title:
Supernova Explosions in the Early Universe: Evolution of Radiative
  Remnants and the Halo Destruction Efficiency

abstract:
  We study the evolution of supernova (SN) remnants of the first stars, taking
proper account of the radiative feedback of the progenitor stars on the
surroundings. We carry out a series of one-dimensional hydrodynamic simulations
with radiative cooling, starting from initial configurations that are drawn
from the results of our earlier radiation hydrodynamic simulations of the first
HII regions. In low-mass (< 10^6 M_sun) halos, the stellar radiation
significantly reduces the ambient gas density prior to the SN explosion. The
blastwave quickly propagates over the halo's virial radius, leading to complete
evacuation of the gas even with the input energy of 10^50 erg. We find that a
large fraction of the remnant's thermal energy is lost in 0.1-10 Myr by line
cooling, whereas, for larger explosion energies, the remnant expands even more
rapidly with decreasing interior density, and cools predominantly via inverse
Compton process. In higher mass halos, the gas density near the explosion site
remains high and the SN shock is heavily confined; the thermal energy of the
remnant is quickly radiated away by free-free emission, even if the total input
energy exceeds the binding energy of halos by two orders of magnitude. We show
that the efficiency of halo destruction is determined not only by the explosion
energy but also by the gas density profile, and thus controlled by radiative
feedback prior to the explosion. Several implications of our results for the
formation of first quasars and second-generation stars in the universe are also
discussed.


title: Revised dynamics or dark matter in galactic and extra galactic scales?

abstract:
  Allowing the energy of a gravitational field to serve partially as its own
source allows gravitating bodies to exhibit stronger fields, as if they were
more massive. Depending on degree of compaction of the body, the field could be
one to five times larger than the newtonian field. This is a comfortable range
of increase in field strength and may prove to be of convenience in the study
of velocity curves of spirals, of velocity dispersions in clusters of galaxies
and in interpreting the Tully-Fisher or Faber-Jackson relations in galaxies or
systems of galaxies. The revised gravitation admits of superposition principle
but only approximately in systems whose components are widely separated. The
revised dynamics admits of the equivalence principle in that, the effective
force acting on a test particle is derived from a potential, and could be
eliminated in a freely falling frame of reference


title: A Supernova Factory in Mrk 273?

abstract:
  We report on 1.6 and 5.0 GHz observations of the ultraluminous infrared
galaxy (ULIRG) Mrk 273, using the European VLBI Network (EVN) and the
Multi-Element Radio-Linked Interferometer Network (MERLIN). We also make use of
published 1.4 GHz VLBA observations of Mrk 273 by Carilli & Taylor (2000). Our
5 GHz images have a maximum resolution of 5-10 mas, which corresponds to linear
resolutions of 3.5-7 pc at the distance of Mrk 273, and are the most sensitive
high-resolution radio observations yet made of this ULIRG. Component N1, often
pinpointed as a possible AGN, displays a steep spectral index ($\alpha = 1.2
\pm 0.1; S_\nu \propto \nu^{-\alpha}$); hence it is very difficult to reconcile
with N1 being an AGN, and rather suggests that the compact nonthermal radio
emission is produced by an extremely high luminous individual radio supernova
(RSN), or a combination of unresolved emission from nested supernova remnants
(SNR), luminous RSNe, or both. Component N2 is partly resolved out into several
compact radio sources --none of which clearly dominates-- and a region of
extended emission about 30 pc in size. The integrated spectral index of this
region is flat ($\alpha = 0.15 \pm 0.1$), which can be interpreted as due to a
superposition of several unresolved components, e.g., RSNe or SNRs, whose radio
emission peaks at different frequencies and is partially free-free absorbed.
The overall extended radio emission from component N is typical of nonthermal,
optically thin radio emission ($\alpha = 0.8 \pm 0.1$), and its 1.4 GHz
luminosity ($L_{1.4 \rm GHz} = (2.2 \pm 0.1)\times 10^{23} $ WHz$^{-1}$) is
consistent with being produced by relativistic electrons diffused away from
supernova remnants in an outburst.


title:
Universal lateral distribution of energy deposit in air showers and its
  application to shower reconstruction

abstract:
  The light intensity distribution in a shower image and its implications to
the primary energy reconstructed by the fluorescence technique are studied.
Based on detailed CORSIKA energy deposit simulations, a universal analytical
formula is derived for the lateral distribution of light in the shower image
and a correction factor is obtained to account for the fraction of shower light
falling into outlying pixels in the detector. The expected light profiles and
the corresponding correction of the primary shower energy are illustrated for
several typical event geometries. This correction of the shower energy can
exceed 10%, depending on shower geometry.


title: Interpreting microlensing signal in QSO 2237+0305: Stars or planets?

abstract:
  The multiply imaged, gravitationally lensed quasar, QSO 2237+0305, has been
the subject of recent optical monitoring campaigns, with its light curves
displaying uncorrelated variability attributed to gravitational microlensing by
masses in the foreground galaxy. Based on these light curves, it has been
claimed that the dominant microlensing population must be a population of
free-floating Jupiter-like objects; such a conclusion is not new, with several
similar claims in the literature. Historically, however, it has been shown that
such conclusions are flawed, with an incorrect interpretation of the complex
caustic network that arises at significant optical depth. This paper examines
this more recent claim, illustrating that it too is flawed.


title:
Temperature fluctuations in HII regions: ionization by Cosmic Rays as a
  key mechanism

abstract:
  We present a detailed model capable of explaining quantitatively the
temperature fluctuations observed in luminous, large HII regions. The model is
based on two assumptions which we justify on the basis of observations: that
the major fraction of the hydrogen in the clouds that form the HII regions is
not photoionized and is essentially HI, this HII is lightly ionized by fluxes
of low energy cosmic rays (CR) produced by processes originating in the hot
stars which illuminate the regions.


title:
Magnetic field in Cepheus A as deduced from OH maser polarimetric
  observations

abstract:
  We present the results of MERLIN polarization mapping of OH masers at 1665
and 1667 MHz towards the Cepheus A star-forming region. The maser emission is
spread over a region of 6 arcsec by 10 arcsec, twice the extent previously
detected. In contrast to the 22 GHz water masers, the OH masers associated with
H II regions show neither clear velocity gradients nor regular structures. We
identified ten Zeeman pairs which imply a magnetic field strength along the
line-of-sight from -17.3 to +12.7 mG. The magnetic field is organised on the
arcsecond scale, pointing towards us in the west and away from us in the east
side. The linearly polarized components, detected for the first time, show
regularities in the polarization position angles depending on their position.
The electric vectors of OH masers observed towards the outer parts of H II
regions are consistent with the interstellar magnetic field orientation, while
those seen towards the centres of H II regions are parallel to the radio-jets.
A Zeeman quartet inside a southern H II region has now been monitored for 25
years; we confirm that the magnetic field decays monotonically over that
period.


title: PHOENIX model chromospheres of mid- to late-type M dwarfs

abstract:
  We present semi-empirical model chromospheres computed with the atmosphere
code PHOENIX. The models are designed to fit the observed spectra of five mid-
to late-type M dwarfs. Next to hydrogen lines from the Balmer series we used
various metal lines, e. g. from Fe {\sc i}, for the comparison between data and
models. Our computations show that an NLTE treatment of C, N, O impacts on the
hydrogen line formation, while NLTE treatment of less abundant metals such as
nickel influences the lines of the considered species itself. For our coolest
models we investigated also the influence of dust on the chromospheres and
found that dust increases the emission line flux.
  Moreover we present an (electronically published) emission line list for the
spectral range of 3100 to 3900 and 4700 to 6800 \AA for a set of 21 M dwarfs
and brown dwarfs. The line list includes the detection of the Na {\sc i} D
lines in emission for a L3 dwarf.


title: Inflationary spectra and violations of Bell inequalities

abstract:
  In spite of the macroscopic character of the primordial fluctuations, the
standard inflationary distribution (that obtained using linear mode equations)
exhibits inherently quantum properties, that is, properties which cannot be
mimicked by any stochastic distribution. This is demonstrated by a Gedanken
experiment for which certain Bell inequalities are violated. These violations
are {\it in principle} measurable because, unlike for Hawking radiation from
black holes, in inflationary cosmology we can have access to both members of
correlated pairs of modes delivered in the same state. We then compute the
effect of decoherence and show that the violations persist provided the
decoherence level (and thus the entropy) lies below a certain non-vanishing
threshold. Moreover, there exists a higher threshold above which no violation
of any Bell inequality can occur. In this regime, the distributions are
``separable'' and can be interpreted as stochastic ensembles of fluctuations.
Unfortunately, the precision which is required to have access to the quantum
properties is so high that, {\it in practice}, an observational verification
seems excluded.


title:
The Large-Scale Electrochemistry and Possible Consequences of Deep
  Impact Mission to Tempel 1

abstract:
  Some consequences of hypervelocity impact onto the comet Tempel 1 nucleus are
considered under assumption that SP comets are fragments of massive icy
envelopes of Ganymede-like bodies saturated by products of ice electrolysis
that underwent global explosions.


title: Abundance Anomalies in NGC6752 - Do AGB Stars Have a Role?

abstract:
  We are in the process of testing a popular theory that the observed abundance
anomalies in the Globular Cluster NGC 6752 are due to `internal pollution' from
intermediate mass asymptotic giant branch stars. To this end we are using a
chemical evolution model incorporating custom-made stellar evolution yields
calculated using a detailed stellar evolution code. By tracing the chemical
evolution of the intracluster gas, which is polluted by two generations of
stars, we are able to test the internal pollution scenario in which the Na- and
Al-enhanced ejecta from intermediate mass stars is either accreted onto the
surfaces of other stars, or goes toward forming new stars.
  In this paper we focus mainly on the nucleosynthetic yields of the AGB stars
and discuss whether these stars are the source of the observed Na-O
anticorrelation. Comparing our preliminary results with observational data
suggests that the qualitative theory is not supported by this quantitative
study.


title: Inflationary spectra and partially decohered distributions

abstract:
  It is generally expected that decoherence processes will erase the quantum
properties of the inflationary primordial spectra. However, given the weakness
of gravitational interactions, one might end up with a distribution which is
only partially decohered. Below a certain critical change, we show that the
inflationary distribution retains quantum properties. We identify four of
these: a squeezed spread in some direction of phase space, non-vanishing
off-diagonal matrix elements, and two properties used in quantum optics called
non-$P$-representability and non-separability. The last two are necessary
conditions to violate Bell's inequalities. The critical value above which all
these properties are lost is associated to the `grain' of coherent states. The
corresponding value of the entropy is equal to half the maximal (thermal)
value. Moreover it coincides with the entropy of the effective distribution
obtained by neglecting the decaying modes. By considering backreaction effects,
we also provide an upper bound for this entropy at the onset of the adiabatic
era.


