipse.
Changes in flux as a function of orbital phase for HD209458b should be
observable with Spitzer, given the previously acheived observational error
bars.


title:
The Effect of Local Galaxy Surface Density on Star Formation for HI
  selected galaxies

abstract:
  We present the result of investigations into two theories to explain the star
formation rate-density relationship. For regions of high galaxy density, either
there are fewer star forming galaxies, or galaxies capable of forming stars are
present but some physical process is suppressing their star formation. We use
HI Parkes All Sky Survey's (HIPASS) HI detected galaxies and infrared and radio
fluxes to investigate star formation rates and efficiencies with respect to
local surface density. For nearby (vel<10000 km\s) HI galaxies we find a strong
correlation between HI mass and star formation rate. The number of HI galaxies
decreases with increasing local surface density. For HI galaxies (1000<vel<6000
km\s) there is no significant change in the star formation rate or the
efficiency of star formation with respect to local surface density. We conclude
the SFR-density relation is due to a decrease in the number of HI star forming
galaxies in regions of high galaxy density and not to the suppression of star
formation.


title: Discovery of Fluorine in Cool Extreme Helium Stars

abstract:
  Neutral fluorine (F I) lines are identified in the optical spectra of cool
EHe stars. These are the first identification of F I lines in a star's
spectrum, and provide the first measurement of fluorine abundances in EHe
stars. The results show that fluorine is overabundant in EHe stars. The
overabundance of fluorine provides evidence for the synthesis of fluorine in
these stars, that is discussed in the light of asymptotic giant branch (AGB)
evolution, and the expectation from accretion of an He white dwarf by a C-O
white dwarf.


title:
On spatial distributions of old globular clusters in clusters of
  galaxies

abstract:
  We investigate structural properties of old, metal-poor globular clusters
(GCs) formed at high redshifts (z>6) and located inside and outside virialized
galaxy-scale halos in clusters of galaxies with the total masses of M_CL based
on high-resolution cosmological simulations with models of GC formation. We
mainly derive the parameter dependences of physical properties of intracluster
GCs (ICGCs) based on the results of 14 models. Our principle results are
summarized as follows. (1) The projected radial density profiles (Sigma_GC) of
ICGCs in clusters with different M_CL can be diverse, though ICGCs have
inhomogeneous, asymmetric, and somewhat elongated distributions in most models.
If Sigma_GC (R) ~ R^alpha, alpha ranges from -1.5 to -2.5 for GCs in clusters.
(2) Although total number of GCs within the central 0.05 Mpc (N_GC,0.05) and
0.2 Mpc (N_GC,0.2) are diverse in different clusters, they can depend weakly on
M_CL in such a way that both N_GC,0.05 and N_GC,0.2 are likely to be larger for
clusters with larger M_CL. (3) Total number of GCs per cluster masses (specific
frequency of GCs for clusters of galaxies) are more likely to be larger in more
massive clusters, mainly because a larger number of earlier virialized objects
can be located in more massive clusters. (4) Spatial distributions of old GCs
in clusters can depend on the truncation epoch of GC formation (z_trun) such
that they can be steeper and more compact in the models with higher z_trun. (5)
The mean metallicity of ICGCs in a cluster can be smaller than that of GCs
within the cluster member galaxy-scale halos by ~ 0.3 in [Fe/H]. Metallicity
distribution functions (MDFs) of ICGCs show peak values around [Fe/H] ~ -1.6
and do not have remarkable bimodality.


title: Solar System: Sifting through the debris

abstract:
  A quadrillion previously unnoticed small bodies beyond Neptune have been
spotted as they dimmed X-rays from a distant source. Models of the dynamics of
debris in the Solar System's suburbs must now be reworked.


title: Quasi-simultaneous five-frequency VLBA observations of PKS 0528+134

abstract:
  We present results of Very Long Baseline Array (VLBA) observations of PKS
0528+134 at five frequencies (2.3, 5.0, 8.4, 15.4, and 22.2 GHz). These
quasi-simultaneous data enable us to study the spectral distribution of Very
Long Baseline Interferometer (VLBI) components for the first time in this
highly variable source, from which the central compact core is identified. Our
observations indicate that there are two bendings for the jet motion at parsec
scale. We provide an approximate spatial fit to the curved jet trajectory using
the Steffen et al. (\cite{Steffen95}) helical model. We further investigate the
proper motions of three jet components, which all show superluminal motion. At
high frequencies (15.4 and 22.2 GHz) we detected a new component, which is
estimated to be related to a radio burst peaking at about 2000.


title:
Scale Factor Dependent Equations of State for Curvature Inspired Dark
  Energy, Phantom Barrier and Late Cosmic Acceleration

abstract:
  Here, it is found that dark energy and dark matter emerge from the
gravitational sector, if non-linear term of scalar curvature is added to
Einstein-Hilbert lagrangian. An equation of state for dark energy, having the
form $p_{\rm de} = - \rho_{\rm de} + f(a) (with $p_{\rm de}(\rho_{\rm de})$
being the pressure(density) for dark energy, $f(a)$ being a function of scale
feactor $a(t)$ and $t$ being the cosmic time) is explored. Interestingly, this
equation of state leads to a phantom barrier ${\rm w}_{\rm de} = p_{\rm
de}/\rho_{\rm de} = - 1$ at $a = a_{\rm w}$. It is found that when $a < a_{\rm
w}, {\rm w}_{\rm de} > - 1$ and ${\rm w}_{\rm de} < - 1$ for $a > a_{\rm w},$
showing a transition from non-phantom to phantom phase at $a = a_{\rm w} < a_0
(a_0$ being current scale factor of the universe). PACS no.: 98.80 Cq.


title:
Cosmological hydrogen recombination: populations of the high level
  sub-states

abstract:
  We present results for the spectral distortions of the Cosmic Microwave
Background (CMB) arising due to bound-bound transitions during the epoch of
cosmological hydrogen recombination at frequencies down to nu~100MHz. We extend
our previous treatment of the recombination problem now including the main
collisional processes and following the evolution of all the hydrogen angular
momentum sub-states for up to 100 shells. We show that, due to the low baryon
density of the Universe, even within the highest considered shell full
statistical equilibrium (SE) is not reached and that at low frequencies the
recombination spectrum is significantly different when assuming full SE for
n>2. We also directly compare our results for the ionization history to the
output of the Recfast code, showing that especially at low redshifts rather big
differences arise. In the vicinity of the Thomson visibility function the
electron fraction differs by roughly -0.6% which affects the temperature and
polarization power spectra by <~1%. Furthermore we shortly discuss the
influence of free-free absorption and line broadening due to electron
scattering on the bound-bound recombination spectrum and the generation of CMB
angular fluctuations due to scattering of photons within the high shells.


title:
The OSACA Database and a Kinematic Analysis of Stars in the Solar
  Neighborhood

abstract:
  We transformed radial velocities compiled from more than 1400 published
sources, including the Geneva--Copenhagen survey of the solar neighborhood
(CORAVEL-CfA), into a uniform system based on the radial velocities of 854
standard stars in our list. This enabled us to calculate the average weighted
radial velocities for more than 25~000 HIPPARCOS stars located in the local
Galactic spiral arm (Orion arm) with a median error of +-1 km/s. We use these
radial velocities together with the stars' coordinates, parallaxes, and proper
motions to determine their Galactic coordinates and space velocities. These
quantities, along with other parameters of the stars, are available from the
continuously updated Orion Spiral Arm CAtalogue (OSACA) and the associated
database. We perform a kinematic analysis of the stars by applying an
Ogorodnikov-Milne model to the OSACA data. The kinematics of the nearest single
and multiple main-sequence stars differ substantially. We used distant
(r\approx 0.2 kpc) stars of mixed spectral composition to estimate the angular
velocity of the Galactic rotation -25.7+-1.2 km/s/kpc, and the vertex
deviation,l=13+-2 degrees, and detect a negative K effect. This negative K
effect is most conspicuous in the motion of A0-A5 giants, and is equal to
K=-13.1+-2.0 km/s/kpc.


title:
The temperature and ionization structure of the emitting gas in HII
  galaxies: Implications for the accuracy of abundance determinations

abstract:
  We propose a methodology to perform a self-consistent analysis of the
physical properties of the emitting gas of HII galaxies adequate to the data
that can be obtained with the XXI century technology. This methodology requires
the production and calibration of empirical relations between the different
line temperatures that should superseed currently used ones based on very
simple, and poorly tested, photo-ionization model sequences.
  As a first step to reach these goals we have obtained simultaneous blue to
far red longslit spectra with the William Herschel Telescope (WHT) of three
compact HII galaxies selected from the Sloan Digital Sky Survey (SDSS) Data
Release 2 (DR2) spectral catalog using the INAOE Virtual Observatory
superserver. Our spectra cover the range from 3200 to 10500 \AA, including the
Balmer jump, the [OII]3727,29 \AA lines, the [SIII]9069,9532 \AA doublet as
well as various weak auroral lines such as [OIII]4363 \AA and [SIII]6312 \AA.
  For the three objects we have measured at least four line temperatures:
T([OIII]), T([SIII]), T([OII]) and T([SII]) and the Balmer continuum
temperature T(Bac). These measurements and a careful and realistic treatment of
the observational errors yield total oxygen abundances with accuracies between
5 and 9%. These accuracies are expected to improve as better calibrations based
on more precise measurements, both on electron temperatures and densities, are
produced.
  ...


