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Infrared interferometry of local AGN has revealed a warm (~300K-400K) polar dust structure that cannot be trivially explained by the putative dust torus of the unified model. This led to the development of the disk+wind scenario which…

Despite much observational and theoretical effort little is presently known about the nature of the luminous non-nuclear X-ray sources which appear to largely surpass the Eddington limit of a few solar masses. Here we present first results…

Astrophysics · Physics 2007-05-23 Manfred W. Pakull , Laurent Mirioni

We present near-infrared VLT-UT1+ISAAC spectroscopy of a sample of 9 extremely red galaxies (ERGs) with R-K>5 and K<19.0. Neither strong emission lines (F_lim<1-5 10^{-16} erg s^{-1}cm^{-2}) nor continuum breaks are detected. From…

This review discusses the current status of our knowledge of emission by dust and molecular gas in high redshift radio galaxies, and the uncertainties in the derivation of physical parameters from these data. The similarity of far-infrared…

Astrophysics · Physics 2007-05-23 Paul P. van der Werf

A significant fraction of the energy emitted in the early Universe came from very luminous galaxies that are largely hidden at optical wavelengths (because of interstellar dust grains); this energy now forms part of the cosmic background…

Astrophysics · Physics 2015-06-24 S. C. Chapman , A. W. Blain , R. J. Ivison , Ian Smail

A novel technique is employed for estimating attenuation curves in galaxies where only photometry and spectroscopic redshifts are available. This technique provides a powerful measure of particular extinction features such as the UV bump at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Charlie Conroy

Rest-frame far-ultraviolet (FUV) luminosities form the `backbone' of our understanding of star formation at all cosmic epochs. FUV luminosities are typically corrected for dust by assuming that extinction indicators which have been…

Astrophysics · Physics 2009-11-07 Eric F. Bell

Old starburst galaxies are deficient in O stars, and hence do not exhibit strong line emission in the optical regime. However, there remain many B stars, which are expected to heat dust grains and generate strong continuum emission in the…

Astrophysics · Physics 2009-10-31 H. Mouri , Y. Taniguchi

Several observational and theoretical arguments suggest that starburst galaxies may rival quasars as sources of metagalactic ionizing radiation at redshifts z > 3. Reionization of the intergalactic medium (IGM) at z > 5 may arise, in part,…

Astrophysics · Physics 2009-10-31 Massimo Ricotti , J. Michael Shull

Ultra-luminous infrared galaxies (ULIRGs) are the most luminous and intense starburst galaxies in the Universe. Both their star-formation rate (SFR) and gas surface mass density are very high, implying a high supernovae rate and an…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Hao-Ning He , Tao Wang , Yi-Zhong Fan , Si-Ming Liu , Da-Ming Wei

Studies of the Hubble Deep Field (HDF) and other deep surveys have revealed an apparent peak in the ultraviolet (UV) luminosity density, and therefore the star-formation rate density, of the Universe at redshifts 1<z<2. We use photometric…

Astrophysics · Physics 2007-05-23 Sebastian M. Pascarelle , Kenneth M. Lanzetta , Alberto Fernandez-Soto

Ultraluminous X-ray sources (ULX) are off-nuclear point sources in nearby galaxies whose X-ray luminosity exceeds the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their luminosity ranges from…

The contribution to the ultraviolet background (UVB) from thermal emission due to gas shock heated during cosmic structure formation is assessed with an updated version of Press-Schechter (Sheth & Tormen 1999) formalism. The calculation is…

Astrophysics · Physics 2007-05-23 F. Miniati

Hydrogen in the Universe was (re)ionised between redshifts $z \approx 10$ and $z \approx 6$. The nature of the sources of the ionising radiation is hotly debated, with faint galaxies below current detection limits regarded as prime…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Mahavir Sharma , Tom Theuns , Carlos S. Frenk , Richard G. Bower , Robert A. Crain , Matthieu Schaller , Joop Schaye

Results from a recent HST survey of field galaxies at wavelengths 1600 Angstroms and 2400 Angstroms are be presented. The data are used to constrain the fraction of Lyman-continuum radiation that escapes from galaxies at redshifts z ~ 1.…

Astrophysics · Physics 2009-11-06 Henry C. Ferguson

Massive galaxies in the early Universe have been shown to be forming stars at surprisingly high rates. Prominent examples are dust-obscured galaxies which are luminous when observed at sub-millimeter (sub-mm) wavelengths and which may be…

The extragalactic background light (EBL) from the far infrared through the visible and extending into the ultraviolet is thought to be dominated by starlight, either through direct emission or through absorption and reradiation by dust.…

High Energy Astrophysical Phenomena · Physics 2010-03-04 Justin D. Finke , Soebur Razzaque , Charles D. Dermer

We present radiative transfer models for submillimeter galaxies with spectroscopic redshifts and mid-infrared spectroscopy from Spitzer/IRS and analyze available Spitzer/MIPS 24, 70 and 160mu data. We use two types of starburst models, a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Andreas Efstathiou , Ralf Siebenmorgen
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