Unnamed: 0 int64 0 41k | title stringlengths 4 274 | category stringlengths 5 18 | summary stringlengths 22 3.66k | theme stringclasses 8
values |
|---|---|---|---|---|
6,000 | New knowledge of the Galactic magnetic fields | astro-ph.GA | The magnetic fields of our Milky Way galaxy are the main agent for cosmic
rays to transport. In the last decade, much new knowledge has been gained from
measurements of the Galactic magnetic fields. In the Galactic disk, from the
RMs of a large number of newly discovered pulsars, the large-scale magnetic
fields along t... | physics |
6,001 | Interstellar medium in the M 43 nebula | astro-ph.GA | We present a list of interstellar absorption lines in the direction of HD
37061 in the M 43 nebula. Some of the absorption lines arise from atomic
excited levels that are uncommon in interstellar clouds. The excited levels of
Fe II are populated by fluorescence. We found a large number of H2 molecular
absorption lines ... | physics |
6,002 | PIERNIK mhd code - a multi-fluid, non-ideal extension of the relaxing-TVD scheme (IV) | astro-ph.GA | We present a new multi-fluid, grid MHD code PIERNIK, which is based on the
Relaxing TVD scheme (Jin & Xin, 1995). The original scheme (see Trac & Pen
(2003) and Pen et al. (2003)) has been extended by an addition of dynamically
independent, but interacting fluids: dust and a diffusive cosmic ray gas,
described within t... | physics |
6,003 | Mid-infrared imaging of 25 local AGN with VLT-VISIR | astro-ph.GA | Aims. High angular resolution N-band imaging is used to discern the torus of
active galactic nuclei (AGN) from its environment in order to allow a
comparison of its mid-infrared properties to the expectations of the unified
scenario for AGN. Methods. We present VLT-VISIR images of 25 low-redshift AGN
of different Seyfe... | physics |
6,004 | A Limit on the Polarized Anomalous Microwave Emission of Lynds 1622 | astro-ph.GA | The dark cloud Lynds 1622 is one of a few specific sites in the Galaxy where,
relative to observed free-free and vibrational dust emission, there is a clear
excess of microwave emission. In order to constrain models for this microwave
emission, and to better establish the contribution which it might make to
ongoing and... | physics |
6,005 | Alignment of Dust by Radiative Torque: Recent Developments | astro-ph.GA | Alignment of dust by radiative torques (RATs) has proven to be the most
promising mechanism to explain alignment in various astrophysical environments,
from comet atmospheres to accretion disks, molecular clouds, and diffuse
interstellar gas. We discuss some of the major advances, which include, first
of all, formulati... | physics |
6,006 | Secular evolution and the assembly of bulges | astro-ph.GA | Bulges are of different types, morphologies and kinematics, from
pseudo-bulges, close to disk properties (Sersic index, rotation fraction,
flatenning), to classical de Vaucouleurs bulges, close to elliptical galaxies.
Secular evolution and bar development can give rise to pseudo-bulges. To ensure
prolonged secular evol... | physics |
6,007 | Radiation pressure and absorption in AGN: results from a complete unbiased sample from Swift | astro-ph.GA | Outward radiation pressure can exceed the inward gravitational pull on gas
clouds in the neighbourhood of a luminous Active Galactic Nucleus (AGN). This
creates a forbidden region for long-lived dusty clouds in the observed columnn
density - Eddington fraction plane. (The Eddington fraction lambda_Edd is the
ratio of t... | physics |
6,008 | Locality of MHD Turbulence in Isothermal Disks | astro-ph.GA | We numerically evolve turbulence driven by the magnetorotational instability
(MRI) in a 3D, unstratified shearing box and study its structure using
two-point correlation functions. We confirm Fromang and Papaloizou's result
that shearing box models with zero net magnetic flux are not converged; the
dimensionless shear ... | physics |
6,009 | Imaging the Circumnuclear Region of NGC 1365 with Chandra | astro-ph.GA | We present the first Chandra/ACIS imaging study of the circumnuclear region
of the nearby Seyfert galaxy NGC 1365. The X-ray emission is resolved into
point-like sources and complex, extended emission. The X-ray morphology of the
extended emission shows a biconical soft X-ray emission region extending ~5 kpc
in project... | physics |
6,010 | Loss cone refilling by flyby encounters--A numerical study of massive black holes in galactic centres | astro-ph.GA | A gap in phase-space, the loss cone (LC), is opened up by a supermassive
black hole (MBH) as it disrupts or accretes stars in a galactic centre. If a
star enters the LC then, depending on its properties, its interaction with the
MBH will either generate a luminous electromagnetic flare or give rise to
gravitational rad... | physics |
6,011 | Perturbative reconstruction of a gravitational lens: when mass does not follow light | astro-ph.GA | The structure and potential of a complex gravitational lens is reconstructed
using the perturbative method presented in Alard 2007, MNRAS, 382L, 58; Alard
2008, MNRAS, 388, 375. This lens is composed of 6 galaxies belonging to a small
group. The lens inversion is reduced to the problem of reconstructing
non-degenerate ... | physics |
6,012 | Direct numerical simulations of the galactic dynamo in the kinematic growing phase | astro-ph.GA | We present kinematic simulations of a galactic dynamo model based on the
large scale differential rotation and the small scale helical fluctuations due
to supernova explosions. We report for the first time direct numerical
simulations of the full galactic dynamo using an unparameterized global