title: An Advanced, Three-Dimensional Plotting Library for Astronomy

abstract:
  We present a new, three-dimensional (3D) plotting library with advanced
features, and support for standard and enhanced display devices. The library -
S2PLOT - is written in C and can be used by C, C++ and FORTRAN programs on
GNU/Linux and Apple/OSX systems. S2PLOT draws objects in a 3D (x,y,z) Cartesian
space and the user interactively controls how this space is rendered at run
time. With a PGPLOT inspired interface, S2PLOT provides astronomers with
elegant techniques for displaying and exploring 3D data sets directly from
their program code, and the potential to use stereoscopic and dome display
devices. The S2PLOT architecture supports dynamic geometry and can be used to
plot time-evolving data sets, such as might be produced by simulation codes. In
this paper, we introduce S2PLOT to the astronomical community, describe its
potential applications, and present some example uses of the library.


title:
Cyber-infrastructure to Support Science and Data Management for the Dark
  Energy Survey

abstract:
  The Dark Energy Survey (DES; operations 2009-2015) will address the nature of
dark energy using four independent and complementary techniques: (1) a galaxy
cluster survey over 4000 deg2 in collaboration with the South Pole Telescope
Sunyaev-Zel'dovich effect mapping experiment, (2) a cosmic shear measurement
over 5000 deg2, (3) a galaxy angular clustering measurement within redshift
shells to redshift=1.35, and (4) distance measurements to 1900 supernovae Ia.
The DES will produce 200 TB of raw data in four bands, These data will be
processed into science ready images and catalogs and co-added into deeper,
higher quality images and catalogs. In total, the DES dataset will exceed 1 PB,
including a 100 TB catalog database that will serve as a key science analysis
tool for the astronomy/cosmology community. The data rate, volume, and duration
of the survey require a new type of data management (DM) system that (1) offers
a high degree of automation and robustness and (2) leverages the existing high
performance computing infrastructure to meet the project's DM targets. The DES
DM system consists of (1) a grid-enabled, flexible and scalable middleware
developed at NCSA for the broader scientific community, (2) astronomy modules
that build upon community software, and (3) a DES archive to support automated
processing and to serve DES catalogs and images to the collaboration and the
public. In the recent DES Data Challenge 1 we deployed and tested the first
version of the DES DM system, successfully reducing 700 GB of raw simulated
images into 5 TB of reduced data products and cataloguing 50 million objects
with calibrated astrometry and photometry.


title:
Mrk 421, Mrk 501, and 1ES 1426+428 at 100 GeV with the CELESTE Cherenkov
  Telescope

abstract:
  We have measured the gamma-ray fluxes of the blazars Mrk 421 and Mrk 501 in
the energy range between 50 and 350 GeV (1.2 to 8.3 x 10^25 Hz). The detector,
called CELESTE, used first 40, then 53 heliostats of the former solar facility
"Themis" in the French Pyrenees to collect Cherenkov light generated in
atmospheric particle cascades. The signal from Mrk 421 is often strong. We
compare its flux with previously published multi-wavelength studies and infer
that we are straddling the high energy peak of the spectral energy
distribution. The signal from Mrk 501 in 2000 was weak (3.4 sigma). We obtain
an upper limit on the flux from 1ES 1426+428 of less than half that of the Crab
flux near 100 GeV. The data analysis and understanding of systematic biases
have improved compared to previous work, increasing the detector's sensitivity.


title:
A catalog of rotational and radial velocities for evolved stars. IV.
  Metal-poor stars

abstract:
  The present paper describes the first results of an observational program
intended to refine and extend the existing vsini measurements of metal-poor
stars, with anemphasis on field evolved stars. The survey was carried out with
the FEROS and CORALIE spectrometers. For the vsini measurements, obtained from
spectral synthesis, we estimate an uncertainty of about 2.0 km/s. Precise
rotational velocities vsini are presented for a large sample of 100 metal-poor
stars, most of them evolving off the main-sequence. For the large majority of
the stars composing the present sample, rotational velocities have been
measured for the first time.


title:
The Nature of Infrared Emission in the Local Group Dwarf Galaxy NGC 6822
  As Revealed by Spitzer

abstract:
  We present Spitzer imaging of the metal-deficient (Z ~30% Z_sun) Local Group
dwarf galaxy NGC 6822. On spatial scales of ~130 pc, we study the nature of IR,
H alpha, HI, and radio continuum emission. Nebular emission strength correlates
with IR surface brightness; however, roughly half of the IR emission is
associated with diffuse regions not luminous at H alpha (as found in previous
studies). The global ratio of dust to HI gas in the ISM, while uncertain at the
factor of ~2 level, is ~25 times lower than the global values derived for
spiral galaxies using similar modeling techniques; localized ratios of dust to
HI gas are about a factor of five higher than the global value in NGC 6822.
There are strong variations (factors of ~10) in the relative ratios of H alpha
and IR flux throughout the central disk; the low dust content of NGC 6822 is
likely responsible for the different H alpha/IR ratios compared to those found
in more metal-rich environments. The H alpha and IR emission is associated with
high-column density (> ~1E21 cm^-2) neutral gas. Increases in IR surface
brightness appear to be affected by both increased radiation field strength and
increased local gas density. Individual regions and the galaxy as a whole fall
within the observed scatter of recent high-resolution studies of the radio-far
IR correlation in nearby spiral galaxies; this is likely the result of depleted
radio and far-IR emission strengths in the ISM of this dwarf galaxy.


title:
INTEGRAL observations of the cosmic X-ray background in the 5-100 keV
  range via occultation by the Earth

abstract:
  We study the spectrum of the cosmic X-ray background (CXB) in energy range
$\sim$5-100 keV. Early in 2006 the INTEGRAL observatory performed a series of
four 30ksec observations with the Earth disk crossing the field of view of the
instruments. The modulation of the aperture flux due to occultation of
extragalactic objects by the Earth disk was used to obtain the spectrum of the
Cosmic X-ray Background(CXB). Various sources of contamination were evaluated,
including compact sources, Galactic Ridge emission, CXB reflection by the Earth
atmosphere, cosmic ray induced emission by the Earth atmosphere and the Earth
auroral emission. The spectrum of the cosmic X-ray background in the energy
band 5-100 keV is obtained. The shape of the spectrum is consistent with that
obtained previously by the HEAO-1 observatory, while the normalization is
$\sim$10% higher. This difference in normalization can (at least partly) be
traced to the different assumptions on the absolute flux from the Crab Nebulae.
  The increase relative to the earlier adopted value of the absolute flux of
the CXB near the energy of maximum luminosity (20-50 keV) has direct
implications for the energy release of supermassive black holes in the Universe
and their growth at the epoch of the CXB origin.


title: Review of the Solar Array Telescopes

abstract:
  For several years the only experiments sensitive to astrophysical gamma rays
with energies beyond the reach of EGRET but below that of the Cherenkov imaging
telescopes have been the "solar tower" detectors. They use >2000 m2 mirror
areas to sample the Cherenkov wavefront generated by <100 GeV gamma rays,
obtaining Crab sensitivities of more than 6$\sigma$ in one ON-source hour. I
will review the history of the solar tower Cherenkov experiments from 1992 to
the present and their key design features. I will describe some successful
analysis strategies, then summarize the principal results obtained.


title:
Earth X-ray albedo for cosmic X-ray background radiation in the 1--1000
  keV band

abstract:
  We present calculations of the reflection of the cosmic X-ray background
(CXB) by the Earth's atmosphere in the 1--1000 keV energy range. The
calculations include Compton scattering and X-ray fluorescent emission and are
based on a realistic chemical composition of the atmosphere. Such calculations
are relevant for CXB studies using the Earth as an obscuring screen (as was
recently done by INTEGRAL). The Earth's reflectivity is further compared with
that of the Sun and the Moon -- the two other objects in the Solar system
subtending a large solid angle on the sky, as needed for CXB studies.


