title:
Universality of electron distributions in high-energy air showers -
  description of Cherenkov light production

abstract:
  The shower simulation code CORSIKA has been used to investigate the electron
energy and angular distributions in high-energy showers. Based on the
universality of both distributions, we develop an analytical description of
Cherenkov light emission in extensive air showers, which provides the total
number and angular distribution of photons. The parameterisation can be used
e.g. to calculate the contribution of direct and scattered Cherenkov light to
shower profiles measured with the air fluorescence technique.


title:
Ultracompact AM CVn Binaries from the Sloan Digital Sky Survey: Three
  Candidates Plus the First Confirmed Eclipsing System

abstract:
  AM CVn systems are a rare (about a dozen previously known) class of
cataclysmic variables, arguably encompassing the shortest orbital periods (down
to about 10 minutes) of any known binaries. Both binary components are thought
to be degenerate (or partially so), likely with mass-transfer from a
helium-rich donor onto a white dwarf, driven by gravitational radiation.
Although rare, AM CVn systems are of high interest as possible SN Ia
progenitors, and because they are predicted to be common sources of gravity
waves in upcoming experiments such as LISA. We have identified four new AM CVn
candidates from the Sloan Digital Sky Survey (SDSS) spectral database. All four
show hallmark spectroscopic characteristics of the AM CVn class: each is devoid
of hydrogen features, and instead shows a spectrum dominated by helium. All
four show double-peaked emission, indicative of helium-dominated accretion
disks. Limited time-series CCD photometric follow-on data have been obtained
for three of the new candidates from the ARC 3.5m; most notably, a 28.3 minute
binary period with sharp, deep eclipses is discovered in one case, SDSS
J0926+3624. This is the first confirmed eclipsing AM CVn, and our data allow
initial estimates of binary parameters for this ultracompact system. The four
new SDSS objects also provide a substantial expansion of the currently
critically-small sample of AM CVn systems.


title: Introduction to Astrophysics of Microquasars

abstract:
  The Astrophysics of microquasars - galactic miniatures of the far distant
quasars - has become one of the most active fields of modern Astronomy in
recent years. Here I review the astronomical methods used for the investigation
of these objects, from Gamma-rays over X-rays and optical to radio wavelengths.
The description of each astronomical method is always followed by an examplary
application on the source LS I+61 303, one of the most observed Be/X-ray binary
systems


title:
Is it possible to consider Dark Energy and Dark Matter as a same and
  unique Dark Fluid?

abstract:
  In the standard model of cosmology, the present evolution of the Universe is
determined by the presence of two components of unknown nature. One of them is
referenced as ``dark matter'' to justify the fact that it behaves
cosmologically like usual baryonic matter, whereas the other one is called
``dark energy'', which is a component with a negative pressure. As the nature
of both dark components remains unknown, it is interesting to consider other
models. In particular, it seems that the cosmological observations can also be
understood for a Universe which does not contain two fluids of unknown nature,
but only one fluid with other properties. To arrive to this conclusion, we will
review the observational constraints from supernovae of type Ia, cosmic
microwave background, large scale structures, and the theoretical results of
big-bang nucleosynthesis. We will try to determine constraints on this unifying
``dark fluid'', and briefly review different possibilities to build models of
dark fluid.


title:
The Solar Neighborhood XV: Discovery of New High Proper Motion Stars
  with mu >= 0.4"/yr between Declinations -47 degrees and 00 degrees

abstract:
  We report the discovery of 152 new high proper motion systems (mu >= 0.4"/yr)
in the southern sky (Declination = -47 degrees to 00 degrees) brighter than
UKST plate R_{59F} =16.5 via our SuperCOSMOS-RECONS (SCR) search. This paper
complements Paper XII in The Solar Neighborhood series, which covered the
region from Declination = -90 degrees to -47 degrees and discussed all 147 new
systems from the southernmost phase of the search. Among the total of 299
systems from both papers, there are 148 (71 in Paper XII, 77 in this paper) new
systems moving faster than 0.5"/yr that are additions to the classic ``LHS''
(Luyten Half Second) sample. These constitute an 8% increase in the sample of
all stellar systems with mu >= 0.5"/yr in the southern sky.
  As in Paper XII, distance estimates are provided for the systems reported
here based upon a combination of photographic plate magnitudes and 2MASS
photometry, assuming all stars are on the main sequence. Two SCR systems from
the portion of the sky included in this paper are anticipated to be within 10
pc, and an additional 23 are within 25 pc. In total, the results presented in
Paper XII and here for this SCR sweep of the entire southern sky include five
new systems within 10 pc and 38 more between 10 and 25 pc. The largest number
of nearby systems have been found in the slowest proper motion bin, 0.6"/yr >
mu >= 0.4"/yr, indicating that there may be a large population of low proper
motion systems very near the Sun.


title: Neutron Catalysis of Resonance Fusion in Stellar Matter

abstract:
  Within the framework of resonance fusion study in stellar matter the features
of system consisted of two alpha particles and one neutron have been
investigated at astrophysical energies. Consideration of three body scattering
has been carried out on base of well-known Faddeev's equations. It is found
that under certain conditions the series of resonance states appear in this
system at very low energies. The lifetimes of these three body resonances are
close to the lifetime of unstable nucleus 8Be. The simple forms of two body
repulsive potentials are taken into account to describe the parameters of the
alpha, alpha resonance and to satisfy n, alpha scattering data at very low
energies. The explanation of resonance phenomena in n, alpha, alpha system is
offered on base of physical model. The effect results from resonance quantum
phenomena in few body dynamics. In turn, the resonance fusion can give
influence on many astrophysical phenomena. The possibility of catalyzing this
new mode of fusion by free neutrons in alpha particle matter is considered too.


title:
Hadronic high-energy gamma-ray emission from the microquasar LS I $+61
  303$

abstract:
  We present a hadronic model for gamma-ray production in the microquasar LS I
$+61 303$. The system is formed by a neutron star that accretes matter from the
dense and slow equatorial wind of the Be primary star. We calculate the
gamma-ray emission originated in $pp$ interactions between relativistic protons
in the jet and cold protons from the wind. After taking into account opacity
effects on the gamma-rays introduced by the different photons fields, we
present high-energy spectral predictions that can be tested with the new
generation Cherenkov telescope MAGIC.


title: Effects of clumping on temperature I: externally heated clouds

abstract:
  We present a study of radiative transfer in dusty, clumpy star-forming
regions. A series of self-consistent, 3-D, continuum radiative transfer models
are constructed for a grid of models parameterized by central luminosity,
filling factor, clump radius, and face-averaged optical depth. The temperature
distribution within the clouds is studied as a function of this
parameterization. Among our results, we find that: (a) the effective optical
depth is smaller in clumpy regions than in equivalent homogeneous regions; (b)
penetration of radiation is drive by the fraction of open sky (FOS) -- which
measures the fraction of solid angle which is devoid of clumps; (c) FOS
increases as clump radius increases and filling factor decreases; (d) for FOS >
0.6-0.8 the sky is sufficiently open that the temperature is relatively
insensitive to FOS; (e) the physical process by which radiation penetrates is
streaming between clumps; (f) filling factor dominates the temperature
distribution for large optical depths, and at small clump radii for small
optical depths; (g) at lower optical depths, the temperature distribution is
most sensitive to filling factors of 1-10 per cent, in accordance with many
observations; (h) direct shadowing can be important approximately one clump
radius behind a clump.


title: The NGC 5846 Group: Dynamics and the Luminosity Function to M_R=-12

abstract:
  We conduct a photometric and spectroscopic survey of a 10 sq. deg. region
surrounding the nearby NGC 5846 group of galaxies, using the
Canada-France-Hawaii and Keck I telescopes to study the population of dwarf
galaxies as faint as M_R=-10. Candidates are identified on the basis of
quantitative surface brightness and qualitative morphological criteria.
Spectroscopic follow up and a spatial correlation analysis provide the basis
for affirming group memberships. Altogether, 324 candidates are identified and
83 have spectroscopic membership confirmation. We argue on statistical grounds
that a total 251 +/- 10 galaxies in our sample are group members. The
observations, together with archival Sloan Digital Sky Survey, ROSAT,
XMM-Newton, and ASCA data, suggest that the giant ellipticals NGC 5846 and NGC
5813 are the dominant components of subgroups separated by 600 kpc in
projection and embedded in a 1.6 Mpc diameter dynamically evolved halo. The
galaxy population is overwhelmingly early type. The group velocity dispersion
is 322 km/s, its virial mass is 8.4 x 10^13 M_sun, and M/L_R = 320 M_sun/L_sun.
The ratio of dwarfs to giants is large compared with other environments in the
Local Supercluster studied and, correspondingly, the luminosity function is
relatively steep, with a faint end Schechter function slope of \alpha_d = -1.3
+/- 0.1 (statistical) +/- 0.1 (systematic) at our completeness limit of M_R =
-12.


title:
Survey for Transiting Extrasolar Planets in Stellar Systems. II.
  Spectrophotometry and Metallicities of Open Clusters

abstract:
  We present metallicity estimates for seven open clusters based on
spectrophotometric indices from moderate-resolution spectroscopy. Observations
of field giants of known metallicity provide a correlation between the
spectroscopic indices and the metallicity of open cluster giants. We use \chi^2
analysis to fit the relation of spectrophotometric indices to metallicity in
field giants. The resulting function allows an estimate of the target-cluster
giants' metallicities with an error in the method of \pm0.08 dex. We derive the
following metallicities for the seven open clusters: NGC 1245,
[m/H]=-0.14\pm0.04; NGC 2099, [m/H]=+0.05\pm0.05; NGC 2324, [m/H]=-0.06\pm0.04;
NGC 2539, [m/H]=-0.04\pm0.03; NGC 2682 (M67), [m/H]=-0.05\pm0.02; NGC 6705,
[m/H]=+0.14\pm0.08; NGC 6819, [m/H]=-0.07\pm0.12. These metallicity estimates
will be useful in planning future extra-solar planet transit searches since
planets may form more readily in metal-rich environments.


title: Probing the Shape of the Galactic Halo with Hyper-Velocity Stars

abstract:
  Precise proper motion measurements (sigma_mu ~ 10 mkas/yr) of the recently
discovered hyper-velocity star (HVS) SDSS J090745.0+024507 would yield
significant constraints on the axis ratios and orientation of a triaxial model
for the Galactic halo. Triaxiality of dark matter halos is predicted by Cold
Dark Matter models of galaxy formation and may be used to probe the nature of
dark matter. However, unless the distance to this star is determined to better
than 10%, these constraints suffer from one-dimensional degeneracies, which we
quantify. We show how proper motion measurements of several HVSs could
simultaneously resolve the distance degeneracies of all such stars and produce
a detailed picture of the triaxial halo. Additional HVSs may be found from
radial velocity surveys or from parallax/proper-motion data derived from GAIA.
High-precision proper-motion measurements of these stars using the Space
Interferometry Mission (SIM PlanetQuest) would substantially tighten the
constraints they yield on the Galactic potential.


