source stringclasses 1
value | date int32 2k 2k | text stringlengths 200 2.03k | token_count int32 35 594 | category stringclasses 1
value |
|---|---|---|---|---|
arxiv_abstracts_gfissore | 2,002 | Selfgravity and QSO disks
It is well known that the outer parts of QSO accretion disks are prone to
selfgravity if heated solely by orbital dissipation. Such disks might be
expected to form stars rather than accrete onto the black hole. The arguments
leading to this conclusion are reviewed. Conversion of a part of the... | 310 | academic |
arxiv_abstracts_gfissore | 2,002 | Synergistic warm inflation
We consider an alternative warm inflationary scenario in which n scalar
fields coupled to a dissipative matter fluid cooperate to produce power--law
inflation. The scalar fields are driven by an exponential potential and the
bulk dissipative pressure coefficient is linear in the expansion ra... | 160 | academic |
arxiv_abstracts_gfissore | 2,002 | The Observational Case for Jupiter Being a Typical Massive Planet
We identify a subsample of the recently detected extrasolar planets that is
minimally affected by the selection effects of the Doppler detection method.
With a simple analysis we quantify trends in the surface density of this
subsample in the period - M... | 158 | academic |
arxiv_abstracts_gfissore | 2,002 | Centimeter searches for molecular line emission from high-redshift
galaxies
We consider the capabilities for detecting low order CO emission lines from
high-z galaxies using the next generation of radio telescopes operating at 22
and 43 GHz. We employ models for the evolution of dusty star forming galaxies
based on s... | 342 | academic |
arxiv_abstracts_gfissore | 2,002 | High time resolution observations of the January 2000 glitch in the Vela
pulsar
Pulsars are rotating neutron stars, sweeping the emission regions from the
magnetic poles across our line of sight. Isolated neutron stars lose angular
momentum through dipole radiation and (possibly) particle winds, hence they
slow down ... | 294 | academic |
arxiv_abstracts_gfissore | 2,002 | Measuring the Virial Masses of Disk Galaxies
I present detailed models for the formation of disk galaxies, and investigate
which observables are best suited as virial mass estimators. Contrary to naive
expectations, the luminosities and circular velocities of disk galaxies are
extremely poor indicators of total virial... | 123 | academic |
arxiv_abstracts_gfissore | 2,002 | Heat expansion of star-like cosmic objects induced by the cosmological
expansion
The heat expansion of a star-like cosmic object, induced by the cosmological
bremsheat production within a moving body, that was predicted by the Projective
Unified field Theoriy of the author, is approximately treated. The difference
to... | 107 | academic |
arxiv_abstracts_gfissore | 2,002 | Identification of Galactic Wind Candidates using Excitation Maps:
Tunable-Filter Discovery of a Shock-Excited Wind in the Galaxy NGC 1482
Multi-line imaging of the nearby disk galaxy NGC 1482 with the Taurus Tunable
Filter (TTF) on the Anglo-Australian Telescope reveals a remarkable
hourglass-shaped [N II] 6583/H-alp... | 300 | academic |
arxiv_abstracts_gfissore | 2,002 | SiO chimneys and supershells in M82
In this Letter we present the first images of the emission of SiO and H13CO+
in the nucleus of the starburst galaxy M82. Contrary to other molecular species
that mainly trace the distribution of the star-forming molecular gas within the
disk, the SiO emission extends noticeably out ... | 286 | academic |
arxiv_abstracts_gfissore | 2,002 | Radial structure of galactic stellar disks
We present the results from our deep optical imaging survey _lim=26-27
V-mag/arcsec^2 of a morphologically selected sample of 72 edge-on disk
galaxies. The question of the global structure of galactic stellar disks,
especially the radial surface brightness profile at large ga... | 163 | academic |
arxiv_abstracts_gfissore | 2,002 | Ultra Compact Objects in the Fornax Cluster of Galaxies: Globular
clusters or dwarf galaxies?