title: Hard X-ray emission of the Earth's atmosphere: Monte Carlo simulations

abstract:
  We perform Monte Carlo simulations of cosmic ray-induced hard X-ray radiation
from the Earth's atmosphere. We find that the shape of the spectrum emergent
from the atmosphere in the energy range 25-300 keV is mainly determined by
Compton scatterings and photoabsorption, and is almost insensitive to the
incident cosmic-ray spectrum. We provide a fitting formula for the hard X-ray
surface brightness of the atmosphere as would be measured by a satellite-born
instrument, as a function of energy, solar modulation level, geomagnetic cutoff
rigidity and zenith angle. A recent measurement by the INTEGRAL observatory of
the atmospheric hard X-ray flux during the occultation of the cosmic X-ray
background by the Earth agrees with our prediction within 10%. This suggests
that Earth observations could be used for in-orbit calibration of future hard
X-ray telescopes. We also demonstrate that the hard X-ray spectra generated by
cosmic rays in the crusts of the Moon, Mars and Mercury should be significantly
different from that emitted by the Earth's atmosphere.


title: GALEX high time-resolution ultraviolet observations of dMe flare events

abstract:
  We present near ultraviolet (NUV:1750 - 2800\AA) and far ultraviolet (FUV:
1350 - 1750\AA) light-curves for flares on 4 nearby dMe-type stars (GJ 3685A,
CR Dra, AF Psc and SDSS J084425.9+513830.5) observed with the GALEX satellite.
Taking advantage of the time-tagged events recorded with the GALEX photon
counting detectors, we present high temporal resolution (<0.01 sec) analysis of
these UV flare data. A statistical analysis of 700 seconds of pre-flare
quiescence data for both CR Dra and SDSS J084425.9+513830.5 failed to reveal
the presence of significant micro-flare activity in time bins of 0.2, 1 and 10
second intervals. Using an appropriate differential emission measure for both
the quiescent and flaring state, it is possible to reproduce the observed
FUV:NUV flux ratios. A major determinant in reproducing this flux ratio is
found to be the value of plasma electron density during the flare. We also
searched the count rate data recorded during each of the four flare events for
periodicity associated with magneto-hydrodynamic oscillations in the active
region coronal loops. Significant oscillations were detected during the flare
events observed on all 4 stars, with periodicities found in the 30 to 40 second
range. Flare oscillations with this periodicity can be explained as acoustic
waves in a coronal loop of length of $\approx 10^{9}$ cm for an assumed plasma
temperature of $5-20 \times 10^{6}$K. This suggests a loop length for these
M-dwarf flares of less than $1/10^{th}$ of the stellar radii. We believe that
this is the first detection of non-solar coronal loop flare oscillations
observed at ultraviolet wavelengths.


title: Pleiades low-mass brown dwarfs: the cluster L dwarf sequence

abstract:
  We present a search for low-mass brown dwarfs in the Pleiades open cluster.
The identification of Pleiades members fainter and cooler than those currently
known allows us to constrain evolutionary models for L dwarfs and to extend the
study of the cluster mass function to lower masses. We conducted a 1.8 deg^2
near-infrared J-band survey at the 3.5m Calar Alto Telescope, with completeness
J~19.0. The detected sources were correlated with those of previously available
optical I-band images (completeness I~22). Using a J versus I-J
colour-magnitude diagram, we identified 18 faint red L-type candidates, with
magnitudes 17.4<J<19.7 and colours I-J>3.2. If Pleiades members, their masses
would span ~0.040-0.020 M_Sol. We performed follow-up HKs-band imaging to
further confirm their cluster membership by photometry and proper motion. Out
of 11 IJ candidates with proper motion measurements, we find six cluster
members, two non-members and three whose membership is uncertain and depends on
the intrinsic velocity dispersion of Pleiades brown dwarfs. This dispersion (>4
mas yr^-1) is at least four times that of cluster stars with masses >1 M_Sol.
Five of the seven other IJ candidates are discarded because their J-Ks colours
are bluer than those of confirmed members. The J versus I-J sequence of the
L-type candidates at J>18 is not as red as theoretical models predict; it
rather follows the field L-dwarf sequence translated to the cluster distance.
This sequence overlapping, also observed in the J versus J-H and J-K diagrams,
suggests that Pleiades and field L dwarfs may have similar spectral energy
distributions and luminosities, and thus possibly similar radii. Also, we find
alpha=0.5+-0.2 for a power-law approximation dN/dM propor. M^-alpha of the
survey mass spectrum in the mass range 0.5-0.026 M_Sol.


title:
Hydrogen-like nitrogen radio line from hot interstellar and warm-hot
  intergalactic gas

abstract:
  Hyperfine structure lines of highly-charged ions may open a new window in
observations of hot rarefied astrophysical plasmas. In this paper we discuss
spectral lines of isotopes and ions abundant at temperatures 10^5-10^7 K,
characteristic for warm-hot intergalactic medium, hot interstellar medium,
starburst galaxies, their superwinds and young supernova remnants. Observations
of these lines will allow to study bulk and turbulent motions of the observed
target and will broaden the information about the gas ionization state,
chemical and isotopic composition.
  The most prospective is the line of the major nitrogen isotope having
wavelength 5.65 mm (Sunyaev and Churazov 1084). Wavelength of this line is
well-suited for observation of objects at z=0.15-0.6 when it is redshifted to
6.5-9 mm spectral band widely-used in ground-based radio observations, and, for
example, for z>=1.3, when the line can be observed in 1.3 cm band and at lower
frequencies. Modern and future radio telescopes and interferometers are able to
observe the absorption by 14-N VII in the warm-hot intergalactic medium at
redshifts above z=0.15 in spectra of brightest mm-band sources. Sub-millimeter
emission lines of several most abundant isotopes having hyperfine splitting
might also be detected in spectra of young supernova remnants.


title: The gamma-ray burst GRB060614 requires a novel explosive process

abstract:
  Over the past decade our physical understanding of gamma-ray bursts (GRBs)
has progressed rapidly thanks to the discovery and observation of their
long-lived afterglow emission. Long-duration (T < 2 s) GRBs are associated with
the explosive deaths of massive stars (``collapsars''), which produce
accompanying supernovae, while the short-duration (T > 2 s) GRBs arise from a
different origin, which has been argued to be the merger of two compact
objects, either neutron stars or black holes. Here we present observations of
GRB060614, a 100-s long burst discovered by the Swift satellite, which require
the invocation of a new explosive process: either a massive ``collapsar'' that
powers a GRB without any associated supernova, or a new type of engine, as
long-lived as the collapsar but without any such massive stellar host. We also
discuss the properties of this burst's redshift z=0.125 host galaxy, which
distinguish it from other long-duration GRBs and suggest that an entirely new
type of GRB progenitor may be required.


title:
MHD Models for Winds from Neutron Stars, and their Interaction with the
  Environment

abstract:
  The recent development of numerical schemes for Relativistic MHD (RMHD)
allows us to model the acceleration and outflow properties of winds from
compact sources. Theoretical models suggest that acceleration and collimation
of the flow are extremely inefficient when the speed is close to $c$, in
contrast with many observations. Numerical results for an axisymmetric rotator,
both in the case of monopolar and dipolar magnetic field will be presented,
suggesting that in ideal RMHD acceleration is indeed inefficient. I will also
mention numerical challenges and stability problems of present simulations.
Finally I will discuss the interaction of a pulsar wind with the surrounding
SNR. I will present emission maps based on numerical simulations of the flow
inside the nebula and how they can be used in comparison with observations to
derive informations about the properties of pulsar winds far away from the
source.


title:
Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing
  Explorer

abstract:
  We have assembled a sample of 1187 thermonuclear (type-I) X-ray bursts from
48 accreting neutron stars by the Rossi X-ray Timing Explorer, spanning more
than ten years. The sample contains examples of two of the three theoretical
ignition regimes and likely examples of the third. We present a detailed
analysis of the variation of the burst profiles, energetics, recurrence times,
presence of photospheric radius expansion, and presence of burst oscillations,
as a function of accretion rate.
  We estimated the distance for 35 sources exhibiting radius-expansion bursts,
and found that the peak flux of such bursts varies typically by 13%. We
classified sources into two main groups based on the burst properties: both
long and short bursts (indicating mixed H/He accretion), and consistently short
bursts (primarily He accretion). The decrease in burst rate observed for both
groups at >0.06 Mdot_Edd (>~2E37 erg/s) is associated with a transition in the
persistent spectral state and (as has been suggested previously) may be related
to the increasing role of steady He-burning. We found examples of bursts
separated by <30 min, including burst triplets and even quadruplets.
  We describe the oscillation amplitudes for 13 of the 16 burst oscillation
sources, as well as the stages and properties of the bursts in which the
oscillations are detected. The burst properties are correlated with the burst
oscillation frequency; sources at <400 Hz generally have consistently short
bursts, while the more rapidly-spinning systems have both long and short
bursts. This correlation suggests either that shear-mediated mixing dominates
the burst properties, or that the nature of the mass donor (and hence the
evolutionary history) has an influence on the long-term spin evolution.