approach. We argue that t... | physics |
6,013 | Keck spectroscopic survey of strongly lensed galaxies in Abell 1703: further evidence for a relaxed, unimodal cluster | astro-ph.GA | Strong gravitational lensing is a unique tool to model with great accuracy
the inner mass distribution of massive galaxy clusters. In particular, clusters
with large Einstein radii provide a wealth of multiply imaged systems in the
cluster core allowing to determine precisely the shape of the central dark
matter profil... | physics |
6,014 | Hyperaccreting Neutron-Star Disks and Neutrino Annihilation | astro-ph.GA | Newborn neutron stars surrounded by hyperaccreting and neutrino-cooled disks
may exist in some gamma-ray bursts (GRBs) and/or supernovae (SNe). In this
paper we further study the structure of such a neutron-star disk based on the
two-region (i.e., inner & outer) disk scenario following our previous work, and
calculate ... | physics |
6,015 | Gas and stars in compact (young) radio sources | astro-ph.GA | Gas can be used to trace the formation and evolution of galaxies as well as
the impact that the nuclear activity has on the surrounding medium. For nearby
compact radio sources, we have used observations of neutral hydrogen - that we
detected in emission distributed over very large scales - combined with the
study of t... | physics |
6,016 | Clustering of red galaxies around the z=1.53 quasar 3C270.1 | astro-ph.GA | In the paradigm of hierarchical galaxy formation, luminous radio galaxies
mark mass assembly peaks that should contain clusters of galaxies. Observations
of the z=1.53 quasar 3C270.1 with the Spitzer Space Telescope at 3.6-24 micron
and with the 6.5-m MMT in the z'- and Y-bands allow detection of potential
cluster memb... | physics |
6,017 | The mass-metallicity gradient relation of early-type galaxies | astro-ph.GA | We present a newly observed relation between galaxy mass and radial
metallicity gradients of early-type galaxies. Our sample of 51 early-type
galaxies encompasses a comprehensive mass range from dwarf to brightest cluster
galaxies. The metallicity gradients are measured out to one effective radius by
comparing nearly a... | physics |
6,018 | Luminous buried AGNs as a function of galaxy infrared luminosity revealed through Spitzer low-resolution infrared spectroscopy | astro-ph.GA | We present the results of Spitzer IRS infrared 5-35 micron low-resolution
spectroscopic energy diagnostics of ultraluminous infrared galaxies (ULIRGs) at
z > 0.15, classified optically as non-Seyferts. Based on the equivalent widths
of polycyclic aromatic hydrocarbon emission and the optical depths of silicate
dust abs... | physics |
6,019 | ARCADE 2 Observations of Galactic Radio Emission | astro-ph.GA | We use absolutely calibrated data from the ARCADE 2 flight in July 2006 to
model Galactic emission at frequencies 3, 8, and 10 GHz. The spatial structure
in the data is consistent with a superposition of free-free and synchrotron
emission. Emission with spatial morphology traced by the Haslam 408 MHz survey
has spectra... | physics |
6,020 | Six more quasars at redshift 6 discovered by the Canada-France High-z Quasar Survey | astro-ph.GA | We present imaging and spectroscopic observations for six quasars at z>5.9
discovered by the Canada-France High-z Quasar Survey (CFHQS). The CFHQS
contains sub-surveys with a range of flux and area combinations to sample a
wide range of quasar luminosities at z~6. The new quasars have luminosities 10
to 75 times lower ... | physics |
6,021 | A Search for H2O Megamasers in High-z Type-2 AGNs | astro-ph.GA | We report a search for H2O megamasers in 274 SDSS type-2 AGNs (0.3 < z <
0.83), half of which can be classified as type-2 QSOs from their [OIII] 5007
luminosity, using the Robert C. Byrd Green Bank Telescope (GBT) and the
Effelsberg 100-m radio telescope. Apart from the detection of the extremely
luminous water vapor m... | physics |
6,022 | Observing Neutral Hydrogen Above Redshift 6: The "Global" Perspective | astro-ph.GA | Above redshift 6, the dominant source of neutral hydrogen in the Universe
shifts from localized clumps in and around galaxies and filaments to a
pervasive, diffuse component of the intergalactic medium (IGM). This transition
tracks the global neutral fraction of hydrogen in the IGM and can be studied,
in principle, thr... | physics |
6,023 | Early-Age Evolution of the Milky Way Related by Extremely Metal-Poor Stars | astro-ph.GA | We exploit the recent observations of extremely metal-poor (EMP) stars in the
Galactic halo and investigate the constraints on the IMF of the stellar
population that left these low-mass survivors of [Fe/H]<-2.5 and the chemical
evolution that they took part in. A high-mass IMF with the typical mass~10Msun
and the overw... | physics |
6,024 | Bars, ovals and lenses in early-type disk galaxies: probes of galaxy evolution | astro-ph.GA | The origin of S0 galaxies is discussed in the framework of early mergers in a
Cold Dark Matter cosmology, and in a scenario where S0s are assumed to be
former spirals stripped of gas. From an analysis of 127 early-type disk
galaxies (S0-Sa), we find a clear correlation between the scale parameters of
the bulge (r_eff) ... | physics |
6,025 | Galaxy shear estimation from stacked images | astro-ph.GA | Statistics of the weak lensing of galaxies can be used to constrain cosmology
if the galaxy shear can be estimated accurately. In general this requires
accurate modelling of unlensed galaxy shapes and the point spread function
(PSF). I discuss suboptimal but potentially robust methods for estimating
galaxy shear by sta... | physics |