title:
Detection of TeV gamma-ray Emission from the Shell-Type Supernova
  Remnant RX J0852.0-4622 with H.E.S.S

abstract:
  We report the detection of TeV gamma-rays from the shell-type supernova
remnant RX J0852.0-4622 with data of 3.2 h of live time recorded with H.E.S.S.
in February 2004. An excess of (700 +/- 60) events from the whole remnant with
a significance of 12 sigma was found. The observed emission region is clearly
extended with a radius of the order of 1 degree and the spatial distribution of
the signal correlates with X-ray observations. The spectrum in the energy range
between 500 GeV and 15 TeV is well described by a power law with a photon index
of 2.1 +/- 0.1(stat) +/- 0.2(syst) and a differential flux at 1 TeV of (2.1 +/-
0.2(stat) +/- 0.6(syst)) 10^{-11} cm^{-2} s^{-1} TeV^{-1}. The integral flux
above 1 TeV was measured to be (1.9 +/- 0.3(stat) +/- 0.6(syst)) 10^{-11}
cm^{-2} s^{-1}, which is at the level of the flux of the Crab nebula at these
energies. More data are needed to draw firm conclusions on the magnetic field
in the remnant and the type of the particle population creating the TeV
gamma-rays.


title:
Separating polarized cosmological and galactic emissions for CMB B-mode
  polarization experiments

abstract:
  In this work we study the relevance of the component separation technique
based on the Independent Component Analysis (ICA) and investigate its
performance in the context of a limited sky coverage observation and from the
viewpoint of our ability to differentiate between cosmological models with
different primordial B-mode content. We focus on the low Galactic emission sky
patch, corresponding to the target of several operating and planned CMB
experiments and which, in many respects, adequately represents a typical
"clean" high latitude sky. We consider two fiducial observations, one operating
at low (40, 90 GHz) and one at high (150, 350 GHz) frequencies and thus
dominated by the synchrotron and thermal dust emission, respectively. We use a
parallel version of the FASTICA code to explore a substantial parameter space
including Gaussian pixel noise level, observed sky area and the amplitude of
the foreground emission and employ large Monte Carlo simulations to quantify
errors and biases pertinent to the reconstruction for different choices of the
parameter values. We identify a large subspace of the parameter space for which
the quality of the CMB reconstruction is excellent. For both the cosmological
models, with and without the primordial gravitational waves, we find that
FASTICA performs extremely well even in the cases when the B mode CMB signal is
up to a few times weaker than the foreground contamination and the noise
amplitude is comparable with the total CMB polarized emission. In addition we
discuss limiting cases of the noise and foreground amplitudes, for which the
ICA approach fails.


title: Galactic Centre stellar winds and Sgr A* accretion

abstract:
  (ABRIDGED) We present in detail our new 3D numerical models for the accretion
of stellar winds on to Sgr A*. In our most sophisticated models, we put stars
on realistic orbits around Sgr A*, include `slow' winds (300 km/s), and account
for radiative cooling. We first model only one phase `fast' stellar winds (1000
km/s). For wind sources fixed in space, the accretion rate is Mdot ~ 1e-5
Msun/yr, fluctuates by < 10%, and is in a good agreement with previous models.
In contrast, Mdot decreases by an order of magnitude for stars following
circular orbits, and fluctuates by ~ 50%. Then we allow a fraction of stars to
produce slow winds. Much of these winds cool radiatively, forming cold clumps
immersed into the X-ray emitting gas. We test two orbital configurations for
the stars in this scenario, an isotropic distribution and two rotating discs
with perpendicular orientation. The morphology of cold gas is quite sensitive
to the orbits. In both cases, however, most of the accreted gas is hot, with an
almost constant Mdot ~ 3e-6 Msun/yr, consistent with Chandra observations. The
cold gas accretes in intermittent, short but powerful episodes which may give
rise to large amplitude variability in the luminosity of Sgr A* on time scales
of 10s to 100s of years. The circularisation radii for the flows are ~ 1e3 and
1e4 Rsch, for the one and two-phase wind simulations, respectively, never
forming the quasi-spherical accretion flows suggested in some previous work.
Our work suggests that, averaged over time scales of 100s to 1000s of years,
the radiative and mechanical luminosity of Sgr A* may be substantially higher
than it is in its current state. Further improvements of the wind accretion
modelling of Sgr A* will rely on improved observational constraints for the
wind properties and stellar orbits.


title:
Detection and imaging of atmospheric radio flashes from cosmic ray air
  showers

abstract:
  The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10^20 eV
remains a mystery. They are likely to be of extragalactic origin, but should be
absorbed within ~50 Mpc through interactions with the cosmic microwave
background. As there are no sufficient powerful accelerators within this
distance from the Galaxy, explanations for UHECRs range from unusual
astrophysical sources to exotic string physics. Also unclear is whether UHECRs
consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these
questions, larger detectors with higher duty cycles and which combine multiple
detection techniques are needed. Radio emission from UHECRs, on the other hand,
is unaffected by attenuation, has a high duty cycle, gives calorimetric
measurements and provides high directional accuracy. Here we report the
detection of radio flashes from cosmic-ray air showers using low-cost digital
radio receivers. We show that the radiation can be understood in terms of the
geosynchrotron effect. Our results show that it should be possible to determine
the nature and composition of UHECRs with combined radio and particle
detectors, and to detect the ultrahigh-energy neutrinos expected from flavour
mixing.


title:
On the relevance of the Tremaine-Weinberg method applied to H-alpha
  velocity field.Pattern speeds determination in M100 (NGC 4321)

abstract:
  The relevance of the Tremaine-Weinberg (TW) method is tested to measure the
bar, spiral and inner structure pattern speeds using a gaseous velocity field.
The TW method is applied to various simulated barred galaxies in order to
demonstrate its validity in seven different configurations, including star
formation or/and dark matter halo. The reliability of the different physical
processes involved and of the various observational parameters are also tested.
The simulations show that the TW method could be applied to the gaseous
velocity fields to get a good estimate of the bar pattern speed, under the
condition that regions of shocks are avoided and measurements are confined to
regions where the gaseous bar is well formed. We successfully apply the TW
method to the \ha velocity field of the Virgo Cluster Galaxy M100 (NGC 4321)
and derive pattern speeds of 55+/-5 km/s/kpc for the nuclear structure, 30+/-2
km/s/kpc for the bar and 20+/-1 km/s/kpc for the spiral pattern, in full
agreement with published determinations using the same method or alternative
ones.


title:
New Low Accretion-Rate Magnetic Binary Systems and their Significance
  for the Evolution of Cataclysmic Variables

abstract:
  Discoveries of two new white dwarf plus M star binaries with striking optical
cyclotron emission features from the Sloan Digital Sky Survey (SDSS) brings to
six the total number of X-ray faint, magnetic accretion binaries that accrete
at rates < 10^{-13} Msun/yr, or <1% of the values normally encountered in
cataclysmic variables. This fact, coupled with donor stars that underfill their
Roche lobes and very cool white dwarfs, brand the binaries as post
common-envelope systems whose orbits have not yet decayed to the point of
Roche-lobe contact. They are pre-magnetic CVs, or pre-Polars. The systems
exhibit spin/orbit synchronism and apparently accrete by efficient capture of
the stellar wind from the secondary star, a process that has been dubbed a
``magnetic siphon''. Because of this, period evolution of the binaries will
occur solely by gravitational radiation, which is very slow for periods >3 hr.
Optical surveys for the cyclotron harmonics appear to be the only means of
discovery, so the space density of pre-Polars could rival that of Polars, and
the binaries provide an important channel of progenitors (in addition to the
asynchronous Intermediate Polars). Both physical and SDSS observational
selection effects are identified that may help to explain the clumping of all
six systems in a narrow range of magnetic field strength around 60 MG.


title:
CMB Tomography: Reconstruction of Adiabatic Primordial Scalar Potential
  Using Temperature and Polarization Maps

abstract:
  Assuming linearity of the perturbations at the time of decoupling, we
reconstruct the primordial scalar potential from the temperature and
polarization anisotropies in the cosmic microwave background radiation. In
doing so we derive an optimal linear filter which, when operated on the
spherical harmonic coefficients of the anisotropy maps, returns an estimate of
the primordial scalar potential fluctuations in a spherical slice. The
reconstruction is best in a thick shell around the decoupling epoch; the
quality of the reconstruction depends on the redshift of the slice within this
shell. With high quality maps of the temperature and polarization anisotropies
it will be possible to obtain a reconstruction of potential fluctuation on
scales between l=2 and l ~ 300 at the redshift of decoupling, with some
information about the three-dimensional shapes of the perturbations in a shell
of width 250Mpc.


title: FUV Spectroscopy of the Dwarf Novae SS Cygni and WX Hydri in Quiescence

abstract:
  We present time-resolved FUV spectra of the dwarf novae SS Cyg and WX Hyi in
quiescence from observations using the Hopkins Ultraviolet Telescope on the
Astro-1 and Astro-2 Space Shuttle missions and the Goddard High Resolution
Spectrograph on the Hubble Space Telescope. Both dwarf novae are characterized
by blue continua that extend to the Lyman limit punctuated by broad emission
lines including transitions of O VI, N V, Si IV, and C IV. The continuum of WX
Hyi can be fit with a white dwarf model with physically reasonable model
parameters, but neither system actually shows unambiguous signatures of white
dwarf emission. The shape and flux of the spectrum of SS Cyg cannot be
self-consistently reconciled with a white dwarf providing all of the FUV
continuum flux. Combination white dwarf/disk or white dwarf/optically thin
plasma models improve the fit but still do not give physically reasonable model
parameters for a quiescent dwarf nova. Assuming that the UV emission lines
arise from the disk, the line shapes indicate that surface fluxes fall roughly
as R^{-2} in both systems. Fits to the double-peaked line profiles in SS Cyg
indicate that the FUV line forming region is concentrated closer to the white
dwarf than that of the optical lines and provide no evidence of a hole in the
inner disk. Although the flux from SS Cyg was relatively constant during all of
our observations, WX Hyi showed significant variability during the GHRS
observations. In WX Hyi, the line and continuum fluxes are (with the exception
of He II) highly correlated, indicating a link between the formation mechanisms
of the line and continuum regions.


