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2014-08-28 | The Gaia-ESO Survey: the chemical structure of the Galactic discs from the first internal data release | Most high-resolution spectroscopic studies of the Galactic discs were mostly
confined to objects in the solar vicinity. Here we aim at enlarging the volume
in which individual chemical abundances are used to characterise both discs,
using the first internal data release of the Gaia-ESO survey. We derive and
discuss the... | 1408.6687v1 |
2015-09-17 | The XMM deep survey in the CDF-S. IX. An X-ray outflow in a luminous obscured quasar at z~1.6 | In active galactic nuclei (AGN)-galaxy co-evolution models, AGN winds and
outflows are often invoked to explain why super-massive black holes and
galaxies stop growing efficiently at a certain phase of their lives. They are
commonly referred to as the leading actors of feedback processes. Evidence of
ultra-fast (v>0.05... | 1509.05413v1 |
2016-12-08 | The distribution of radioactive $^{44}$Ti in Cassiopeia A | The distribution of elements produced in the inner-most layers of a supernova
explosion is a key diagnostic for studying the collapse of massive stars. Here
we present the results of a 2.4 Ms \textit{NuSTAR} observing campaign aimed at
studying the supernova remnant Cassiopeia A (Cas A). We perform
spatially-resolved s... | 1612.02774v1 |
2020-06-06 | EMPRESS. II. Highly Fe-Enriched Metal-poor Galaxies with $\sim 1.0$ (Fe/O)$_\odot$ and $0.02$ (O/H)$_\odot$ : Possible Traces of Super Massive ($>300 M_{\odot}$) Stars in Early Galaxies | We present element abundance ratios and ionizing radiation of local young
low-mass (~$10^{6}$ M_sun) extremely metal poor galaxies (EMPGs) with a 2%
solar oxygen abundance (O/H)_sun and a high specific star-formation rate
(sSFR~300 Gyr$^{-1}$), and other (extremely) metal poor galaxies, which are
compiled from Extremel... | 2006.03831v2 |
2021-07-02 | On the use of field RR Lyrae as Galactic probes: IV. New insights into and around the Oosterhoff dichotomy | We discuss the largest and most homogeneous spectroscopic dataset of field RR
Lyrae variables (RRLs) available to date. We estimated abundances using both
high-resolution and low-resolution ({\Delta S} method) spectra for fundamental
(RRab) and first overtone (RRc) RRLs. The iron abundances for 7,941 RRLs were
suppleme... | 2107.00919v1 |
2018-02-13 | Disentangling superconducting and magnetic orders in NaFe_1-xNi_xAs using muon spin rotation | Muon spin rotation and relaxation studies have been performed on a "111"
family of iron-based superconductors NaFe_1-xNi_xAs. Static magnetic order was
characterized by obtaining the temperature and doping dependences of the local
ordered magnetic moment size and the volume fraction of the magnetically
ordered regions.... | 1802.04458v1 |
2022-06-24 | The origin and evolution of the normal Type Ia SN 2018aoz with infant-phase reddening and excess emission | SN~2018aoz is a Type Ia SN with a $B$-band plateau and excess emission in the
infant-phase light curves $\lesssim$ 1 day after first light, evidencing an
over-density of surface iron-peak elements as shown in our previous study.
Here, we advance the constraints on the nature and origin of SN~2018aoz based
on its evolut... | 2206.12437v1 |
2022-10-31 | A JWST Near- and Mid-Infrared Nebular Spectrum of the Type Ia Supernova 2021aefx | We present JWST near- and mid-infrared spectroscopic observations of the
nearby normal Type Ia supernova SN 2021aefx in the nebular phase at $+255$ days
past maximum light. Our Near Infrared Spectrograph (NIRSpec) and Mid Infrared
Instrument (MIRI) observations, combined with ground-based optical data from
the South Af... | 2211.00038v2 |
1995-10-11 | Is the X-ray spectrum of the Seyfert 2 galaxy NGC5252 intrinsically flat? | The first X-ray observation of the Seyfert 2 galaxy NGC5252 is reported. ASCA
collected $\sim 4000$ photons/detector enough to perform an accurate spectral
analysis of this source. The luminosity of NGC5252 is L$_{\rm X}$(0.7-10 keV)
$\simeq 2.6 \times 10^{43}$ erg s$^{-1}$, typical of a Seyfert 1 galaxy. A
simple desc... | 9510064v1 |
1996-04-10 | The Hubble constant from $^{56}$Co-powered Nebular Candles | Type Ia supernovae (SNe Ia), produced by the thermonuclear explosion of white
dwarf (WD) stars, are used here to derive extragalactic distances and an
estimate of the Hubble constant from their emission signatures at late phases
({\it Nebular SNe Ia Method}, NSM). The method, first developed in
Ruiz--Lapuente \& Lucy (... | 9604044v1 |
1996-06-27 | ASCA observations of Seyfert 1 galaxies: II. Relativistic Iron K-alpha emission | We present evidence for widespread relativistic effects in the central
regions of active galactic nuclei. In a sample of 18 Seyfert 1 galaxies
observed by \asca, 14 show an iron K$\alpha$ line which is is resolved, with
mean width $\sigma_{\rm K\alpha}=0.43\pm 0.12$~keV for a gaussian profile (Full
Width at Half Maximu... | 9606169v2 |
1998-04-27 | A Strange Star Model for Pulsars | It is suggested in this paper that the `bare' strange star might be not bare,
and there could be a magnetosphere around it. As a strange star might be an
intensely magnetized rotator, the induced unipolar electric field would be
large enough to construct a magnetosphere around the strange matter core.