6,026 | Comparison of Relativistic Iron Line Models | astro-ph.GA | The analysis of the broad iron line profile in the X-ray spectra of active
galactic nuclei and black hole X-ray binaries allows us to constrain the spin
parameter of the black hole. We compare the constraints on the spin value for
two X-ray sources, MCG-6-30-15 and GX 339-4, with a broad iron line using
present relativ... | physics |
6,027 | Nobeyama Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of Further Luminous Infrared Galaxies | astro-ph.GA | We report the results of interferometric HCN(1-0) and HCO+(1-0) observations
of four luminous infrared galaxies (LIRGs), NGC 2623, Mrk 266, Arp 193, and NGC
1377, as a final sample of our systematic survey using the Nobeyama Millimeter
Array. Our survey contains the most systematic interferometric,
spatially-resolved, ... | physics |
6,028 | Ionized Gas in the Smith Cloud | astro-ph.GA | We present WHAM observations of Halpha, [N II], and [S II] in the Smith
Cloud. A map of Halpha emission from the cloud shows ionized gas coincident
with the brightest H I emission, but nearly-as-bright Halpha in some regions
with faint H I. The ionized mass of the cloud is at least as large as the
neutral mass, > 10^6 ... | physics |
6,029 | The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies | astro-ph.GA | We model the large kinematic data sets for the four Milky Way dwarf
spheroidal (dSph) satellites: Carina, Fornax, Sculptor and Sextans, recently
published by Walker et al. The member stars are selected using a reliable
dynamical interloper removal scheme tested on simulated data. Our member
selection is more restrictiv... | physics |
6,030 | A forming, dust enshrouded disk at z=0.43: the first example of a late type disk rebuilt after a major merger? | astro-ph.GA | Abreg: By combining HST/UDF imagery with kinematics from VLT/GIRAFFE we
derive a physical model of distant galaxy J033245.11-274724.0 in a way similar
to what can be done in the nearby Universe. Here we study the properties of a
distant compact LIRGs galaxy. Given the photometric and spectro photometric
accuracies, we ... | physics |
6,031 | Environments of QSOs at Redshifts 0.9 to 1.3 | astro-ph.GA | We analyse new deep g and i-band imaging with the CFHT of 16 QSOs in the
redshift range 0.9 to 1.3. The principal points of interest are the symmetry
and signs of tidal effects in the QSO hosts and nearby (`companion') galaxies.
The sample measures are compared with similar measures on randomly selected
field galaxy sa... | physics |
6,032 | Serendipity observations of far infrared cirrus emission in the Spitzer Infrared Nearby Galaxies Survey: Analysis of far-infrared correlations | astro-ph.GA | We present an analysis of far-infrared dust emission from diffuse cirrus
clouds. This study is based on serendipitous observations at 160 microns at
high galactic latitude with the Multiband Imaging Photometer (MIPS) onboard the
Spitzer Space Telescope by the Spitzer Infrared Nearby Galaxies Survey (SINGS).
These obser... | physics |
6,033 | The early evolution of the star cluster mass function | astro-ph.GA | Several recent studies have shown that the star cluster initial mass function
(CIMF) can be well approximated by a power law, with indications for a
steepening or truncation at high masses. This contribution considers the
evolution of such a mass function due to cluster disruption, with emphasis on
the part of the mass... | physics |
6,034 | Predictions of polarized dust emission from interstellar clouds: spatial variations in the efficiency of radiative torque alignment | astro-ph.GA | Polarization carries information about the magnetic fields in interstellar
clouds. The observations of polarized dust emission are used to study the role
of magnetic fields in the evolution of molecular clouds and the initial phases
of star-formation. We study the grain alignment with realistic simulations,
assuming th... | physics |
6,035 | Probing the age and structure of the nearby very young open clusters NGC 2244 and NGC 2239 | astro-ph.GA | The very young open cluster (OC) NGC 2244 in the Rosette Nebula was studied
with field-star-decontaminated 2MASS photometry, which shows the main-sequence
(MS) stars and an abundant pre-MS (PMS) population. Fundamental and structural
parameters were derived with colour-magnitude diagrams (CMDs), stellar radial
density ... | physics |
6,036 | Interplay of CR-driven galactic wind, magnetic field, and galactic dynamo in spiral galaxies | astro-ph.GA | From our radio observations of the magnetic field strength and large-scale
pattern of spiral galaxies of different Hubble types and star formation rates
(SFR) we conclude that - though a high SFR in the disk increases the total
magnetic field strength in the disk and the halo - the SFR does not change the
global field ... | physics |
6,037 | Formation of Interstellar Clouds: Parker Instability with Phase Transitions | astro-ph.GA | We follow numerically the nonlinear evolution of the Parker instability in
the presence of phase transitions from a warm to a cold HI interstellar medium
in two spatial dimensions. The nonlinear evolution of the system favors modes
that allow the magnetic field lines to cross the galactic plane. Cold HI clouds
form wit... | physics |
6,038 | A top-heavy stellar initial mass function in starbursts as an explanation for the high mass-to-light ratios of ultra compact dwarf galaxies | astro-ph.GA | It has been shown recently that the dynamical V-band mass-to-light ratios of
compact stellar systems with masses from 10^6 to 10^8 Solar masses are not
consistent with the predictions from simple stellar population (SSP) models.
