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Related papers: disnht: modeling X-ray absorption from distributed…

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We present a simple, largely empirical but physically motivated model to interpret the mid- and far-infrared spectral energy distributions of galaxies consistently with the emission at ultraviolet, optical and near-infrared wavelengths. Our…

Astrophysics · Physics 2009-11-13 Elisabete da Cunha , Stephane Charlot , David Elbaz

We explore the possibility of resolving an image of a damped Lyman alpha (DLA) system in absorption against an extended, diffuse background X-ray source. Typical columns of neutral hydrogen in DLAs are high enough to block out up to ~30% of…

Astrophysics · Physics 2009-11-10 Mark Dijkstra , Zoltan Haiman , Caleb Scharf

The standard model of cosmic ray heating-induced desorption of interstellar ices is based on a continuous representation of the sporadic desorption of ice mantle components from classical (0.1 micron) dust grains. This has been re-evaluated…

Solar and Stellar Astrophysics · Physics 2022-08-17 Jonathan M. C. Rawlings

Photoabsorption of atomic oxygen in the energy region below the $\rm 1s^{-1}$ threshold in x-ray spectroscopy from {\it Chandra} and {\it XMM-Newton} is observed in a variety of x-ray binary spectra. Photoabsorption cross sections…

High Energy Astrophysical Phenomena · Physics 2015-06-16 B. M. McLaughlin , C. P. Ballance , K. P. Bowen , D. J. Gardenghi , W. C. Stolte

Diffuse and translucent molecular clouds fill a vast majority of the interstellar space in the galactic disk being thus the most typical objects of the Interstellar Medium (ISM). Recent advances in observational techniques of modern optical…

Solar and Stellar Astrophysics · Physics 2013-04-18 T. Weselak

Resolving the phase structure of neutral hydrogen (HI) is crucial for understanding the life cycle of the interstellar medium (ISM). However, accurate measurements of HI temperature and density are limited by the availability of background…

Astrophysics of Galaxies · Physics 2020-08-19 Claire E. Murray , J. E. G. Peek , Chang-Goo Kim

X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered by X-ray surveys, the selected AGN are poorly sampled. Deep…

Astrophysics of Galaxies · Physics 2025-05-21 E. Pouliasis , A. Ruiz , I. Georgantopoulos , A. Akylas , N. A. Webb , F. J. Carrera , S. Mateos , A. Nebot , M. G. Watson , F. X. Pineau , C. Motch

Diffusion models achieve state-of-the-art generative performance but suffer from high computational costs during inference due to the repeated evaluation of a heavy neural network. In this work, we propose Dual-Rate Diffusion, a method to…

Machine Learning · Computer Science 2026-05-19 Grigory Bartosh , David Ruhe , Emiel Hoogeboom , Jonathan Heek , Thomas Mensink , Tim Salimans

Until now, the spectral changes observed from persistent to dipping intervals in dipping low-mass X-ray binaries were explained by invoking progressive and partial covering of an extended emission region. Here, we propose a novel and…

Astrophysics · Physics 2009-11-11 L. Boirin , M. Diaz Trigo , M. Mendez , A. N. Parmar , J. S. Kaastra

We investigate the scaling relation between the observed amount of absorption in the X-ray spectra of Gamma Ray Burst (GRB) afterglows and the absorber redshift. Through dedicated numerical simulations of an ideal instrument, we establish…

In high mass X-ray binaries (HMXBs), an accreting compact object orbits a high mass star which loses mass through a dense and inhomogeneous wind. Using the compact object as an X-ray backlight, the time variability of the absorbing column…

High Energy Astrophysical Phenomena · Physics 2020-11-25 I. El Mellah , V. Grinberg , J. O. Sundqvist , F. A. Driessen , M. A. Leutenegger

We present XMM-Newton spectral analysis of all 38 Seyfert galaxies from the Palomar spectroscopic sample of galaxies. These are found at distances of up to 67 Mpc and cover the absorbed 2-10 keV luminosity range ~10^38-10^43 ergs/s. Our aim…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Akylas , I. Georgantopoulos

We present results of the XMM-Newton observation on the bright X-ray binary Cyg X-2. In our analysis we focus upon the absorption and scattering of the X-ray emission by interstellar dust. The scattering halo around Cyg X-2, observed with…

Astrophysics · Physics 2009-11-11 E. Costantini , M. J. Freyberg , P. Predehl

Context: Redshifts are fundamental for our understanding of extragalactic X-ray sources. Ambiguous counterpart associations, expensive optical spectroscopy and/or multimission multiwavelength coverage to resolve degeneracies make estimation…

Instrumentation and Methods for Astrophysics · Physics 2018-10-17 Charlotte Simmonds , Johannes Buchner , Mara Salvato , Li-Ting Hsu , Franz Erik Bauer

Radiative transfer models in a spherical, turbulent interstellar medium (ISM) in which the photon source is situated at the center are calculated to investigate the correlation between the scattered light and the dust column density. The…

Astrophysics of Galaxies · Physics 2015-06-17 Kwang-Il Seon , Adolf N. Witt

With current wide-field near-infrared (NIR) instruments the scattered light in the near-infrared can be mapped over large areas. Below A_V ~ 10 the surface brightness is directly proportional to the column density, and at slightly higher…

Astrophysics · Physics 2009-11-11 M. Juvela , V. -M. Pelkonen , P. Padoan , K. Mattila

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

Astrophysics · Physics 2007-05-23 J. M. Cordes

We present an analysis of the X-ray properties of sources detected in the 13H XMM-Newton deep (200ks) field. In order to constrain the absorbed AGN population, we use extensive Monte Carlo simulations to directly compare the X-ray colours…

Astrophysics · Physics 2009-11-11 T. Dwelly , M. J. Page , N. S. Loaring , K. O. Mason , I. McHardy , K. Gunn , T. Sasseen

We present maps of the Galactic X-ray Halo and constrain the location of X-ray absorbing gas using the X-ray radiation transfer as distance a indicator. Based on a consistent model of the soft X-ray background (SXRB) and the ROSAT all-sky…

Astrophysics · Physics 2015-06-24 J. Pradas , J. Kerp

We consider from a general point of view the problem of determining the extinction in dense molecular clouds. We use a rigorous statistical approach to characterize the properties of the most widely used optical and infrared techniques,…

Astrophysics · Physics 2009-11-11 Marco Lombardi
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