title: Mapping dark matter with cosmic magnification

abstract:
  We develop a new tool to generate statistically precise dark matter maps from
the cosmic magnification of galaxies with distance estimates. We show how to
overcome the intrinsic clustering problem using the slope of the luminosity
function, because magnificability changes strongly over the luminosity
function, while intrinsic clustering only changes weakly. This may allow
precision cosmology beyond most current systematic limitations. SKA is able to
reconstruct projected matter density map at smoothing scale $\sim 10^{'}$ with
S/N$\geq 1$, at the rate of 200-4000 deg$^2$ per year, depending on the
abundance and evolution of 21cm emitting galaxies. This power of mapping dark
matter is comparable to, or even better than that of cosmic shear from deep
optical surveys or 21cm surveys.


title:
Measurement of Pressure Dependent Fluorescence Yield of Air: Calibration
  Factor for UHECR Detectors

abstract:
  In a test experiment at the Final Focus Test Beam of the Stanford Linear
Accelerator Center, the fluorescence yield of 28.5 GeV electrons in air and
nitrogen was measured. The measured photon yields between 300 and 400 nm at 1
atm and 29 deg C are Y(760 Torr, air) = 4.42 +/- 0.73 and Y(760 Torr, nitrogen)
= 29.2 +/- 4.8 photons per electron per meter. Assuming that the fluorescence
yield is proportional to the energy deposition of a charged particle traveling
through air, good agreement with measurements at lower particle energies is
observed.


title: Galaxy formation and cosmic-ray acceleration in a magnetized universe

abstract:
  We study the linear magneto-hydrodynamical behaviour of a Newtonian cosmology
with a viscous magnetized fluid of finite conductivity and generalise the Jeans
instability criterion. The presence of the field favors the anisotropic
collapse of the fluid, which in turn leads to further magnetic amplification
and to an enhanced current-sheet formation in the plane normal to the ambient
magnetic field. When the currents exceed a certain threshold, the resulting
electrostatic turbulence can dramatically amplify the resistivity of the medium
(anomalous resistivity). This could trigger strong electric fields and
subsequently the acceleration of ultra-high energy cosmic rays (UHECRs) during
the formation of protogalactic structures.


title:
Spitzer Observations of G Dwarfs in the Pleiades: Circumstellar Debris
  Disks at 100 Myr Age

abstract:
  Fluxes and upper limits in the wavelength range from 3.6 to 70 microns from
the Spitzer Space Telescope are provided for twenty solar-mass Pleiades
members. One of these stars shows a probable mid-IR excess and two others have
possible excesses, presumably due to circumstellar debris disks. For the star
with the largest, most secure excess flux at MIPS wavelengths, HII1101, we
derive Log(L[dust]/L[Sun]) ~ -3.8 and an estimated debris disk mass of 4.2 x
10^-5 M(Earth) for an assumed uniform dust grain size of 10 microns If the
stars with detected excesses are interpreted as stars with relatively recent,
large collision events producing a transient excess of small dust particles,
the frequency of such disk transients is about ~ 10 % for our ~ 100 Myr,
Pleiades G dwarf sample. For the stars without detected 24-70 micron excesses,
the upper limits to their fluxes correspond to approximate 3 sigma upper limits
to their disk masses of 6 x 10^-6 M(Earth) using the MIPS 24 micron upper
limit, or 2 x 10^-4 M(Earth) using the MIPS 70 micron limit. These upper limit
disk masses (for "warm" and "cold" dust, respectively) are roughly consistent,
but somewhat lower than, predictions of a heuristic model for the evolution of
an "average" solar-mass star's debris disk based on extrapolation backwards in
time from current properties of the Sun's Kuiper belt.


title:
Oxygen in Galactic Disk Stars: non-LTE abundances from the 777 nm O I
  triplet

abstract:
  Oxygen abundances for a large sample of dwarf and giant stars kinematically
selected to be part of the Galactic thin and thick disks have been determined
from a non-LTE analysis of the O I triplet lines at 777 nm. The abundance
analysis was performed using the infrared flux method temperature scale,
trigonometric surface gravities, and accurate atomic data. Within this
framework, the ionization balance of iron lines could not be satisfied and so
we adopted the iron abundances from Fe II lines only given that they are
relatively less sensitive to changes in the atmospheric parameters. We show the
resulting [O/Fe] vs. [Fe/H] relationship and briefly discuss its implications.


title: The Frequency of Carbon Rich Stars Among Extremely Metal Poor Stars

abstract:
  We demonstrate that there are systematic scale errors in the [Fe/H] values
determined by the Hamburg/ESO Survey (and by the HK Survey by inference) for
certain extremely metal poor (EMP) highly C-enhanced giants. The consequences
of these scale errors are that a) the fraction of carbon stars at extremely low
metallicities has been substantially overestimated in several papers in the
recent literature b) the number of EMP stars known is somewhat lower than has
been quoted in the recent literature c) the yield for EMP stars by the HK and
the HES Survey is somewhat lower than is stated in the recent literature. A
preliminary estimate for the frequency of Carbon stars among the giants in the
HES sample with -4 < [Fe/H] < -2.0 dex is 7.4 \pm 2.9%, and for C-rich giants
with [C/Fe] > +1.0 dex is 14.4 \pm 4%.
  Here we present the key results of detailed abundance analyses of 14 C-stars
selected from the HES as candidate EMP stars, of ~50 such stars analyzed. About
80% of such C-stars show highly enhanced Ba as well, with C enhanced by a
factor of about 100, and [Ba/C] roughly Solar. These stars often show prominent
lead lines, The remaining 20% of the C-stars do not show an enhancemement of
the s-process neutron capture elements around the Ba peak. They tend to be the
most metal-poor stars studied. We suggest that all these EMP C-stars are the
remnants of the secondary in a mass transfer binary system where the former
primary was an AGB star, which transferred substantial mass at that
evolutionary stage. (published abstract will be shorter due to space
limitations)


title:
Discovery of a Strongly Lensed Galaxy at z=3.9 behind a z=0.83 Galaxy
  Cluster

abstract:
  We report the discovery and spectroscopic confirmation of three
gravitationally-lensed images of a galaxy at z=3.9 in the background of a
distant, rich cluster of galaxies at z=0.83, on the basis of observations with
Faint Object Camera And Spectrograph (FOCAS) on the Subaru telescope. We
construct a simple lens model of the cluster mass distribution based on Jee et
al.'s weak lensing mass estimates from deep, high-resolution images by Advanced
Camera for Surveys (ACS) on the Hubble Space Telescope. The lens model can
account simultaneously for the observed image configuration and the flux ratio
of the closer pair located close to the critical curve. The parities of the
three images are also consistent with the lensing hypothesis. Since this galaxy
is apparently bright (i'_{AB} \sim 23.7) for its redshift due to the
magnification, it serves as a good high redshift target on which we can make
extensive and detailed studies based on multi-wavelength imaging and
spectroscopy.


title: Dynamical phasing of Type II Cepheids

abstract:
  In this paper we examine the problems of phasing using light curves and offer
an alternate technique using the changes in acceleration to establish the zero
point. We give astrophysical justification as to why this technique is useful
and apply the technique to a selection of Type II Cepheids. We then examine
some limitations of the technique which qualify its use.


title:
Observational constraints on low redshift evolution of dark energy: How
  consistent are different observations?

abstract:
  The dark energy component of the universe is often interpreted either in
terms of a cosmological constant or as a scalar field. A generic feature of the
scalar field models is that the equation of state parameter w= P/rho for the
dark energy need not satisfy w=-1 and, in general, it can be a function of
time. Using the Markov chain Monte Carlo method we perform a critical analysis
of the cosmological parameter space, allowing for a varying w. We use
constraints on w(z) from the observations of high redshift supernovae (SN), the
WMAP observations of CMB anisotropies and abundance of rich clusters of
galaxies. For models with a constant w, the LCDM model is allowed with a
probability of about 6% by the SN observations while it is allowed with a
probability of 98.9% by WMAP observations. The LCDM model is allowed even
within the context of models with variable w: WMAP observations allow it with a
probability of 99.1% whereas SN data allows it with 23% probability. The SN
data, on its own, favors phantom like equation of state (w<-1) and high values
for Omega_NR. It does not distinguish between constant w (with w<-1) models and
those with varying w(z) in a statistically significant manner. The SN data
allows a very wide range for variation of dark energy density, e.g., a
variation by factor ten in the dark energy density between z=0 and z=1 is
allowed at 95% confidence level. WMAP observations provide a better constraint
and the corresponding allowed variation is less than a factor of three.
Allowing for variation in w has an impact on the values for other cosmological
parameters in that the allowed range often becomes larger. (Abridged)


title: Interaction between Physics and Cosmology

abstract:
  Recent results indicate the presence of a cosmological constant (or related
dark energy) in the universe. It has been conjectured recently that the
interaction parameters of physical theories may be dependant on the size
parameter of the universe, related to the cosmological constant. We investigate
whether such effects will help in explaining baryogenesis in early universe.
They do seem to succeed.


title:
The Baryonic Tully-Fisher Relation of Galaxies with Extended Rotation
  Curves and the Stellar Mass of Rotating Galaxies

abstract:
  I investigate the Baryonic Tully-Fisher relation for a sample of galaxies
with extended 21 cm rotation curves spanning the range 20 < Vf < 300 km/s. A
variety of scalings of the stellar mass-to-light ratio are considered. For each
prescription for M/L, I give fits of the form Md = A Vf^x. Presumably, the
prescription that comes closest to the correct value will minimize the scatter
in the relation. The fit with minimum scatter has A = 50 solar masses/(km/s)^4
and x = 4. This relation holds over five decades in mass. Galaxy color, stellar
fraction, and M/L are correlated with each other and with Md, in the sense that
more massive galaxies tend to be more evolved. There is a systematic dependence
of the degree of maximality of disks on surface brightness. High surface
brightness galaxies typically have M/L ~ 3/4 of the maximum disk value, while
low surface brightness galaxies typically attain ~ 1/4 of this amount.