The relation between the Ultra Compact Objects (UCOs) recently discovered in
the Fornax cluster (Drinkwater et al. 2000, Hilker et al. 1999) and the
brightest globular clusters associated with the central galaxy NGC 1399 has... | 308 | academic |
arxiv_abstracts_gfissore | 2,002 | Measuring the properties of extragalactic dust and implications for the
Hubble diagram
Scattering and absorption of light by a homogeneous distribution of
intergalactic large dust grains has been proposed as an alternative,
non-cosmological explanation for the faintness of Type Ia supernovae at z im
0.5 . We investig... | 238 | academic |
arxiv_abstracts_gfissore | 2,002 | On the Optimization of Broad-Band Photometry for Galaxy Evolution
Studies
We have derived the uncertainties to be expected in the derivation of galaxy
physical properties (star formation history, age, metallicity, reddening) when
comparing broad-band photometry to the predictions of evolutionary synthesis
models. We ... | 366 | academic |
arxiv_abstracts_gfissore | 2,002 | Determination of stellar parameters with GAIA
The GAIA Galactic survey satellite will obtain photometry in 15 filters of
over 10^9 stars in our Galaxy across a very wide range of stellar types. No
other planned survey will provide so much photometric information on so many
stars. I examine the problem of how to determ... | 312 | academic |
arxiv_abstracts_gfissore | 2,002 | When did the Large Elliptical Galaxies Form?
The simple reading of the evidence is that the large elliptical galaxies
existed at about the present star mass and comoving number density at redshift
z=2. This is subject to the usual uncertainties of measurement and
interpretation in astronomy, but should be taken seriou... | 97 | academic |
arxiv_abstracts_gfissore | 2,002 | The Light Curve of S Andromedae
Historical observations of S And, in combination with the color versus
rate-of-decline relationship for well-observed SN 1991bg-like supernovae, are
used to estimate a rate of decline Delta m15 (B) = 2.21 and an intrinsic color
at maximum [B(0) - V(0)]o = 1.32 for SN 1885A. | 94 | academic |
arxiv_abstracts_gfissore | 2,002 | The stellar velocity dispersion of the lens galaxy in MG2016+112 at
z=1.004
We present a direct measurement of the stellar velocity dispersion of the
early-type lens galaxy D in the system MG2016+112 (z=1.004), determined from a
spectrum obtained with the Echelle Spectrograph and Imager (ESI) on the W.M.
Keck-II Tele... | 426 | academic |
arxiv_abstracts_gfissore | 2,002 | Evidence for Nearby Supernova Explosions
Supernova explosions are one of the most energetic--and potentially
lethal--phenomena in the Universe. Scientists have speculated for decades about
the possible consequences for life on Earth of a nearby supernova, but
plausible candidates for such an event were lacking. Here w... | 209 | academic |
arxiv_abstracts_gfissore | 2,002 | A Coupled Dynamical and Chemical Model of Starless Cores of Magnetized
Molecular Clouds: I. Formulation and Initial Results
We develop a detailed chemical model for the starless cores of strongly
magnetized molecular clouds, with the ambipolar diffusion-driven dynamic
evolution of the clouds coupled to the chemistry ... | 369 | academic |
arxiv_abstracts_gfissore | 2,002 | Holographic Discreteness of Inflationary Perturbations
The holographic entropy bound is used to estimate the quantum-gravitational
discreteness of inflationary perturbations. In the context of scalar inflaton
perturbations produced during standard slow-roll inflation, but assuming that
horizon-scale perturbations ``fr... | 207 | academic |
arxiv_abstracts_gfissore | 2,002 | Observing Quanta on a Cosmic Scale
Our entire galaxy, like all others, originated as a fairly smooth patch of
binding energy, which in turn originated as a single quantum perturbation of
the inflaton field on a subatomic scale during inflation. The best preserved
relic of these perturbations is the anisotropy of the m... | 120 | academic |
arxiv_abstracts_gfissore | 2,002 | Bifurcation for Dynamical Systems of Planet-Belt Interaction
The dynamical systems of planet-belt interaction are studied by the
fixed-point analysis and the bifurcation of solutions on the parameter space is
discussed. For most cases, our analytical and numerical results show that the
locations of fixed points are de... | 168 | academic |
arxiv_abstracts_gfissore | 2,002 | An artificial meteors database as a test for the presence of weak
showers
We have constructed an artificial meteor database resembling in all details
the real sample collected by the observers of the Comets and Meteors Workshop
in the years 1996-1999. The artificial database includes the sporadic meteors