This kind of ma... | 9804278v1 |
1998-10-07 | Stellar Metallicities and SNIa Rates in the Early-type Galaxy NGC5846 from ROSAT and ASCA Observations | In this paper we analyze the diffuse X-ray coronae surrounding the elliptical
galaxy NGC5846, combining measurements from two observatories, ROSAT and ASCA.
We map the gas temperature distribution and find a central cool region within
an approximately isothermal gas halo extending to a radius of about 50 kpc, and
evide... | 9810107v1 |
1999-02-25 | Chemical Evolution on the Scale of Clusters of Galaxies, and Beyond | Clusters of galaxies allow a direct estimate of the metallicity and metal
production yield on the largest scale so far. The ratio of the total iron mass
in the ICM to the total optical luminosity of the cluster (the iron
mass-to-light-ratio) is the same for all clusters which ICM is hotter than
$\sim 2$ keV, and the el... | 9902361v2 |
1999-04-12 | Presupernova Evolution of Rotating Massive Stars I: Numerical Method and Evolution of the Internal Stellar Structure | The evolution of rotating stars with zero-age main sequence (ZAMS) masses in
the range 8 to 25 M_sun is followed through all stages of stable evolution. The
initial angular momentum is chosen such that the star's equatorial rotational
velocity on the ZAMS ranges from zero to ~ 70 % of break-up. Redistribution of
angula... | 9904132v2 |
1999-07-12 | The Steep Spectrum Quasar PG1404+226 with ASCA, HST and ROSAT | (abridged) We present and discuss our observations of the NL quasar
PG1404+226 with ASCA and HST, and a re-analysis of our earlier observations
with ROSAT. The soft X-ray spectrum is very steep and displays an absorption
feature (edge or line at ~1.1 keV). We have applied a variety of models to the
ASCA and ROSAT spect... | 9907150v1 |
1999-10-11 | ASCA and ROSAT observations of nearby cluster cooling flows | We present a detailed analysis of the X-ray properties of the cooling flows
in a sample of nearby, X-ray bright clusters of galaxies using high-quality
ASCA spectra and ROSAT X-ray images. We demonstrate the need for multiphase
models to consistently explain the spectral and imaging X-ray data for the
clusters. The mas... | 9910188v2 |
1999-11-03 | Hard X-ray Emission From Low Mass X-ray Binaries | We report on Rossi X-ray Timing Explorer observations of four type I X-ray
bursters; namely 1E1724-3045, GS1826-238, SLX1735-269 and KS1731-260. The first
three were in a low state (LS) whereas KS1731-260 was in a high state. The LS
sources have very similar power spectra, displaying high frequency noise up to
\~200 Hz... | 9911042v1 |
2000-02-10 | Atomic data from the Iron Project.XLIII. Transition probabilities for Fe V | An extensive set of dipole-allowed, intercombination, and forbidden
transition probabilities for Fe V is presented. The Breit-Pauli R-matrix (BPRM)
method is used to calculate 1.46 x 10^6 oscillator strengths for the allowed
and intercombination E1 transitions among 3,865 fine-structure levels dominated
by configuratio... | 0002230v1 |
2000-03-03 | J-Band Infrared Spectroscopy of a Sample of Brown Dwarfs Using Nirspec on Keck II | Near-infrared spectroscopic observations of a sample of very cool, low-mass
objects are presented with higher spectral resolution than in any previous
studies. Six of the objects are L-dwarfs, ranging in spectral class from L2 to
L8/9, and the seventh is a methane or T-dwarf. These new observations were
obtained during... | 0003035v1 |
2000-03-06 | X-ray Spectra of a large sample of Quasars with ASCA | The results from an X-ray spectral analysis of a large sample of quasars,
observed with ASCA, are presented. Data reduction leaves 62 quasars, 35
radio-loud and 27 radio-quiet, suitable for spectral analysis. Differences are
found between the radio-quiet quasars (RQQs) and the radio-loud quasars (RLQs),
in agreement wi... | 0003080v1 |
2000-03-17 | ASCA Observation of the New Transient X-ray Pulsar XTE J0111.2-7317 in the Small Magellanic Cloud | The new transient X-ray pulsar XTE J0111.2-7317 was observed with Advanced
Satellite for Cosmology and Astrophysics (ASCA) on 1998 November 18, a few days
after its discovery with the Proportional Counter Array onboard the Rossi X-ray
Timing Explorer. The source was detected at a flux level of 3.6x10^-10 erg
cm^-2 s^-1... | 0003251v1 |
2000-05-31 | Accretion disk models and their X-ray reflection signatures. I. Local spectra | X-ray illumination of accretion disks is an invaluable diagnostic of the
structure of these disks because of the associated iron K$\alpha$ emission.
Here we point out that the resulting reflected spectra depend very sensitively
on the geometry of the X-ray source, and that this fact can be efficiently used
to test thes... | 0005597v1 |
2000-06-23 | The Origin of the X-ray and Ultraviolet Emission in NGC 7469 | We present a spectral analysis of a 30d, near-continuous observation of the
Seyfert 1 galaxy NGC 7469 with RXTE. Daily integrations show strong spectral
changes during the observation. Ourmain result is that we find the X-ray
spectral index to be correlated with the UV flux. Furthermore, the broad-band
X-ray photon flu... | 0006339v1 |
2000-09-12 | The Composite Broad Band Spectrum of Cir X-1 at the Periastron: a Peculiar Z-source | We report on the spectral analysis of the peculiar source Cir X-1 observed by
the BeppoSAX satellite when the X-ray source was near the periastron. A flare
lasting $\sim 6 \times 10^3$ s is present at the beginning of the observation.