title: An Unusual System of HI Filaments near WR 5 and HD 17603

abstract:
  We report the discovery of a system of unusual HI filaments which appear to
be associated with molecular clouds in the Perseus spiral arm of our Galaxy. We
investigate the hypothesis that this system is the result of a directed flow of
dissociated gas from clouds trapped within an extended wind flow from massive
stars. The Wolf-Rayet star WR 5 and the OIb(f) star HD 17603 are identified as
candidate driving sources. However, an examination of this hypothesis within
the context of the theory of mass-loaded winds shows that these two stars alone
cannot account for the energetics and kinematics of the required spherically
symmetric wind flow. Unless the apparent association between HI, molecular gas,
and stars is an accidental one, we suggest that other as-yet unidentified stars
must have contributed to driving the filaments.


title:
Fast Edge Corrected Measurement of the Two-Point Correlation Function
  and the Power Spectrum

abstract:
  We present two related techniques to measure the two-point correlation
function and the power spectrum with edge correction in any spatial dimensions.
The underlying algorithm uses fast Fourier transforms for calculating the
two-point function with an heuristically weighted edge corrected estimator.
Once the correlation function is measured, we estimate the power spectrum via
numerical integration of the Hankel transform connecting the two. We introduce
an efficient numerical technique based on Gauss-Bessel-quadrature and double
exponential transformation. This, combined with our, or any similar, two-point
function estimator leads to a novel edge corrected estimator for power spectra.
The pair of techniques presented are the Euclidean analogs of those developed
and widely used in cosmic microwave background research for spherical maps.


title: Weighing Neutrinos with Galaxy Cluster Surveys

abstract:
  Large future galaxy cluster surveys, combined with cosmic microwave
background observations, can achieve a high sensitivity to the masses of
cosmologically important neutrinos. We show that a weak lensing selected sample
of ~100,000 clusters could tighten the current upper bound on the sum of masses
of neutrino species by an order of magnitude, to a level of 0.03 eV. Since this
statistical sensitivity is below the best existing lower limit on the mass of
at least one neutrino species, a future detection is likely, provided that
systematic errors can be controlled to a similar level.


title: Introduction to Higher Order Spatial Statistics in Cosmology

abstract:
  In this lecture notes I concentrate on the classic and widely applicable
characterization of higher order statistics by joint moments, a.k.a. higher
order correlation functions, and directly related statistics. I put special
emphasis on recent results, especially the connection of spatial statistics
with symmetries.


title:
A Radio Counterpart for the Unidentified TeV Source HESS J1813-178: The
  Radio-Gamma-Ray Connection

abstract:
  We discovered independently the shell-type supernova remnant G12.82-0.02,
recently reported by Brogan et al. (2005), which is coincident with the
unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic
plane. Estimating the ambient starlight at the location of this source from the
integrated Ly alpha luminosity of the nearby H II region W33, we conclude that
inverse Compton emission is a viable explanation for the observed TeV emission.
Examining remnants in the survey of Aharonian et al. (2005a) including those
detected above 200 Gev and those not detected, we find a strikingly large range
of more than three orders of magnitude in the radio to TeV flux ratios. We
briefly explore the possible explanations of this range and the implications
for the TeV emission mechanism.


title: Secular Evolution Via Bar-Driven Gas Inflow: Results from BIMA SONG

abstract:
  We present an analysis of the molecular gas distributions in the 29 barred
and 15 unbarred spirals in BIMA SONG. For CO-bright galaxies, we confirm the
conclusion by Sakamoto et al. (1999b) that barred spirals have higher molecular
gas concentrations in the central kiloparsec. The SONG sample also includes 27
galaxies below the CO brightness limit used by Sakamoto et al. Even in these
CO-faint galaxies we show that high central gas concentrations are more common
in barred galaxies, consistent with radial inflow driven by the bar. However,
there is a significant population of early-type (Sa--Sbc) barred spirals (6 of
19) that have little or no molecular gas detected in the nuclear region and out
to the bar co-rotation radius. In these galaxies, the bar has already driven
most of the gas within the bar to the nuclear region, where it has been
consumed by star formation. The median nuclear gas mass is over four times
higher in early type bars; since the gas consumption rate is an order of
magnitude higher in early type bars, early types must have significantly higher
bar-driven inflows. The lower inflow rates in late type bars can be attributed
to differences in bar structure between early and late types. Despite
bar-driven inflows, the data indicate that it is highly unlikely for a late
type galaxy to evolve into an early type via bar-induced gas inflow.
Nonetheless, secular evolutionary processes are undoubtedly present, and
pseudo-bulges are inevitable; evidence for pseudo-bulges is likely to be
clearest in early-type galaxies because of their high gas inflow rates and
higher star formation activity (abridged).


title: Finding the Electromagnetic Counterparts of Cosmological Standard Sirens

abstract:
  The gravitational waves (GW) emitted during the coalescence of supermassive
black holes (SMBHs) in the mass range 10^4-10^7 M_sun will be detectable out to
high redshifts with LISA. We calculate the size and orientation of the
three-dimensional error ellipse in solid angle and redshift within which the
LISA event could be localized using the GW signatures alone. We take into
account uncertainties in LISA's measurements of the luminosity distance and
direction to the source, in the background cosmology, in weak gravitational
lensing magnification due to inhomogeneities along the line of sight, and
potential source peculiar velocities. We find that weak lensing errors exceed
other sources of uncertainties by nearly an order of magnitude. Under the
plausible assumption that BH mergers are accompanied by gas accretion leading
to Eddington-limited quasar activity, we then compute the number of quasars
that would be found in a typical LISA error volume, as a function of BH mass
and redshift. We find that low redshifts offer the best opportunities to
identify quasar counterparts to cosmological standard sirens, and that the LISA
error volume will typically contain a single near-Eddington quasar at z=1. This
will allow a straightforward test of the hypothesis that BH mergers are
accompanied by bright quasar activity and, if the hypothesis proves correct,
will guarantee the identification of a unique quasar counterpart. This would
yield unprecedented tests of the physics of SMBH accretion, and offer an
alternative method to precisely constrain cosmological parameters [abridged].


title:
The oscillation effects on thermalization of the neutrinos in the
  universe with low reheating temperature

abstract:
  We study how the oscillations of the neutrinos affect their thermalization
process during the reheating period with temperature O(1) MeV in the early
universe. We follow the evolution of the neutrino density matrices and
investigate how the predictions of big bang nucleosynthesis vary with the
reheating temperature. For the reheating temperature of several MeV, we find
that including the oscillations makes different predictions, especially for
$^4$He abundance. Also, the effects on the lower bound of the reheating
temperature from cosmological observations are discussed.


title: Early star formation in the Galaxy from beryllium and oxygen abundances

abstract:
  We investigate the evolution of the star formation rate in the early Galaxy
using beryllium and oxygen abundances in metal poor stars. Specifically, we
show that stars belonging to two previously identified kinematical classes (the
so-called ``accretion'' and ``dissipative'' populations) are neatly separated
in the [O/Fe] vs. Log(Be/H) diagram. The dissipative population follows the
predictions of our model of Galactic evolution for the thick disk component,
suggesting that the formation of this stellar population occurred on a
timescale significantly longer (by a factor ~5-10) than the accretion
component. The latter shows a large scatter in the [O/Fe] vs. Log(Be/H)
diagram, probably resulting from the inhomogeneous enrichment in oxygen and
iron of the protogalactic gas. Despite the limitation of the sample, the data
suggest that the combined use of products of spallation reactions (like
beryllium) and elemental ratios of stellar nucleosynthesis products (like
[O/Fe]) can constrain theoretical models for the formation and early evolution
of our Galaxy.


title: A large HI cloud near the centre of the Virgo cluster

abstract:
  We report the discovery of a large HI cloud in the central regions of the
Virgo cluster. It is 110 x 25 kpc in size and contains 3.4 x 10^8 Msol of HI.
The morphology and kinematics of this cloud strongly suggest that it consists
of HI removed from the galaxy NGC 4388 by ram-pressure stripping. It is more
likely the result of an interaction of the ISM of NGC 4388 with the hot halo of
the M86 group and not with the ICM centred on M87. The large extent of the
plume suggests that gas stripped from cluster galaxies can remain neutral for
at least 10^8 yr. Locally, the column density is well above 10^20 cm^-2,
suggesting that the intra-cluster HII regions known to exist in Virgo may have
formed from gas stripped from cluster galaxies. The existence of the HI plume
suggests that stripping of infalling spirals contributes to the enrichment of
the ICM. The HI object in the Virgo cluster recently reported by Minchin et al.
may have a similar origin and may therefore not be a ``dark galaxy''.


title:
Hard X-ray and Gamma-ray Emission Induced by Ultra-High Energy Protons
  in Cluster Accretion Shocks

abstract:
  All sufficiently massive clusters of galaxies are expected to be surrounded
by strong accretion shocks, where protons can be accelerated to $\sim
10^{18}$-$10^{19}$ eV under plausible conditions. Such protons interact with
the cosmic microwave background and efficiently produce very high energy
electron-positron pairs, which then radiate synchrotron and inverse Compton
emission, peaking respectively at hard X-ray and TeV gamma-ray energies.
Characterized by hard spectra (photon indices $\sim 1.5$) and spatial
distribution tracing the accretion shock, these can dominate over other
nonthermal components depending on the shock magnetic field. HESS and other
Cerenkov telescopes may detect the TeV emission from nearby clusters,
notwithstanding its extended nature. The hard X-rays may be observable by
future imaging facilities such as NeXT, and possibly also by ASTRO-E2/HXD. Such
detections will not only provide a clear signature of ultra-high energy proton
acceleration, but also an important probe of the accretion shock itself as well
as magnetic fields in the outermost regions of clusters.


title:
HST/ACS observations of the old and metal-poor Sagittarius dwarf
  irregular galaxy

abstract:
  We have obtained deep color-magnitude diagrams of the Sagittarius dwarf
irregular galaxy with the HST/ACS. The new diagrams unveil for the first time
the star formation history of SagDIG.
  We identify a small population of red horizontal branch stars, which sets the
first epoch of star formation in SagDIG back to ~9-10 Gyr ago. This shows that
SagDIG has been able to maintain a very low mean metallicity (-2.2<[Fe/H]<-1.9)
over a 10 Gyr life time, and most importantly, that all Local Group dwarf
galaxies share an ancient (~10 Gyr) initial episode of star formation. Thus, at
the moment, IZw18 remains the only exception to this general trend, favoring
the so-called ``young galaxy'' scenario. However, a re-analysis of ACS
observations of IZw18 suggests that an older RGB population may be present also
in IZw18.
  We also compare the distribution of atomic hydrogen with that of stellar
populations of various ages. We find little correlation between stellar
populations older than ~1 Gyr and the HI. In particular we fail to find any
generation of stars that preferentially lie within the large HI hole. We
therefore exclude the possibility that the SagDIG ring-like HI distribution is
the result of multiple supernova events. Alternative scenarios have to be
explored.