and also eve... | 191 | academic |
arxiv_abstracts_gfissore | 2,002 | How good are the predictions for oscillation frequencies
We have used available intermediate degree p-mode frequencies for the solar
cycle 23 to check the validity of previously derived empirical relations for
frequency shifts (Jain et al.: 2000, Solar Phys., 192, 487). We find that the
calculated and observed frequen... | 145 | academic |
arxiv_abstracts_gfissore | 2,002 | Variation of solar irradiance and mode frequencies during Maunder
minimum
Using the sunspot numbers reported during the Maunder minimum and the
empirical relations between the mode frequencies and solar activity indices,
the variations in the total solar irradiance and 10.7 cm radio flux for the
period 1645 to 1715 i... | 109 | academic |
arxiv_abstracts_gfissore | 2,002 | Convective intensification of magnetic flux tubes in stellar
photospheres
The convective collapse of thin magnetic flux tubes in the photospheres of
sun-like stars is investigated using realistic models of the superadiabatic
upper convection zone layers of these stars. The strengths of convectively
stable flux tubes ... | 163 | academic |
arxiv_abstracts_gfissore | 2,002 | Imaging and spectroscopy of the faint remnant G 114.3+0.3
We present the first calibrated CCD images of the faint supernova remnant G
114.3+0.3 in the emission lines of [OII], [OIII], Halpha+[NII] and [SII]. The
deep low ionization CCD images reveal diffuse emission in the south and central
areas of the remnant. These... | 300 | academic |
arxiv_abstracts_gfissore | 2,002 | ESO Imaging Survey. Exploring the optical/infrared imaging data of
CDF-S: Point Sources
This paper describes the methodology currently being implemented in the EIS
pipeline for analysing optical/infrared multi-colour data. The aim is to
identify different classes of objects as well as possible undesirable features
as... | 314 | academic |
arxiv_abstracts_gfissore | 2,002 | Patterns in the weak shear 3-point correlation function
We explore the scale and angular dependence of the cosmic shear three-point
correlation function. The shear field is found to have a much more complex
three-point function than the convergence field, but it also exhibits specific
motifs which draw signatures of g... | 202 | academic |
arxiv_abstracts_gfissore | 2,002 | Young close isolated compact objects
We suggest that the seven radio-quiet isolated neutron stars observed with
ROSAT are young cooling objects associated to recent near-by supernova
explosions which formed runaway stars and the Local Bubble, affecting the
topology of the interstellar medium in the vicinity of the Sun... | 129 | academic |
arxiv_abstracts_gfissore | 2,002 | Stellar Orbits Near Sagittarius A*
We present new SHARP/NTT stellar proper motion and accelaration data covering
an interval from 1992 to 2000: 1) We combine the high precision but shorter
time scale NIRC/Keck data with the lower precision but longer time scale
SHARP/NTT data set; 2) We statistically correct the obser... | 367 | academic |
arxiv_abstracts_gfissore | 2,002 | Detection of non-Gaussian Signatures in the VIRMOS-DESCART Lensing
Survey
We have detected non-Gaussian signatures in the VIRMOS-DESCART weak lensing
survey from a measurement of the three-point shear correlation function,
following the method developed by Bernardeau et al. (2002). We obtain a
2.4-sigma signal over f... | 204 | academic |
arxiv_abstracts_gfissore | 2,002 | The Local Interstellar Ultraviolet Radiation Field
I have used the Hipparcos Input Catalog, together with Kurucz model stellar
atmospheres, and information on the strength of the interstellar extinction, to
create a model of the expected intensity and spectral distribution of the local
interstellar ultraviolet radiati... | 239 | academic |
arxiv_abstracts_gfissore | 2,002 | Do Type Ia Supernovae prove Lambda > 0 ?
The evidence for positive cosmological constant from Type Ia
supernovae is reexamined.
Both high redshift supernova teams are found to underestimate the effects of
host galaxy extinction. The evidence for an absolute magnitude- decay time
relation is much weakened if supernova... | 255 | academic |
arxiv_abstracts_gfissore | 2,002 | Obscuring Material around Seyfert Nuclei with Starbursts
The structure of obscuring matter in the environment of active galactic
nuclei with associated nuclear starbursts is investigated using 3-D
hydrodynamical simulations. Simple analytical estimates suggest that the
obscuring matter with energy feedback from supern... | 312 | academic |
arxiv_abstracts_gfissore | 2,002 | On the validity of the discrete ordinates method in spherical geometry
The discrete ordinates method with angular parameters is discussed in light