The luminosity during the persistent emission is $1 \times 10^{38}$ erg
s$^{-1}$, whi... | 0009183v1 |
2000-10-26 | A High Resolution Method for Measuring Cosmic Ray Composition beyond 10 TeV | The accurate determination of the elemental composition of cosmic rays at
high energies is expected to provide crucial clues on the origin of these
particles. Previous direct measurements of composition have been limited by
experiment collecting power, resulting in marginal statistics above $10^{14}$
eV, precisely the ... | 0010554v2 |
2000-11-29 | Variable X-ray Absorption in the Seyfert 2 Galaxy Mrk 348 | We present RXTE monitoring observations of the Seyfert 2 galaxy Mrk 348
spanning a 6 month period. The time-averaged spectrum in the 3-20 keV band
shows many features characteristic of a Compton-thin Seyfert 2 galaxy, namely a
hard underlying power-law continuum (photon index = 1.8) with heavy soft X-ray
absorption (N_... | 0011542v1 |
2001-01-22 | Spectral Evolution of the Continuum and Disc Line in Dipping in GRO J1655-40 | The discovery is reported of emission features in the X-ray spectrum of GRO
J1655-40 obtained using Rossi-XTE on 1997, Feb 26. The features have been
fitted firstly by two Gaussian lines, which in four spectra have average
energies of 5.85+/-0.08 keV and 7.32+/-0.13 keV, strongly suggestive that these
are the red- and ... | 0101388v1 |
2001-05-18 | The CHANDRA HETGS X-ray Grating Spectrum of Eta Car | Eta Car may be the most massive and luminous star in the Galaxy and is
suspected to be a massive, colliding wind binary system. The CHANDRA X-ray
observatory has obtained a calibrated, high-resolution X-ray spectrum of the
star uncontaminated by the nearby extended soft X-ray emisssion. Our 89 ksec
CHANDRA observation ... | 0105335v2 |
2001-06-29 | Secondary antiprotons and propagation of cosmic rays in the Galaxy and heliosphere | High-energy collisions of cosmic-ray nuclei with interstellar gas are
believed to be the mechanism producing the majority of cosmic ray antiprotons.
Due to the kinematics of the process they are created with a nonzero momentum;
the characteristic spectral shape with a maximum at ~2 GeV and a sharp decrease
towards lowe... | 0106567v2 |
2001-07-17 | The Unique Type Ia Supernova 2000cx in NGC 524 | We present extensive photometric and spectroscopic observations of the Type
Ia supernova (SN Ia) 2000cx in the S0 galaxy NGC 524, which reveal it to be
peculiar. Photometrically, SN 2000cx is different from all known SNe Ia, and
its light curves cannot be fit well by the fitting techniques currently
available. There is... | 0107318v1 |
2001-09-03 | The BeppoSAX 0.1 - 100 keV Spectrum of the X-ray Pulsar 4U 1538-52 | We report the results of temporal and spectral analysis performed on the
X-ray pulsar 4U 1538-52 observed by BeppoSAX. We obtained a new estimate of the
spin period of the neutron star P=528.24 \pm 0.01 s (corrected for the orbital
motion of the X-ray source): the source is still in the spin-up state, as since
1988. Th... | 0109031v1 |
2001-10-08 | The Population of Weak MgII Absorbers. II The Properties of Single-Cloud Systems | We present an investigation of MgII absorbers characterized as single-cloud
weak systems at z~1. We measured column densities and Doppler parameters for
MgII and FeII in 15 systems found in HIRES/Keck spectra at 6.6 km/s. Using
these quantities and CIV, Lyman alpha and Lyman limit absorption observed with
FOS/HST (reso... | 0110191v1 |
2001-10-29 | Kinetic equilibrium of iron in the atmospheres of cool dwarf stars II. Weak Fe I lines in the solar spectrum | NLTE line formation calculations of FeI in the solar atmosphere are extended
to include weak optical lines. Previously established atomic models are used to
discriminate between different ways of treating collisional interaction
processes. To derive a common solar FeI abundance from both strong and weak
lines, fine-tun... | 0110605v1 |
2002-02-04 | The structure and radiation spectra of illuminated accretion discs in AGN. I. Moderate illumination | We present detailed computations of the vertical structure of an accretion
disc illuminated by hard X-ray radiation with the code {\sc titan-noar}
suitable for Compton thick media. The energy generated via accretion is
dissipated partially in the cold disc as well as in the X-ray source. We study
the differences betwee... | 0202069v2 |
2002-02-21 | The BeppoSAX view of bright Compton-thin Seyfert 2 galaxies | We present the analysis of 31 observations of 20 bright Compton thin Seyfert
2s, in the 0.1-200 keV band, performed with the BeppoSAX satellite. The sample
consists of all Seyfert 2s in the BeppoSAX public archive, with a 2-10 keV flux
higher than 5x10^(-12) erg/cm^2/s. The good statistics available and the broad
energ... | 0202392v1 |
2002-03-05 | The Reddest Quasars II. A gravitationally-lensed FeLoBAL quasar | We report the discovery of a z=2.65 low-ionization iron broad absorption line
quasar, FIRST J100424.9+122922, which is gravitationally-lensed by a galaxy at
z~0.95. The object was discovered as part of a program to find very red quasars
by matching the FIRST radio survey with the 2-MASS near-infrared survey.