title:
Post-glitch variability in the Anomalous X-ray Pulsar 1RXS
  J170849.0-400910

abstract:
  We report on the first XMM-Newton observation of the Anomalous X-ray Pulsar
1RXS J170849.0-400910. The source was observed in 2003 August and was found at
a flux level a factor of about two lower than previous observations. Moreover,
a significant spectral evolution appears to be present, the source exhibiting a
much softer spectrum than in the past. Comparison of the present properties of
1RXS J170849.0-400910 with those from archival data shows a clear correlation
between the X-ray flux and the spectral hardness. In particular, the flux and
the spectral hardness reached a maximum level close to the two glitches the
source experienced in 1999 and in 2001, and successively decreased. Although
the excellent XMM-Newton spectral resolution should in principle allow us to
detect the absorption line reported in a phase-resolved spectrum with BeppoSAX
and interpreted as a cyclotron feature, we found no absorption features,
neither in the phase averaged spectrum nor in the phase resolved spectra. We
discuss in detail both the possibilities that the feature in the BeppoSAX data
may have resulted from a spurious detection or that it is real and
intrinsically variable. We then discuss a possible explanation for the glitches
and for the softening of the source emission which followed the flux decrease,
in the framework of the magnetar model.


title: Pieces of the puzzle: Ancient substructure in the Galactic disk

abstract:
  We search for signatures of past accretion events in the Milky Way in the
recently published catalogue by Nordstrom et al.(2004), containing accurate
spatial and kinematic information as well as metallicities for 13240 nearby
stars. To optimize our strategy, we use numerical simulations to characterize
the properties of the debris from disrupted satellites. We find that stars with
a common progenitor should show distinct correlations between their orbital
parameters; in particular, between the apocentre A and pericentre P, as well as
their z-angular momentum (L_z). In the APL-space, such stars are expected to
cluster around regions of roughly constant eccentricity.
  The APL space for the Nordstrom catalogue exhibits a wealth of substructure,
much of which can be linked to dynamical perturbations induced by spiral arms
and the Galactic bar. However, our analysis also reveals a statistically
significant excess of stars on orbits of common (moderate) eccentricity,
analogous to the pattern expected for merger debris. Besides being dynamically
peculiar, the 274 stars in these substructures have very distinct metallicity
and age distributions, providing further evidence of their extra-Galactic
provenance. It is possible to identify among these stars, three coherent Groups
with characteristic ages and metallicities, that, in all likelihood, correspond
to the remains of disrupted satellites. [abridged]


title:
An abrupt drop in the coherence of the lower kilohertz QPO in 4U
  1636-536

abstract:
  Using archival data from the Rossi X-ray Timing Explorer (RXTE), we study in
a systematic way the variation of the quality factor and amplitude of the lower
and upper kHz quasi-periodic oscillations (QPO) in the low-mass X-ray binary
4U1636-536, over a frequency range from ~550 Hz to ~1200 Hz. When represented
in a quality factor versus frequency diagram, the upper and lower QPOs follow
two different tracks, suggesting that they are distinct phenomena, although not
completely independent because the frequency difference of the two QPOs, when
detected simultaneously, remains within ~60 Hz of half the neutron star spin
frequency (at 581 Hz). The quality factor of the lower kHz QPO increases with
frequency up to a maximum of ~200 at ~850 Hz, then drops precipitously to Q~50
at the highest detected frequencies ~920 Hz. A ceiling of the lower QPO
frequencies at 920 Hz is also clearly seen in a frequency versus count rate
diagram.
  The quality factor provides a measure of the coherence of the underlying
oscillator. For exponentially damped sinusoidal shots, the highest Q observed
corresponds to an oscillator coherence time of ~ 0.1 seconds. All existing QPO
models face challenges in explaining such a long coherence time and the
significantly different behaviours of the quality factors of the upper and
lower QPOs reported here. It is therefore difficult to be certain of the
implications of the abrupt change in the lower QPO at ~850 Hz. We discuss
various possible causes, including that the drop in coherence is ultimately
caused by effects related to the innermost stable circular orbit (abridged).


title: Jets Driven by Accretion Onto Spinning Black Holes

abstract:
  We present a theoretical model for driving jets by accretion onto Kerr black
holes and try to give an answer to the following question: How much energy
could be extracted from a rotating black hole and its accretion disk in order
to power relativistic jets in Active Galactic Nuclei?


title: The Modelling of InfraRed Dark Clouds

abstract:
  This paper presents results from modelling 450 micron and 850 micron
continuum and HCO+ line observations of three distinct cores of an infrared
dark cloud (IRDC) directed toward the W51 GMC. In the sub-mm continuum these
cores appear as bright, isolated emission features. One of them coincides with
the peak of 8.3 micron extinction as measured by the Midcourse Space Experiment
satellite. Detailed radiative transfer codes are applied to constrain the
cores' physical conditions to address the key question: Do these IRDC-cores
harbour luminous sources? The results of the continuum model, expressed in the
$\chi^2$ quality-of-fit parameter, are also constrained by the absence of 100
micron emission from IRAS. For the sub-mm emission peaks this shows that
sources of 300 solar luminosities are embedded within the cores. For the
extinction peak, the combination of continuum and HCO+ line modelling indicates
that a heating source is present as well. Furthermore, the line model provides
constraints on the clumpiness of the medium. All three cores have similar
masses of about 70-150 solar masses and similar density structures. The
extinction peak differs from the other two cores by hosting a much weaker
heating source, and the sub-mm emission core at the edge of the IRDC deviates
from the other cores by a higher internal clumpiness.


title:
Detection and analysis of a new INTEGRAL hard X-ray transient, IGR
  J17285-2922

abstract:
  We present the transient nature of INTEGRAL source IGR J17285-2922,
identified from a single period of activity during an IBIS/ISGRI Galactic
Centre Deep Exposure in September 2003. The source has a maximum detection
significance of 14 sigma in the 20-100 keV energy range and exhibits a flux of
6.5 mCrab before it moves out of the ISGRI field of view. The source is visible
to at least 150 keV and its spectrum can be fit with a power law slope of
Gamma=2.1+/-0.17; a more physical model could not be fit due to poor
statistics. Detected characteristics are consistent with the source being a
Galactic low-mass X-ray binary harbouring a black hole or neutron star.


title: Magnetars origin and progenitors with enhanced rotation

abstract:
  Among a dozen known magnetar candidates there are no binary objects. As an
estimate of a fraction of binary neutron stars is about 10% it is reasonable to
address the question of solitarity of magnetars, to estimate theoretically the
fraction of binary objects among them, and to mark o probable companions. We
present population synthesis calculations of binary systems. Our goal is to
estimate the number of neutron stars originated from progenitors with enhanced
rotation, as such compact objects can be expected to have large magnetic
fields, ie. they can be magnetars. The fraction of such neutron stars in our
calculations is about 13-16%. Most of these objects are isolated due to
coalescences of components prior to a neutron star formation, or due to a
system disruption after a supernova explosion. The fraction of such neutron
stars in survived binaries is about 1% or lower. Their most numerous companions
are black holes.


title:
Spiral galaxies with a central plateau in the gas velocity curve along
  the major axis

abstract:
  We present the minor-axis kinematics of ionized gas and stars for a sample of
5 spiral galaxies, which are characterized by either a zero or a shallow gas
velocity gradient along their major axis. The asymmetric velocity profiles
observed along the minor axis of NGC 4064 and NGC 4189 can be explained as due
to the presence of a bar. This is also the case of NGC 4178 where the innermost
portion of the gaseous disk is nearly face on. In NGC 4424 and NGC 4941, we
measured non-zero gas velocities only in the central regions along the minor
axis and gas velocities drop to zero at larger radii. This kinematic feature is
suggestive of the presence of an orthogonally-rotating gaseous component which
is confined in the innermost regions (i.e. an inner polar disk) to be confirmed
with integral-field spectroscopy.


title:
A Chandra Observation of the Nearby Lenticular Galaxy NGC 5102: Where
  are the X-ray Binaries?

abstract:
  We present results from a 34 ks Chandra/ACIS-S observation of the nearby
(d=3.1 Mpc) lenticular galaxy NGC 5102, previously shown to have an unusually
low X-ray luminosity. We detect eleven X-ray point sources within the the
$D_{25}$ optical boundary of the galaxy (93% of the light), one third to one
half of which are likely to be background AGN. One source is coincident with
the optical nucleus and may be a low-luminosity AGN. Only two sources with an
X-ray luminosity greater than 10$^{37}$ ergs s$^{-1}$ in the 0.5-5.0 keV band
were detected, one of which is statistically likely to be a background AGN. We
expected to detect 6 such luminous sources if the XRB population scales
linearly with optical magnitude of the host galaxy. NGC 5102 has an unusually
low number of XRBs. NGC 5102 is unusually blue for its morphological type, and
has undergone at least two recent bursts of star formation. We present the
results of optical/UV spectral synthesis analysis and demonstrate that a
significant fraction ($>$50%) of the stars in this galaxy are comparatively
young ($<3\times10^9$ years old). If the lack of X-ray binaries is related to
the relative youth of most of the stars, this would support models of LMXB
formation and evolution that require wide binaries to shed angular momentum on
a timescale of Gyrs. We find that NGC 5102 has an unusually low specific
frequency of globular clusters ($S_N\sim$0.4), which could also explain the
lack of LMXBs. We also detect diffuse X-ray emission in the central $\sim$1 kpc
of the galaxy. This hot gas is most likely a superbubble created by multiple
supernovae of massive stars born during the most recent star burst, and is
driving the shock into the ISM which was inferred from optical observations.


title: Discovery of Oxygen Kalpha X-ray Emission from the Rings of Saturn

abstract:
  Using the Advanced CCD Imaging Spectrometer (ACIS), the Chandra X-ray
Observatory (CXO) observed the Saturnian system for one rotation of the planet
(~37 ks) on 20 January, 2004, and again on 26-27 January, 2004. In this letter
we report the detection of X-ray emission from the rings of Saturn. The X-ray
spectrum from the rings is dominated by emission in a narrow (~130 eV wide)
energy band centered on the atomic oxygen K-alpha fluorescence line at 0.53
keV. The X-ray power emitted from the rings in the 0.49-0.62 keV band is 84 MW,
which is about one-third of that emitted from Saturn disk in the photon energy
range 0.24-2.0 keV. Our analysis also finds a clear detection of X-ray emission
from the rings in the 0.49-0.62 keV band in an earlier (14-15 April, 2003)
Chandra ACIS observation of Saturn. Fluorescent scattering of solar X-rays from
oxygen atoms in the H2O icy ring material is the likely source mechanism for
ring X-rays, consistent with the scenario of solar photo-production of a
tenuous ring oxygen atmosphere and ionosphere recently discovered by Cassini.