of the recent extension of its underlying hypothesis. The analysis shows that
the method, although it compares very well with the trajectory of photons
model, it addresses ... | 76 | academic |
arxiv_abstracts_gfissore | 2,002 | Cosmological Implications of Massive Neutrinos
The massive neutrinos gravitational infall and their inprints left on the CMB
temperature and matter density fluctuations power spectra are analysed taking
into account the massive neutrino properties: the mass degeneracy, the phase
space mixing, the lepton asymmetry. | 65 | academic |
arxiv_abstracts_gfissore | 2,002 | The Luminosity Dependence of UV Absorption in AGN
We describe the results of a survey of the UV absorption properties of the
Boroson & Green sample of AGN, which extends from the Seyfert (M_V -21) to
the luminous quasar (M_V -27) level. The survey is based mostly on HST
archival data available for > 1/2 of the 87 samp... | 328 | academic |
arxiv_abstracts_gfissore | 2,002 | A Very Sensitive 21cm Survey for Galactic High-Velocity HI
Very sensitive HI 21cm observations have been made in 860 directions at dec
>= -43deg in search of weak, Galactic, high-velocity HI emission lines at
moderate and high Galactic latitudes. One-third of the observations were made
toward extragalactic objects. Th... | 335 | academic |
arxiv_abstracts_gfissore | 2,002 | A Correlation Between Inclination and Color in the Classical Kuiper Belt
We have measured broadband optical BVR photometry of 24 Classical and
Scattered Kuiper belt objects (KBOs), approximately doubling the published
sample of colors for these classes of objects. We find a statistically
significant correlation betwee... | 264 | academic |
arxiv_abstracts_gfissore | 2,002 | On the formation of massive stars
We calculate numerically the collapse of slowly rotating, non-magnetic,
massive molecular clumps, which conceivably could lead to the formation of
massive stars. Because radiative acceleration on dust grains plays a critical
role in the clump's dynamical evolution, we utilize a wavele... | 327 | academic |
arxiv_abstracts_gfissore | 2,002 | Galaxy morphology in the rich cluster Abell 2390
We have analysed images of the field of A2390 obtained with the CFHT and HST.
The analysis fits models to bulge and disk components to several hundred
galaxies, with about equal samples from the cluster and field. We also have
assessed and graded asymmetries in the imag... | 208 | academic |
arxiv_abstracts_gfissore | 2,002 | H2, D/H and the CMBR Temperature at z = 3.025 Toward QSO 0347-3819
A new molecular hydrogen cloud has been identified at z = 3.025 in the
absorption-line spectrum of the quasar 0347-3819 observed with the UVES
spectrograph at the VLT/Kueyen telescope. At the same redshift numerous metal
lines and the DI Ly-5, Ly-8, Ly... | 366 | academic |
arxiv_abstracts_gfissore | 2,002 | The Chemical Evolution of the Solar Neighbourhood: the Effect of
Binaries
In this paper we compute the time evolution of the elements (4He, 12C, 14N,
16O, 20Ne, 24Mg, 28Si, 32S, 40Ca and 56Fe) and of the supernova rates in the
solar neighbourhood by means of a galactic chemical evolutionary code that
includes in deta... | 369 | academic |
arxiv_abstracts_gfissore | 2,002 | Astrometric Microlensing of Distant Sources due to the Stars in the
Galaxy
We investigate properties of astrometric microlensing of distant sources
(such as QSOs and radio galaxies) caused by stars in the Galaxy, mainly
focusing on application to the VERA (VLBI Exploration of Radio Astrometry)
project. Assuming typic... | 384 | academic |
arxiv_abstracts_gfissore | 2,002 | Self-similar cosmological expansion of collisional gas
We derive similarity solutions for the expansion of negative initial density
perturbations M/M r^-s (s>0) in an Einstein-de Sitter universe
filled with collisional baryonic gas and collisionless matter. The solutions
are obtained for planar, cylindrical, and spher... | 223 | academic |
arxiv_abstracts_gfissore | 2,002 | Quantum-gravity phenomenology with gamma rays and UHE cosmic rays
In recent years several ideas for experimental searches of effects induced by
quantum properties of space-time have been discussed. Some of these ideas
concern the role in quantum spacetime of the ordinary Lorentz symmetry of
classical flat spacetime. D... | 134 | academic |
arxiv_abstracts_gfissore | 2,002 | X-ray transient AGN and galaxies, and why we need new soft X-ray surveys
X-ray transience is the most extreme form of variability observed in AGN or
normal non-active galaxies. While factors of 2-3 on timescales of days to years
are quite common among AGN, X-ray transients appear only once and vanish from
the X-ray sk... | 226 | academic |