J100424.9+... | 0203065v1 |
2002-04-03 | Characterising the complex absorber in NGC 4151 | We present a detailed analysis of the complex absorption apparent in the 2-6
keV X-ray spectrum of the bright nearby Seyfert galaxy NGC 4151. We first
utilize the large bandpass and medium spectral resolution afforded by BeppoSAX
data to construct a 1-100 keV spectral template, which assumes the absorption
arises in bo... | 0204057v2 |
2002-06-20 | Membership, metallicity and lithium abundances for solar-type stars in NGC 6633 | We present spectroscopic observations of candidate F, G and K type stars in
NGC 6633, an open cluster with a similar age to the Hyades. We identify 10 new
cluster members including one short period binary system. Combining this survey
with that of Jeffries (1997), we identify a total of 30 solar-type members. We
have u... | 0206367v1 |
2002-08-08 | BeppoSAX observations of the EXS 1737.9-2952 region II: Analysis of sources | (Abridged) Spectral and time variability analysis of the region of the hard
X-ray transient EXS 1737.9-2952 near the Galactic Centre (GC), using data from
the Narrow Field Instruments of BeppoSAX is reported. The main results are the
MECS spectra of the 10 identified sources. Fluxes obtained with spectral fits
are 1.7-... | 0208179v1 |
2002-08-22 | Chemical Abundances in Twelve Red Giants of the Large Magellanic Cloud from High-Resolution Infrared Spectroscopy | High-resolution infrared spectra (R=50,000) have been obtained for twelve
red-giant members of the LMC with the Gemini South 8.3-meter telescope plus
Phoenix spectrometer. Quantitative chemical abundances of carbon-12, carbon-13,
nitrogen-14, and oxygen-16 were derived from molecular lines of CO, CN, and OH,
while sodi... | 0208417v1 |
2002-10-10 | Abundances in Stars from the Red Giant Branch Tip to Near the Main Sequence Turn Off in M5 | We present the iron abundance and abundance ratios for 18 elements with
respect to Fe in a sample of stars with a wide range in luminosity from
luminous giants to stars near the turnoff in the globular cluster M5. The
analyzed spectra, obtained with HIRES at the Keck Observatory, are of high
dispersion (R=35,000). We f... | 0210245v1 |
2003-02-24 | XMM-NEWTON High Resolution Spectroscopy of NGC 5548 | We analyze a 137 ks exposure X-ray spectrum of the Seyfert 1 galaxy NGC 5548
obtained with the XMM-Newton Reflection Grating Spectrometer. Due to the long
exposure time, the spectrum is of higher statistical quality than the previous
observations of this AGN. Therefore, we detect for the first time in NGC 5548
inner-sh... | 0302493v1 |
2003-03-03 | XMM-Newton and Chandra Observations of the Galaxy Group NGC 5044. II. Metal Abundances and Supernova Fraction | Using new XMM and Chandra observations we present an analysis of the metal
abundances of the hot gas within a radius of 100 kpc of the bright nearby
galaxy group NGC 5044. Motivated by the inconsistent abundance and temperature
determinations obtained by different observers for X-ray groups, we provide a
detailed inves... | 0303054v2 |
2003-04-01 | Near-IR Properties of Galaxy Clusters: Luminosity as a Binding Mass Predictor and the State of Cluster Baryons | We explore the near-infrared properties of galaxies within 27 galaxy clusters
using data from the Two Micron All Sky Survey (2MASS). For a subsample of 13
clusters with available X-ray imaging data, we examine both the properties of
the galaxies and the intracluster medium. We show that the K-band luminosity is
correla... | 0304033v2 |
2003-04-09 | Peculiar Broad Absorption Line Quasars found in DPOSS | With the recent release of large (i.e., > hundred million objects),
well-calibrated photometric surveys, such as DPOSS, 2MASS, and SDSS,
spectroscopic identification of important targets is no longer a simple issue.
In order to enhance the returns from a spectroscopic survey, candidate sources
are often preferentially ... | 0304166v1 |
2003-04-11 | The Contribution of Particle Impact to the Production of Fe K Emission from Accreting Black Holes | The iron K line is perhaps the most important spectral diagnostic available
in the study of accreting black holes. The line is thought to result from the
reprocessing of external X-rays by the surface of the accretion disk. However,
as is observed in the solar corona, illumination by energetic particles may
also produc... | 0304218v1 |
2003-04-14 | BeppoSAX Observations of Centaurus A: the Hard Continuum and the Iron Line Feature | The radio galaxy Centaurus A was observed by the BeppoSAX satellite five
times from 1997 to 2000. From July 6 1999 to August 17 1999, the source was
also simultaneously pointed by COMPTEL on-board of the satellite CGRO.