title:
State transition and flaring activity of IGR J17464-3213/H1743-322 with
  SPI/INTEGRAL telescope

abstract:
  IGR J17464-3213, already known as the HEAO-1 transient source H1743-322, has
been detected during a state transition by the SPI/INTEGRAL telescope. We
describe the spectral evolution and flaring activity of IGR
J17464-3213/H1743-322 from 2003 March 21 to 2003 April 22. During the first
part, the source followed a continuous spectral softening, with the peak of the
spectral energy distribution shifting from 100 keV down to a few keV. However
the thermal disk and the hard X-ray components had a similar intensity,
indicating that the source was in an intermediate state throughout our
observations and evolving toward the soft state. In the second part of our
observations, the ASM/RXTE and SPI/INTEGRAL light curve showed a strong flaring
activity. Two flare events lasting about 1 day each have been detected with SPI
and are probably due to instabilities in the accretion disk associated with the
state transition. During these flares, the low (1.5-12 keV) and high (20-200
keV) energy fluxes monitored with ASM/RXTE and SPI/INTEGRAL, are correlated and
the spectral shape (above 20 keV) remains unchanged while the luminosity
increases by a factor greater than 2.


title:
Star Cluster Survival in Star Cluster Complexes under Extreme Residual
  Gas Expulsion

abstract:
  After the stars of a new, embedded star cluster have formed they blow the
remaining gas out of the cluster. Especially winds of massive stars and
definitely the on-set of the first supernovae can remove the residual gas from
a cluster. This leads to a very violent mass-loss and leaves the cluster out of
dynamical equilibrium. Standard models predict that within the cluster volume
the star formation efficiency (SFE) has to be about 33 per cent for sudden
(within one crossing-time of the cluster) gas expulsion to retain some of the
stars in a bound cluster. If the efficiency is lower the stars of the cluster
disperse mostly. Recent observations reveal that in strong star bursts star
clusters do not form in isolation but in complexes containing dozens and up to
several hundred star clusters, i.e. in super-clusters. By carrying out
numerical experiments for such objects placed at distances >= 10 kpc from the
centre of the galaxy we demonstrate that under these conditions (i.e. the
deeper potential of the star cluster complex and the merging process of the
star clusters within these super-clusters) the SFEs can be as low as 20 per
cent and still leave a gravitationally bound stellar population. Such an object
resembles the outer Milky Way globular clusters and the faint fuzzy star
clusters recently discovered in NGC 1023.


title: High Energy Neutrinos as a Probe for New Physics and Astrophysics

abstract:
  A review of the recent achievements in high energy neutrino physics and,
partly, neutrino astrophysics is presented. It is argued that experiments with
high energy neutrinos of natural origin can be used for a search of new physics
effects beyond the electroweak scale.


title:
KASCADE measurements of energy spectra for elemental groups of cosmic
  rays: Results and open problems

abstract:
  A composition analysis of KASCADE air shower data is performed by means of
unfolding the two-dimensional frequency spectrum of electron and muon numbers.
Aim of the analysis is the determination of energy spectra for elemental groups
representing the chemical composition of primary cosmic rays. Since such an
analysis depends crucially on simulations of air showers the two different
hadronic interaction models QGSJet and SIBYLL are used for their generation.
The resulting primary energy spectra show that the knee in the all particle
spectrum is due to a steepening of the spectra of light elements but, also,
that neither of the two simulation sets is able to describe the measured data
consistently over the whole energy range with discrepancies appearing in
different energy regions.


title: TeV Dark Matter detection by Atmospheric Cerenkov Telescopes

abstract:
  Ground based Atmospheric Cerenkov Telescopes have recently unveiled a TeV
gamma-ray signal from the direction of the Galactic Centre. We examine whether
these gamma-rays, observed by the VERITAS, CANGAROO-II and HESS collaborations,
may arise from annihilations of dark matter particles. Emission from nearby
dwarf spheroidals, such as Sagittarius, could provide a test of this scenario.


title: The Heated Core of the Radio-Quiet Galaxy Cluster A644

abstract:
  We present an analysis of a Chandra ACIS-I observation of the massive galaxy
cluster A644. This cluster was previously classified as a cooling flow, but no
radio emission has been detected from its cD galaxy. Outside the core (R ~75
kpc ~0.03R_vir) the hot ICM has properties consistent with a (relaxed)
cool-core cluster out to the largest radii investigated (R ~415 kpc ~0.14
R_vir). Over this region the gravitating mass profile is described well by a
Navarro-Frenk-White profile with concentration parameter, c = 6.1 +/- 1.2, and
virial radius, R_vir = 2.9 +/- 0.4 Mpc. However, inside the core the
temperature and entropy profiles reverse their inward radial decline and rise
at the center; the inner temperature profile is inconsistent with a constant at
the 2.3 sigma level. Although the core region does not display X-ray cavities
or filamentary structures characteristic of radio-loud, cool-core clusters, the
peak of the X-ray emission is offset from that of the centroid of the global
X-ray halo by ~60 kpc. The position of the cD galaxy lies approximately between
the X-ray peak and centroid, further testifying to a merger origin for the
properties of the X-ray emission in the core. We discuss the implications of
A644 and the small number of radio-quiet, cool-core clusters for the AGN
feedback paradigm to suppress cooling flows in clusters.


title:
FUSE Measurements of Far Ultraviolet Extinction. II. Magellanic Cloud
  Sight Lines

abstract:
  We present an extinction analysis of 9 paths through the LMC and SMC based on
FUSE observations. To date, just two LMC sight lines have probed dust grain
composition and size distributions in the Clouds using spectra including
wavelengths as short as 950 A. We supplement these with results from 4 regions
distinguished by their IR through UV extinction curves and grouped as LMCAvg,
LMC2, SMC bar and SMC wing. Despite the distinct characters of Milky Way and
Magellanic Cloud extinction, our results are generally analogous to those found
for Galactic curves in that the FUSE portions of each extinction curve are
described reasonably well by FM curves fitted only to longer wavelength data
and lack any dramatic new extinction features, and any deviations from the CCM
formalism continue into FUV wavelengths. An MEM analysis of these curves
suggests that LMCAvg and SMC wing sight lines require more silicon and/or
carbon in dust than current abundance measurements would allow, while the
requirements for LMC2 and SMC bar sight lines do not fully tax the available
reservoirs. An intermediate product of this analysis is the measurement of new
H_2 abundances in the Magellanic Clouds. Collectively considering Cloud sight
lines that possess significant H_2 column densities, E(B-V)/N(HI) ratios are
reduced by significant factors relative to the Galactic mean, whereas the
corresponding E(B-V)/N(H_2) values more closely resemble their Galactic
counterpart. These trends reflect the fact that among these sight lines
f(H_2)-values are lower than those common in the Milky Way for paths with
similar degrees of reddening.


title: Type Ia Supernovae: Simulations and Nucleosynthesis

abstract:
  We present our first nucleosynthesis results from a numerical simulation of
the thermonuclear disruption of a static cold Chandrasekhar-mass C/O white
dwarf. The two-dimensional simulation was performed with an adaptive-mesh
Eulerian hydrodynamics code, FLASH, that uses as a flame capturing scheme the
evolution of a passive scaler. To compute the isotopic yields and their
velocity distribution, 10,000 massless tracer particles are embedded in the
star. The particles are advected along streamlines and provide a Lagrangian
description of the explosion. We briefly describe our verification tests and
preliminary results from post-processing the particle trajectories with a
modest (214 isotopes) reaction network.


title: The star formation history of damped Lyman alpha absorbers

abstract:
  The local power law relationship between the surface densities of neutral
hydrogen gas and star formation rate (SFR) can be used to explore the SFR
properties of damped Lyman alpha (DLA) systems at higher redshift. We find that
while the SFR densities for DLA systems are consistent with luminous star
forming galaxies at redshifts below z~0.6, at higher redshifts their SFR
density is too low for them to provide a significant contribution to the cosmic
star formation history (SFH). This suggests that the majority of DLAs may be a
distinct population from the Lyman break galaxies (LBGs) or submillimeter
star-forming galaxies that together dominate the SFR density at high redshift.
It is also possible that the DLAs do not trace the bulk of the neutral gas at
high redshift. The metallicity properties of DLAs are consistent with this
interpretation. The DLAs show a metal mass density lower by two orders of
magnitude at all redshifts than that inferred from the SFH of the universe.
These results are consistent with DLAs being dominated by low mass systems
having low SFRs or a late onset of star formation, similar to the star
formation histories of dwarf galaxies in the local universe.


title: Cluster scaling and its redshift evolution from XMM-Newton

abstract:
  We put together the results of XMM-Newton observations of a number of
representative group and cluster samples at low and high redshifts. These
results confirm the entropy ramp as an explanation of the observed scaling
relations. We observe a mild evolution in the entropy of clusters. The observed
degree of evolution is consistent with expectations of the shock heating at a
fixed overdensity (500) with respect to the critical density in LCDM. The study
of the evolution in the pressure scaling imposes strong requirements in the
definition of the average temperature of the cluster. The scaling temperature
should be consistent to better than the 10% level. Once such a consistency is
achieved, no additional evolution in the pressure has been detected in addition
to the prediction of the shock heating in the LCDM Universe.


title: A universal velocity distribution of relaxed collisionless structures

abstract:
  Several general trends have been identified for equilibrated,
self-gravitating collisionless systems, such as density or anisotropy profiles.
These are integrated quantities which naturally depend on the underlying
velocity distribution function (VDF) of the system. We study this VDF through a
set of numerical simulations, which allow us to extract both the radial and the
tangential VDF. We find that the shape of the VDF is universal, in the sense
that it depends only on two things namely the dispersion (radial or tangential)
and the local slope of the density. Both the radial and the tangential VDF's
are universal for a collection of simulations, including controlled collisions
with very different initial conditions, radial infall simulation, and
structures formed in cosmological simulations.


title:
A Divided Universe: Red and Blue Galaxies and their Preferred
  Environments

abstract:
  (Summary) Making use of scaling relations between the central and the total
galaxy luminosity of a dark matter halo as a function of the halo mass, and the
scatter in these relations, we present an empirical model to describe the
luminosity function (LF) of galaxies. We extend this model to describe relative
statistics of early-type, or red, and late-type, or blue, galaxies, with the
fraction of early type galaxies at halo centers, relative to the total sample,
determined only by the halo mass and the same fraction in the case of
satellites is taken to be dependent on both the halo mass and the satellite
galaxy luminosity. This simple model describes the conditional luminosity
functions, LF of galaxies as a function of the halo mass, measured with the 2dF
galaxy group catalog from cluster to group mass scales. Using 2dF measurements,
we extract information related to conditional mass function for halos from
extreme voids to dense regions in terms of the galaxy overdensity. We also
calculate the probability distribution function of halo mass, as a function of
the galaxy overdensity, and use these probabilities to address preferred
environments of red and blue galaxies. Our model also allow us to make
predictions, for example, galaxy bias as a function of the galaxy type and
luminosity, the void mass function, and the average galaxy luminosity as a
function of the density environment.