title: The M Dwarf GJ 436 and its Neptune-Mass Planet

abstract:
  We determine stellar parameters for the M dwarf GJ 436 that hosts a
Neptune-mass planet. We employ primarily spectral modeling at low and high
resolution, examining the agreement between model and observed optical spectra
of five comparison stars of type, M0-M3. Modeling high resolution optical
spectra suffers from uncertainties in TiO transitions, affecting the predicted
strengths of both atomic and molecular lines in M dwarfs. The determination of
Teff, gravity, and metallicity from optical spectra remains at ~10%. As
molecules provide opacity both in lines and as an effective continuum,
determing molecular transition parameters remains a challenge facing models
such as the PHOENIX series, best verified with high resolution and
spectrophotometric spectra. Our analysis of GJ 436 yields an effective
temperature of Teff = 3350 +/- 300 K and a mass of 0.44 Msun. New Doppler
measurements for GJ 436 with a precision of 3 m/s taken during 6 years improve
the Keplerian model of the planet, giving a minimum mass, M sin i = 0.0713 Mjup
= 22.6 Mearth, period, P = 2.6439 d, and e = 0.16 +/- 0.02. The noncircular
orbit contrasts with the tidally circularized orbits of all close-in
exoplanets, implying either ongoing pumping of eccentricity by a more distant
companion, or a higher Q value for this low-mass planet. The velocities indeed
reveal a long term trend, indicating a possible distant companion.


title:
Monte Carlo Simulations of Globular Cluster Evolution. IV. Direct
  Integration of Strong Interactions

abstract:
  We study the dynamical evolution of globular clusters containing populations
of primordial binaries, using our newly updated Monte Carlo cluster evolution
code with the inclusion of direct integration of binary scattering
interactions. We describe the modifications we have made to the code, as well
as improvements we have made to the core Monte Carlo method. We present several
test calculations to verify the validity of the new code, and perform many
comparisons with previous analytical and numerical work in the literature. We
simulate the evolution of a large grid of models, with a wide range of initial
cluster profiles, and with binary fractions ranging from 0 to 1, and compare
with observations of Galactic globular clusters. We find that our code yields
very good agreement with direct N-body simulations of clusters with primordial
binaries, but yields some results that differ significantly from other
approximate methods. Notably, the direct integration of binary interactions
reduces their energy generation rate relative to the simple recipes used in
Paper III, and yields smaller core radii. Our results for the structural
parameters of clusters during the binary-burning phase are now in the tail of
the range of parameters for observed clusters, implying that either clusters
are born significantly more or less centrally concentrated than has been
previously considered, or that there are additional physical processes beyond
two-body relaxation and binary interactions that affect the structural
characteristics of clusters.


title: The gamma-ray binaries LS 5039, LS I +61 303 and PSR B1259-63

abstract:
  Three binaries are now established sources of emission at very high energies
(>1e11 eV). They are composed of a massive star and a compact object. The
emission can be due to the interaction of the relativistic wind from a young ms
pulsar with the stellar wind of the companion, by which rotation-power ends up
as non-thermal flux. Variations at VHE energies are explained as due to
gamma-gamma absorption and/or changes in shock location along the orbit.
Resolved radio emission is due to cooling particles trailing the pulsar.


title: Spectral energy distribution of super-Eddington flows

abstract:
  Spectral properties of super-Eddington accretion flows are investigated by
means of a parallel line-of-sight calculation. The subjacent model, taken from
two-dimensional radiation hydrodynamic simulations by Ohsuga et al. (2005),
consists of a disc accretion region and an extended atmosphere with high
velocity outflows. The non-gray radiative transfer equation is solved,
including relativistic effects, by applying the FLD approximation.
  The calculated spectrum is composed of a thermal, blackbody-like emission
from the disc which depends sensitively on the inclination angle, and of high
energy X-ray and gamma-ray emission from the atmosphere. We find mild beaming
effects in the thermal radiation for small inclination angles. If we compare
the face-on case with the edge-on case, the average photon energy is larger by
a factor of ~1.7 due mainly to Doppler boosting, while the photon number
density is larger by a factor of ~3.7 due mainly to anisotropic matter
distribution around the central black hole. This gives an explanation for the
observed X-ray temperatures of ULXs which are too high to be explained in the
framework of intermediate-mass black holes.
  While the main features of the thermal spectral component are consistent with
more detailed calculations of slim accretion discs, the atmosphere induces
major changes in the high-energy part, which cannot be reproduced by existing
models. In order to interpret observational data properly, simple approaches
like the Eddington-Barbier approximation cannot be applied.


title:
Energy transport, overshoot, and mixing in the atmospheres of M-type
  main- and pre-main-sequence objects

abstract:
  We constructed hydrodynamical model atmospheres for mid M-type main-, as well
as pre-main-sequence (PMS) objects. Despite the complex chemistry encountered
in these cool atmospheres a reasonably accurate representation of the radiative
transfer is possible, even in the context of time-dependent and
three-dimensional models. The models provide detailed information about the
morphology of M-type granulation and statistical properties of the convective
surface flows. In particular, we determined the efficiency of the convective
energy transport, and the efficiency of mixing by convective overshoot. The
convective transport efficiency was expressed in terms of an equivalent
mixing-length parameter alpha in the formulation of mixing-length theory (MLT)
given by Mihalas (1978). Alpha amounts to values around 2 for matching the
entropy of the deep, adiabatically stratified regions of the convective
envelope, and lies between 2.5 and 3.0 for matching the thermal structure of
the deep photosphere. For current spectral analysis of PMS objects this implies
that MLT models based on alpha=2.0 overestimate the effective temperature by
100 K and surface gravities by 0.25 dex. The average thermal structure of the
formally convectively stable layers is little affected by convective overshoot
and wave heating, i.e., stays close to radiative equilibrium conditions. Our
models suggest that the rate of mixing by convective overshoot declines
exponentially with geometrical distance to the Schwarzschild stability
boundary. It increases at given effective temperature with decreasing
gravitational acceleration.


title:
Gould Belt Kinematics on the Base of the Open Clusters and
  Ob-Associations

abstract:
  The kinematic parameters of the Gould Belt are redetermined using modern data
on the motion of nearby young ($\log t<7.91$) open clusters, OB-associations
and moving stellar groups. The modelling carried out shows that the residual
velocities achieve the maximal values equal to -4 km s$^{-1}$ for rotation (in
the direction of the Galactic rotation) and $+4$ km s$^{-1}$ for expansion,
when the distance from the kinematic centre is about 300 pc. We assumed the
following parameters of the Gould Belt centre: $l_\circ=128^\circ$ and
$R_\circ=150$ pc. It is shown that the whole structure of the Gould Belt is
moving relative to the local standard of rest with a velocity of $10.7\pm0.7$
km s$^{-1}$ in the direction towards $l=274\pm4^\circ$, $b=-1\pm3^\circ$. Using
the rotation velocity, we obtained the virial estimation of the Gould Belt mass
as $1.5\times 10^6 M_\odot$.


title: Investigation of Negative K-Effect Using the Osaca Catalogue

abstract:
  We created and are constantly updating the Orion Spiral Arm CAtalogue (OSACA)
for stars with known coordinates, parallaxes, proper motions and radial
velocities. It is shown that there is an effect of contraction appearing in
motion of giants of A0--A5 spectral classes which attains a value of K=-13+-2
km/s/kpc. We try to link this effect to the periodic structure of residual
velocity field of stars in the solar neighborhood, which is caused by spiral
density waves.


title: Variations of the HeII 1640A Line in B0e--B2.5e Stars

abstract:
  Using the IUE data archive, we have examined the SWP-camera echellograms of
74 B0--B2.5e stars for statistically significant fluctuations in the He II
("Halpha") 1640A line profile. In this sample we found that the HeII line is
occasionally variable in 10 stars over short to long timescales. The
HeII-variable stars discovered are lambda Eri, omega Ori, mu Cen, 6 Cep, HD
67536, psi-1 Ori, eta Cen, pi Aqr, 2 Vul, and 19 Mon. The most frequent two
types of variability are an extended blue wing absorption and a weakening of
the line along the profile. Other types of variability are a weak emission in
the red wing and occasionally a narrow emission feature. In the overwhelming
number of cases, the CIV resonance doublet exhibits a similar response; rarely,
it can exhibit a variation in the opposite sense. Similar responses are also
often seen in the SiIV doublet, and occasionally even the SiIII 1206A line. We
interpret the weakenings of HeII and of high-velocity absorptions of CIV to
localized decreases in the photospheric temperature, although this may not be a
unique interpretation. We discuss the variable blue wing absorptions and red
wing emissions in terms of changes in the velocity law and mass flux carried by
the wind. In the latter case, recent experimental models by Venero, Cidale, &
Ringuelet require that during such events the wind must be heated to 35kK at
some distance from the star.