Centaurus A has a complex spectrum with multiple extended components and a
strongly absorbed (N_H\si... | 0304244v1 |
2003-06-13 | Abundances in the Neutral Interstellar Medium of I Zw 18 from FUSE Observations | We report on new FUSE far-UV spectroscopy of the most metal-poor blue compact
dwarf galaxy I Zw 18. The new data represent an improvement over previous FUSE
spectra by a factor of 1.7 in the signal-to-noise. Together with a larger
spectral coverage (917-1188 angstroms), this allows us to characterize
absorption lines i... | 0306290v1 |
2003-06-17 | Kinetic equilibrium of iron in the atmospheres of cool stars III. The ionization equilibrium of selected reference stars | Non-LTE line formation calculations of Fe I are performed for a small number
of reference stars to investigate and quantify the efficiency of neutral
hydrogen collisions. Using the atomic model that was described in previous
publications, the final discrimination with respect to hydrogen collisions is
based on the cond... | 0306337v1 |
2003-08-01 | Variations in the Abundance Pattern of Extremely Metal-poor Stars and Nucleosynthesis in Population III Supernovae | We calculate nucleosynthesis in Population (Pop) III supernovae (SNe) and
compare the yields with various abundance patterns of extremely metal-poor
(EMP) stars. We assume that the observed EMP stars are the second generation
stars, which have the metal-abundance patterns of Pop III SNe. Previous
theoretical yields of ... | 0308029v3 |
2003-11-24 | Sulphur and zinc abundances in Galactic stars and damped Lyman-alpha systems | High resolution spectra of 34 halo population dwarf and subgiant stars have
been obtained with VLT/UVES and used to derive sulphur abundances from the
8694.0, 8694.6 A and 9212.9, 9237.5 A SI lines. In addition, iron abundances
have been determined from 19 FeII lines and zinc abundances from the 4722.2,
4810.5 ZnI line... | 0311529v1 |
2004-01-21 | First Stellar Abundances in the Dwarf Irregular Galaxy Sextans A | We present the abundance analyses of three isolated A-type supergiant stars
in the dwarf irregular galaxy Sextans A from high-resolution spectra the UVES
spectrograph at the VLT. Detailed model atmosphere analyses have been used to
determine the stellar atmospheric parameters and the elemental abundances of
the stars. ... | 0401411v1 |
2004-03-15 | Raising the Dead: Clues to Type Ia Supernova Physics from the Remnant 0509-67.5 | We present Chandra X-ray observations of the young supernova remnant (SNR)
0509-67.5 in the Large Magellanic Cloud (LMC), believed to be the product of a
Type Ia supernova (SN Ia). The remnant is very round in shape, with a distinct
clumpy shell-like structure. Our Chandra data reveal the remnant to be rich in
silicon,... | 0403343v2 |
2004-04-20 | XMM-Newton EPIC observations of 21 low-redshift PG quasars | We present an X-ray spectral analysis of 21 low redshift quasars observed
with XMM-Newton EPIC. All the sources are Palomar Green quasars with redshifts
between 0.05 and 0.4 and have low Galactic absorption along the line-of-sight.
A large majority of quasars in the sample (19/21) exhibit a significant soft
excess belo... | 0404385v1 |
2004-08-23 | Detectability of GRB Iron Lines by Swift, Chandra and XMM | The rapid acquisition of positions by the upcoming Swift satellite will allow
the monitoring for X-ray lines in GRB afterglows at much earlier epochs than
was previously feasible. We calculate the possible significance levels of iron
line detections as a function of source redshift and observing time after the
trigger,... | 0408414v3 |
2005-02-16 | The FUSE Spectrum of the Planetary Nebula SwSt 1: Evidence for Inhomogeneities in the Gas and Dust | [Abridged] We present Far Ultraviolet Spectroscopic Explorer (FUSE)
observations of the young, compact planetary nebula (PN) SwSt 1 along the line
of sight to its central star HD 167362. We detect circumstellar absorption
lines from several species against the continuum of the central star. The
physical parameters of t... | 0502321v1 |
2005-08-18 | Spectroscopic abundance analysis of dwarfs in young open cluster IC 4665 | We report a detailed spectroscopic abundance analysis for a sample of 18 F-K
dwarfs of the young open cluster IC 4665. Stellar parameters and element
abundances of Li, O, Mg, Si, Ca, Ti, Cr, Fe and Ni have been derived using the
spectroscopic synthesis tool SME (Spectroscopy Made Easy). Within the
measurement uncertain... | 0508387v1 |
2005-12-20 | Elemental Abundance Survey of The Galactic Thick Disk | [Abridged abstract] We have performed an abundance analysis for 176 F- and G-
dwarfs of the Galactic thick disk component. Using accurate radial velocities
combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic
orbital parameters were computed. We estimate the probability for a star to
belong to th... | 0512505v1 |
2006-01-20 | The Hamburg/ESO R-process Enhanced Star survey (HERES) III. HE 0338-3945 and the formation of the r+s stars | We have derived abundances of 33 elements and upper limits for 6 additional
elements for the metal-poor ([Fe/H] = -2.42) turn-off star HE 0338-3945 from
high-quality VLT-UVES spectra. The star is heavily enriched, by about a factor
of 100 relative to iron and the Sun, in the heavy s-elements (Ba, La, ..). It
is also he... | 0601476v1 |
2006-02-27 | Chemical evolution in Sersic 159-03 observed with XMM-Newton | Using a new long X-ray observation of the cluster of galaxies Sersic 159-03
with XMM-Newton, we derive radial temperature and abundance profiles using
single- and multi-temperature models. The fits to the EPIC and RGS spectra
prefer multi-temperature models especially in the core. The radial profiles of
oxygen and iron... | 0602582v1 |
2006-03-10 | Metal Enrichment of the ICM: a 3-D Picture of Chemical and Dynamical Properties | We develop a model for the metal enrichment of the intracluster medium (ICM)
that combines a cosmological non-radiative hydrodynamical N-Body/SPH simulation
of a cluster of galaxies, and a semi-analytic model of galaxy formation. The
novel feature of our hybrid model is that the chemical properties of the
diffuse gas i... | 0603270v1 |