title:
Spectral analysis of early-type stars using a genetic algorithm based
  fitting method

abstract:
  We present the first automated fitting method for the quantitative
spectroscopy of O- and early B-type stars with stellar winds. The method
combines the non-LTE stellar atmosphere code FASTWIND from Puls et al. (2005)
with the genetic algorithm based optimizing routine PIKAIA from Charbonneau
(1995), allowing for a homogeneous analysis of upcoming large samples of
early-type stars (e.g. Evans et al. 2005). In this first implementation we use
continuum normalized optical hydrogen and helium lines to determine
photospheric and wind parameters. We have assigned weights to these lines
accounting for line blends with species not taken into account, lacking
physics, and/or possible or potential problems in the model atmosphere code. We
find the method to be robust, fast, and accurate. Using our method we analysed
seven O-type stars in the young cluster Cyg OB2 and five other Galactic stars
with high rotational velocities and/or low mass loss rates (including 10lac,
zeta Oph, and tau Sco) that have been studied in detail with a previous version
of FASTWIND. The fits are found to have a quality that is comparable or even
better than produced by the classical ``by eye'' method. We define errorbars on
the model parameters based on the maximum variations of these parameters in the
models that cluster around the global optimum. Using this concept, for the
investigated dataset we are able to recover mass-loss rates down to ~6d-8
Msun/yr to within an error of a factor of two. Comparison of our derived
spectroscopic masses with those derived from stellar evolutionary models are in
very good agreement, i.e. based on the limited sample that we have studied we
do not find indications for a mass discrepancy.


title: The Minimum Stellar Mass in Early Galaxies

abstract:
  The conditions for the fragmentation of the baryonic component during merging
of dark matter halos in the early Universe are studied. We assume that the
baryonic component undergoes a shock compression. The characteristic masses of
protostellar molecular clouds and the minimum masses of protostars formed in
these clouds decrease with increasing halo mass. This may indicate that the
initial stellar mass function in more massive galaxies was shifted towards
lower masses during the initial stages of their formation. This would result in
an increase of the number of stars per unit halo mass, i.e., the efficiency of
star formation.


title: Halo Mass Profiles and Low Surface Brightness Galaxies Rotation Curves

abstract:
  A recent study has claimed that the rotation curve shapes and mass densities
of Low Surface Brightness (LSB) galaxies are largely consistent with
$\Lambda$CDM predictions, in contrast to a large body of observational work. I
demonstrate that the method used to derive this conclusion is incapable of
distinguishing the characteristic steep CDM mass-density distribution from the
core-dominated mass-density distributions found observationally: even
core-dominated pseudo-isothermal haloes would be inferred to be consistent with
CDM. This method can therefore make no definitive statements on the
(dis)agreement between the data and CDM simulations. After introducing an
additional criterion that does take the slope of the mass-distribution into
account I find that only about a quarter of the LSB galaxies investigated are
possibly consistent with CDM. However, for most of these the fit parameters are
so weakly constrained that this is not a strong conclusion. Only 3 out of 52
galaxies have tightly constrained solutions consistent with $\Lambda$CDM. Two
of these galaxies are likely dominated by stars, leaving only one possible dark
matter dominated, CDM-consistent candidate, forming a mere 2 per cent of the
total sample. These conclusions are based on comparison of data and simulations
at identical radii and fits to the entire rotation curves. LSB galaxies that
are consistent with CDM simulations, if they exist, seem to be rare indeed.


title:
Timing measurements and proper motions of 74 pulsars using the Nanshan
  radio telescope

abstract:
  We have measured the positions of 74 pulsars from regular timing observations
using the Nanshan radio telescope at Urumqi Observatory between 2000 January
and 2004 August (MJD 51500 -- 53240). Proper motions were determined for these
pulsars by comparing their current positions with positions given in pulsar
catalogues. We compare our results to earlier measurements in the literature
and show that, in general, the values agree. New or improved proper motions are
obtained for 16 pulsars. The effect of period fluctuations and other timing
noise on the determination of pulsar positions is investigated. For our sample,
the mean and rms transverse velocities are 443 and 224 km/s respectively,
agreeing with previous work even though we determine distances using the new
NE2001 electron density model.


title:
Hadronic multiparticle production in extensive air showers and
  accelerator experiments

abstract:
  Using CORSIKA for simulating extensive air showers, we study the relation
between the shower characteristics and features of hadronic multiparticle
production at low energies. We report about investigations of typical energies
and phase space regions of secondary particles which are important for muon
production in extensive air showers. Possibilities to measure relevant
quantities of hadron production in existing and planned accelerator experiments
are discussed.


title: Eta Car through the eyes of interferometers

abstract:
  The core of the nebula surrounding Eta Carinae has recently been observed
with VLT/NACO, VLTI/VINCI, VLTI/MIDI and VLTI/AMBER in order to spatially and
spectrally constrain the warm dusty environment and the central object.
Narrow-band images at 3.74 and 4.05 micron reveal the structured
butterfly-shaped dusty environment close to the central star with an
unprecedented spatial resolution of about 60 mas. VINCI has resolved the
present-day stellar wind of Eta Carinae on a scale of several stellar radii
owing to the spatial resolution of the order of 5 mas (11 AU). The VINCI
observations show that the object is elongated with a de-projected axis ratio
of approximately 1.5. Moreover the major axis is aligned with that of the large
bipolar nebula that was ejected in the 19th century. Fringes have also been
obtained in the Mid-IR with MIDI using baselines of 75m. A peak of correlated
flux of 100 Jy is detected 0.3" south-east from the photocenter of the nebula
at 8.7 micron is detected. This correlated flux is partly attributed to the
central object but it is worth noting that at these wavelengths, virtually all
the 0.5" x 0.5" central area can generate detectable fringes witnessing the
large clumping of the dusty ejecta. These observations provide an upper limit
for the SED of the central source from 3.8 to 13.5 micron and constrain some
parameters of the stellar wind which can be compared to Hillier's model.
Lastly, we present the great potential of the AMBER instrument to study the
numerous near-IR emissive lines from the star and its close vicinity. In
particular, we discuss its ability to detect and follow the faint companion.


title: Origin of long-period Alfv{\'e}n waves in the solar wind

abstract:
  We suggest that the observed long-period Alfv{\'e}n waves in the solar wind
may be generated in the solar interior due to the pulsation of the Sun in the
fundamental radial mode. The period of this pulsation is about 1 hour. The
pulsation causes a periodical variation of density and large-scale magnetic
field, this affecting the Alfv{\'e}n speed in the solar interior. Consequently
the Alfv{\'e}n waves with the half frequency of pulsation (i.e. with the double
period) can be parametrically amplified in the interior below the convection
zone due to the recently suggested swing wave-wave interaction. Therefore the
amplified Alfv{\'e}n waves have periods of several hours. The waves can
propagate upwards through the convection zone to the solar atmosphere and cause
the observed long-period Alfv{\'e}n oscillations in the solar wind.


title: Optical SETI with Imaging Cherenkov Telescopes

abstract:
  The idea of searching for optical signals from extraterrestrial civilizations
has become increasingly popular over the last five years, with dedicated
projects at a number of observatories. The method relies on the detection of a
brief (few ns), intense light pulse with fast photon detectors. Ground-based
gamma-ray telescopes such as the Whipple 10m, providing a large mirror area and
equipped with an array of photomultiplier tubes (PMTs), are ideal instruments
for this kind of observation if the background of cosmic-ray events can be
rejected. We report here on a method for searching for optical SETI pulses,
using background discrimination techniques based on the image shape.


title:
Flaring and self-shadowed disks around Herbig Ae stars: simulations for
  10 micron interferometers

abstract:
  We present simulations of the interferometric visibilities of Herbig Ae star
disks. We investigate whether interferometric measurements in the 10 micrometer
atmospheric window are sensitive to the presence of an increased scale height
at the inner disk edge, predicted by recent models. Furthermore, we investigate
whether such measurements can discriminate between disks with a ``flaring''
geometry and disks with a ``flat'' geometry. We show that both these questions
can be addressed, using measurements at a small number of appropriately chosen
baselines. The classification of Herbig Ae stars in two groups, based on the
appearance of the spectral energy distribution (SED), has been attributed to a
difference in disk geometry. Sources with a group I SED would have a flaring
outer disk geometry, whereas the disk of group II sources is proposed to be
flat (or ``self-shadowed''). We show that this hypothesis can be tested using
long-baseline interferometric measurements in the micrometer atmospheric
window.


title:
Near Infrared Survey of Populous Clusters in the LMC: Preliminary
  Results

abstract:
  We report preliminary results from our near-infrared JHK survey of star
clusters in the LMC. The primary goals of the survey are to study the
three-dimensional structure and distance of the LMC. In 2003 and 2004 we used
the Infrared Side Port Imager (ISPI) on the CTIO 4m to obtain near infrared
photometry for a sample of populous LMC clusters. We utilize the K-band
luminosity of core helium burning red clump (RC) stars to obtain individual
cluster distances and present a preliminary assessment of the structure and
geometry of the LMC based on a subset of our data.


title: Stephan's Quintet with XMM-Newton

abstract:
  The prototype compact group known as Stephan's Quintet (SQ) was observed with
XMM-Newton in order to complement the excellent resolution of Chandra with high
sensitivity to extended emission. SQ is a dynamic environment whose main
effect, at both X-ray and optical wavelengths, appears to be ISM stripping.
This is manifested by: 1) secular evolution of morphological types towards
earlier types and 2) growth of diffuse emission. Virtually all cold, warm and
hot gas in SQ is found outside of the member galaxies. XMM-Newton offers the
opportunity to study the hot gas with unprecedented sensitivity. We find two
main components: 1) extended high surface brightness emission from shocked gas
associated with an ongoing collision and 2) even more extended and unrelaxed
diffuse emission that follows the stripped stellar envelope of the group.


title: X-ray Emission from NGC 1808: More than a Complex Starburst

abstract:
  Earlier observations of NGC 1808 in various wavebands (X-ray, optical,
near-infrared, radio) provided evidence for the existence of either a starburst
or a Seyfert 2 nucleus. We here present the results of multiwavelength
XMM-Newton and Chandra observations, which directly prove the co-existence of
thermal diffuse plasma and non-nuclear unresolved point-like sources associated
with the starburst activity, along with a Low Luminosity Active Galactic
Nucleus (LLAGN) or an Ultra Luminous X-ray source (ULX). The broad bandwidth of
XMM-Newton allows us to show that the unresolved nuclear source in NGC 1808
dominates the hard X-ray spectrum, while the emission in the soft regime, below
1 keV, is dominated by a thermal component associated to an extended starburst.
Both EPIC and RGS data provide reliable detections of a number of emission
lines from heavy elements, with abundances ranging from roughly 0.7 to 2.2
Z_sol for different elements. However, no 6.4 keV Fe K-alpha fluorescence line
emission was detected. The analysis of the nuclear region of NGC 1808 allows us
to detect and disentangle the contribution of an unresolved nuclear X-ray
source and the starburst region, but the exact nature of the nucleus remains
unknown. The observed luminosity of NGC 1808 is L(2-10 keV)=(1.61+/-0.06)E+40
erg/s. A comparison of our OM 212 nm image with a CTIO 4-m telescope H-alpha
frame shows a good general correspondence between the emission from massive
stars and warm ionized gas, with minor deviations near the ends of the bar in
NGC 1808. An aditional, very soft thermal spectral component with kT~0.1 keV
has been discovered in the XMM-Newton spectral analysis, which most likely
originates from the halo of NGC 1808.