title: The Enrichment History of Baryons in the Universe

abstract:
  We present predictions for the cosmic metal budget in various phases of
baryons from redshift z=6-0, taken from a cosmological hydrodynamic simulation
that includes a well-constrained model for enriched galactic outflows. We find
that substantial amounts of metals are found in every baryonic phase at all
epochs, with diffuse intergalactic gas dominating the metal budget at early
epochs and stars and halo gas dominating at recent epochs. We provide a full
accounting of metals in the context of the missing metals problem at z~2.5,
showing that ~40% of the metals are in galaxies, and the remainder is divided
between diffuse IGM gas and shocked gas in halos and filamentary structures.
Comparisons with available observations of metallicity and metal mass fraction
evolution show broad agreement. We predict stars have a mean metallicity of
one-tenth solar already at z=6, which increases slowly to one-half solar today,
while stars just forming today have typically solar metallicity. Our HI column
density-weighted mean metallicity (comparable to Damped Ly-alpha system
metallicities) slowly increases from one-tenth to one-third solar from z=6-1,
then falls to one-quarter solar at z=0. The global mean metallicity of the
universe tracks ~50% higher than that of the diffuse phase down to z~1, and by
z=0 it has a value around one-tenth solar. Metals move towards higher densities
and temperatures with time, peaking around the mean cosmic density at z=2 and
an overdensity of 100 at z=0. We study how carbon and oxygen ions trace the
path of metals in phase space, and show that OIII-OVII lines provide the most
practical option for constraining intergalactic medium metals at z<2.


title:
Evaluating Dark Energy Probes using Multi-Dimensional Dark Energy
  Parameters

abstract:
  We investigate the value of future dark energy experiments by modeling their
ability to constrain the dark energy equation of state. Similar work was
recently reported by the Dark Energy Task Force (DETF) using a two dimensional
parameterization of the equation of state evolution. We examine constraints in
a nine dimensional dark-energy parameterization, and find that the best
experiments constrain significantly more than two dimensions in our 9D space.
Consequently the impact of these experiments is substantially beyond that
revealed in the DETF analysis, and the estimated cost per ``impact'' drops by
about a factor of ten as one moves to the very best experiments. The DETF
conclusions about the relative value of different techniques and of the
importance of combining techniques are unchanged by our analysis.


title: A Spectroscopic Study of Field and Runaway OB Stars

abstract:
  Identifying binaries among runaway O- and B-type stars offers valuable
insight into the evolution of open clusters and close binary stars. Here we
present a spectroscopic investigation of 12 known or suspected binaries among
field and runaway OB stars. We find new orbital solutions for five single-lined
spectroscopic binaries (HD 1976, HD 14633, HD 15137, HD 37737, and HD 52533),
and we classify two stars thought to be binaries (HD 30614 and HD 188001) as
single stars. In addition, we reinvestigate their runaway status using our new
radial velocity data with the UCAC2 proper motion catalogs. Seven stars in our
study appear to have been ejected from their birthplaces, and at least three of
these runaways are spectroscopic binaries and are of great interest for future
study.


title: Lensing of 21cm Absorption "Halos" of $z\sim$20-30 First Galaxies

abstract:
  Extended 21cm absorption regions (dubbed ``21cm absorption halos'') around
first galaxies at $z\sim 30$ are likely the first distinctive structures
accessible to radio observations. Though the radio array capable of detecting
and resolving them must have $\sim 200$ km$^2$ total collecting area, given the
great impact of such detections to the understanding of the reionization
process and cosmology, such radio survey would be extremely profitable. As an
example, we point out a potentially useful byproduct of such survey. The
resolved 21cm absorption ``halos'', likely close to spherical, can serve as
(almost) ideal sources for measuring the {\it cosmic shear} and mapping the
matter distribution to $z\sim 30$. We investigate the expected lensing signal
and consider a variety of noise contributions on the shear measurement. We find
that S/N $\sim 1$ can be achieved for individual ``halos''. Given millions of
21cm absorption ``halos'' across the sky, the total S/N will be comparable to
traditional shear measurement of $\sim$$10^9$ galaxies at $z\sim 1$.


title: Color-charged Quark Matter in Astrophysics?

abstract:
  Color confinement is only a supposition, which has not been proved in QCD
yet. It is proposed here that macroscopic quark gluon plasma in astrophysics
could hardly maintain colorless because of causality. The authors expected that
the existence of chromatic strange quark stars as well as chromatic strangelets
preserved from the QCD phase transition in the early universe could be
unavoidable if their colorless correspondents do exist.


title: Spherical Trigonometry of the Projected Baseline Angle

abstract:
  The basic geometry of a stellar interferometer with two telescopes consists
of a baseline vector and a direction to a star. Two derived vectors are the
delay vector, and the projected baseline vector in the plane of the wavefronts
of the stellar light. The manuscript deals with the trigonometry of projecting
the baseline further outwards onto the celestial sphere. The position angle of
the projected baseline is defined, measured in a plane tangential to the
celestial sphere, tangent point at the position of the star. This angle
represents two orthogonal directions on the sky, differential star positions
which are aligned with or orthogonal to the gradient of the delay recorded in
the u-v plane. The North Celestial Pole is chosen as the reference direction of
the projected baseline angle, adapted to the common definition of the
"parallactic" angle.


title: Radio Sources Toward Galaxy Clusters at 30 GHz

abstract:
  Extra-galactic radio sources are a significant contaminant in cosmic
microwave background and Sunyaev-Zel'dovich effect experiments. Deep
interferometric observations with the BIMA and OVRO arrays are used to
characterize the spatial, spectral, and flux distributions of radio sources
toward massive galaxy clusters at 28.5 GHz. We compute counts of mJy source
fluxes from 89 fields centered on known massive galaxy clusters and 8
non-cluster fields. We find that source counts in the inner regions of the
cluster fields (within 0.5 arcmin of the cluster center) are a factor of 8.9
(+4.3,-2.8) times higher than counts in the outer regions of the cluster fields
(radius greater than 0.5 arcmin). Counts in the outer regions of the cluster
fields are in turn a factor of 3.3 (+4.1,-1.8) greater than those in the
non-cluster fields. Counts in the non-cluster fields are consistent with
extrapolations from the results of other surveys. We compute spectral indices
of mJy sources in cluster fields between 1.4 and 28.5 GHz and find a mean
spectral index of alpha = 0.66 with an rms dispersion of 0.36, where flux is
proportional to frequency raised to negative alpha. The distribution is skewed,
with a median spectral index of 0.72 and 25th and 75th percentiles of 0.51 and
0.92, respectively. This is steeper than the spectral indices of stronger field
sources measured by other surveys.


title: Spin-orbit interactions in black-hole binaries

abstract:
  We perform numerical simulations of black-hole binaries to study the exchange
of spin and orbital angular momentum during the last, highly nonlinear, stages
of the coalescence process. To calculate the transfer of angular momentum from
orbital to spin, we start with two quasi-circular configurations, one with
initially non-spinning black holes, the other with corotating black holes. In
both cases the binaries complete almost two orbits before merging. We find
that, during these last orbits, the specific spin (a/m) of each horizon
increases by only 0.012 for the initially non-spinning configuration, and by
only 0.006 for the initially corotating configuration. By contrast, the
corotation value for the specific spin should increase from 0.1 at the initial
proper separation of 10M to 0.33 when the proper separation is 5M. Thus the
spin-orbit coupling is far too weak to tidally lock the binary to a corotating
state during the late-inspiral phase. We also study the converse transfer from
spin into orbital motion. In this case, we start the simulations with parallel,
highly-spinning non-boosted black holes. As the collision proceeds, the system
acquires a non-head-on orbital motion, due to spin-orbit coupling, that leads
to the radiation of angular momentum. We are able to accurately measure the
energy and angular momentum losses and model their dependence on the initial
spins.


title: Dark Energy, Dark Matter and Gravity

abstract:
  We discuss the motivation for high accuracy relativistic gravitational
experiments in the Solar System and complementary cosmological tests. We focus
our attention on the issue of distinguishing a generic scalar-theory of gravity
as the underlying physical theory from the usual general relativistic picture,
where one expects the presence of fundamental scalar fields associated, for
instance, to inflation, dark matter and dark energy.


title:
Constraints on the Inflationary Expansion from Three Year WMAP, small
  scale CMB anisotropies and Large Scale Structure Data Sets

abstract:
  We present the constraints on inflationary parameters in a flat $\Lambda$CDM
universe obtained by WMAP three year data release, plus smaller scale CMB and
two LSS data sets, 2dF and SDSS (treated separately). We use a Markov Chain
Monte Carlo (MCMC) technique combined with an analytic description of the
inflationary spectra in terms of the horizon flow functions (HFF). By imposing
a consistency condition for the tensor-to-scalar ratio, we study the
constraints both on single field standard inflation and on inflation with the
violation of the null energy condition, which leads to a blue spectrum for
gravitational waves. For standard inflation, the constraint on the
tensor-to-scalar ratio we obtain from CMB data and 2dF05 is: $r_{0.01} < 0.26$
at 2 $\sigma$ cl. Without the consistency condition between the
tensor-to-scalar ratio and the tensor slope, the constraints on the tensor
amplitude is not significantly changed, but the constraints on the HFFs are
significantly relaxed. We then show that when the third HFF $\epsilon_3$ is
allowed to be non-zero and to be of order unity, a large negative (at $2
\sigma$) value for the running of the scalar spectral index in standard
inflation is found in any set of data we consider.