arxiv_abstracts_gfissore | 2,002 | Diffraction-limited speckle interferometry and modeling of the
circumstellar envelope of R CrB at maximum and minimum light
We present the first speckle interferometric observations of R CrB, the
prototype of a class of peculiar stars which undergo irregular declines in
their visible light curves. The observations we... | 299 | academic |
arxiv_abstracts_gfissore | 2,002 | Probing the evolution of massive galaxies with the K20 survey
The motivations and the status of the K20 survey are presented. The first
results on the evolution of massive galaxies and the comparison with the
predictions of the currently competing scenarios of galaxy formation are also
discussed. | 57 | academic |
arxiv_abstracts_gfissore | 2,002 | Experimental study of a proximity focusing Cherenkov counter prototype
for the AMS experiment
A study prototype of Proximity Focussing Ring Imaging Cherenkov counter has
been built and tested with several radiators using separately cosmic-ray
particles and 12C beam fragmentation products at several energies. Counter
... | 95 | academic |
arxiv_abstracts_gfissore | 2,002 | Tidally induced radial-velocity variations in close binaries
A theoretical framework for the determination of tidally induced
radial-velocity variations in a component of a close binary is presented. Both
the free and the forced oscillations of the component are treated as linear,
isentropic perturbations of a spheric... | 316 | academic |
arxiv_abstracts_gfissore | 2,002 | Search for star clusters close to the Galactic plane with DENIS
An automated search for star clusters close to the Galactic plane (|b| < 5
deg) was carried out on the Point Source Catalogue of the DENIS survey. 44
the Galactic plane have been observed and calibrated. The method allowed to
retrieve 22 known star cluste... | 137 | academic |
arxiv_abstracts_gfissore | 2,002 | Event rates and timescale distributions from realistic microlensing
models of M31
We provide a set of microlensing event rate maps for M31, the Andromeda
Galaxy. Rates for M31 microlensing were calculated on the basis of a four
component model of the lens and source populations: disk and bulge sources
lensed by bulge... | 199 | academic |
arxiv_abstracts_gfissore | 2,002 | The runaway growth of intermediate-mass black holes in dense star
clusters
We study the growth rate of stars via stellar collisions in dense star
clusters, calibrating our analytic calculations with direct N-body simulations
of up to 65536 stars, performed on the GRAPE family of special-purpose
computers. We find tha... | 232 | academic |
arxiv_abstracts_gfissore | 2,002 | Cosmological implications of old galaxies at high redshifts
Old high- z galaxies are important tools for understanding the structure
formation problem and may become the key to determine the ultimate fate of the
Universe. In this letter, the inferred ages of the three oldest galaxies
at high redshifts reported in the ... | 221 | academic |
arxiv_abstracts_gfissore | 2,002 | The lensing system towards the doubly imaged quasar SBS 1520+530
The gravitational potential responsible for the lensing effect in SBS
1520+530 is studied over length scales from a few arc-seconds to a few
arc-minutes. For this purpose, we use sharply deconvolved Hubble Space
Telescope images in the optical and near-I... | 293 | academic |
arxiv_abstracts_gfissore | 2,002 | Chandra Discovery of a Tree in the X-ray Forest towards PKS 2155-304:
the Local Filament?
We present the first X-ray detection of resonant absorption from warm/hot
local gas either in our Galaxy, or in the Intergalactic space surrounding our
Galaxy, along the line of sight toward the blazar PKS 2155-304. The Chandra
... | 423 | academic |
arxiv_abstracts_gfissore | 2,002 | X-ray sources in the starburst spiral galaxy M83: nuclear region and
discrete source population
Chandra has resolved the starburst nuclear region of the face-on grand-design
spiral M83. Eighty-one point sources are detected above 3.5 sigma in the ACIS
S3 image, and 15 of them are within the inner 16-arcsec region of ... | 450 | academic |
arxiv_abstracts_gfissore | 2,002 | Do the Infrared Emission Features Need Ultraviolet Excitation? The PAH
Model in UV-Poor Reflection Nebulae
One of the major challenges to identification of the 3.3, 6.2, 7.7, 8.6, and
11.3um interstellar IR emission bands with polycyclic aromatic hydrocarbon
(PAH) molecules has been the recent detection of these band... | 401 | academic |
arxiv_abstracts_gfissore | 2,002 | Interstellar scintillation as the origin of rapid radio variability in
the quasar J1819+3845
Quasars shine brightly due to the liberation of gravitational energy as
matter falls onto a supermassive black hole in the centre of a galaxy.