title:
The Monopole Moment of the Three-Point Correlation Function of the
  2-degree Field Galaxy Redshift Survey

abstract:
  We measure the monopole moment of the three-point correlation function on
scales $1\mpc-70\mpc$ in the Two degree Field Galaxy Redshift Survey (2dFGRS).
Volume limited samples are constructed using a series of integral magnitudes
bins between $M = -18 ... -22$. Our measurements with a novel edge-corrected
estimator represent most, if not all, three-point level monopole or angular
averaged information in the catalogue. We fit a perturbative non-linear bias
model to a joint data vector formed from the estimated two- and three-point
correlation functions. Two different models are used: an analytic model based
on Eulerian perturbation theory including bias and redshift distortions, and a
phenomenological bias model based on the direct redshift space measurements in
the large Virgo simulations. To interpret the clustering results, we perform a
three parameter Gaussian maximum likelihood analysis. In the canonical $-21
\sim -20$ volume limited sample we find $\sigma_8 = 0.93^{+0.06}_{-0.2}$, $b =
1.04^{+0.23}_{-0.09}$, and $b_2 = -0.06^{+0.003}_{-0.001}$. Our estimate of
$\sigma_8$, is robust across the different volume limited samples constructed.
These results, based solely on the large scale clustering of galaxies, are in
excellent agreement with previous analyses using the Wilkinson Anisotropy
Probe: this is a spectacular success of the concordance model. We also present
two-parameter fits for the bias parameters, which are in excellent agreement
with previous findings of the bias evolution in the 2dFGRS.


title: Dynamical bar instability in a relativistic rotational core collapse

abstract:
  We investigate the rotational core collapse of a rapidly rotating
relativistic star by means of a 3+1 hydrodynamical simulations in conformally
flat spacetime of general relativity. We concentrate our investigation to the
bounce of the rotational core collapse, since potentially most of the
gravitational waves from it are radiated around the core bounce. The dynamics
of the star is started from a differentially rotating equilibrium star of T/W ~
0.16 (T is the rotational kinetic energy and W is the gravitational binding
energy of the equilibrium star), depleting the pressure to initiate the
collapse and to exceed the threshold of dynamical bar instability. Our finding
is that the collapsing star potentially forms a bar when the star has a
toroidal structure due to the redistribution of the angular momentum at the
core bounce. On the other hand, the collapsing star weakly forms a bar when the
star has a spheroidal structure. We also find that the bar structure of the
star is destroyed when the torus is destroyed in the rotational core collapse.
Since the collapse of a toroidal star potentially forms a bar, it can be a
promising source of gravitational waves which will be detected in advanced
LIGO.


title: What we do and do not know about the s-process

abstract:
  AGB stars are the source for the main component of the $s$-process. Here we
discuss both the properties which are reasonably well known and those which
still suffer from substantial uncertainties. In the former case, we are fairly
sure that the $s$-process contribution from AGB stars comes from masses between
about 1 and 3 $\msun$, and the dominant neutron source is the
$^{13}$C$(\alpha$,n)$^{16}$O reaction. In the latter category remains the
formation mechanism for the $^{13}$C-pocket. Attempts at including rotation
seem to inhibit neutron capture reactions. Explaining the observations seems to
require a spread in the size of the $^{13}$C-pocket so some stochastic process,
such as rotation, must be involved.


title: Evolutionary Consequences of Dusty Tori in Active Galactic Nuclei

abstract:
  Deep surveys of {\em Chandra} and {\em HST} (Hubble Space Telescope) show
that active galactic nucleus (AGN) populations are changing with hard X-ray
luminosities. This arises an interesting question whether the dusty torus is
evolving with the central engines. We assemble a sample of 50 radio-quiet PG
quasars to tackle this problem. The covering factors of the dusty tori can be
estimated from the multiwavelength continuum. We find they are strongly
correlated with the hard X-ray luminosity. Interestingly this correlation
agrees with the fraction of type II AGNs discovered by {\em Chandra} and {\em
HST}, implying strong evidence for that the AGN population changing results
from the evolution of the tori. We also find that the frequencies of the dips
around 1$\mu$m in the continuum correlate with the covering factors in the
present sample, indicating the dip frequencies are adjusted by the covering
factors. In the scenario of fueling black hole from the torus, the covering
factor is a good and the dip frequency is a potential indicator of the torus
evolution.


title:
Boundary Effective Field Theory and Trans-Planckian Perturbations:
  Astrophysical Implications

abstract:
  We contrast two approaches to calculating trans-Planckian corrections to the
inflationary perturbation spectrum: the New Physics Hypersurface [NPH] model,
in which modes are normalized when their physical wavelength first exceeds a
critical value, and the Boundary Effective Field Theory [BEFT] approach, where
the initial conditions for all modes are set at the same time, and modified by
higher dimensional operators enumerated via an effective field theory
calculation. We show that these two approaches -- as currently implemented --
lead to radically different expectations for the trans-Planckian corrections to
the CMB and emphasize that in the BEFT formalism we expect the perturbation
spectrum to be dominated by quantum gravity corrections for all scales shorter
than some critical value. Conversely, in the NPH case the quantum effects only
dominate the longest modes that are typically much larger than the present
horizon size. Furthermore, the onset of the breakdown in the standard
inflationary perturbation calculation predicted by the BEFT formalism is likely
to be associated with a feature in the perturbation spectrum, and we discuss
the observational signatures of this feature in both CMB and large scale
structure observations. Finally, we discuss possible modifications to both
calculational frameworks that would resolve the contradictions identified here.


title: Polarization of high-energy pulsar radiation in the striped wind model

abstract:
  The Stokes parameters of the pulsed synchrotron radiation produced in the
striped pulsar wind model are computed and compared with optical observations
of the Crab pulsar. We assume the main contribution to the wind emissivity
comes from a thin transition layer where the dominant toroidal magnetic field
reverses its polarity. The radial component of the field is neglected, but a
small meridional component is added. The resulting radiation is linearly
polarized (Stokes V=0). In the off-pulse region, the electric vector lies in
the direction of the projection on the sky of the rotation axis of the pulsar.
This property is unique to the wind model and in good agreement with the data.
Other properties such as a reduced degree of polarization and a characteristic
sweep of the polarization angle within the pulses are also reproduced. These
properties are qualitatively unaffected by variations of the wind Lorentz
factor, the electron injection power law index and the inclination of the line
of sight.


title: Some statistics of Galactic SNRs

abstract:
  The selection effects applicable to the identification of Galactic supernova
remnants (SNRs) at radio wavelengths are discussed. Low surface brightness
remnants are missing, as are those with small angular sizes (including young
but distant SNRs). Several statistical properties of Galactic SNRs are
discussed, including the surface-brightness/diameter (Sigma-D) relation. The
wide range of intrinsic properties of Galactic remnants with known distances,
and the observational selection effects, means that the Sigma-D relation is of
limited use to derive diameters and hence distances for individual SNRs, or for
statistical studies.


title:
Structural properties of dwarf elliptical galaxies and the connection
  with (ordinary) elliptical galaxies

abstract:
  This article reviews the popular reasons for the belief that dwarf elliptical
galaxies and (ordinary) elliptical galaxies are distinct and separate species.
They include: light-profile shape (or similarly image concentration); the
magnitude-central surface brightness diagram; the magnitude-effective surface
brightness diagram (or similarly the magnitude-effective radius diagram); and
the Fundamental Plane. It is shown how a continuous trend between luminosity
and a) light-profile shape, and b) central surface brightness (until the onest
of core formation at M_B ~ -20.5 mag, results in a unification of the dwarf
elliptical and (ordinary) elliptical galaxies. Neither the above four reasons,
nor the luminosity function (at least in the Virgo cluster) provide evidence
for a division at M_B = -18 mag between the dwarf elliptical and (ordinary)
elliptical galaxies. Instead, they appear to be continuous extensions of each
other.


title: The Alpha Magnetic Spectrometer on the International Space Station

abstract:
  The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed
to operate on the International Space Station (ISS). The aim of AMS is the
direct detection of charged particles in the rigidity range from 0.5 GV to few
TV to perform high statistics studies of cosmic rays in space and search for
antimatter and dark matter. This will be possible because of the large
geometrical acceptance, a very accurate energy determination and a very precise
particle identification through redundant measurements of its energy, velocity
and electric charge. AMS is scheduled to be placed on the ISS at the beginning
of 2008 for a 3 year exposure.


title:
Rights and wrongs of the Hipparcos data: A critical assessment of the
  Hipparcos catalogue

abstract:
  A critical assessment of the quality of the Hipparcos data, partly supported
by a completely new analysis of the raw data, is presented with the aim of
clarifying reliability issues that have surfaced since the publication of the
Hipparcos catalogue in 1997. A number of defects in the data are identified,
such as scan-phase discontinuities and effects of external hits. These defects
can be repaired when re-reducing the raw data. Instabilities in the
great-circle reduction process are recognised and identified in a number of
data sets. These resulted mainly from the difficult observing conditions
imposed by the anomalous orbit of the satellite. The stability of the basic
angle over the mission is confirmed, but the connectivity between the two
fields of view has been less than optimal for some parts of the sky. Both are
fundamental conditions for producing absolute parallaxes. Although there is
clear room for improvement of the Hipparcos data, the catalogue as published
remains generally reliable within the quoted accuracies. Some of the findings
presented here are also relevant for the forthcoming Gaia mission.


title: A new reduction of the raw Hipparcos data

abstract:
  We present an outline of a new reduction of the Hipparcos astrometric data,
the justifications of which are described in the accompanying paper. The
emphasis is on those aspects of the data analysis that are fundamentally
different from the ones used for the catalogue published in 1997. The new
reduction uses a dynamical modelling of the satellite's attitude. It
incorporates provisions for scan-phase discontinuities and hits, most of which
have now been identified. Solutions for the final along-scan attitude (the
reconstruction of the satellite's scan phase), the abscissa corrections and the
instrument model, originally solved simultaneously in the great-circle
solution, are now de-coupled. This is made possible by starting the solution
iterations with the astrometric data from the published catalogue. The
de-coupling removes instabilities that affected great-circle solutions for
short data sets in the published data. The modelling-noise reduction implies
smaller systematic errors, which is reflected in a reduction of the
abscissa-error correlations by about a factor 40. Special care is taken to
ensure that measurements from both fields of view contribute significantly to
the along-scan attitude solution. This improves the overall connectivity of the
data and rigidity of the reconstructed sky, which is of critical importance to
the reliability of the astrometric data. The changes in the reduction process
and the improved understanding of the dynamics of the satellite result in
considerable formal-error reductions for stars brighter than 8th magnitude.