title: Dynamics of Extended Spinning Masses in a Gravitational Field

abstract:
  We develop a first-order approximation method for the influence of spin on
the motion of extended spinning test masses in a gravitational field. This
approach is illustrated for approximately circular equatorial motion in the
exterior Kerr spacetime. In this case, the analytic results for the first-order
approximation are compared to the numerical integration of the exact system and
the limitations of the first-order results are pointed out. Furthermore, we
employ our analytic results to illustrate the gravitomagnetic clock effect for
spinning particles.


title: On the extrasolar multi-planet system around HD160691

abstract:
  We re-analyze the precision radial velocity (RV) observations of HD160691 (mu
Ara) by the Anglo-Australian Planet Search Team. The star is supposed to host
two Jovian companions (HD160691b, HD160691c) in long-period orbits about 630
days and about 2500 days, respectively) and a hot-Neptune (HD160691d) in about
9 days orbit. We perform a global search for the best fits in the orbital
parameters space with a hybrid code employing the genetic algorithm and simplex
method. The stability of Keplerian fits is verified with the N-body model of
the RV signal that takes into account the dynamical constraints (so called GAMP
method). Our analysis reveals a signature of the fourth, yet unconfirmed,
Jupiter-like planet HD160691e in about 307 days orbit. Overall, the global
architecture of four-planet configuration recalls the Solar system. All
companions of mu Ara move in quasi-circular orbits. The orbits of two inner
Jovian planets are close to the 2:1 mean motion resonance. The alternative
three-planet system involves two Jovian planets in eccentric orbits (e about
0.3), close to the 4:1 MMR, but it yields a significantly worse fit to the
data. We also verify a hypothesis of the 1:1 MMR in the subsystem of two inner
Jovian planets in the four-planet model.


title:
Effect of PSR J0737-3039 on the DNS Merger Rate and Implications for GW
  Detection

abstract:
  We present the current estimates of the Galactic merger rate of
double-neutron-star (DNS) systems. Using a statistical analysis method, we
calculate the probability distribution function (PDF) of the rate estimates,
which allows us to assign confidence intervals to the rate estimates. We
calculate the Galactic DNS merger rate based on the three known systems
B1913+16, B1534+12, and J0737-3039. The discovery of J0737-3039 increases the
estimated DNS merger rate by a factor ~6 than what is previously known. The
most likely values of DNS merger rate lie in the range 3-190 per Myr depending
on different pulsar models. Motivated by a strong correlation between the peak
rate estimates and a pulsar luminosity function, we calculate a 'global'
probability distribution as a single representation of the parameter space
covered by different pulsar population models. We compare the global PDF with
the observed supernova Ib/c rate, which sets an upper limit on the DNS merger
rate. Finally, we remark on implications of new discoveries such as of
J1756-2251, the 4th DNS in the Galactic disk, and J1906+0746, a possible DNS
system.


title:
Resonant Cyclotron Scattering in Three Dimensions and the Quiescent
  Non-thermal X-ray Emission of Magnetars

abstract:
  Although the surface of a magnetar is a source of bright thermal X-rays, its
spectrum contains substantial non-thermal components. The X-ray emission is
pulsed, with pulsed fractions that can be as high as ~ 70%. Several properties
of magnetars indicate the presence of persistent, static currents flowing
across the stellar surface and closing within the magnetosphere. The charges
supporting these currents supply a significant optical depth to resonant
cyclotron scattering in the 1-100 keV band. Here we describe a Monte Carlo
approach to calculating the redistribution of thermal seed photons in frequency
and angle by multiple resonant scattering in the magnetosphere. The calculation
includes the full angular dependence of the cyclotron scattering cross section,
the relativistic Doppler effect due to the motion of the charges, and allows
for an arbitrary particle velocity distribution and magnetic field geometry. We
construct synthetic spectra and pulse profiles for arbitrary orientations of
the spin axis, magnetic axis, and line of sight, using a self-similar, twisted
dipole field geometry, and assuming that the seed photons are supplied by
single-temperature black body emission from the stellar surface. Pulse profiles
and 1-10 keV spectra typical of AXPs are easily produced by this model, with
pulsed fractions of ~ 50%. However, this model cannot reproduce the hard,
rising energy spectra that are observed from SGRs during periods of activity,
without overproducing the thermal emission peak. This suggests that the 1-100
keV emission of SGRs has a common origin with the hard X-ray emission detected
from some AXPs above ~20 keV.


title:
Thermalization in Relativistic Outflows and the Correlation between
  Spectral Hardness and Apparent Luminosity in Gamma-ray Bursts

abstract:
  We present an interpretation of the phenomenological relations between the
spectral peak, isotropic luminosity and duration of long gamma ray bursts that
have been discovered by Amati et al., Ghirlanda et al., Firmani et al., and
Liang & Zhang. In our proposed model, a jet undergoes internal dissipation
which prevents its bulk Lorentz factor from exceeding 1/theta (theta being the
jet opening angle) until it escapes from the core of its progenitor star, at a
radius of order 1e10 cm; dissipation may continue at larger radii. The
dissipated radiation will be partially thermalized, and we identify its thermal
peak (Doppler boosted by the outflow) with E_pk. The radiation comes, in
effect, from within the jet photosphere. The non-thermal, high energy part of
the GRB emission arises from Comptonization of this radiation by relativistic
electrons and positrons outside the effective photosphere. This model can
account naturally not only for the surprisingly small scatter in the various
claimed correlations, but also for the normalization, as well as the slopes. It
then has further implications for the jet energy, the limiting jet Lorentz
factor, and the relation of the energy, opening angle and burst duration to the
mass and radius of the stellar stellar progenitor. The observed relation
between pulse width and photon frequency can be reproduced by inverse-Compton
emission at ~ 1e14 cm from the engine, but there are significant constraints on
the energy distribution and isotropy of the radiating particles.


title:
Early reionization by decaying particles in the light of three year WMAP
  data

abstract:
  We study the reionization histories where ionizing UV photons are emitted
from decaying particles, in addition to usual contributions from stars and
quasars, taking account of the fact that the universe is not fully ionized
until z = 6 as observed by Sloan Digital Sky Survey. Likelihood analysis of the
three-year data from the WMAP (Wilkinson Microwave Anisotropy Probe) severely
constrains the decaying particle scenario.In particular, the decaying particle
with relatively short lifetime is not favored by the polarization data.


title: The non-LTE line formation of neutral carbon in late-type stars

abstract:
  We investigate the non-Local Thermodynamic Equilibrium (non-LTE) line
formation of neutral carbon in late-type stars in order to remove some of the
potential systematic errors in stellar abundance analyses employing C I
features. The statistical equilibrium code MULTI was used on a grid of
plane-parallel 1D MARCS atmospheric models. Within the parameter space
explored, the high-excitation C I lines are stronger in non-LTE due to the
combined effect of line source function drop and increased lower level
population; the relative importance of the two effects depends on the
particular combination of Teff, log g, [Fe/H] and [C/Fe] and on the analysed C
I line. As a consequence, the non-LTE abundance corrections are negative and
can be substantially so, for example ~-0.4 dex in halo turn-off stars at
[Fe/H]~-3. The magnitude of the non-LTE corrections is rather insensitive to
whether inelastic H collisions are included or not. Our results have
implications on studies of nucleosynthetic processes and on Galactic chemical
evolution models. When applying our calculated corrections to recent
observational data, the upturn in [C/O] at low metallicity might still be
present (thus apparently still necessitating contributions from massive Pop.
III stars for the carbon production), but at a lower level and possibly with a
rather shallow trend of ~-0.2 dex/dex below [O/H]~-1


title: Prototype finline-coupled TES bolometers for CLOVER

abstract:
  CLOVER is an experiment which aims to detect the signature of gravitational
waves from inflation by measuring the B-mode polarization of the cosmic
microwave background. CLOVER consists of three telescopes operating at 97, 150,
and 220 GHz. The 97-GHz telescope has 160 feedhorns in its focal plane while
the 150 and 220-GHz telescopes have 256 horns each. The horns are arranged in a
hexagonal array and feed a polarimeter which uses finline-coupled TES
bolometers as detectors. To detect the two polarizations the 97-GHz telescope
has 320 detectors while the 150 and 220-GHz telescopes have 512 detectors each.
To achieve the target NEPs (1.5, 2.5, and 4.5x10^-17 W/rtHz) the detectors are
cooled to 100 mK for the 97 and 150-GHz polarimeters and 230 mK for the 220-GHz
polarimeter. Each detector is fabricated as a single chip to ensure a 100%
operational focal plane. The detectors are contained in linear modules made of
copper which form split-block waveguides. The detector modules contain 16 or 20
detectors each for compatibility with the hexagonal arrays of horns in the
telescopes' focal planes. Each detector module contains a time-division SQUID
multiplexer to read out the detectors. Further amplification of the multiplexed
signals is provided by SQUID series arrays. The first prototype detectors for
CLOVER operate with a bath temperature of 230 mK and are used to validate the
detector design as well as the polarimeter technology. We describe the design
of the CLOVER detectors, detector blocks, and readout, and present preliminary
measurements of the prototype detectors performance.