title:
Fluorine Abundance Variations in Red Giants of the Globular Cluster M4
  and Early-Cluster Chemical Pollution

abstract:
  We present fluorine abundances in seven red-giant members of the globular
cluster M4 (NGC 6121). These abundances were derived from the HF (1--0) R9 line
at 2.3357 microns in high-resolution infrared spectra obtained with the Phoenix
spectrograph on Gemini-South. Many abundances in the target stars have been
studied previously, so that their overall abundance distributions are
well-mapped. The abundance of fluorine is found to vary by more than a factor
of 6, with the F-19 variations being correlated with the already established
oxygen variations, and anti-correlated with the sodium and aluminium
variations. In this paper we thus add fluorine to the list of elements known to
vary in globular cluster stars, and this provides further evidence that
H-burning is the root cause of the chemical inhomegeneities. The fact that F-19
is found to decrease in the M4 stars, as the signature of H-burning appears,
indicates that the polluting stars must have masses greater than about 3.5
solar masses, as less massive stars than this should produce, not destroy,
fluorine.


title:
Corrections for gravitational lensing of supernovae: better than
  average?

abstract:
  We investigate the possibility of correcting for the magnification due to
gravitational lensing of standard candle sources, such as Type Ia supernovae.
Our method uses the observed properties of the foreground galaxies along the
lines-of-sight to each source and the accuracy of the lensing correction
depends on the quality and depth of these observations as well as the
uncertainties in translating the observed luminosities to the matter
distribution in the lensing galaxies. The current work is limited to cases
where the matter density is dominated by the individual galaxy halos. However,
it is straightforward to generalize the method to include also gravitational
lensing from cluster scale halos. We show that the dispersion due to lensing
for a standard candle source at z=1.5 can be reduced from about 7% to ~< 3%,
i.e. the magnification correction is useful in reducing the scatter in the Type
Ia Hubble diagram, especially at high redshifts where the required long
exposure times makes it hard to reach large statistics and the dispersion due
to lensing becomes comparable to the intrinsic Type Ia scatter.


title: Lensing magnification of supernovae in the GOODS-fields

abstract:
  Gravitational lensing of high-redshift supernovae is potentially an important
source of uncertainty when deriving cosmological parameters from the measured
brightness of Type Ia supernovae, especially in deep surveys with scarce
statistics. Photometric and spectroscopic measurements of foreground galaxies
along the lines-of-sight of 33 supernovae discovered with the Hubble Space
Telescope, both core-collapse and Type Ia, are used to model the magnification
probability distributions of the sources. Modelling galaxy halos with SIS or
NFW-profiles and using M/L scaling laws provided by the Faber-Jackson and
Tully-Fisher relations, we find clear evidence for supernovae with lensing
(de)magnification. However, the magnification distribution of the Type Ia
supernovae used to determine cosmological distances matches very well the
expectations for an unbiased sample, i.e.their mean magnification factor is
consistent with unity. Our results show that the lensing distortions of the
supernova brightness can be well understood for the GOODS sample and that
correcting for this effect has a negligible impact on the derived cosmological
parameters.


title: Molecular Hydrogen in the Damped Ly alpha Absorber of Q1331+170

abstract:
  We used HST/STIS to obtain the spectrum of molecular hydrogen associated with
the damped Ly$\alpha$ system at $z_{\rm abs}=1.7765$ toward the quasar
Q1331+170 at $z_{\rm em}=2.084$. Strong ${\rm H}_2$ absorption was detected,
with a total ${\rm H}_2$ column density of $N({\rm H}_2)=(4.45\pm 0.36)\times
10^{19} {\rm cm^{-2}}$.The molecular hydrogen fraction is $f_{{\rm
H}_2}=\frac{2N_{\rm H_2}}{N_{\rm HI}+2N_{\rm H_2}}=(5.6\pm 0.7)%$, which is the
greatest value reported so far in any redshifted damped Ly$\alpha$ system. This
results from the combined effect of a relatively high dust-to-gas ratio, a low
gas temperature, and an extremely low ambient UV radiation field. Based on the
observed population of $J$ states, we estimate the photo-absorption rate to be
$R_{\rm abs}=(7.6\pm 2.4)\times 10^{-13} {\rm s^{-1}}$, corresponding to a
local UV radiation field of $J(1000{\rm \AA})\approx 2.1\times 10^{-3}
J_{1000{\rm \AA},\odot}$, where $J_{1000{\rm \AA},\odot}$ is the UV intensity
at $1000 \AA$ in the solar neighborhood. This is comparable with the
metagalactic UV background intensity at this redshift, and implies an extremely
low star formation rate in the absorber's environment. The observed CO-to-H$_2$
column density ratio is $\frac{N_{\rm CO}}{N_{\rm H_2}}<2.5\times 10^{-7}$,
which is similar to the value measured for diffuse molecular clouds in the
Galactic ISM. Finally, applying the inferred physical conditions to the
observed C I fine structure excitation (Songaila {\it et al.} 1994), we
estimate the cosmic microwave background temperature to be $T_{\rm CMB}=(7.2\pm
0.8) {\rm K}$ at $z=1.77654$, consistent with the predicted value of $7.566
{\rm K}$ from the standard cosmology.


title:
What are the temperatures of T Tauri stars? - Constraints from coeval
  formation of young eclipsing binaries

abstract:
  We show how the assumption of coeval formation can be used to constrain the
effective temperatures of the components of young eclipsing double-lined
spectroscopic binaries. Our method extends the approach of White et al. (1999)
to a two-step analysis. The first step compares evolutionary models to the
observed masses and radii and selects those models that predict ages that are
consistent with coeval formation. The second step then uses these models to
constrain the effective temperatures. We applied the method on literature
values of the stellar parameters of the eclipsing binaries RX J0529.4+0041 A
and V1174 Ori and confirm that V1174 Ori A has dwarf-like temperatures at an
age of 9 Myrs, while we cannot draw any conclusions for RX J0529.4+0041 A and
V1174 Ori B. Considering these binaries, we find that none of the evolutionary
models gives coeval solutions simultaneously in mass, radius and effective
temperature.


title: Normal Nearby Galaxies

abstract:
  Following on from IRAS, ISO has provided a huge advancement in our knowledge
of the phenomenology of the infrared (IR) emission of normal galaxies and the
underlying physical processes. Highlights include: the discovery of an extended
cold dust emission component, present in all types of gas-rich galaxies and
carrying the bulk of the dust luminosity; the definitive characterisation of
the spectral energy distribution in the IR, revealing the channels through
which stars power the IR light; the derivation of realistic geometries for
stars and dust from ISO imaging; the discovery of cold dust associated with HI
extending beyond the optical body of galaxies; the remarkable similarity of the
near-IR (NIR)/ mid-IR (MIR) SEDs for spiral galaxies, revealing the importance
of the photo-dissociation regions in the energy budget for that wavelength
range; the importance of the emission from the central regions in shaping up
the intensity and the colour of the global MIR luminosity; the discovery of the
``hot'' NIR continuum emission component of interstellar dust; the predominance
of the diffuse cold neutral medium as the origin for the main interstellar
cooling line, [CII] 158 micron, in normal galaxies.


title: The large asymmetric HI envelope of the isolated galaxy NGC 864 (CIG 96)

abstract:
  We present a HI synthesis imaging study of NGC 864 (CIG 96), a spiral galaxy
well isolated from similarly sized companions, yet presenting an intriguing
asymmetry in its integral HI spectrum. The asymmetry in the HI profile is
associated with a strong kinematical perturbation in the gaseous envelope of
the galaxy, where at one side the decay of the rotation curve is faster than
keplerian. We detect a small (M(HI) = 5 x 10^6 Msun) galaxy with a faint
optical counterpart at around 80 kpc projected distance from NGC 864. This
galaxy is probably not massive enough to have caused the perturbations in NGC
864. We discuss alternatives, such as the accretion of a gaseous companion at a
radial velocity lower than the maximum.


title: Whole-Earth Decompression Dynamics

abstract:
  The principles of Whole-Earth Decompression Dynamics are disclosed leading to
a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics
incorporates elements of and unifies the two seemingly divergent dominant
theories of continential displacement, plate tectonics theory and Earth
expansion theory. Whole-Earth decompression is the consequence of Earth
formation from within a Jupiter-like protoplanet with subsequent loss of gases
and ices and concomitant rebounding. The initial whole-Earth decompression is
expected to result in a global system of major primary decompression cracks
appearing in the rigid crust which persist as the basalt feeders for the
global, mid-oceanic ridge system. As the Earth subsequently decompresses, the
area of the Earth's surface increases by the formation of secondary
decompression cracks, often located near the continental margins, presently
identified as oceanic trenches. These secondary decompression cracks are
subsequently in-filled with basalt, extruded from the mid-oceanic ridges, which
traverses the ocean floor by gravitational creep, ultimately plunging into
secondary decompression cracks, emulating subduction. Much of the evidence
presented in support of plate tectonics supports Whole-Earth Decompression
Dynamics, but without necessitating mantle convection/circulation or basalt
re-cycling. Moreover, the timescale for Earth decompression is not constrained
to the last 200 million years, the maximum age of the current ocean floor.


title:
STEllar Content and Kinematics from high resolution galactic spectra via
  Maximum A Posteriori

abstract:
  We introduce STECKMAP (STEllar Content and Kinematics via Maximum A
Posteriori), a method to recover the kinematical properties of a galaxy
simultaneously with its stellar content from integrated light spectra. It is an
extension of STECMAP (astro-ph/0505209) to the general case where the velocity
distribution of the underlying stars is also unknown.
  %and can be used as is for the analysis of large sets of data. The
reconstructions of the stellar age distribution, the age-metallicity relation,
and the Line-Of-Sight Velocity Distribution (LOSVD) are all non-parametric,
i.e. no specific shape is assumed. The only a propri we use are positivity and
the requirement that the solution is smooth enough. The smoothness parameter
can be set by GCV according to the level of noise in the data in order to avoid
overinterpretation. We use single stellar populations (SSP) from PEGASE-HR
(R=10000, lambda lambda = 4000-6800 Angstrom, Le Borgne et al. 2004) to test
the method through realistic simulations. Non-Gaussianities in LOSVDs are
reliably recovered with SNR as low as 20 per 0.2 Angstrom pixel. It turns out
that the recovery of the stellar content is not degraded by the simultaneous
recovery of the kinematic distribution, so that the resolution in age and error
estimates given in Ocvirk et al. 2005 remain appropriate when used with
STECKMAP. We also explore the case of age-dependent kinematics (i.e. when each
stellar component has its own LOSVD). We separate the bulge and disk components
of an idealized simplified spiral galaxy in integrated light from high quality
pseudo data (SNR=100 per pixel, R=10000), and constrain the kinematics (mean
projected velocity, projected velocity dispersion) and age of both components.