Variations in the radiation received from active galactic nuclei (AGN) are
studied... | 278 | academic |
arxiv_abstracts_gfissore | 2,002 | Bow Shocks from Neutron Stars: Scaling Laws and HST Observations of the
Guitar Nebula
The interaction of high-velocity neutron stars with the interstellar medium
produces bow shock nebulae, where the relativistic neutron star wind is
confined by ram pressure. We present multi-wavelength observations of the
Guitar Neb... | 342 | academic |
arxiv_abstracts_gfissore | 2,002 | The X-ray Spectra of VY Scl Stars Are Not Blackbodies
Using ASCA data, we find, contrary to other researchers using ROSAT data,
that the X-ray spectra of the VY Scl stars TT Ari and KR Aur are poorly fit by
an absorbed blackbody model but are well fit by an absorbed thermal plasma
model. The different conclusions abou... | 275 | academic |
arxiv_abstracts_gfissore | 2,002 | Stellar Velocity Dispersion and Black Hole Mass in the Blazar Markarian
501
The recently discovered correlation between black hole mass and stellar
velocity dispersion provides a new method to determine the masses of black
holes in active galaxies. We have obtained optical spectra of Markarian 501, a
nearby gamma-ray... | 329 | academic |
arxiv_abstracts_gfissore | 2,002 | Low-Luminosity AGNs and Unification
More than one third of all nearby galaxies show indications of low-luminosity
nuclear activity. These low-luminosity AGNs (LLAGNs) are traditionally
classified into a variety of categories depending on their forbidden-line
ratios and on the presence or absence of broad-line emission... | 159 | academic |
arxiv_abstracts_gfissore | 2,002 | The Formation of the First Globular Clusters in Dwarf Galaxies Before
the Epoch of Reionization
We explore a mechanism for the formation of the first globular clusters,
operating during the assembly of dwarf galaxies at high redshifts, z > 10. The
substructure in the dark matter and the corresponding potential wells ... | 213 | academic |
arxiv_abstracts_gfissore | 2,002 | Spectrophotometry and structural analysis of 5 comets
We discuss the morphology and spectrophotometry of 5 comets visible in
August, 2001. We decompose comae into coma profiles and azimuthally
renormalized images, in which general and local features are quantitatively
comparable. Comet 19P/Borrelly showed a strong gas... | 362 | academic |
arxiv_abstracts_gfissore | 2,002 | Do Young Neutron Stars Which Show Themselves As AXPs, SGRs and Radio
Pulsars Accrete?
We examined the fall-back disk models, and in general accretion, proposed to
explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters
(SGRs), and radio pulsars (PSRs). We checked the possibility of some gas
rem... | 201 | academic |
arxiv_abstracts_gfissore | 2,002 | The ROSAT All-Sky Survey: a Catalog of Clusters of Galaxies in a Region
of 1 Ster around the South Galactic Pole
A field of 1.013 ster in the ROSAT all-sky survey (RASS), centered on the
south galactic pole (SGP), has been searched in a systematic, objective manner
for clusters of galaxies. The procedure relied on a ... | 344 | academic |
arxiv_abstracts_gfissore | 2,002 | On the Nature of the X-ray Emission from the Galactic Center Region
The origin of the X-ray emission from the central region of the Galaxy has
remained a mystery, despite extensive study over the past two decades. A
fundamental question is the relative contribution of the point-source and
diffuse components of this em... | 309 | academic |
arxiv_abstracts_gfissore | 2,002 | Chandra Imaging of the Gamma-Ray Source GeV J1809-2327
We report on Chandra imaging observations of the Galactic Unidentified
-ray source GEV J1809-2327, comparing the X-ray images with new VLA
1.46 GHz and 4.86 GHz maps. The X-ray images reveal a point source connected to
a non-thermal X-ray/radio nebula, supporting... | 122 | academic |
arxiv_abstracts_gfissore | 2,002 | Numerical Models of the ISM
I review recent results from numerical simulations on the structure and
dynamics of the ISM, and attempt to put together a coherent dynamical scenario.
In particular, I discuss results on 1) the spatial distribution of the gas
components, showing that reasonable agreement between simulation... | 352 | academic |
arxiv_abstracts_gfissore | 2,002 | Relation of SiO maser emission to IR radiation in evolved stars based on
the MSX observation
Based on the space MSX observation in bands A(8 m), C(12 m),
D(15 m) and E(21 m), and the ground SiO maser observation of evolved
stars by the Nobeyama 45-m telescope in the v=1 and v=2 J=1-0 transitions, the
relation between... | 168 | academic |
arxiv_abstracts_gfissore | 2,002 | A formula for the number of days between the winter solstice and the
latest sunrise
A simple closed-form expression for the number of days between the winter
solstice and the latest sunrise is derived. Formulas for the summer solstice
and the sunset are derived as well. These approximate formulas make it easy to
see ... | 120 | academic |
arxiv_abstracts_gfissore | 2,002 | How much will we learn from the CMB ?