2006-04-05 | Abundance analysis of 5 early-type stars in the young open cluster IC2391 | It is unclear whether chemically peculiar stars of the upper main sequence
represent a class completely distinct from normal A-type stars, or whether
there exists a continuous transition from the normal to the most peculiar late
F- to early B-type stars. A systematic abundance analysis of open cluster
early-type stars ... | 0604100v1 |
2006-06-20 | Diffuse, Non-Thermal X-ray Emission from the Galactic Star Cluster Westerlund 1 | We present the diffuse X-ray emission identified in Chandra observations of
the young, massive Galactic star cluster Westerlund 1. After removing
point-like X-ray sources down to a completeness limit of 2e31 erg/s, we
identify 3e34 erg/s (2--8 keV) of diffuse emission. The spatial distribution of
the emission can be de... | 0606492v1 |
2006-08-06 | The magnetic Bp star 36 Lyncis, II. A spectroscopic analysis of its co-rotating disk | We report on the physical properties of the disk-like structure of B8 IIIp
star 36 Lyncis from line syntheses of phase-resolved, high resolution spectra
obtained from the IUE archives and from newly obtained ground-based H$\alpha$
spectra. This disk is highly inclined to the rotational axis and betrays its
existence ev... | 0608134v1 |
2006-09-14 | Evidence for relativistic features in the X-ray spectrum of Mrk 335 | We present an analysis of hard X-ray features in the spectrum of the bright
Sy 1 galaxy Mrk 335 observed by the XMM-Newton satellite. Our analysis confi
rms the presence of a broad, ionised iron Kalpha emission line in the spectrum,
first found by Gondoin et al. The broad line can be modeled successfully by
relativisti... | 0609414v1 |
2006-09-20 | Type Ia Supernova Light Curves | The diversity of Type Ia supernova (SN Ia) photometry is explored using a
grid of 130 one-dimensional models. It is shown that the observable properties
of SNe Ia resulting from Chandrasekhar-mass explosions are chiefly determined
by their final composition and some measure of ``mixing'' in the explosion. A
grid of fin... | 0609562v1 |
2006-10-09 | First stars VII. Lithium in extremely metal poor dwarfs | Aims. This study aims to determine the level and constancy of the Spite
plateau as definitively as possible from homogeneous high-quality VLT-UVES
spectra of 19 of the most metal-poor dwarf stars known. Methods. Our
high-resolution (R ~ 43000), high S/N spectra are analysed with OSMARCS 1D LTE
model atmospheres and tur... | 0610245v2 |
2006-10-10 | A longer XMM-Newton look at I Zwicky 1: Variability of the X-ray continuum, absorption, and iron Kalpha line | We present the second XMM-Newton observation (85 ks) of the narrow-line
Seyfert 1 galaxy (NLS1) I Zw 1 and describe its mean spectral and timing
characteristics. On average, I Zw 1 is ~35 per cent dimmer in 2005 than in the
shorter (20 ks) 2002 observation. Between the two epochs the intrinsic
absorption column density... | 0610283v2 |
2006-10-13 | Revealing the High Energy Emission from the Obscured Seyfert Galaxy MCG -5-23-16 with Suzaku | We report on a 100 ks Suzaku observation of the bright, nearby (z=0.008486)
Seyfert 1.9 galaxy MCG -5-23-16. The broad-band (0.4-100 keV) X-ray spectrum
allows us to determine the nature of the high energy emission with little
ambiguity. The X-ray continuum consists of a cutoff power-law of photon index
$\Gamma=1.9$, a... | 0610434v1 |
2006-11-15 | The broad band spectrum and variability of NGC 4151 observed by BeppoSAX | We present an analysis of all SAX observations of NGC 4151. This source was
observed 5 times from 1996 to 2001 with durations ranging from a day to four
days. The intrinsic continuum, is absorbed at low energies by a complex system:
a cold patchy absorber plus a warm uniform screen photoionized by the central
continuum... | 0611470v1 |
2006-12-18 | An XMM-Newton view of the X-ray flat radio-quiet quasar PG 1416-129 | (abridged) The radio-quiet quasar PG1416-129 (z=0.129) exhibits atypical
optical and X-ray properties. Between 1990 and 2000, in response to its optical
continuum decrease, the ``classical'' broad component of Hbeta almost
completely disappeared, with a factor of 10 decrease in the line flux. In the
X-ray band, this ob... | 0612485v1 |
2006-12-21 | Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits | To aid in the physical interpretation of planetary radii constrained through
observations of transiting planets, or eventually direct detections, we compute
model radii of pure hydrogen-helium, water, rock, and iron planets, along with
various mixtures. Masses ranging from 0.01 Earth masses to 10 Jupiter masses at
orbi... | 0612671v4 |
2007-01-05 | A High-Abundance Arc in the Compact Group of Galaxies HCG 62: An AGN- or Merger-Induced Metal Outflow? | We present a Chandra study of the metal distribution in the X-ray bright
compact group of galaxies HCG 62. We find that the diffuse X-ray emission is
peaked at the core of the central galaxy NGC 4778, and is dominated by the
contribution of the hot gas. The diffuse emission is roughly symmetric within
\simeq0.25^{\prim... | 0701119v1 |
2007-03-16 | Coronal Abundances in Orion Nebula Cluster Stars | Following the Chandra Orion Ultradeep Project (COUP) observation, we have
studied the chemical composition of the hot plasma in a sample of 146 X-ray
bright pre-main sequence stars in the Orion Nebula Cluster. We report
measurements of individual element abundances for a subsample of 86
slightly-absorbed and bright X-r... | 0703439v1 |
2002-03-15 | Distribution of carbon atoms in iron-carbon fcc phase: an experimental and theoretical study | This paper presents an experimental and theoretical study of the distribution
of carbon atoms in the octahedral interstitial sites of the face-centered cubic
(fcc) phase of the iron-carbon system. The experimental part of the work
consists of Mossbauer measurements in Fe-C alloys with up to about 12 atomic
percent C, w... | 0203327v1 |
1998-09-16 | Slow Magnetic Monopole: Interaction with Matter and New Possibility of Their Detection | The possibility of existence of a magnetic monopole has been surveyed by P.