title: Core and Conal Component Analysis of Pulsar B1237+25

abstract:
  The paper provides a new analysis of this famous five-component ({\bf M})
pulsar. In addition to the star's core-active ``abnormal'' mode, we find two
distinct behaviors within its ``normal'' mode, a ``quiet-normal'' mode with
regular 2.8-period subpulse modulation and little or no core activity, and a
``flare-normal'' mode, where the core is regularly bright and a nearly 4-period
modulation is maintained. The ``flare-normal'' mode appears to be an
intermediate state between the ``quiet normal'' and ``abnormal'' behaviors.
Short 5--15-pulse ``flare-normal''-mode ``bursts'' and ``quiet normal''
intervals alternate with each other quasi-periodically, making a cycle some
60--80 pulses in duration. ``Abnormal''-mode intervals are interspersed within
this overall cycle, usually persisting for only a few pulses, but occasionally
lasting for scores or even many hundreds of pulses. Within subsequences where
the core is exceptionally quiet, the pulsar provides a nearly ``textbook''
example of a central PA sightline traverse--with a PA rate measured to be at
least some 180$\deg/\deg$. On this basis it is shown that the sightline impact
angle $\beta$ must be about 0.25\degr or some 5% of the outer conal beam
radius. The star's core component is found to be incomplete, despite the fact
that the core's full antisymmetric circularly polarized signature is present.
We find that the star's PA traverse is disrupted through the action of
orthogonally polarized linear power in the longitude range of the core
component. This behavior is modeled to show its effect. Finally, the star
provides two well defined fiducial points from which emission-height estimates
can be computed, the respective centers of both the linear PA traverse and the
zero-crossing point of the circular polarization signature.


title:
Terrestrial Planet Formation in Disks with Varying Surface Density
  Profiles

abstract:
  The ``minimum-mass solar nebula'' (MMSN) model estimates the surface density
distribution of the protoplanetary disk by assuming the planets to have formed
in situ. However, significant radial migration of the giant planets likely
occurred in the Solar system, implying a distortion in the values derived by
the MMSN method. The true density profiles of protoplanetary disks is therefore
uncertain. Here we present results of simulations of late-stage terrestrial
accretion, each starting from a disk of planetary embryos. We assume a
power-law surface density profile that varies with heliocentric distance r as
r^-alpha, and vary alpha between 1/2 and 5/2 (alpha = 3/2 for the MMSN model).
We find that for steeper profiles (higher values of alpha), the terrestrial
planets (i) are more numerous, (ii) form more quickly, (iii) form closer to the
star, (iv) are more massive, (v) have higher iron contents, and (vi) have lower
water contents. However, the possibility of forming potentially habitable
planets does not appear to vary strongly with alpha.


title: Simulating the outer layers of Procyon A: a comparison with the Sun

abstract:
  Compared to the Sun, the atmospheric structure and convective flow in Procyon
A exhibit the following characteristics: (1) the highly superadiabatic
transition layer (SAL) is located at much shallower optical depth; it is in a
dynamically active region, and its outer region is located part of the time in
the optically thin atmosphere; (2) the outer region of the SAL moves from an
optically thin region to thick region and back again over a time of 20-30
minutes. This motion, which is driven by the granulation, takes place in a time
approximately half the turnover time of the largest granules; The main reason
for the radically different radiative-convective behaviour in Procyon A
compared to the Sun is the role played by turbulent eddies in determining the
overall flow/thermal structure. The turbulent pressure and turbulent kinetic
energy can exceed 50 % of the local gas pressure (compared to about 10-20 % in
the Sun). The Procyon A simulation thus reveals two distinct timescales - the
autocorrelation time of the vertical velocity and the characteristic timescale
of the SAL which is tied to granulation. Just below the surface the
autocorrelation decay time is about 5 minutes in Procyon A, and the SAL motion
timescale is 20-30 mins. When the SAL penetrates the optically thin region
there are efficient radiative losses and the peak of the SAL is low. We
speculate that these losses damp out the relative amplitudes in luminosity
(temperature fluctuations) compared to velocity (Doppler). Although this will
not affect the frequencies of the peaks in the power spectrum, it will probably
lower the average amplitude of the peaks relative to the noise background.


title: Dynamics of a Dust Crystal with Two Different Size Dust Species

abstract:
  A self-consistent three-dimensional model for a complex (dusty) plasma is
used to study the effects of multiple-sized dust grains in a dust crystal. In
addition to the interparticle forces, which interact through a Yukawa
potential, the model includes the effects of gravity, the variation of the
sheath potential above the powered electrode, and a radial confining potential.
Simulations studied various ratios of a mix of 6.5- and 8.9-micron monodisperse
particles and compared their correlation functions, electric potential energy
of the crystal formations, and the dispersion relations for in-plane and
out-of-plane dust lattice wave (DLW) modes for two different sheath
thicknesses. In the 7 mm sheath, the particles formed two layers in the
vertical direction by size, and acted as a two-layer crystal with weak
correlation between the layers. In the 3 mm sheath, the particles formed an
essentially monolayer crystal; however the crystal dynamics showed some
characteristics of a bilayer crystal.


title: Point Source Extraction with MOPEX

abstract:
  MOPEX (MOsaicking and Point source EXtraction) is a package developed at the
Spitzer Science Center for astronomical image processing. We report on the
point source extraction capabilities of MOPEX. Point source extraction is
implemented as a two step process: point source detection and profile fitting.
Non-linear matched filtering of input images can be performed optionally to
increase the signal-to-noise ratio and improve detection of faint point
sources. Point Response Function (PRF) fitting of point sources produces the
final point source list which includes the fluxes and improved positions of the
point sources, along with other parameters characterizing the fit. Passive and
active deblending allows for successful fitting of confused point sources.
Aperture photometry can also be computed for every extracted point source for
an unlimited number of aperture sizes. PRF is estimated directly from the input
images. Implementation of efficient methods of background and noise estimation,
and modified Simplex algorithm contribute to the computational efficiency of
MOPEX. The package is implemented as a loosely connected set of perl scripts,
where each script runs a number of modules written in C/C++. Input parameter
setting is done through namelists, ASCII configuration files. We present
applications of point source extraction to the mosaic images taken at 24 and 70
micron with the Multiband Imaging Photometer (MIPS) as part of the Spitzer
extragalactic First Look Survey and to a Digital Sky Survey image. Completeness
and reliability of point source extraction is computed using simulated data.


title: The 15-21 um PAH plateau

abstract:
  We present 14--21 um emission spectra of star forming regions and compare
them with the PAH spectra from the Ames PAH database. We show that while the
emission in this region can be quite variable, the bulk of these variations can
be accommodated by variations in the IS PAH population.


title:
The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 With a
  Large Dense Core

abstract:
  Doppler measurements from Subaru and Keck have revealed radial velocity
variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass
planet in a 2.8766 day orbit. Photometric observations at Fairborn Observatory
have detected three complete transit events with depths of 0.003 mag at the
predicted times of conjunction. HD 149026 is now the second brightest star with
a transiting extrasolar planet. The mass of the star, based on interpolation of
stellar evolutionary models, is 1.3 +/- 0.1 solar masses; together with the
Doppler amplitude, K=43.3 m s^-1, we derive a planet mass Msin(i)=0.36 Mjup,
and orbital radius of 0.042 AU. HD 149026 is chromospherically inactive and
metal-rich with spectroscopically derived [Fe/H]=+0.36, Teff=6147 K, log g=4.26
and vsin(i)=6.0 km s^-1. Based on Teff and the stellar luminosity of 2.72 Lsun,
we derive a stellar radius of 1.45 Rsun. Modeling of the three photometric
transits provides an orbital inclination of 85.3 +/- 1.0 degrees and (including
the uncertainty in the stellar radius) a planet radius of 0.725 +/- 0.05 Rjup.
Models for this planet mass and radius suggest the presence of a ~67 Mearth
core composed of elements heavier than hydrogen and helium. This substantial
planet core would be difficult to construct by gravitational instability.


title: Using ACT arrays as Intensity Interferometers

abstract:
  The Narrabri intensity interferometer was successfully used until 1974 to
observe 32 stars, all brighter than B=+2.5, among which some were found to have
an angular diameter as small as 0.41+/-0.03 milli-arc-seconds (mas). The
technique was then abandoned in favor of Michelson interferometry. Here we
consider the technical feasibility and scientific potential of implementing
intensity interferometry on Imaging Air Cherenkov Telescope arrays. The
scientific motivations are varied, including stellar diameter measurements and
investigations of the circumstellar environment. Long baselines and short
wavelengths are easily accesible to this technique, making it uniquely suited
for some applications.


title:
VLA H53alpha radio recombination line observations of the ultraluminous
  infrared galaxy Arp 220

abstract:
  We present high angular resolution (0.7'') observations made with the Very
Large Array (VLA) of the radio recombination line (RRL) H53alpha and radio
continuum emission at 43 GHz from the ultraluminous infrared galaxy (ULIRG) Arp
220. The 43 GHz continuum emission shows a compact structure (~2'') with two
peaks separated by ~1'', the East (E) and West (W) components, that correspond
to each galactic nucleus of the merger. The spectral indices for both the E and
W components, using radio continuum images at 8.3 and 43 GHz are typical of
synchrotron emission (alpha ~ -1.0). Our 43 GHz continuum and H53alpha line
observations confirm the flux densities predicted by the models proposed by
Anantharamaiah et al. This agreement with the models implies the presence of
high-density (~ 100,000 cm^-3) compact HII regions (~ 0.1 pc) in Arp 220. The
integrated H53alpha line emission is stronger toward the non-thermal radio
continuum peaks, which are also coincident with the peaks of molecular emission
of the H2CO. The coincidence between the integrated H53alpha and the H2CO maser
line emission suggests that the recent star forming regions, traced by the high
density gas, are located mainly in regions that are close to the two radio
continuum peaks. A velocity gradient of ~ 0.30 km/s/pc in the H53alpha RRL is
observed toward the E component and a second velocity gradient of ~ 0.15
km/s/pc is detected toward the W component. The orientations of these velocity
gradients are in agreement with previous CO, HI and OH observations. The
kinematics of the high-density ionized gas traced by the H53alpha line are
consistent with two counter rotating disks as suggested by the CO and HI
observations.


title:
Discovery of new quasi-periodic oscillations in the X-ray transient
  source V~0332+53

abstract:
  We report the discovery of a new quasi-period oscillation (QPO) at 0.22 Hz,
centered on the source spin frequency of the high mass X-ray binary system
V~0332+53 when the source was observed during its November 2004/March 2005
outburst by {\em RXTE}. Besides this new QPO, we also detected the known 0.05
Hz QPO. Both the 0.22 and 0.05 Hz QPOs stand out clearly at a mid-flux level of
the outburst within January 15--19 2005, and later at an even lower flux level
as the width of 0.22 Hz QPO drops. No evolution of the centroid frequency with
the flux is seen in either QPO. The rms value below 10 keV is around 4--6% for
both QPOs and decreases at higher energies. We discuss our results in the
context of current QPO models.