title: Possible hot spots excited by the relativistic jets of Cygnus X-3

abstract:
  We present the results of a deep search for associated radio features in the
vicinity of the microquasar Cygnus X-3. The motivation behind is to find out
evidence for interaction between its relativistic jets and the surrounding
interstellar medium, which could eventually allow us to perform calorimetry of
the total energy released by this microquasar during its flaring lifetime.
Remarkably, two radio sources with mJy emission level at centimeter wavelengths
have been detected in excellent alignment with the position angle of the inner
radio jets. We propose that these objects could be the hot spots where the
relativitic outflow collides with the ambient gas in analogy with
Fanaroff-Riley II radio galaxies. These candidate hot spots are within a few
arc-minutes of Cygnus X-3 and, if physically related, the full linear extent of
the jet would reach tens of parsecs. We discuss here the evidence currently
available to support this hypothesis based on both archival data and our own
observations.


title:
Near-infrared integral-field spectroscopy of violent starburst
  environments

abstract:
  Near-infrared (NIR) integral-field spectroscopy (IFS) of violent starburst
environments at high spatial (and spectral) resolution has the potential to
revolutionise our ideas regarding the local interactions between the
newly-formed massive stars and the interstellar medium (ISM) of their host
galaxies. To illustrate this point, I present NIR IFS analysis of the central
starburst region of NGC 1140, obtained with CIRPASS on Gemini-South. While
strong [FeII] emission is found throughout the galaxy, higher-order Brackett
emission is predominantly associated with the northern starburst region. Based
on the spatial distributions of the [FeII] versus Brackett line emission, I
conclude that a galaxy-wide starburst was induced several x 10^7 yr ago, with
more recent starburst activity concentrated around the northern starburst
region. I look forward and discuss the exciting prospects that IFS at higher
spatial (and spectral) resolution will allow us trace (i) the massive outflows
("superwinds") expected to originate in the dense, young massive star clusters
commonly found in intense starburst environments, and (ii) their impact on the
galaxy's ISM.


title:
FIRST-based survey of Compact Steep Spectrum sources, II. MERLIN and VLA
  observations of Medium-sized Symmetric Objects

abstract:
  A new sample of candidate Compact Steep Spectrum (CSS) sources that are much
weaker than the CSS source prototypes has been selected from the VLA FIRST
catalogue. MERLIN `snapshot' observations of the sources at 5 GHz indicate that
six of them have an FR II-like morphology, but are not edge-brightened as is
normal for Medium-sized Symmetric Objects (MSOs) and FR IIs. Further
observations of these six sources with the VLA at 4.9 GHz and MERLIN at 1.7
GHz, as well as subsequent full-track observations with MERLIN at 5 GHz of what
appeared to be the two sources of greatest interest are presented. The results
are discussed with reference to the established evolutionary model of CSS
sources being young but in which not all of them evolve to become old objects
with extended radio structures. A lack of stable fuelling in some of them may
result in an early transition to a so-called coasting phase so that they fade
away instead of growing to become large-scale objects. It is possible that one
of the six sources (1542+323) could be labelled as a prematurely `dying' MSO or
a `fader'.


title:
Astrophysical Production of Microscopic Black Holes in a Low
  Planck-scale World

abstract:
  In the framework of brane-world models lowering the Planck scale to the TeV
range, it has recently been pointed out that small black holes could be formed
at particle colliders or by neutrinos interactions in the atmosphere. This
article aims at reviewing other places and epochs where microscopic black holes
could be formed : the interstellar medium and the early Universe. The related
decay channels and the propagation of the emitted particles are studied to
conclude that, in spite of the large creation rate for such black holes, the
amount of produced particles do not conflict with experimental data. This
shows, from the astronomical viewpoint, that models with large extra dimensions
making the gravity scale much lower are compatible with observations.


title:
Changes in the global parameters of polytropic stars induced by the
  appearance of the soft core

abstract:
  The effect of a soft phase core appearance in the center of polytropic star
is analyzed by means of linear response theory. Approximate formulae for the
changes of radius, moment of inertia and mass-energy of non-rotating
configuration with arbitrary adiabatic indices are presented, followed by an
example evaluation of astrophysical observables.


title: Large-scale magnetic field of the G8 dwarf xi Bootis A

abstract:
  We investigate the magnetic geometry of the active G8 dwarf xi Bootis A, from
spectropolarimetric observations obtained in 2003 with the MuSiCoS echelle
spectropolarimeter at the Telescope Bernard Lyot (Observatoire du Pic du Midi,
France). We repeatedly detect a photospheric magnetic field, with periodic
variations consistent with rotational modulation. Circularly polarized (Stokes
V) line profiles present a systematic asymmetry, showing up as an excess in
amplitude and area of the blue lobe of the profiles. A direct modeling of
Stokes V profiles suggests that the global magnetic field is composed of two
main components, with an inclined dipole and a large-scale toroidal field. We
derive a dipole intensity of about 40 G, with an inclination of 35 degrees of
the dipole with respect to the rotation axis. The toroidal field strength is of
order of 120 G. A noticeable evolution of the field geometry is observed over
the 40 nights of our observing window and results in an increase of the field
strength and of the dipole inclination.
  This study is the first step of a long-term monitoring of xi Bootis A and
other active solar-type stars, with the aim to investigate secular fluctuations
of stellar magnetic geometries induced by activity cycles.


title: Recent Searches for the Radio Lines of NH_3 in Comets

abstract:
  Radio observations in the ammonia inversion lines of four comets, C/2001 A2
(LINEAR), 153P/Ikeya-Zhang, C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR), were
performed at the Effelsberg 100-m Radio Telescope during their respective close
approaches to Earth. None of the four lowest energy metastable lines
(J,K=J),J=1--4, could be detected in these comets. We derive the following 3
sigma upper bounds on the NH_3 production rate, and c omparing to the
corresponding water production rates, percentage NH_3 abundances relative to
H_2O:
  Q(NH_3) < 1.9x10^26 s^-1 (0.63%) for C/2001 A2 (LINEAR),
  Q(NH_3) < 2.7x10^26 s^-1 (0.13%) for C/2001 Q4 (NEAT),
  Q(NH_3) < 2.3x10^27 s^-1 (0.74%) for C/2002 T7 (LINEAR) and Q(NH_3) <=
6.3x10^26 s^-1 (0.63%) for Comet 153P/Ikeya-Zhang.
  At 0.74% or less, the ammonia-to-water ratios are factors of 2 below the
value for C/1995 O1 (Hale-Bopp) and 1P/Halley, suggesting chemical diversity
between comets. The 18-cm lines of OH were clearly detected in the two comets
observed during the 2004 campaign, thereby validating the cometary ephemerides.


title:
Feedback and metal enrichment in cosmological SPH simulations I. A model
  for chemical enrichment

abstract:
  We discuss a model for treating chemical enrichment by SNII and SNIa
explosions in simulations of cosmological structure formation. Our model
includes metal-dependent radiative cooling and star formation in dense
collapsed gas clumps. Metals are returned into the diffuse interstellar medium
by star particles using a local SPH smoothing kernel. A variety of chemical
abundance patterns in enriched gas arise in our treatment owing to the
different yields and lifetimes of SNII and SNIa progenitor stars. In the case
of SNII chemical production, we adopt metal-dependent yields. Because of the
sensitive dependence of cooling rates on metallicity, enrichment of galactic
haloes with metals can in principle significantly alter subsequent gas infall
and the build up of the stellar components. Indeed, in simulations of isolated
galaxies we find that a consistent treatment of metal-dependent cooling
produces 25% more stars outside the central region than simulations with a
primordial cooling function. In the highly-enriched central regions, the
evolution of baryons is however not affected by metal cooling, because here the
gas is always dense enough to cool. A similar situation is found in
cosmological simulations because we include no strong feedback processes which
could spread metals over large distances and mix them into unenriched diffuse
gas. We demonstrate this explicitly with test simulations which adopt
super-solar cooling functions leading to large changes both in the stellar mass
and in the metal distributions. We also find that the impact of metallicity on
the star formation histories of galaxies may depend on their particular
evolutionary history. Our results hence emphasise the importance of feedback
processes for interpreting the cosmic metal enrichment.


title:
Clustering of SZ clusters on a past light-cone: acoustic oscillations
  and constraints on dark energy

abstract:
  In this paper we study the clustering of SZ-selected galaxy clusters on a
past light-cone, particularly paying attention to the possibility of
constraining properties of dark energy. The prospects of detecting baryonic
features in the cluster power spectrum for a wide and shallow survey like
PLANCK, and for an SPT-like narrow and deep survey are discussed. It is
demonstrated that these future blank sky SZ surveys will have capability to
improve significantly over the recently announced detection of baryonic
oscillations based on the SDSS Luminous Red Galaxy (LRG) sample. We carry out
parameter estimation using Fisher matrix approach taking into account the
anisotropic nature of the power spectrum due to redshift space and cosmological
distortions. The clustering signal which is not too sensitive to systematic
uncertainties serves as a valuable piece of information that in combination
with other sources of data helps in breaking degeneracies between the
cosmological parameters.


title: Radio Detection of Cosmic Ray Air Showers with Codalema

abstract:
  Studies of the radio detection of Extensive Air Showers is the goal of the
demonstrative experiment CODALEMA. Previous analysis have demonstrated that
detection around $5.10^{16}$ eV was achieved with this set-up. New results
allow for the first time to study the topology of the electric field associated
to EAS events on a event by event basis.


title: The luminous host galaxies of high redshift BL Lac objects

abstract:
  (abridged) We present near-infrared Ks-band imaging of 13 high redshift (0.6
< z < 1.3) BL Lac objects. We clearly detect the host in eight objects, and
marginally in three others. In all cases, the host galaxy is well represented
by an r^1/4 surface brightness law. The host galaxies of high redshift BL Lacs
are large (<R(e)> ~7 kpc) and very luminous (<M(K)> = -27.9+-0.7), ~3 mag
brighter than L*, and ~1 mag brighter than brightest cluster galaxies. They are
also ~1 mag brighter than low redshift radio galaxies and appear to deviate
from their K-z relationship. On the other hand, the high luminosities agree
with the few optical studies of high redshift BL Lac hosts. The nuclear
luminosity and the nucleus-galaxy luminosity ratio of the high redshift BL Lacs
are much larger than those in low redshift BL Lacs. This may be due to either a
higher intrinsic nuclear luminosity, or enhanced luminosity because of strong
beaming. Contrary to what is observed in low redshift BL Lacs, the luminosities
of the host galaxy and of the nucleus are fairly well correlated, as expected
from the black hole mass - bulge luminosity relationship. High redshift BL Lacs
radiate with a wide range of power with respect to their Eddington luminosity,
and this power is intermediate between those in nearby BL Lacs and in luminous
radio-loud quasars. The high redshift BL Lac host galaxies appear to be ~2 mag
brighter than those at low redshift. This is likely due to a strong selection
effect in the surveys of BL Lacs that makes observable only the most luminous
sources at z > 0.5 and produces a correlation between the nuclear and the host
luminosity. However, this may also suggest strong luminosity evolution which is
inconsistent with a simple passive evolution of the host galaxies, and requires
a contribution from relatively recent star formation episodes.