Top-heavy stellar initial mass functions (IMFs) in these so-called ultra
compact dwarf gala... | physics |
6,039 | Ionization of Infalling Gas | astro-ph.GA | H-alpha emission from neutral halo clouds probes the radiation and
hydrodynamic conditions in the halo. Armed with such measurements, we can
explore how radiation escapes from the Galactic plane and how infalling gas can
survive a trip through the halo. The Wisconsin H-Alpha Mapper (WHAM) is one of
the most sensitive i... | physics |
6,040 | The warm ionized medium in spiral galaxies | astro-ph.GA | This article reviews observations and models of the diffuse ionized gas that
permeates the disk and halo of our Galaxy and others. It was inspired by a
series of invited talks presented during an afternoon scientific session of the
65th birthday celebration for Professor Carl Heiles held at Arecibo Observatory
in Augus... | physics |
6,041 | The Outer Disk of the Milky Way Seen in 21-cm Absorption | astro-ph.GA | Three recent surveys of 21-cm line emission in the Galactic plane, combining
single dish and interferometer observations to achieve resolution of 1 arcmin
to 2 arcmin, 1 km/s, and good brightness sensitivity, have provided some 650
absorption spectra with corresponding emission spectra for study of the
distribution of ... | physics |
6,042 | Physical Conditions in the Narrow-Line Region of Markarian 3. II. Photoionization Modeling Results | astro-ph.GA | We have examined the physical conditions in the narrow-line region (NLR) of
the Seyfert 2 galaxy Markarian 3, using long-slit spectra obtained with the
Hubble Space Telescope/Space Telescope Imaging Spectrograph and photoionization
models. We find three components of photoionized gas in the NLR. Two of these
components... | physics |
6,043 | Review of results from EROS Microlensing search for Massive Compact Objects | astro-ph.GA | We present the results of the EROS2 search for the hidden galactic matter of
the halo through the gravitational microlensing of stars in the Magellanic
clouds. Microlensing was also searched for and found in the Milky-Way plane,
where foreground faint stars are expected to lens background stars. A total of
67 million o... | physics |
6,044 | Near-Infrared Spectroscopy of Seyfert Galaxies. Nuclear Activity and Stellar Population | astro-ph.GA | Near-infrared spectroscopic data for the five Seyfert galaxies with jet-gas
interaction Mrk 348, Mrk 573, Mrk 1066, NGC 7212, and NGC 7465, taken with the
LIRIS near-infrared camera/spectrometer at the William Herschel Telescope (WHT)
are reported. The long-slit spectra reveal the characteristic strong emission
lines o... | physics |
6,045 | Limits on chemical complexity in diffuse clouds: search for CH3OH and HC5N absorption | astro-ph.GA | Context: An unexpectedly complex polyatomic chemistry exists in diffuse
clouds, allowing detection of species such as C2H, C3H2, H2CO and NH3 which
have relative abundances that are strikingly similar to those inferred toward
the dark cloud TMC-1
Aims: We probe the limits of complexity of diffuse cloud polyatomic
che... | physics |
6,046 | Two Types of Magnetohydrodynamic Sheath Jets | astro-ph.GA | Recent observations of astrophysical jets emanating from various galactic
nuclei strongly suggest that a double layered structure, or a spine-sheath
structure, is likely to be their common feature. We propose that such a sheath
jet structure can be formed magnetohydrodynamically within a valley of the
magnetic pressure... | physics |
6,047 | A sample of GHz-peaked spectrum sources selected at RATAN-600: spectral and variability properties | astro-ph.GA | We describe a new sample of 226 GPS (GHz-Peaked Spectrum) source candidates
selected using simultaneous 1-22 GHz multi-frequency observations with the
RATAN-600 radio telescope. Sixty objects in our sample are identified as GPS
source candidates for the first time. The candidates were selected on the basis
of their bro... | physics |
6,048 | Monte Carlo Simulations of Star Clusters - VI. The globular cluster NGC 6397 | astro-ph.GA | We describe Monte Carlo models for the dynamical evolution of the nearby
globular cluster NGC 6397. The code includes treatments of two-body relaxation,
most kinds of three- and four-body interactions involving primordial binaries
and those formed dynamically, the Galactic tide, and the internal evolution of
both singl... | physics |
6,049 | Feedback from central black holes in elliptical galaxies. I: models with either radiative or mechanical feedback but not both | astro-ph.GA | The importance of the radiative feedback from SMBHs at the centers of
elliptical galaxies is not in doubt, given the well established relations among
electromagnetic output, black hole mass and galaxy optical luminosity. In
addition, feedback due to mechanical and thermal deposition of energy from jets
and winds emitte... | physics |
6,050 | Star formation histories of resolved galaxies | astro-ph.GA | The colour-magnitude diagrams of resolved stellar populations are the best
tool to study the star formation histories of the host galactic regions. In
this review the method to derive star formation histories by means of synthetic
colour-magnitude diagrams is briefly outlined, and the results of its
application to reso... | physics |
6,051 | IR Dust Bubbles II: Probing the Detailed Structure and Young Massive Stellar Populations of Galactic HII Regions | astro-ph.GA | We present an analysis of late-O/early-B-powered, parsec-sized bubbles and
associated star-formation using 2MASS, GLIMPSE, MIPSGAL and MAGPIS surveys.