title: An X-ray Galaxy Cluster Survey for Investigations of Dark Energy

abstract:
  The amount and nature of dark energy (DE) can be tightly constrained by
measuring the spatial correlation features and evolution of a sample of ~
100,000 galaxy clusters over the redshift range 0<z < 1.5. Such an X-ray survey
will discover all collapsed structures with mass above 3.5e14 solar masss at
redshifts z<2 (i.e. the full range where such objects are expected) in the high
Galactic latitude sky. Above this mass threshold the tight correlations between
X-ray observables and mass allow direct interpretation of the data. We describe
the constraints on Dark Energy that can be inferred from such a survey, using
powerful self-calibration techniques to relate the X-ray observables
(luminosity and temperature) to the underlying mass.


title:
Very Large H II Regions Around Proto-Clusters of Galaxies During
  Reionization

abstract:
  The physical basis for the belief that the abundant old dwarf galaxies seen
in present-day galaxy clusters formed before reionization of the universe is
very compelling, because (1) the observed faint end slope of the galaxy
luminosity function ascends from a shallower slope at brighter magnitudes and
tracks that of dark matter halo mass function, and (2) that steep power-law
slope is observed to extend all the way to galaxies of inferred velocity
dispersion of ~10km/s. We then show that the number of ionizing photons emitted
by these dwarf galaxies should be able to produce an H II region at least as
large as each proto-cluster region, occupying at least 20% of the entire IGM
volume at z >= 6. A more likely scenario is that our estimate of the ionizing
photon production rate based on these dwarfs under-estimates the true rate from
proto-clusters by a factor of ~5 for a variety of physically plausible reasons,
in which case a fully self- consistent picture emerges. Specific implications
include (1) Strong clustering of sources would collectively produce very large
individual H II regions of sizes up to ~100Mpc before overlapping with others,
having important implications for upcoming radio and CMB observations. There
should be large spatial fluctuations of neutral fraction in the intergalactic
medium up to cluster scales of ~100Mpc. We give an H II region size function.
(2) The ionizing sources at z~6 are expected to be highly biased with a bias
factor >=15. (3) Large H II regions would enable largely unattenuated
transmission of flux of a significant number of sources prior to reionization.
When more sensitive observations become available, one should expect to see
clusters of fainter sources in the vicinity of known galaxies at z>6.


title: Helical Jet in the Gravitationally Lensed Blazar PKS1830-211

abstract:
  Recent radio VLBI observations of the complex gravitationally lensed system
PKS1830-211 have thrown up some questions with regard to the processes occuring
at the heart of the blazar source at a redshift of 2.51, which is viewed almost
straight down the jet axis. This work links, by a model of a helical jet
tracked by ballistically ejected plasmons from a precessing nozzle,
observations on the scale of tens of microarcseconds to those on the scale of
milliarcseconds. An observed jet precession period of 1.08 years is inferred
from the model, translating to an intrinsic period of 30.8 years for a source
at redshift 2.51 and an assumed jet bulk velocity of 0.99 c. This fits well
with the picture of an active galactic nucleus hosting a binary black hole
system at its centre, with the jet emitted by one member of the system, and the
precession as being due to its orbital motion around its companion.


title: Preliminary results of the analysis of the BATSE TTE data

abstract:
  The Compton Gamma Ray Observatory (CGRO) observed many types of data and one
of them is the time-tagged photon events (TTE data). We use the Bayesian block
analysis, using Bayesian statistics, analyses the TTE data. Our results;
calculations of duration (T100), count rates (burst photon numbers in different
channels) and count peaks (in 64, 16 and 4 ms). We present the duration, the
peak duration and the distance between peaks distributions. Principal Component
Analysis (PCA) has been also applied. The PCA shows interesting results, such
as channel 4 (highest energy channel) probably is very important.


title:
Primary proton spectrum in the energy range $5-10^3$ TeV from the sea
  level muon spectrum

abstract:
  Primary proton spectrum in the energy range $5-10^3$ TeV is reconstructed
from the sea level muon spectrum with the use of QGSJET01 and SYBILL2.1
interaction models. Heavier nuclei are taken in accordance with the direct
measurements data, 100% uncertainty in helium flux is accounted for. The
obtained proton intensity strongly contradicts to the available data of balloon
experiments, exceeding them at the least by 100% for QGSJET01. This discrepancy
is due to the combined effect of primary nucleon flux underestimation in the
direct measurements and incorrect description of extensive air shower
development. In the latter case it is required earlier shower development and
harder spectra of secondary pions and kaons in comparison with QGSJET01. This
conclusion is in agreement with the obtained by the KASCADE group on the basis
of events rate study.


title:
Two approaches to the cosmic ray "knee" problem and the experimental
  data

abstract:
  Two approaches to the old problem of the so-called "knee" in cosmic ray
spectrum are compared with the existing experimental data. It is shown that
"standard astrophysical model" of the knee is not supported by some
experimental data, while the alternative model agrees better with the data.


title: Power Law Spectra in the Nature: Analogies with the Cosmic Ray Spectrum

abstract:
  Examples of the power law spectra observations in the Nature are given. It is
shown that the observed meteoroid mass spectrum is very similar to the observed
cosmic ray energy spectrum. It is concluded that the "knees" observed in both
spectra have a similar origin: the Earth's atmosphere. Both spectra are studied
by indirect methods through secondary components and specific behavior of these
components in the atmosphere could produce the "knee" even in a case when
primary spectrum follows a pure power law.


title: Search for Aligned Events in Muon Groups Deep Underground

abstract:
  A search for aligned events has been done throughout the muon group events
measured with Baksan Underground Scintillation Telescope (BUST) during a long
period of time. Only groups of multiplicity >3 for muon threshold energies
equal to 0.25; 0.85; 2.0 and 3.2 TeV were selected for the analysis. A
distribution of the events on the alignment parameter /lambda has been obtained
and compared with the results of Monte-Carlo simulation made for this
experiment. Upper limit for aligned muon groups flux is given.


title: Fast multilevel radiative transfer

abstract:
  The vast majority of recent advances in the field of numerical radiative
transfer relies on approximate operator methods better known in astrophysics as
Accelerated Lambda-Iteration (ALI). A superior class of iterative schemes, in
term of rates of convergence, such as Gauss-Seidel and Successive
Overrelaxation methods were therefore quite naturally introduced in the field
of radiative transfer by Trujillo Bueno & Fabiani Bendicho (1995); it was
thoroughly described for the non-LTE two-level atom case. We describe hereafter
in details how such methods can be generalized when dealing with non-LTE
unpolarised radiation transfer with multilevel atomic models, in
monodimensional geometry.


title:
Assessment of saddle-point-mass predictions for astrophysical
  applications

abstract:
  Using available experimental data on fission barriers and ground-state
masses, a detailed study on the predictions of different models concerning the
isospin dependence of saddle-point masses is performed. Evidence is found that
several macroscopic models yield unrealistic saddle-point masses for very
neutron-rich nuclei, which are relevant for the r-process nucleosynthesis.


title: New optical polarization measurements of quasi-stellar objects. The data

abstract:
  New linear polarization measurements (mainly in the V band) are presented for
203 quasi-stellar objects (QSOs). The sample is made up of 94 QSOs located in
the North Galactic Pole (NGP) region and of 109 QSOs in the South Galactic Pole
(SGP) region. First time measurements have been obtained for 184 QSOs. Among
them, 109 known radio-emitters, 42 known Broad Absorption Line (BAL) QSOs, and
1 gravitationally lensed quasi-stellar object. We found high polarization
levels (p > 3%) for 12 QSOs, including the BAL QSO SDSS J1409+0048. For 10
objects, measurements obtained at different epochs do exist. Two of them show
evidence for variability: the highly polarized BL Lac candidate PKS 1216-010
and the radio source PKS 1222+037


title:
High resolution spectroscopy of bright subdwarf B stars - I. Radial
  velocity variables

abstract:
  Radial velocity curves for 15 bright subdwarf B binary systems have been
measured using high precision radial velocity measurements from high S/N
optical high-resolution spectra. In addition, two bright sdB stars are
discovered to be radial velocity variable but the period could not yet be
determined. The companions for all systems are unseen. The periods range from
about 0.18 days up to more than ten days. The radial velocity semi amplitudes
are found to lie between 15 and 130 km/s. Using the mass functions, the masses
of the unseen companions have been constrained to lower limits of 0.03 up to
0.55 M_sun, and most probable values of 0.03 up to 0.81 M_sun. The invisible
companions for three of our program stars are undoubtedly white dwarfs. In the
other cases they could be either white dwarfs or main sequence stars. For two
stars the secondaries could possibly be brown dwarfs. As expected, the orbits
are circular for most of the systems. However, for one third of the program
stars we find slightly eccentric orbits with small eccentricities of
e~0.02-0.06. This is the first time that non-circular orbits have been found in
sdB binaries. No correlation with the orbital period can be found.


title:
Simulations and parametrisation of radio emission from cosmic ray air
  showers

abstract:
  Cosmic ray air showers are known to emit pulsed radio emission at frequencies
around a few tens of MHz. Accompanying the experimental efforts of the LOPES
project, situated at the KASCADE-Grande site of the Forschungszentrum
Karlsruhe, we have modeled the underlying emission mechanism in the scheme of
coherent geosynchrotron radiation from electron-positron pairs deflected in the
earth's magnetic field. As a follow-up to our earlier analytical calculations,
we have developed a Monte Carlo simulation based on analytic parametrisations
of air shower properties, including longitudinal and lateral particle
distributions, particle energy and track-length distributions, and the
longitudinal shower development as a whole. Here we present detailed simulation
results. Important findings are the absence of significant asymmetries in the
total field strength emission pattern in spite of the asymmetry introduced by
the geomagnetic field, the polarisation characteristics of the geosynchrotron
emission, allowing an unambiguous test of the geomagnetic emission mechanism,
and the dependence of the radio emission on important shower parameters such as
the shower zenith angle, the primary particle energy and the depth of the
shower maximum. As a particularly useful result, these dependences have been
summarized in a simple parametrisation formula, providing a solid basis for the
interpretation of experimental data gathered with current and future
experiments.