Dirac even in 1931, and then from the point of view of the modern theory by
A.M. Polyakov and G.~ 'tHooft in 1974. Numerous and unsuccessful attempts of
experimental search for monopole in cosmic rays and on accelerators in high
energy particle... | 9809420v3 |
2004-06-08 | Three-Neutrino Oscillations of Atmospheric Neutrinos, theta13, Neutrino Mass Hierarchy and Iron Magnetized Detectors | We derive predictions for the Nadir angle (theta_n) dependence of the ratio
Nmu-/Nmu+ of the rates of the mu- and mu+ multi-GeV events, and for the mu- -
mu+ event rate asymmetry, A_{mu-mu+}=[Nmu- - Nmu+]/[Nmu- + Nmu+], in
iron-magnetized calorimeter detectors (MINOS, INO) in the case of 3-neutrino
oscillations of the ... | 0406096v1 |
2007-05-16 | Viscous Torque and Dissipation in the Inner Region of a Thin Accretion Disk: Implications for Measuring Black Hole Spin | We consider a simple Newtonian model of a steady accretion disk around a
black hole. The model is based on height-integrated hydrodynamic equations,
alpha-viscosity, and a pseudo-Newtonian potential that results in an innermost
stable circular orbit (ISCO) that closely approximates the one predicted by GR.
We find that... | 0705.2244v3 |
2007-06-08 | The Merger in Abell 576: A Line of Sight Bullet Cluster? | Using a combination of Chandra and XMM observations, we confirmed the
presence of a significant velocity gradient along the NE/E-W/SW direction in
the intracluster gas of the cluster Abell 576. The results are consistent with
a previous ASCA SIS analysis of this cluster. The error weighted average over
ACIS-S3, EPIC MO... | 0706.1073v1 |
2007-06-07 | An X-ray Spectral Analysis of the Central Regions of NGC 4593 | We present a detailed analysis of XMM-Newton EPIC-pn data for the Seyfert-1
galaxy NGC 4593. We discuss the X-ray spectral properties of this source as
well as its variations with time. The 0.5-10 keV spectrum shows significant
complexity beyond a simple power-law form, with clear evidence existing for a
"soft excess" ... | 0706.1083v1 |
2007-06-15 | High-resolution FUSE and HST ultraviolet spectroscopy of the white dwarf central star of Sh 2-216 | LS V +4621 is the DAO-type central star of the planetary nebula Sh 2-216. We
perform a comprehensive spectral analysis of high-resolution, high-S/N
ultraviolet observations obtained with FUSE and STIS aboard the HST as well as
the optical spectrum of LS V +4621 by means of state-of-the-art NLTE
model-atmosphere techniq... | 0706.2256v1 |
2007-08-09 | Suzaku wide-band X-ray Spectroscopy of the Seyfert 2 AGN in NGC 4945 | Suzaku observed a nearby Seyfert 2 galaxy NGC4945, which hosts one of the
brightest active galactic nuclei above 20 keV. Combining data from the X-ray
CCD camera (XIS) and the Hard X-ray Detector (HXD), the AGN intrinsic nuclear
emission and its reprocessed signals were observed simultaneously. The
intrinsic emission i... | 0708.1201v1 |
2007-09-05 | Atomic Diffusion and Mixing in Old Stars I. VLT/FLAMES-UVES Observations of Stars in NGC 6397 | We present a homogeneous photometric and spectroscopic analysis of 18 stars
along the evolutionary sequence of the metal-poor globular cluster NGC 6397
([Fe/H] = -2), from the main-sequence turnoff point to red giants below the
bump. The spectroscopic stellar parameters, in particular stellar-parameter
differences betw... | 0709.0639v1 |
2007-12-20 | Comparing Suzaku and XMM-Newton Observations of the Soft X-ray Background: Evidence for Solar Wind Charge Exchange Emission | We present an analysis of a pair of Suzaku spectra of the soft X-ray
background (SXRB), obtained from pointings on and off a nearby shadowing
filament in the southern Galactic hemisphere. Because of the different Galactic
column densities in the two pointing directions, the observed emission from the
Galactic halo has ... | 0712.3538v1 |
2008-01-08 | GMASS Ultradeep Spectroscopy of Galaxies at redshift z~2. I. The stellar metallicity | Context: Galaxy metallicities have been measured to redshift z~2 by gas-phase
oxygen abundances of the interstellar medium using the R23 and N2 methods.
Galaxy stellar metallicities provide crucial data for chemical evolution models
but have not been assessed reliably much outside the local Universe. Aims: We
determine... | 0801.1193v1 |
2008-03-10 | X-ray absorption in distant type II QSOs | We present the results of the X-ray spectral analysis of an
XMM-Newton-selected type II QSO sample with z>0.5 and 0.5-10 keV flux of 0.3-33
x 10^{-14} erg/s/cm^2. The distribution of absorbing column densities in type
II QSOs is investigated and the dependence of absorption on X-ray luminosity
and redshift is studied.
... | 0803.1440v1 |
2008-04-06 | V2051 Oph after superoutburst: out-of-plane material and the superhump light source | We performed a detailed spectroscopic analysis of the dwarf nova V2051 Oph at
the end of its 1999 superoutburst. We studied and interpreted the simultaneous
behaviour of various emission lines.