abstract:
  The concept of a stare-mode astrometric space mission is introduced. The
traditionally accepted mode of operation for a mapping astrometric space
mission is that of a continuously scanning satellite, like the successful
Hipparcos and planned Gaia missions. With the advent of astrometry missions
mapping out stars to 20th magnitude, the stare-mode becomes competitive. A
stare-mode of operation has several advantages over a scanning missions if
absolute parallax and throughput issues can be successfully addressed.
Requirements for a stare-mode operation are outlined. The mission precision for
a stare-mode astrometric mission is derived as a function of instrumental
parameters with examples given. The stare-mode concept has been accepted as
baseline for the NASA roadmap study of the Origins Billions Star Survey (OBSS)
mission and the Milli-arcsecond Pathfinder Survey (MAPS) micro-satellite
proposed project.


title: The Tensor Desert

abstract:
  We consider the question of whether it is worth building an experiment with
the sole purpose of bringing the detectable limit on the tensor-to-scalar
ratio, r, down to 10^{-3}. We look at the inflationary models which give a
prediction in this region and recap the current situation with the tensor mode,
showing that there are only three known models of inflation which give
definitive predictions in the region 10^{-3}<r<10^{-2}.


title: Optical and Infrared Emission from the AXPs and SGRs

abstract:
  We show that the irradiated accretion disk model can account for all the
optical and infrared observations of the anomalous X-ray pulsars in the
persistent state. Model fits do not constrain the outer disk radii, while
placing an upper limit to the inner disk radii, and thus to the strength of the
dipole component of the stellar magnetic field. While magnetar fields (B_* >
10^{14} G) in higher multipoles are compatible with the irradiated disk model,
magnetic dipole components of magnetar strength are not consistent with optical
data.


title: The MareNostrum Universe

abstract:
  The MareNostrum Universe is one of the biggest SPH cosmological simulations
done so far. It contains more than 2 billion particles (2 times 1024^3) in a
500 Mpc/h cubic volume. This simulation has been performed on the MareNostrum
supercomputer at the Barcelona Supercomputer Center. We have obtained more than
0.5 million halos with masses greater than a typical Milky Way galaxy halo. We
report results about the halo mass function, the shapes of dark matter and gas
distributions in halos, the baryonic fraction in galaxy clusters and groups,
baryon oscillations in the dark matter and the halo power spectra as well as
the distribution and evolution of the gas fraction at large scales.


title: Nebular emission lines in IRAS 17347-3139

abstract:
  We report the detection of nebular emission lines in the optical and
mid-infrared spectra of IRAS 17347-3139, a heavily obscured OH/IR star which
may be rapidly evolving from the AGB to the PN stage. The presence of emission
lines is interpreted as a clear indication that the ionization of its
circumstellar envelope has already started. This source belongs to the rare
class of objects known as `OHPNe' displaying both OH maser and radio continuum
emission. However, unlike the rest of stars in this class, prominent C-rich
dust features are detected in its mid-infrared spectrum, which makes the
analysis of this star particularly interesting.


title: The Halo Mass Function Redshift Dependence

abstract:
  It has recently been shown that the correct halo mass function high mass
behaviour may be obtained by an appropriate treatment of the all-mass-at-center
problem. Here we show that the treatment of this problem leads to an
accumulated mass fraction, F, which is not a universal function of the linear
variance of the density contrast, but depends also on the shape of the power
spectrum. For relevant power spectra F is a universal function of two
quantities: the linear variance and a quantity related to the local shape (at
the given mass scale) of the power spectrum. This implies, for a given shape of
the power spectrum, a redshift dependence of the mass function, which is quite
important for a cold dark matter power spectrum. Our results are in good
agreement with numerical simulations.


title:
NGC 4654: polarized radio continuum emission as a diagnostic tool for a
  galaxy--cluster interaction

abstract:
  A recent comparison between deep VLA HI observations and dynamical models of
the Virgo cluster spiral galaxy NGC 4654 has shown that only a model involving
a combination of a tidal interaction and ram pressure can reproduce the data.
Deep radio polarization studies, together with detailed MHD modeling, can
independently verify those conclusions, that are based on HI observations and
dynamical models. We performed deep polarized radio-continuum observations of
the Virgo cluster spiral galaxy NGC 4654 with the Effelsberg 100m telescope at
8.35 GHz and the VLA at 4.85 GHz. Detailed 3D MHD simulations were made to
determine the large-scale magnetic field and the emission distribution of the
polarized radio continuum in the model, during the galaxy evolution within the
cluster environment. This direct comparison between the observed and simulated
polarized radio continuum emission corroborates the earlier results, that the
galaxy had a recent rapid close encounter with NGC 4639 and is undergoing weak
ram pressure by the intracluster medium. This combination of deep radio
polarization studies and detailed MHD modeling thus gives us unique insight
into the interactions of a galaxy with its cluster environment. It represents a
diagnostic tool that is complementary to deep HI observations.


title: Forbush Decrease Data with a Simple Model

abstract:
  On October 28, 2003 an earthward-directed coronal mass ejection (CME) was
observed from SOHO/LASCO imagery in conjunction with an X17 solar flare. The
CME, traveling at nearly 2000 km/s, impacted the Earth on October 29, 2003
causing ground-based particle detectors to register a counting rate drop known
as a Forbush decrease. In addition to affecting the rate of cosmic rays, the
CME was also responsible for causing anisotropies in the direction of
incidence. Data from Project GRAND, an array of proportional wire chambers, are
presented during the time of this Forbush decrease. A simple model for CME
propagation is proposed and we present an argument based on gyroradius that
shows that a magnetic field of the radius calculated for the ejecta is
sufficient to deflect energetic charged particles of an energy detectable by
GRAND.


title:
Virgo cluster early-type dwarf galaxies with the Sloan Digital Sky
  Survey. II. Early-type dwarfs with central star formation

abstract:
  Despite the common picture of an early-type dwarf (dE) as a quiescent galaxy
with no star formation and little gas, we identify 23 dEs that have blue
central colors caused by recent or ongoing star formation in our sample of 476
Virgo cluster dEs. In addition, 14 objects that were mostly classified as
(candidate) BCDs have similar properties. Among the certain cluster members,
the dEs with blue centers reach a fraction of more than 15% of the dE
population at brighter (B<=16) magnitudes. A spectral analysis of the centers
of 16 galaxies reveals in all cases an underlying old population that dominates
the mass, with M(old)>=90% for all but one object. Therefore the majority of
these galaxies will appear like ordinary dEs within ~one Gigayear or less after
the last episode of star formation. Their overall gas content is less than that
of dwarf irregular galaxies, but higher than that of ordinary dEs. Their
flattening distribution suggests the shape of a thick disk, similar to what has
been found for dEs with disk features in Paper I of this series. Their
projected spatial distribution shows no central clustering, and their
distribution with projected local density follows that of irregular galaxies,
indicative of an unrelaxed population. This is corroborated by their velocity
distribution, which displays two side peaks characteristic of recent infall. We
discuss possible formation mechanisms (ram-pressure stripping, tidally induced
star formation, harassment) that might be able to explain both the disk shape
and the central star formation of the dEs with blue centers.


title: The Baryon Content of Extremely Low Mass Dwarf Galaxies

abstract:
  We investigate the gas content and baryonic Tully-Fisher relationship for
extremely low luminosity dwarf galaxies in the absolute magnitude range -13.5 >
Mr > -16. The sample is selected from the Sloan Digital Sky Survey and consists
of 101 galaxies for which we have obtained follow-up HI observations using the
Arecibo Observatory and Green Bank Telescope. This represents the largest
homogeneous sample of dwarfs at low luminosities with well-measured HI and
optical properties. The sample spans a range of environments, from dense groups
to truly isolated galaxies. The average neutral gas fraction is f_gas=0.6,
significantly exceeding that of typical gas-rich galaxies at higher
luminosities. Dwarf galaxies are therefore less efficient at turning gas into
stars over their lifetimes. The strong environmental dependence of the gas
fraction distribution demonstrates that while internal processes can reduce the
gas fractions to roughly f_gas=0.4, external processes are required to fully
remove gas from a dwarf galaxy. The average rotational velocity of our sample
is vrot=50 km/s. Including more massive galaxies from the literature, we fit a
baryonic Tully-Fisher slope of M_baryon \propto vrot^(3.70+/- 0.15). This slope
compares well with CDM models that assume an equal baryon to dark matter ratio
at all masses. While gas stripping or other processes may modify the baryon to
dark matter ratio for dwarfs in the densest environments, the majority of dwarf
galaxies in our sample have not preferentially lost significant baryonic mass
relative to more massive galaxies.