title:
Fluctuations in the EAS radio signal derived with improved Monte Carlo
  simulations based on CORSIKA

abstract:
  Cosmic ray air showers are known to emit pulsed radio emission which can be
understood as coherent geosynchrotron radiation arising from the deflection of
electron-positron pairs in the earth's magnetic field. Here, we present
simulations carried out with an improved version of our Monte Carlo code for
the calculation of geosynchrotron radiation. Replacing the formerly
analytically parametrised longitudinal air shower development with
CORSIKA-generated longitudinal profiles, we study the radio flux variations
arising from inherent fluctuations between individual air showers.
Additionally, we quantify the dependence of the radio emission on the nature of
the primary particle by comparing the emission generated by proton- and
iron-induced showers. This is only the first step in the incorporation of a
more realistic air shower model into our Monte Carlo code. The inclusion of
highly realistic CORSIKA-based particle energy, momentum and spatial
distributions together with an analytical treatment of ionisation losses will
soon allow simulations of the radio emission with unprecedented detail. This is
especially important to assess the emission strengths at large radial
distances, needed for event-to-event comparisons of the radio signals measured
by LOPES in conjunction with KASCADE-Grande and for considerations regarding
large arrays of radio antennas intended to measure the radio emission from
ultra-high energy cosmic rays, as with LOFAR or in the Pierre Auger
Observatory.


title:
Is The Fe M-shell Absorber Part of The Outflow in Active Galactic
  Nuclei?

abstract:
  The X-ray emission of many active galactic nuclei (AGNs) is absorbed between
15 and 17 Angstrom by means of unresolved (inner-shell) transition arrays
(UTAs) of Fe M-shell ions. The outflow velocities implied by the Doppler shifts
of the individual UTAs in the spectrum have never before been measured. Thus,
the Fe-M absorber has been commonly assumed to be part of the ionized AGN
outflow, whose velocities are readily obtained from more easily measured
spectral lines. The best spectrum of Fe-M absorption is available from the
integrated 900 ks Chandra HETGS observations of NGC 3783, in which some Fe-M
ions are clearly resolved. We measure the velocities of the individual Fe-M
ions in NGC 3783 for the first time. Surprisingly, we find that the Fe-M
absorber, most noticeably Fe$^{+8}$, Fe$^{+9}$, and Fe$^{+10}$, is not
outflowing at the same velocity as the previously known wind. In fact, it
appears to be stationary and therefore not part of the outflow at all. It
could, alternatively, be ascribed to the skin of the dusty torus. This reduces
appreciably the mass loss rate estimated for the NGC 3783 outflow and perhaps
for other similar sources as well, in which the various Fe-M ions are not
resolved.


title:
Star formation rate density and the stochastic background of
  gravitational waves

abstract:
  There is in the literature a number of papers addressing the stochastic
background of gravitational waves (GWs) generated by an ensemble of
astrophysical sources. The main ingredient in such studies is the so called
star formation rate density (SFRD), which gives the density of stars formed per
unit time. Some authors argue, however, that there is, in the equation that
determines the amplitude of the stochastic background of GWs, an additional
(1+z) term dividing the SFRD, which would account for the effect of cosmic
expansion onto the time variable. We argue here that the inclusion of this
additional term is wrong. In order to clarify where the inclusion of the (1+z)
term is really necessary, we briefly discuss the calculation of event rates in
the study of GRBs (gamma ray bursts) from cosmological origin.


title:
Statistical and systematic uncertainties in the event reconstruction and
  S(1000) determination by the Pierre Auger surface detector

abstract:
  We discuss the statistical and systematic uncertainties in the event
reconstruction (core location, and determination of S(1000), i.e., the signal
at a distance of 1000 m from the shower core) by the Pierre Auger surface
detector for showers with zenith angle less than 60 degrees. The method is
based on a maximum likelihood method where the reference lateral distribution
function is obtained through the experimental data. We also discuss S(1000) as
primary energy estimator.


title: Sulphur abundance in Galactic stars

abstract:
  We investigate sulphur abundance in 74 Galactic stars by using high
resolution spectra obtained at ESO VLT and NTT telescopes. For the first time
the abundances are derived, where possible, from three optical multiplets:
Mult. 1, 6, and 8. By combining our own measurements with data in the
literature we assemble a sample of 253 stars in the metallicity range -3.2 <
[Fe/H] < +0.5. Two important features, which could hardly be detected in
smaller samples, are obvious from this large sample: 1) a sizeable scatter in
[S/Fe] ratios around [Fe/H] ~ -1 ; 2) at low metallicities we observe stars
with [S/Fe] ~ 0.4, as well as stars with higher [S/Fe] ratios. The latter do
not seem to be kinematically different from the former ones. Whether the latter
finding stems from a distinct population of metal-poor stars or simply from an
increased scatter in sulphur abundances remains an open question.


title:
Radio and X-ray Profiles in Supernova Remnants Undergoing Efficient
  Cosmic Ray Production

abstract:
  The strong shocks in young supernova remnants (SNRs) should accelerate cosmic
rays (CRs) and no doubt exists that \rel electrons are produced in SNRs.
However, direct and convincing evidence that SNRs produce CR nuclei has not yet
been obtained and may, in fact, be long in coming if current gamma-ray
observatories do not see an unambiguous pion-decay feature. Nevertheless, the
lack of an observed pion-decay feature does not necessarily mean that CR ions
are not abundantly produced since ions do not radiate efficiently. If CR ions
are produced efficiently by diffusive shock acceleration (DSA), their presence
will modify the hydrodynamics of the SNR and produce morphological effects
which can be clearly seen in radiation produced by electrons. We describe in
some detail our CR-hydro model, which couples DSA with the remnant
hydrodynamics, and the synchrotron emission expected for two distinct parameter
sets representing type Ia and type II supernovae. Several morphological
features emerge in radial profiles, including the forward shock precursor,
which are observable with current X-ray observatories and which should
definitively show if young SNRs produce CR ions efficiently or not. For the
specific case of SN 1006, we conclude, as have others, that the extremely short
X-ray scale heights observed near the outer shock argue convincingly for the
efficient production of CR ions.


title:
Probing the cosmic microwave background temperature using the
  Sunyaev-Zeldovich effect

abstract:
  We discuss the possibility to constrain the relation between redshift and
temperature of the cosmic microwave background (CMB) using multifrequency
Sunyaev-Zeldovich (SZ) observations. We have simulated a catalog of clusters of
galaxies detected through their SZ signature assuming the sensitivities that
will be achieved by the {\it Planck} satellite at 100, 143 and 353 GHz, taking
into account the instrumental noise and the contamination from the Cosmic
Infrared Background and from unresolved radiosources. We have parametrized the
cosmological temperature-redshift law as $T\propto (1+z)^{(1-a)}$. Using two
sets of SZ flux density ratios (100/143 GHz, which is most sensitive to the
parametrization of the $T-z$ law, and 143/353 GHz, which is most sensitive to
the peculiar velocities of the clusters) we show that it is possible to recover
the $T-z$ law assuming that the temperatures and redshifts of the clusters are
known. From a simulated catalog of $\sim 1200$ clusters, the parameter $a$ can
be recovered to an accuracy of 10$^{-2}$. Sensitive SZ observations thus appear
as a potentially useful tool to test the standard law. Most cosmological models
predict a linear variation of the CMB temperature with redshift. The discovery
of an alternative law would have profound implications on the cosmological
model, implying creation of energy in a manner that would still maintain the
black-body shape of the CMB spectrum at redshift zero.


title:
Corrections of Errors in `The First Detections of the Extragalactic
  Background Light at 3000, 5500, and 8000 \AA. I, II, and III'

abstract:
  We correct errors in Bernstein, Freedman & Madore (2002abc), a series of
papers in which we described observations of the optical extragalactic
background light (EBL). These errors pertain to the measurement of zodiacal
light, given in the second paper of this series. Making these corrections leads
to a net decrease of 0.5($\pm$0.6)% in our zodiacal light measurement and a
corresponding increase in the inferred extragalactic background light of
roughly $0.5 (\pm 0.6) \times 10^{-9}$ ergs sec$^{-1}$ cm$^{-2}$ sr$^{-1}$
\AA$^{-1}$. For comparison, the originally--quoted EBL flux at 5500\AA was $2.7
(\pm1.4) \times 10^{-9}$ in the same units ($1\sigma$ combined systematic and
statistical uncertainty). We provide a detailed discussion of these errors and
also discuss the evolution of this work prior to the (2002) papers. We note
that corrections of the factual errors in our (2002) papers yield a result that
is consistent with the results and errors quoted there. However, this is not
intended to be a new or updated analysis, and it does not address some
methodological objections which have been raised to our prior work.


title:
Formation and Evolution of Planetary Systems: Placing Our Solar System
  in Context with Spitzer

abstract:
  We summarize the progress to date of our Legacy Science Program entitled "The
Formation and Evolution of Planetary Systems" (FEPS) based on observations
obtained with the Spitzer Space Telescope during its first year of operation.
In addition to results obtained from our ground-based preparatory program and
our early validation program, we describe new results from a survey for
near-infrared excess emission from the youngest stars in our sample as well as
a search for cold debris disks around sun-like stars. We discuss the
implications of our findings with respect to current understanding of the
formation and evolution of our own solar system.


title:
The Chandra High Energy Transmission Grating: Design, Fabrication,
  Ground Calibration and Five Years in Flight

abstract:
  Details of the design, fabrication, ground and flight calibration of the High
Energy Transmission Grating, HETG, on the Chandra X-ray Observatory are
presented after five years of flight experience. Specifics include the theory
of phased transmission gratings as applied to the HETG, the Rowland design of
the spectrometer, details of the grating fabrication techniques, and the
results of ground testing and calibration of the HETG. For nearly six years the
HETG has operated essentially as designed, although it has presented some
subtle flight calibration effects.


title:
Thermal evolution and activity of Comet 9P/Tempel 1 and simulation of a
  deep impact

abstract:
  We use a quasi 3-D thermal evolution model for a spherical comet nucleus,
which takes into account the diurnal and latitudinal variation of the solar
flux, but neglects lateral heat conduction. We model the thermal evolution and
activity of Comet 9P/Tempel 1, in anticipation of the Deep Impact mission
encounter with the comet. We also investigate the possible outcome of a
projectile impact, assuming that all the energy is absorbed as thermal energy.
An interesting result of this investigation, is that the estimated amount of
dust ejected due to the impact is equivalent to 2--2.6 days of activity, during
"quiet" conditions, at perihelion.
  We show that production rates of volatiles that are released in the interior
of the nucleus depend strongly on the porous structure, in particular on the
surface to volume ratio of the pores. We develop a more accurate model for
calculating this parameter, based on a distribution of pore sizes, rather than
a single, average pore size.