Three bubbles were selected from the Churchwell et al. (2007) catalog. We
confirm that the structure identified in Watson et al. (2008) holds in less
energetic bubbles, ... | physics |
6,052 | Imaging galactic diffuse clouds: CO emission, reddening and turbulent flow in the gas around Zeta Oph | astro-ph.GA | Methods: 12CO emission is imaged in position and position-velocity space
analyzed statistically, and then compared with maps of total reddening and with
models of the C+ - CO transition in H2-bearing diffuse clouds. Results: Around
Zeta Oph, 12CO emission appears in two distinct intervals of reddening centered
near EBV... | physics |
6,053 | Multiplicity of nuclear dust lanes and dust lane shocks in the Milky Way bar | astro-ph.GA | Aims: We show the existence of a small family of inner-galaxy dust lanes and
dust lane standing shocks beyond the two major ones that were previously known
to exist Methods: We analyze images of CO emission in the inner regions of the
Galaxy Results: The peculiar kinematics of the major dust lane features are
repeated ... | physics |
6,054 | A CO J=1-0 Survey of common optical/uv absorption sightlines | astro-ph.GA | Context: Over the past thirty years a wealth of observations of CO and other
molecules in optical/uv absorption in diffuse clouds has accumulated for which
no comparable CO emission line data exist. Aims: To acquire mm-wave J=1-0 CO
emission line profiles toward a substantial sample of commonly-studied
optical/uv absor... | physics |
6,055 | The flat oxygen abundance gradient in the extended disk of M83 | astro-ph.GA | We have obtained deep multi-object optical spectra of 49 HII regions in the
outer disk of the spiral galaxy M83 (=NGC 5236) with the FORS2 spectrograph at
the Very Large Telescope. The targets span the range in galactocentric distance
between 0.64 and 2.64 times the R25 isophotal radius (5.4-22.3 kpc), and 31 of
them a... | physics |
6,056 | Time-dependent H2 formation and protonation | astro-ph.GA | Methods: The microscopic equations of H2-formation and protonation are
integrated numerically over time in such a manner that the overall structures
evolve self-consistently under benign conditions. Results: The equilibrium H2
formation timescale in an H I cloud with N(H) ~ 4x10^{20}/cm^2 is 1-3 x 10^7
yr, nearly indep... | physics |
6,057 | GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release | astro-ph.GA | The Parkes Galactic All-Sky Survey (GASS) is a survey of Galactic atomic
hydrogen (HI) emission in the Southern sky covering declinations $\delta \leq
1^{\circ}$ using the Parkes Radio Telescope. The survey covers $2\pi$
steradians with an effective angular resolution of ~16', at a velocity
resolution of 1.0 km/s, and ... | physics |
6,058 | Magnetic structure of our Galaxy: A review of observations | astro-ph.GA | The magnetic structure in the Galactic disk, the Galactic center and the
Galactic halo can be delineated more clearly than ever before. In the Galactic
disk, the magnetic structure has been revealed by starlight polarization within
2 or 3 kpc of the Solar vicinity, by the distribution of the Zeeman splitting
of OH mase... | physics |
6,059 | Optical Variability of the Radio Source J 1128+5925 -- II. Confirmation of its Optical Quietness | astro-ph.GA | The source J 1128+5925 was found recently to show strong intraday variability
at radio wavelengths and its radio variability may come from interstellar
scintillation. In optical, the object was quiet in our 2007 monitoring session.