title: Star formation in Perseus

abstract:
  We present a complete survey of current star formation in the Perseus
molecular cloud, made at 850 and 450 micron with SCUBA at the JCMT. Covering 3
deg^2, this submillimetre continuum survey for protostellar activity is second
in size only to that of rho Ophiuchus (Johnstone et al. 2004). Complete above
0.4 msun (5 sigma detection in a 14'' beam), we detect a total of 91 protostars
and prestellar cores. Of these, 80% lie in clusters, representative of star
formation across the Galaxy. Two of the groups of cores are associated with the
young stellar clusters IC348 and NGC1333, and are consistent with a steady or
reduced star formation rate in the last 0.5 Myr, but not an increasing one. In
Perseus, 40--60% of cores are in small clusters (< 50 msun) and isolated
objects, much more than the 10% suggested from infrared studies. Complementing
the dust continuum, we present a C^18O map of the whole cloud at 1' resolution.
The gas and dust show filamentary structure of the dense gas on large and small
scales, with the high column density filaments breaking up into clusters of
cores. The filament mass per unit length is 5--11 msun per 0.1 pc. Given these
filament masses, there is no requirement for substantial large scale flows
along or onto the filaments in order to gather sufficient material for star
formation. We find that the probability of finding a submillimetre core is a
strongly increasing function of column density, as measured by C^18O integrated
intensity, prob(core) proportional to I^3.0. This power law relation holds down
to low column density, suggesting that there is no A_v threshold for star
formation in Perseus, unless all the low-A_v submm cores can be demonstrated to
be older protostars which have begun to lose their natal molecular cloud.


title:
Star-formation in NGC 4038/4039 from broad- and narrow band photometry:
  Cluster Destruction?

abstract:
  Accurately determining the star formation history in NGC 4038/4039 -- ``The
Antennae'' is hampered by extinction. We therefore used near infrared images
obtained with ISAAC at the VLT and with SOFI at the NTT to determine the recent
star formation history in this merger. In combination with archival HST data,
we determined ages, extinction and other parameters for single star clusters,
and properties of the cluster population as a whole. About 70% of the K_s-band
detected star clusters with masses >= 10^5 M_sun are younger than 10 Myrs
(approximately an e-folding time for cluster ages), which we interpret as
evidence for rapid dissolution but not free expansion. The total mass of K-band
selected clusters is about 5-10x10^8 M_sun and represents about 3-6% of the
total molecular gas. This takes into account only the detected clusters and in
view of the rapid dissolution means that this is only a lower limit to the
total mass of stars produced in clusters during the burst. Studies of cluster
formation in other galaxies recently suggested short cluster dissolution
timescales, too, which means that star formation rates may have been severely
underestimated in the past. Extinction is strongly variable and very high in
some regions, but around A_V=1.3 mag on average. Even though most clusters are
detected at least in I-band, only the information about individual cluster ages
and extinction allows to avoid uncertainties of orders of magnitude in star
formation rate estimates determined from optical fluxes. From the distribution
of individual cluster extinction vs. age, which is significantly higher for
clusters below 8-9 Myr than for older clusters, we infer that this is the time
by which a typical cluster blows free of its native dust cocoon.


title: No evidence of "gray" dust from composite quasar spectra

abstract:
  Two recent studies based on composite reddened quasar spectra have indicated
the presence of `gray' dust in quasar environments. This gray dust has a
relatively flat extinction law in the UV, consistent with the theoretical
expectation of a lack of small dust grains close to a quasar. In contrast,
individual reddened quasars in the Sloan Digital Sky Survey tend to have steep
extinction laws in the UV, similar to that in the SMC. We analyze the method
used in determining extinction laws from composite quasar spectra in order to
resolve this discrepancy. We show that quasars reddened by SMC-type dust that
are present in quasar samples have a negative correlation between E_{B-V} and
redshift, due to selection effects. The fact that the highest redshift quasars
(which contribute to the UV part of a composite spectrum) are less extincted
leads to shallower extinction in the UV. We construct a composite quasar
spectrum from a simulated sample of quasars reddened by SMC-type dust and show
that the extinction curve derived from the composite does not recover the
intrinsic extinction law. We conclude there is no evidence of gray dust in
quasar environments.


title: Exploring X-ray emission and absorption in AGN with XMM-Newton EPIC

abstract:
  Broad band X-ray spectra of high statistical quality obtained with the EPIC
instruments on XMM-Newton are being used to address key issues in AGN Physics,
including the evidence for strong gravity, massive and energetic outflows and
the effects of reflection and absorption in cold dense matter. A progress
report on these topics is presented by reference to high quality EPIC spectra
of 5 bright Seyfert galaxies covering a wide range in luminosity.


title:
VLT Spectroscopy of Globular Cluster Systems, I. The Photometric and
  Spectroscopic Dataset

abstract:
  We present Lick line-index measurements of extragalactic globular clusters in
seven early-type galaxies (NGC 1380, 2434, 3115, 3379, 3585, 5846, and 7192)
with different morphological types (E-S0) located in field and group/cluster
environments. High-quality spectra were taken with the FORS2 instrument at
ESO's Very Large Telescope. About 50% of our data allow an age resolution dt/t
~ 0.3 and a metallicity resolution ~0.25-0.4 dex, depending on the absolute
metallicity. Globular cluster candidates are selected from deep B, V, R, I, K
FORS2/ISAAC photometry with 80-100% success rate inside one effective radius.
Using combined optical/near-infrared colour-colour diagrams we present a method
to efficiently reduce fore-/background contamination down to <10%. We find
clear signs for bi-modality in the globular cluster colour distributions of NGC
1380, 3115, and 3585. The colour distributions of globular clusters in NGC
2434, 3379, 5846, and 7192 are consistent with a broad single-peak
distribution. For the analysed globular cluster systems the slopes of projected
radial surface density profiles, of the form Sigma(R) ~ R^-Gamma, vary between
~0.8 and 2.6. Using globular clusters as a tracer population we determine total
dynamical masses of host galaxies out to large radii (~1.6 - 4.8 Reff). For the
sample we find masses in the range ~8.8*10^10 Msolar up to ~1.2*10^12 Msolar.
The line index data presented here will be used in accompanying papers of this
series to derive ages, metallicities and abundance ratios. A compilation of
currently available high-quality Lick index measurements for globular clusters
in elliptical, lenticular, and late-type galaxies is provided and will serve to
augment the current data set. [abridged]


title: GSC 4232.2830, an Eclipsing Binary with Elliptical Orbit

abstract:
  The discovery of an Algol type eclipsing variable star having highly
elliptical orbit with the period of 11.628 day is reported.


title:
Black hole-neutron star binaries in general relativity: effects of
  neutron star spin

abstract:
  We present new sequences of general relativistic, quasiequilibrium black
hole-neutron star binaries. We solve for the gravitational field in the
conformal thin-sandwich decomposition of Einstein's field equations, coupled to
the equations of relativistic hydrostatic equilibrium for a perfect fluid. We
account for the black hole by solving these equations in the background metric
of a Schwarzschild black hole whose mass is much larger than that of the
neutron star. The background metric is treated in Kerr-Schild as well as
isotropic coordinates. For the neutron star, we assume a polytropic equation of
state with adiabatic index Gamma=2, and solve for both irrotational and
corotational configurations. By comparing the results of irrotational and
synchronized configurations with the same background metric, we conclude that
the effect of the rotation on the location of tidal break-up is only on the
order of a few percent. The different choices in the background also lead to
differences of order a few percent, which may be an indication of the level to
which these configurations approximate quasiequilibrium.


title: A Jovian-mass Planet in Microlensing Event OGLE-2005-BLG-071

abstract:
  We report the discovery of a several-Jupiter mass planetary companion to the
primary lens star in microlensing event OGLE-2005-BLG-071. Precise (<1%)
photometry at the peak of the event yields an extremely high signal-to-noise
ratio detection of a deviation from the light curve expected from an isolated
lens. The planetary character of this deviation is easily and unambiguously
discernible from the gross features of the light curve. Detailed modeling
yields a tightly-constrained planet-star mass ratio of q=m_p/M=0.0071+/-0.0003.
This is the second robust detection of a planet with microlensing,
demonstrating that the technique itself is viable and that planets are not rare
in the systems probed by microlensing, which typically lie several kpc toward
the Galactic center.


title:
Can the Steep Mass Profile of A1689 Be Explained by a Triaxial Dark
  Halo?

abstract:
  The steep mass profile of A1689 derived from recent detailed lensing
observations is not readily reconciled with the low concentration halos
predicted by the standard CDM model. However, halo triaxiality may act to bias
the profile constraints derived assuming a spherically symmetric mass
distribution, since lensing relates only to the projected mass distribution. A
degree of halo triaxiality is inherent to the CDM structure formation, arising
from the collision-less nature of the dark matter. Here we compare the
CDM-based model predictions of triaxial halo with the precise lensing
measurements of A1689 based on the ACS/HST and Subaru data, over a wide range
of 10kpc<r<2Mpc. The model lensing profiles cover the intrinsic spread of halo
mass and shape, and are projected over all inclinations when comparing with the
data. We show that the model parameters are only weakly constrained and
strongly degenerate mainly because of the lack of information along the line of
sight. In particular, the limits on the concentration parameter become less
restrictive with increasing triaxiality. Yet, by comparing the obtained
constraints with expected probability distributions for the axis ratio and
concentration parameters computed from numerical simulations, we find that ~6%
of cluster-size halos in the CDM model can match the A1689 lensing observations
at the 2-sigma level, corresponding to cases where the major-axis of the halo
is aligned with the line of sight. Thus halo triaxiality could reduce the
apparent discrepancy between theory and observation. This hypothesis needs to
be further explored by a statistical lensing study for other clusters as well
as by complementary three-dimensional information derived using X-ray,
kinematics, and SZ effect observations.