We obtained high-resolution echelle spectroscopic data at ESO's NTT with
EMMI, covering the spectral range of 4000--7500 Ang... | 0804.0898v1 |
2008-08-18 | On the nature of unabsorbed Seyfert 2 galaxies | We present an analysis of six 12 um selected Seyfert 2 galaxies that have
been reported to be unabsorbed in the X-ray. By comparing the luminosities of
these galaxies in the mid-IR (12um), optical ([O III]) and hard X-ray (2-10
keV), we show that they are all under-luminous in the 2-10 keV X-ray band. Four
of the objec... | 0808.2385v1 |
2008-09-12 | Absorption features in the spectra of X-ray bursting neutron stars | The discovery of photospheric absorption lines in XMM-Newton spectra of the
X-ray bursting neutron star in EXO0748-676 by Cottam and collaborators allows
us to constrain the neutron star mass-radius ratio from the measured
gravitational redshift. A radius of R=9-12km for a plausible mass range of
M=1.4-1.8Msun was deri... | 0809.2170v2 |
2008-10-02 | Detection of blueshifted emission and absorption and a relativistic Iron line in the X-ray spectrum of ESO 323-G077 | We report on the X-ray observation of the Seyfert 1 ESO323-G077 performed
with XMM-Newton. The spectra show a complex spectrum with conspicuous
absorption and emission features. The continuum emission can be modelled with a
power law with an index of 1.99+/-0.02 in the whole XMM-Newton energy band,
marginally consisten... | 0810.0513v1 |
2008-12-04 | The evolution of the Galactic metallicity gradient from high-resolution spectroscopy of open clusters | Open clusters offer a unique possibility to study the time evolution of the
radial metallicity gradients of several elements in our Galaxy, because they
span large intervals in age and Galactocentric distance, and both quantities
can be more accurately derived than for field stars. We re-address the issue of
the Galact... | 0812.0854v1 |
2009-01-29 | Novel Superconducting Characteristics and Unusual Normal-State Properties in Iron-based Pnictide Superconductors: 57Fe-NMR and 75As-NQR/NMR studies in REFeAsO_1-y (RE=La,Pr,Nd) and Ba0.6K0.4Fe2As2 | We discuss the novel superconducting characteristics and unusual normal-state
properties of iron (Fe)-based pnictide superconductors REFeAsO$_{1-y}$
(RE=La,Pr,Nd) and Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$($T_{c}=$ 38 K) by means of
$^{57}$Fe-NMR and $^{75}$As-NQR/NMR. In the superconducting state of
LaFeAsO$_{0.7}$ ($T_{c}=$... | 0901.4607v2 |
2009-02-06 | Effective area calibration of the Reflection Grating Spectrometers of XMM-Newton. I. X-ray spectroscopy of the Crab nebula | The Crab nebula and pulsar have been widely used as a calibration source for
X-ray instruments. The in-flight effective area calibration of the Reflection
Grating Spectrometers (RGS) of XMM-Newton depend upon the availability of
reliable calibration sources. We investigate how the absolute effective area
calibration of... | 0902.1094v1 |
2009-04-09 | Interplay of Rare Earth and Iron magnetism in RFeAsO with R = La, Ce, Pr, and Sm: A muon spin relaxation study and symmetry analysis | We report zero field muon spin relaxation (muSR) measurements on RFeAsO with
R = La, Ce, Pr, and Sm. We study the interaction of the FeAs and R (rare earth)
electronic systems in the non superconducting magnetically ordered parent
compounds of RFeAsO{1-x}Fx superconductors via a detailed comparison of the
local hyperfi... | 0904.1563v3 |
2009-04-17 | Pnictogen height as a possible switch between high-T_c nodeless and low-T_c nodal pairings in the iron based superconductors | We study the effect of the lattice structure on the spin-fluctuation mediated
superconductivity in the iron pnictides adopting the five-band models of
several virtual lattice structures of LaFeAsO as well as actual materials such
as NdFeAsO and LaFePO obtained from the maximally-localized Wannier orbitals.
Random phase... | 0904.2612v2 |
2009-05-27 | The detection of Broad Iron K and L line emission in the Narrow-Line Seyfert 1 Galaxy 1H0707-495 using XMM-Newton | Since the discovery of the first broad iron-K line in 1995 from the Seyfert
Galaxy MCG--6-30-15, broad iron-K lines have been found in several other
Seyfert galaxies, from accreting stellar mass black holes and even from
accreting neutron stars. The iron-K line is prominent in the reflection
spectrum created by the har... | 0905.4383v1 |
2009-06-19 | Dynamical Mean-Field Theory within an Augmented Plane-Wave Framework: Assessing Electronic Correlations in the Iron Pnictide LaFeAsO | We present an approach that combines the local density approximation (LDA)
and the dynamical mean-field theory (DMFT) in the framework of the
full-potential linear augmented plane waves (FLAPW) method. Wannier-like
functions for the correlated shell are constructed by projecting local orbitals
onto a set of Bloch eigen... | 0906.3735v2 |
2009-07-17 | Composition and fate of short-period super-Earths: The case of CoRoT-7b | The discovery of CoRoT-7b, a planet of radius 1.68 +/- 0.09 R_E, mass 4.8 +/-
0.8 M_E and orbital period of 0.854 days demonstrates that small planets can
orbit extremely close to their star. We use knowledge of hot Jupiters, mass
loss estimates and models for the interior structure and evolution of planets
to understa... | 0907.3067v2 |
2009-08-17 | Role of emission angular directionality in spin determination of accreting black holes with broad iron line | Spin of an accreting black hole can be determined by spectroscopy of the
emission and absorption features produced in the inner regions of an accretion
disc. We discuss the method employing the relativistic line profiles of iron in
the X-ray domain, where the emergent spectrum is blurred by general
relativistic effects... | 0908.2387v4 |
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