title: Spontaneous axisymmetry breaking of Saturn's external magnetic field

abstract:
  Saturn's magnetic field is remarkably axisymmetric. Its dipole axis is
inclined by less than 0.2 deg with respect to its rotation axis. Rotationally
driven convection of magnetospheric plasma breaks the axisymmetry of its
external magnetic field. Field aligned currents transfer angular momentum from
the planet to a tongue of outflowing plasma. This transfer slows the rate of
rotation of the ionosphere relative to that of the underlying atmosphere. The
currents are the source for the non-axisymmetric components of the field. The
common rotation rates of these components and Saturn's kilometric radio (SKR)
bursts is that of the plasma near the orbit of Enceladus, and by extension the
rotation rate in the ionosphere to which this plasma is coupled. That rate
tells us nothing about the rotation rate of Saturn's deep interior. Of that we
remain ignorant. Magnetic perturbations with magnitudes similar to those
observed by Cassini are produced for Mdot ~ 10^4 g/s, a value similar to
estimates for the rate of production of plasma from Saturn's E-ring.
Enhancement of the SKR occurs in a narrow range of longitudes where the tip of
the outgoing plasma stream connects to the auroral ionosphere via field lines
that are bowed outwards by currents that supply the plasma's centripetal
acceleration. (abridged)


title:
Dense, Fe-rich Ejecta in Supernova Remnants DEM L238 and DEM L249: A New
  Class of Type Ia Supernova?

abstract:
  We present observations of two LMC supernova remnants (SNRs), DEM L238 and
DEM L249, with the Chandra and XMM-Newton X-ray satellites. Bright central
emission, surrounded by a faint shell, is present in both remnants. The central
emission has an entirely thermal spectrum dominated by strong Fe L-shell lines,
with the deduced Fe abundance in excess of solar and not consistent with the
LMC abundance. This Fe overabundance leads to the conclusion that DEM L238 and
DEM L249 are remnants of thermonuclear (Type Ia) explosions. The shell emission
originates in gas swept up and heated by the blast wave. A standard Sedov
analysis implies about 50 solar masses in both swept-up shells, SNR ages
between 10,000 and 15,000 yr, low (< 0.05 cm^-3) preshock densities, and
subluminous explosions with energies of 3x10^50 ergs. The central Fe-rich
supernova ejecta are close to collisional ionization equilibrium. Their
presence is unexpected, because standard Type Ia SNR models predict faint
ejecta emission with short ionization ages. Both SNRs belong to a previously
unrecognized class of Type Ia SNRs characterized by bright interior emission.
Denser than expected ejecta and/or a dense circumstellar medium around the
progenitors are required to explain the presence of Fe-rich ejecta in these
SNRs. Substantial amounts of circumstellar gas are more likely to be present in
explosions of more massive Type Ia progenitors. DEM L238, DEM L249, and similar
SNRs could be remnants of ``prompt'' Type Ia explosions with young (~100 Myr
old) progenitors.


title: Extrasolar Planets: A Galactic Perspective

abstract:
  The host stars of extrasolar planets tend to be metal-rich. We have examined
the data for these stars for evidence of trends in other galactic parameters,
without success. However, several ESP hosts are likely to be members of the
thick disk population, indicating that planet formation has occurred throughout
the full lifetime of the Galactic disk. We briefly consider the radial
metallicity gradient and age-metallicity relation of the Galactic disk, and
complete a back-of-the envelope estimate of the likely number of solar-type
stars with planetary companions with 6 < R < 10 kpc.


title:
Just dust : About the (in)applicability of rotating dust solutions as
  realistic galaxy models

abstract:
  Solutions of the stationary axisymmetric Einstein equations describing the
interior of circularly rotating dust are investigated in order to study their
potential applicability as galaxy models. It is shown that such interior
solutions cannot be used as global metrics without becoming unphysical in
certain regions of space. Although definite results concerning the
non-existence of a continuation into a vacuum can only be derived for interior
solutions describing rigidly rotating dust, the present analysis exhibits that
the case of non-rigidly rotating dust would in general also be inadequate as a
physically reasonable galaxy model.


title: Hubble Space Telescope Images of Magellanic Cloud Planetary Nebulae

abstract:
  We present images and slitless spectra which were obtained in HST surveys of
Planetary Nebulae (PNe) in both the Large and Small Magellanic Clouds, using
the Space Telescope Imaging Spectrograph. These new data on 59 PNe (54 in the
LMC and five in the SMC) permit us to determine the nebular dimensions and
morphology in the monochromatic light of several emission lines: Halpha, [N II]
lambda 6583 and [O III] lambda 5007, plus others of varying ionization,
including [O I], He I, and [S II]. We describe the nebular morphology and
related features in detail. This survey, when combined with similar data from
our prior HST programs and other archived PN images, brings the total of
nebulae imaged with HST to 114 in the LMC and 35 in the SMC. We describe
various basic properties for the sample, including sizes, morphologies,
densities, and completeness. Trends in [O III] lambda 5007 flux, surface
brightness, and electron density with physical radius suggest that many
nebulae, particularly those with bipolar morphology, may be optically thick
even at large size. Bipolars also show the most extreme values of [N II]/Halpha
flux ratios, which is a rough indicator N enrichment.


title:
Discovery of a Metal-Line Absorber Associated with a Local Dwarf
  Starburst Galaxy

abstract:
  We present optical and near-infrared images, H I 21 cm emission maps, optical
spectroscopy, and Hubble Space Telescope/Space Telescope Imaging Spectrograph
ultraviolet spectroscopy of the QSO/galaxy pair SBS 1122+594/IC 691. The QSO
sight line lies at a position angle of 27 degrees from the minor axis of the
nearby dwarf starburst galaxy IC 691 (cz_gal = 1204+-3 km/s, L_B ~ 0.09 L*,
current star formation rate = 0.08-0.24 solar masses per year) and 33 kpc (6.6
arcmin) from its nucleus. We find that IC 691 has an H I mass of M_HI =
(3.6+-0.1) x 10^8 solar masses and a dynamical mass of M_dyn = (3.1+-0.5) x
10^10 solar masses. The UV spectrum of SBS 1122+594 shows a metal-line
(Ly-alpha + C IV) absorber near the redshift of IC 691 at cz_abs = 1110+-30
km/s. Since IC 691 is a dwarf starburst and the SBS 1122+594 sight line lies in
the expected location for an outflowing wind, we propose that the best model
for producing this metal-line absorber is a starburst wind from IC 691. We
place consistent metallicity limits on IC 691 ([Z/Zsun] ~ -0.7) and the
metal-line absorber ([Z/Zsun] < -0.3). We also find that the galaxy's escape
velocity at the absorber location is v_esc = 80+-10 km/s and derive a wind
velocity of v_w = 160+-50 km/s. Thus, the evidence suggests that IC 691
produces an unbound starburst wind that escapes from its gravitational
potential to transport metals and energy to the surrounding intergalactic
medium.


title: The Deuterium to Hydrogen Abundance Ratio Towards the QSO SDSS1558-0031

abstract:
  We present a measurement of the D/H abundance ratio in a metal-poor damped
Lyman alpha (DLA) system along the sightline of QSO SDSS1558-0031. The DLA
system is at redshift z = 2.70262, has a neutral column density of
log(NHI)=20.67+/-0.05 cm^2, and a gas-phase metallicity [O/H]= -1.49 which
indicates that deuterium astration is negligible. Deuterium absorption is
observed in multiple Lyman series with a column density of
log(NDI)=16.19+/-0.04 cm^2, best constrained by the deuterium Lyman-11 line. We
measure log(D/H) = -4.48+/-0.06, which when combined with previous measurements
along QSO sightlines gives a best estimate of log(D/H) = -4.55+/-0.04, where
the 1-sigma error estimate comes from a jackknife analysis of the weighted
means. Using the framework of standard big bang nucleosynthesis, this value of
D/H translates into a baryon density of Omega_b h^2 = 0.0213 +/- 0.0013 +/-
0.0004 where the error terms represent the 1-sigma errors from D/H and the
uncertainties in the nuclear reaction rates respectively. Combining our new
measurement with previous measurements of D/H, we no longer find compelling
evidence for a trend of D/H with NHI.