Here we report the results of our new optical monitoring of this source in
2008. In addi... | physics |
6,060 | Parsec-scale Jet in the Distant Gigahertz-Peaked Spectrum Quasar PKS 0858-279 | astro-ph.GA | The high redshift GPS quasar PKS 0858-279 exhibits the following properties
which make the source unusual. Our RATAN-600 monitoring of 1-22 GHz spectrum
has detected broad-band radio variability with high amplitude and relatively
short time scale. In the same time, the milliarcsecond scale structure observed
in a snaps... | physics |
6,061 | Modeling the effects of dust evolution on the SEDs of galaxies of different morphological type | astro-ph.GA | We present photometric evolution models of galaxies, in which, in addition to
the stellar component, the effects of an evolving dusty interstellar medium
have been included with particular care. Starting from the work of Calura,
Pipino & Matteucci (2008), in which chemical evolution models have been used to
study the e... | physics |
6,062 | AGN and starburst in bright Seyfert galaxies: from IR photometry to IR spectroscopy | astro-ph.GA | Infrared photometry and later infrared spectroscopy provided powerful
diagnostics to distinguish between the main emission mechanisms in galaxies:
AGN and Starburst. After the pioneering work on infrared photometry with IRAS
in the far-IR and the S.Pedro Martir and ESO ground-based work in the near-IR,
ISO photometry e... | physics |
6,063 | Parsec-scale properties of GHz-Peaked Spectrum sources from 2.3 and 8.6 GHz VLBI surveys | astro-ph.GA | We investigate the sample of 213 GPS sources selected from simultaneous
multi-frequency 1-22 GHz observations obtained with RATAN-600 radio telescope.
We use publicly available data to characterize parsec-scale structure of the
selected sources. Among them we found 121 core dominated sources, 76 Compact
Symmetric Objec... | physics |
6,064 | The thermal-viscous disk instability model in the AGN context | astro-ph.GA | Accretion disks in AGN should be subject to the same type of instability as
in cataclysmic variables (CVs) or in low-mass X-ray binaries (LMXBs), which
leads to dwarf nova and soft X-ray transient outbursts. It has been suggested
that this thermal/viscous instability can account for the long term variability
of AGNs. W... | physics |
6,065 | A systematic fitting scheme for caustic-crossing microlensing events | astro-ph.GA | We outline a method for fitting binary-lens caustic-crossing microlensing
events based on the alternative model parameterisation proposed and detailed in
Cassan (2008). As an illustration of our methodology, we present an analysis of
OGLE-2007-BLG-472, a double-peaked Galactic microlensing event with a source
crossing ... | physics |
6,066 | Resolving the obscuring torus in NGC 1068 with the power of infrared interferometry: Revealing the inner funnel of dust | astro-ph.GA | We present new interferometric data obtained with MIDI (MID infrared
Interferometric instrument) for the Seyfert II galaxy NGC 1068, with an
extensive coverage of sixteen uv points. These observations resolve the nuclear
mid-infrared emission from NGC 1068 in unprecedented detail with a maximum
resolution of 7 mas. For... | physics |
6,067 | Blue Hook Stars in Globular Clusters | astro-ph.GA | Blue hook (BHk) stars are a rare class of horizontal branch stars that so far
have been found in only very few Galactic globular clusters (GCs). The dominant
mechanism for producing these objects is currently still unclear. In order to
test if the presence of BHk populations in a given GC is linked to specific
physical... | physics |
6,068 | Finite source effects in microlensing: A precise, easy to implement, fast and numerical stable formalism | astro-ph.GA | The goal of this paper is to provide a numerically fast and stable
description for the microlensing amplification of an extended source (either
uniform or limb-darkened) that holds in any amplification regime. We show that
our method of evaluating the amplification can be implemented into a
light-curve fitting routine ... | physics |
6,069 | The EROS2 search for microlensing events towards the spiral arms: the complete seven season results | astro-ph.GA | The EROS-2 project has been designed to search for microlensing events
towards any dense stellar field. The densest parts of the Galactic spiral arms
have been monitored to maximize the microlensing signal expected from the stars
of the Galactic disk and bulge. 12.9 million stars have been monitored during 7
seasons to... | physics |
6,070 | Spitzer View of Young Massive Stars in the LMC HII Complex N44 | astro-ph.GA | The HII complex N44 in the Large Magellanic Cloud (LMC) provides an excellent
site to perform a detailed study of star formation in a mild starburst, as it
hosts three regions of star formation at different evolutionary stages and it
is not as complicated and confusing as the 30 Doradus giant HII region. We have
obtain... | physics |
6,071 | First detection of optical light from SNR G279.0+1.1 | astro-ph.GA | This is the initial paper in a series presenting the first optical detections
and subsequent follow-up spectroscopy of known Southern Galactic supernova
remnants (SNRs) previously discovered in the radio. These new detections come
from the AAO/UKST HAlpha survey of the Southern Galactic plane which has opened
up fresh ... | physics |
6,072 | Role of galactic gaseous halos in recycling enriched winds from bulges to disks: A new bulge-disk chemical connection | astro-ph.GA | We demonstrate for the first time that gaseous halos of disk galaxies can
play a vital role in recycling metal-rich gas ejected from the bulges and thus
in promoting chemical evolution of disks. Our numerical simulations show that
metal-rich stellar winds from bulges in disk galaxies can be accreted onto the
thin disks... | physics |