The purpose of this article is to give a brief account of what we hope to
learn from the future CMB experiments, essentially from the point of view of
primordial cosmology. After recalling what we have already learnt, the
principles of parameter extraction from the data are summar... | 108 | academic |
arxiv_abstracts_gfissore | 2,002 | Scaling Relation to Understand Non-Detection of Cold Gas at the Cluster
Center
Recent XMM-Newton observations of clusters of galaxies have indicated the
soft X-ray spectra to be inconsistent with the simple isobaric cooling flow
model. There is almost no feature of the cold gas expected from the model. This
shows tha... | 161 | academic |
arxiv_abstracts_gfissore | 2,002 | Observations of SiO Maser Sources within a Few Parsec from the Galactic
Center
Mapping and monitoring observations of SiO maser sources near the Galactic
center were made with the Nobeyama 45-m telescope at 43 GHz. Rectangular
mapping an area of approximately 200'' x 100''$ in a 30'' grid, and triangular
mapping in a... | 382 | academic |
arxiv_abstracts_gfissore | 2,002 | Confidence Limits of Evolutionary Synthesis Models
The probabilistic nature of the IMF in stellar systems implies that clusters
of the same mass and age do not present the same unique values of their
observed parameters. Instead they follow a distribution. We address the study
of such distributions in terms of their c... | 148 | academic |
arxiv_abstracts_gfissore | 2,002 | Radio observations of the circumnuclear ring in NGC6951
We present sensitive, high-resolution radio observations of the circumnuclear
region of the barred spiral galaxy NGC6951. These observations reveal a ring of
radio emission with many discrete components and a marginally resolved nuclear
component. We compare the ... | 82 | academic |
arxiv_abstracts_gfissore | 2,002 | X-ray Spectra and Pulse Frequency Changes in SAX J2103.5+4545
The November 1999 outburst of the transient pulsar SAX J2103.5+4545 was
monitored with the large area detectors of the Rossi X-Ray Timing Explorer
until the pulsar faded after a year. The 358 s pulsar was spun up for 150 days,
at which point the flux droppe... | 442 | academic |
arxiv_abstracts_gfissore | 2,002 | The black hole - bulge mass relation in active and inactive galaxies
New virial black-hole mass estimates are presented for a sample of 72 AGN
covering three decades in optical luminosity. Using a model in which the AGN
broad-line region (BLR) has a flattened geometry, we investigate the
M_bh)-L_bulge relation for a c... | 303 | academic |
arxiv_abstracts_gfissore | 2,002 | Physical Properties of Trans-Neptunian Object (20000) Varuna
We present new time-resolved photometric observations of the bright
trans-Neptunian object (20000) Varuna and use them to study the rotation
period, shape, and color. In observations from 2001 February and April, we find
a best-fit two-peaked lightcurve with... | 337 | academic |
arxiv_abstracts_gfissore | 2,002 | Magnetic fields and radio polarization of barred galaxies - 3D dynamo
simulations
A three-dimensional (3D) MHD model is applied to simulate the evolution of a
large-scale magnetic field in a barred galaxy possessing a gaseous halo
extending to about 2.8 kpc above the galactic plane. As the model input we use
a time-d... | 315 | academic |
arxiv_abstracts_gfissore | 2,002 | The time variation in infrared water-vapour bands in Mira variables
The time variation in the water-vapour bands in oxygen-rich Mira variables
has been investigated using multi-epoch ISO/SWS spectra of four Mira variables
in the 2.5-4.0 micron region. All four stars show H2O bands in absorption
around minimum in the v... | 417 | academic |
arxiv_abstracts_gfissore | 2,002 | On Core Collapse Supernovae in Normal and in Seyfert Galaxies
This paper estimates the relative frequency of different types of
core-collapse supernovae, in terms of the ratio f between the number of type
Ib--Ic and of type II supernovae. We estimate f independently for all normal
and Seyfert galaxies whose radial vel... | 302 | academic |
arxiv_abstracts_gfissore | 2,002 | A SAURON study of M32: measuring the intrinsic flattening and the
central black hole mass
We present dynamical models of the nearby compact elliptical galaxy M32,
using high quality kinematical measurements, obtained with the integral-field
spectrograph SAURON mounted on the William Herschel Telescope on La Palma. We... | 257 | academic |
arxiv_abstracts_gfissore | 2,002 | MERLIN radio detection of an interaction zone within a binary Orion
proplyd system
Presented here are high angular resolution MERLIN 5 GHz (6 cm) continuum
observations of the binary proplyd system, LV 1 in the Orion nebula, which
consists of proplyd 168--326SE and its binary proplyd companion 168--326NW
(separation ... | 277 | academic |
arxiv_abstracts_gfissore | 2,002 | Pulsations and orbital modulation of the intermediate polar 1WGA
J1958.2+3232
We present optical photometry, spectroscopy and photopolarimetry, as well as
ASCA X-ray observations, of the recently discovered intermediate polar 1WGA
J1958.2+3232. Through the first detection of an optical beat frequency, we
confirm the ... | 243 | academic |
arxiv_abstracts_gfissore | 2,002 | An AGN Hertzsprung-Russell Diagram
Detailed examination of the balance between star-formation and nuclear
activity in AGN and starburst galaxies leads to the composition of an
Hertzsprung-Russell diagram in which possible evolutionary tracks can be drawn.