title: Outflows in AGN/Starburst-Composite Ultraluminous Infrared Galaxies

abstract:
  Galactic superwinds occur in almost all infrared-luminous galaxies with star
formation rates (SFRs) above 10 M_sun/yr, as shown by studies of the NaI D
interstellar absorption line. We demonstrate that this result also applies to
ultraluminous infrared galaxies (ULIRGs) which host an active galactic nucleus
(AGN) embedded in a strong starburst (SFR > 100 M_sun/yr) by studying a sample
of 26 Seyfert ULIRGs in NaI D. The infrared luminosity of these galaxies is
powered jointly by the AGN and starburst. We find that there are hints of the
influence of the AGN on outflows in Seyfert 2/starburst composites, but the
evidence is not yet statistically conclusive. The evidence we find is lower
wind detection rates (i.e., wind opening angles) in Seyfert 2 ULIRGs than in
galaxies of comparable L_IR, higher velocities than in galaxies of comparable
SFR, and correlations between the neutral gas and the ionized gas in the
extended narrow-line region. Though the AGN probably contributes to the
outflows in Seyfert 2 ULIRGs, its momentum and energy injection is equal to or
less than that of the starburst. Similarly, the outflow mechanical luminosity
(energy outflow rate) per unit radiative luminosity is the same for starburst
and Seyfert 2 ULIRGs. In the nuclei of Seyfert 1s, we observe small-scale
outflows that are powered solely by the AGN. However, in Mrk~231, we observe
both a high-velocity, small-scale and low-velocity, extended outflow. The
latter may be powered by a starburst or radio jet. These large-scale,
lower-velocity outflows certainly exist in other Seyfert 1 ULIRGs, but they are
washed out by the light of the nucleus.


title:
Heating the bubbly gas of galaxy clusters with weak shocks and sound
  waves

abstract:
  Using hydrodynamic simulations and a technique to extract the rotational
component of the velocity field, we show how bubbles of relativistic gas
inflated by AGN jets in galaxy clusters act as a catalyst, transforming the
energy carried by sound and shock waves to heat. The energy is stored in a
vortex field around the bubbles which can subsequently be dissipated. The
efficiency of this process is set mainly by the fraction of the cluster volume
filled by (sub-)kpc scale filaments and bubbles of relativistic plasma.


title: Water Masers Toward Ultracompact HII Regions

abstract:
  We present a survey in the 6_{16}-5_{23} rotational water transition toward
33 galactic ultracompact HII regions. Maser emission is detected toward 18 of
these sources; two are new detections. High quality spectra are provided for
all 18 sources. We discuss the detection rate of this survey and the
correlation of various maser properties with other physical parameters. In
addition, we report wide-bandwidth (316 km/s), moderate-resolution (~ 3'')
water maser observations of the HH80-81 region. We report the first detection
of water maser emission at the approximate velocity of the molecular core. This
emission is coincident with the extreme tip of the thermal jet, and
well-removed from the much stronger and well-known maser emission at the
position of VLA-3.


title: The Physics of Flames in Type Ia Supernovae

abstract:
  We extend a low Mach number hydrodynamics method developed for terrestrial
combustion, to the study of thermonuclear flames in Type Ia supernovae. We
discuss the differences between 2-D and 3-D Rayleigh-Taylor unstable flame
simulations, and give detailed diagnostics on the turbulence, showing that the
kinetic energy power spectrum obeys Bolgiano-Obukhov statistics in 2-D, but
Kolmogorov statistics in 3-D. Preliminary results from 3-D reacting bubble
calculations are shown, and their implications for ignition are discussed.


title: An XMM-Newton and Chandra Study of the Starburst Galaxy IC 10

abstract:
  We present an X-ray study of our nearest starburst galaxy IC 10, based on
XMM-Newton and Chandra observations. A list of 73 XMM-Newton and 28 Chandra
detections of point-like X-ray sources in the field is provided; a substantial
fraction of them are likely stellar objects in the Milky Way due to the low
Galactic latitude location of IC 10. The brightest source in the IC 10 field,
X-1, shows a large variation by a factor of up to $\sim 6$ on time scales
during the XMM-Newton observation. The X-ray spectra of the source indicate the
presence of a multi-color blackbody accretion disk with an inner disk
temperature T_{in} \approx 1.1 keV. These results are consistent with the
interpretation of the source as a stellar mass black hole, probably accreting
from a Wolf-Rayet star companion. We infer the mass of this black hole to be
about 4 Msun if it is not spinning, or a factor of up to about 6 higher if
there is significant spinning. We also detect an apparent diffuse soft X-ray
emission component of IC 10. An effective method is devised to remove the X-ray
CCD-readout streaks of X-1 that strongly affect the study of the diffuse
component in the XMM-Newton and Chandra observations. We find that the diffuse
X-ray morphology is oriented along the optical body of the galaxy and is
chiefly associated with starburst regions. The diffuse component can be
characterized by an optically thin thermal plasma with a mean temperature of
$\sim 4 \times 10^6$ K and a 0.5-2 keV luminosity of $\sim 8 \times 10^{37}
{\rm erg s^{-1}}$, representing only a small fraction of the expected
mechanical energy inputs from massive stars in the galaxy. There is evidence
that the hot gas is driving outflows from the starburst regions; therefore, the
bulk of the energy inputs may be released in a galactic wind.


title: Detailed Chemical Abundances of Extragalactic Globular Clusters

abstract:
  We outline a method to measure the detailed chemical composition of
extragalactic (unresolved) globular clusters (GCs) from echelle spectra of
their integrated light. Our goal is to use this method to measure abundance
patterns of GCs in distant spiral and elliptical galaxies to constrain their
formation histories. To develop this technique we have obtained a ``training
set'' of integrated-light spectra of resolved GCs in the Milky Way and LMC by
scanning across the clusters during exposures. Our training set also include
spectra of individual stars in those GCs from which abundances can be obtained
in the normal way to provide a check on our integrated-light results. We
present here the preliminary integrated-light analysis of one GC in our
training set, NGC 104 (47 Tuc), and outline some of the techniques utilized and
problems encountered in that analysis.


title:
Joint Efficient Dark-energy Investigation (JEDI): a Candidate
  Implementation of the NASA-DOE Joint Dark Energy Mission (JDEM)

abstract:
  JEDI will probe dark energy in three independent ways by measuring the
expansion history of the universe: (1) using type Ia supernovae as cosmological
standard candles over a range of distances, (2) using baryon oscillations as a
cosmological standard ruler over a range of cosmic epochs, (3) mapping the weak
gravitational lensing distortion by foreground galaxies of the images of
background galaxies at different distances. JEDI will unravel the nature of
dark energy with accuracy and precision.
  JEDI is a 2m-class space telescope with the unique ability of simultaneous
wide-field imaging (0.8-4.2 micron in five bands) and multi-slit spectroscopy
(0.8-3.2 micron) with a field of view of 1 square degree. What makes JEDI
efficient is its ability to simultaneously obtain high signal-to-noise ratio,
moderate resolution slit spectra for all supernovae and ~ 5000 galaxies in its
wide field of view, and to combine imaging and spectroscopy so that the
appropriate balance of time is devoted to each.
  JEDI will measure the cosmic expansion history H(z) as a free function to <
2% accuracy in redshift bins of 0.2-0.3. Assuming a flat universe and
\sigma(\Omega_m)=0.01 (0.03), JEDI could measure a departure from a vanilla
\Lambda CDM model (w_0=-1, w'=0) with \sigma(w_0)=0.013 (0.031) and
\sigma(w')=0.046 (0.063). JEDI will obtain the well-sampled lightcurves in Z,
J, H, K, L bands and spectra of ~ 14,000 type Ia supernovae with redshifts
ranging from 0 to 1.7; the redshifts of ~ 10-100 million galaxies to H ~ 23 and
z ~ 4 over 1000-10,000 square degrees; and measurements of the shapes of
galaxies over 1000-10,000 square degrees in Z,J,H,K,L for > 10^9 galaxies to H
\~ 25.


title:
Searching for merger debris in the Galactic halo: Chemodynamical
  evidence based on local blue HB stars

abstract:
  We report on the discovery of a group of local A-type blue horizontal-branch
(HBA) stars moving in a prograde, comet-like orbit with very similar kinematics
and abundances. This serendipitously discovered group contains 5 or 6 local HBA
stars venturing very close to the Galactic centre; their [Fe/H] is around -1.7,
and they seem to present minimum scatter in at least Mg, Si, Ti, Fe, Al, and Cr
abundances. This ``Cometary Orbit Group'' (COG) was found while we were testing
a new method to detect the debris associated with the merger of smaller,
specific protogalactic entities into our galaxy. The method is primarily
intended to identify field HBA stars with similar kinematics and detailed,
multi-species abundance patterns as seen among members of a surviving remnant
(e.g., omega Centauri). Quite possibly, the COG is the remnant, on a highly
decayed orbit, of a merging event that took place in the relatively remote past
(i.e., at least one revolution ago).


title:
Relation between the hardness ratio and time in the first 2 seconds for
  compatible samples of short and long gamma-ray bursts

abstract:
  In this paper, we randomly selected a sample (sample 1) of long gamma-ray
bursts, with its size being the same as that of the short burst group (sample
2) (N=500), from the Current BATSE Bursts Catalog. We randomly selected a short
burst and assigned its T90 to each of these long bursts. We thus constructed a
long burst sample with both the sample size and the distribution of T90 being
the same as those of the short burst sample obtained from the Current BATSE
Bursts Catalog. Then we calculated the hardness ratio ($hr_{T}$) over the
assigned T90 for the long bursts and over their own T90 for the shout bursts,
and studied the relation between the hardness ratio and the corresponding T90
for these two samples. We also calculated the hardness ratio ($hr_{t}$) over
the randomly selected 64 ms time intervals within the T90, and investigated the
relation between this hardness ratio and the selected 64 ms time interval. In
addition, the $hr_{t}$ within and beyond the first 2 seconds for all the long
bursts (sample 3; N=1541) were also investigated. We found that the KS
probabilities of the distributions of the $hr_{T}$ (7.15337E-15) and $hr_{t}$
(9.54833E-10) for samples 1 and 2 are very small, and the average value of
$hr_{T}$ and $hr_{t}$ of short bursts are obviously larger than that of the
long bursts. The correlations between log$hr_{T}$ and logT90, and between
log$hr_{t}$ and log t, for samples 1 and 2 are different. These show that short
and long bursts in the first 2 seconds have different characters and they
probably originate from different progenitors. For sample 3, for the two time
intervals, the KS probability is 5.35828E-5, which suggests that the hardness
ratios in different time intervals for long bursts are also different.


title:
Growth of Hydrodynamic Perturbations in Accretion Disks: Possible Route
  to Non-Magnetic Turbulence

abstract:
  We study the possible origin of hydrodynamic turbulence in cold accretion
disks such as those in star-forming systems and quiescent cataclysmic
variables. As these systems are expected to have neutral gas, the turbulent
viscosity is likely to be hydrodynamic in origin, not magnetohydrodynamic.
Therefore MRI will be sluggish or even absent in such disks. Although there are
no exponentially growing eigenmodes in a hydrodynamic disk, because of the
non-normal nature of the eigenmodes, a large transient growth in the energy is
still possible, which may enable the system to switch to a turbulent state. For
a Keplerian disk, we estimate that the energy will grow by a factor of 1000 for
a Reynolds number close to a million.

categories: astro-ph cond-mat.soft cond-mat.stat-mech physics.flu-dyn