6,073 | Magnetism in the nearby galaxy M33 | astro-ph.GA | Using high-resolution data of the linearly polarized intensity and
polarization angle at 3.6, 6.2, and 20 cm together with a 3-D model of the
regular magnetic field, we study variations of the structure, strength, and
energy density of the magnetic field in the Scd galaxy M33. The regular
magnetic field consists of a h... | physics |
6,074 | NLS1 galaxies and estimation of their central black hole masses from the X-ray excess variance method | astro-ph.GA | Black hole mass determination in active galaxies is a key issue in
understanding various luminosity states. In the present paper we try to
generalise the mass determination method based on the X-ray excess variance,
successfully used for typical broad line Seyfert 1 galaxies (BLS1) to Narrow
Line Seyfert 1 (NLS1) galax... | physics |
6,075 | Radio Recombination Lines toward the Galactic Center Lobe | astro-ph.GA | The Galactic Center lobe is a degree-tall shell seen in radio continuum
images of the Galactic center (GC) region. If it is actually located in the GC
region, formation models would require massive energy input (e.g., starburst or
jet) to create it. At present, observations have not strongly constrained the
location or... | physics |
6,076 | Conclusions from the image analysis of the VSOP Survey | astro-ph.GA | In February 1997, the Japanese radio astronomy satellite HALCA was launched
to provide the space-bourne element for the VLBI Space Observatory Programme
(VSOP) mission. A significant fraction of the mission time was to be dedicated
to the VSOP Survey of bright compact Active Galactic Nuclei (AGN) at 5 GHz,
which was le... | physics |
6,077 | The cluster birthline in M33 | astro-ph.GA | We test the reliability of infrared (IR) emission to trace star formation in
individual star-forming sites of M33, and outline a new method for testing the
distribution function of massive stars in newly formed clusters. We select IR
sources from the Spitzer survey of M33 and show that the IR and Halpha
luminosities ar... | physics |
6,078 | 3D MHD simulations of magnetic fields and radio polarization of barred galaxies | astro-ph.GA | We present results of three-dimensional, fully nonlinear MHD simulations of a
large-scale magnetic field evolution in a barred galaxy. The model does not
take into consideration the dynamo process. We find that the obtained magnetic
field configurations are highly similar to the observed maps of the polarized
intensity... | physics |
6,079 | The ISM in Distant Galaxies | astro-ph.GA | The interstellar medium (ISM) is a key ingredient in galaxy formation and
evolution as it provides the molecular gas reservoir which fuels star formation
and supermassive black hole accretion. Yet the ISM is one of the least studied
aspects of distant galaxies. Molecular and atomic transitions at
(sub)millimetre wavele... | physics |
6,080 | Spatially Resolved Galaxy Star Formation and its Environmental Dependence II. Effect of the Morphology-Density Relation | astro-ph.GA | In this second of a series of papers on spatially resolved star formation, we
investigate the impact of the density-morphology relation of galaxies on the
spatial variation of star formation (SF) and its dependence on environment. We
find that while a density-morphology relation is present for the sample, it
cannot sol... | physics |
6,081 | A complete 12CO 2--1 map of M51 with HERA: II. Total gas surface densities and gravitational stability | astro-ph.GA | To date the onset of large-scale star formation in galaxies and its link to
gravitational stability of the galactic disk have not been fully understood.
The nearby face-on spiral galaxy M51 is an ideal target for studying this
subject. This paper combines CO, dust, HI, and stellar maps of M51 and its
companion galaxy t... | physics |
6,082 | Disentangling the circumnuclear environs of Centaurus A: I. High resolution molecular gas imaging | astro-ph.GA | We present high resolution images of the 12CO(2-1) emission in the central 1'
(1 kpc) of NGC 5128 (Centaurus A), observed using the SMA. We elucidate for the
first time the distribution and kinematics of the molecular gas in this region
with a resolution of 6'.0 x 2'.4 (100 pc x 40 pc). We spatially resolve the
circumn... | physics |
6,083 | Discs of Satellites: the new dwarf spheroidals | astro-ph.GA | The spatial distributions of the most recently discovered ultra faint dwarf
satellites around the Milky Way and the Andromeda galaxy are compared to the
previously reported discs-of-satellites (DoS) of their host galaxies. In our
investigation we pay special attention to the selection bias introduced due to
the limited... | physics |
6,084 | On the number of young stellar discs in the Galactic Centre | astro-ph.GA | Observations of the Galactic Centre show evidence of disc-like structures of
very young stars orbiting the central super-massive black hole within a
distance of a few 0.1 pc. While it is widely accepted that about half of the
stars form a relatively flat disc rotating clockwise on the sky, there is a
substantial ongoin... | physics |
6,085 | Do Moderate-Luminosity Active Galactic Nuclei Suppress Star Formation? | astro-ph.GA | The growth of supermassive black holes and their host galaxies are thought to
be linked, but the precise nature of this symbiotic relationship is still
poorly understood. Both observations and simulations of galaxy formation
suggest that the energy input from active galactic nuclei (AGN), as the central
supermassive bl... | physics |
6,086 | Kinematic and Excitation Structure of the NGC 1068 Narrow-Line Region | astro-ph.GA | We investigated the kinematic and excitation structure of the NGC 1068
narrow-line region (NLR). We obtained profiles of several emission lines,
[OIII]$\lambda$5007, H$\beta$, [OI]$\lambda$6300 and [FeVII]$\lambda$6087 at