It is likely that these tracks also relate to the level of obsc... | 71 | academic |
arxiv_abstracts_gfissore | 2,002 | Chemical Evolution Models of Local dSph Galaxies
We calculate chemical evolution models for 4 dwarf spheroidal satellites of
the Milky Way (Carina, Ursa Minor, Leo I and Leo II) for which reliable
non-parametric star formation histories have been derived. In this way, the
independently obtained star formation historie... | 368 | academic |
arxiv_abstracts_gfissore | 2,002 | ATCA radio imaging of the ProPlyD-like objects in the giant HII region
NGC 3603
Three cometary-shaped objects in the giant HII region NGC 3603, originally
found and identified as proto-planetary disks (ProPlyDs) by Brandner et al.
2000 using HST+VLT in the optical and near-infrared, have been detected with
the Austra... | 299 | academic |
arxiv_abstracts_gfissore | 2,002 | Observational Constraints on the Topology (Global Geometry) of the
Universe
The Universe is a physical object. Physical objects have shapes and sizes.
General relativity is insufficient to describe the global shape and size of the
Universe: the Hilbert-Einstein equations only treat limiting quantities towards
an arbi... | 189 | academic |
arxiv_abstracts_gfissore | 2,002 | Mid-infrared observations of the SGR 1900+14 error box
We report on mid-infrared observations of the compact stellar cluster located
in the proximity of SGR 1900+14, and the radio/X-ray position of this
soft-gamma repeater. Observations were performed in May and June of 2001 when
the bursting source was in an active s... | 124 | academic |
arxiv_abstracts_gfissore | 2,002 | How is the Reionization Epoch Defined?
We study the effect of a prolonged epoch of reionization on the angular power
spectrum of the Cosmic Microwave Background. Typically reionization studies
assume a sudden phase transition, with the intergalactic gas moving from a
fully neutral to a fully ionized state at a fixed r... | 233 | academic |
arxiv_abstracts_gfissore | 2,002 | The Angular Momentum of Gas in Proto-Galaxies I. Implications for the
Formation of Disk Galaxies
We use non-radiative N-body/SPH simulations of structure formation in a LCDM
cosmology to compare the angular momentum distributions of dark matter and gas
in a large sample of halos. We show that the two components have ... | 336 | academic |
arxiv_abstracts_gfissore | 2,002 | Resolving subdwarf B stars in binaries by HST imaging
The origin of subluminous B stars is still an unsolved problem in stellar
evolution. Single star as well as close binary evolution scenarios have been
invoked but until now have met with little success. We have carried out a small
survey of spectroscopic binary can... | 402 | academic |
arxiv_abstracts_gfissore | 2,002 | Search for Supersymmetric Dark Matter with Superfluid He3 (MACHe3)
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for
direct Dark Matter search, using superfluid He3 as a sensitive medium. This
paper presents a phenomenological study done with the DarkSUSY code, in order
to investigate the d... | 100 | academic |
arxiv_abstracts_gfissore | 2,002 | The Initial Mass Function of Stars: Evidence for Uniformity in Variable
Systems
The distribution of stellar masses that form in one star-formation event in a
given volume of space is called the initial mass function (IMF). The IMF has
been estimated from low-mass brown dwarfs to very massive stars. Combining IMF
esti... | 181 | academic |
arxiv_abstracts_gfissore | 2,002 | High Density Neutron Star Equation of State from 4U 1636-53 Observations
A bound on the compactness of the neutron star in the low mass x-ray binary
4U 1636-53 is used to estimate the equation of state of neutron star matter at
high density. Observations of 580 Hz oscillations during the rising phase of
x-ray bursts f... | 192 | academic |
arxiv_abstracts_gfissore | 2,002 | Effects of Relativistic Expansion on the Late-time Supernova Light
Curves
The effects of relativistic expansion on the late-time supernova light curves
are investigated analytically, and a correction term to the (quasi-)exponential
decay is obtained by expanding the observed flux in terms of (), where
() is the maxim... | 318 | academic |
End of preview. Expand in Data Studio
No dataset card yet
- Downloads last month
- 22