high-velocity resolution (R ~ 7500 - 11000), and confirmed that they showed
different profiles. Th... | physics |
6,087 | Candidate microlensing events from M31 observations with the Loiano telescope | astro-ph.GA | Microlensing observations towards M31 are a powerful tool for the study of
the dark matter population in the form of MACHOs both in the Galaxy and the M31
halos, a still unresolved issue, as well as for the analysis of the
characteristics of the M31 luminous populations. In this work we present the
second year results ... | physics |
6,088 | Multiband imaging observations of a prominent dust lane galaxy NGC 4370 | astro-ph.GA | In this paper we present extinction properties of interstellar dust in a
prominent dust lane galaxy NGC 4370 based on the optical broad band (BVRI)
imaging observations taken from the Himalaya Chandra Telescope (HCT), Hanle and
the near-IR (J,H,K$_s$) images taken from the 2MASS archive. NGC 4370 belongs
to the Virgo c... | physics |
6,089 | An optical spectroscopic survey of the 3CR sample of radio galaxies with z<0.3. I. Presentation of the data | astro-ph.GA | We present a homogeneous and 92 % complete dataset of optical nuclear spectra
for the 113 3CR radio sources with redshifts < 0.3, obtained with the
Telescopio Nazionale Galileo. For these sources we could obtain uniform and
uninterrupted coverage of the key spectroscopic optical diagnostics. The
observed sample, includ... | physics |
6,090 | On the evolution of the molecular line profiles induced by the propagation of C-shock waves | astro-ph.GA | We present the first results of the expected variations of the molecular line
emission arising from material recently affected by C-shocks (shock
precursors). Our parametric model of the structure of C-shocks has been coupled
with a radiative transfer code to calculate the molecular excitation and line
profiles of shoc... | physics |
6,091 | Statistics of Centroids of Velocity | astro-ph.GA | We review the use of velocity centroids statistics to recover information of
interstellar turbulence from observations. Velocity centroids have been used
for a long time now to retrieve information about the scaling properties of the
turbulent velocity field in the interstellar medium. We show that, while they
are usef... | physics |
6,092 | How complex is the obscuration in AGN? New clues from the Suzaku monitoring of the X-ray absorbers in NGC7582 | astro-ph.GA | We present the results of a Suzaku monitoring campaign of the Seyfert 2
galaxy, NGC7582. The source is characterized by very rapid (on timescales even
lower than a day) changes of the column density of an inner absorber, together
with the presence of constant components arising as reprocessing from a
Compton-thick mate... | physics |
6,093 | Dynamically dominant magnetic fields in the diffuse interstellar medium | astro-ph.GA | Observations show that magnetic fields in the interstellar medium (ISM) often
do not respond to increases in gas density as would be naively expected for a
frozen-in field. This may suggest that the magnetic field in the diffuse gas
becomes detached from dense clouds as they form. We have investigated this
possibility ... | physics |
6,094 | Galactic outflows and the chemical evolution of dwarf galaxies | astro-ph.GA | Galactic winds in dwarf galaxies are driven by the energy released by
supernova explosions and stellar winds following an intense episode of star
formation, which create an over-pressured cavity of hot gas. Although the
luminosity of the star formation episode and the mass of the galaxy play a key
role in determining t... | physics |
6,095 | The complex, variable near infrared extinction towards the Nuclear Bulge | astro-ph.GA | Using deep J, H and Ks-band observations, we have studied the near-infrared
(nIR) extinction of the Nuclear Bulge (NB) and we find significant, complex
variations on small physical scales. We have applied a new variable nIR colour
excess method, V-NICE, to measure the extinction; this method allows for
variation in bot... | physics |
6,096 | Hints of High Core Faraday Rotations from a Joint Analysis of VLBA and Optical Polarization Data | astro-ph.GA | Although the continua of radio-loud Active Galactic Nuclei (AGN) are
typically dominated by synchrotron radiation over virtually the entire
spectrum, it is not clear whether the radio and higher-frequency emission
originate in the same or different parts of the jet. Several different
radio--optical correlations based o... | physics |
6,097 | Rest-frame UV versus optical morphologies of galaxies using Sersic profile fitting: the importance of morphological K-correction | astro-ph.GA | We show a comparison of the rest-frame UV morphologies of a sample of 162
intermediate redshift (median redshift 1.02) galaxies with their rest-frame
optical morphologies. We select our sample from the deepest near-UV image
obtained with the Hubble Space Telescope (HST) using the WFPC2 (F300W) as part
of the parallel o... | physics |
6,098 | Using the minimum spanning tree to trace mass segregation | astro-ph.GA | We present a new method to detect and quantify mass segregation in star
clusters. It compares the minimum spanning tree (MST) of massive stars with
that of random stars. If mass segregation is present, the MST length of the
most massive stars will be shorter than that of random stars. This difference
can be quantified ... | physics |
6,099 | A study of the kinematics near WR-stars in the IC10 galaxy | astro-ph.GA | A study of the ionized and neutral gas kinematics near 23 WR stars in the Irr
galaxy IC10 are provided. For most of the stars sings of the WR winds impact on
the interstellar medium were detected. A rough estimate of the power of wind WR
stars is about ~(0.01-0.84) 10^38 erg / sec. | physics |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.