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Related papers: The redshift distribution of the X-ray background

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We investigate the X-ray variability characteristics of hard X-ray selected AGNs (based on Swift/BAT data) in the soft X-ray band using the RXTE/ASM data. The uncertainties involved in the individual dwell measurements of ASM are critically…

Astrophysics of Galaxies · Physics 2011-02-11 V. R. Chitnis , J. K. Pendharkar , D. Bose , V. K. Agrawal , A. R. Rao , R. Misra

We present a carefully selected sample of short gamma-ray bursts (SGRBs) observed by the Swift satellite up to June 2013. Inspired by the criteria we used to build a similar sample of bright long GRBs (the BAT6 sample), we selected SGRBs…

We use simulations to predict the X-ray surface brightness distribution arising from hot, cosmologically distributed diffuse gas. The distribution is computed for two bands: 0.5-2 keV and 0.1-0.4 keV, using a cosmological-constant dominated…

Astrophysics · Physics 2009-11-06 Greg L. Bryan , G. Mark Voit

(Abridged) We present the LogN-LogS and spatial distributions of X-ray point sources in seven Galactic Bulge (GB) fields within 4 deg from the Galactic Center (GC). We compare the properties of 1159 X-ray point sources discovered in our…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Jaesub Hong , Maureen van den Berg , Jonathan E. Grindlay , Silas Laycock

Recent evidence appears to link gamma-ray bursts (GRBs) to star-forming regions in galaxies at cosmological distances. If short-lived massive stars are the progenitors of GRBs, the rate of events per unit cosmological volume should be an…

Astrophysics · Physics 2008-11-26 Cristiano Porciani , Piero Madau

Using data from the DEEP2 galaxy redshift survey and the All Wavelength Extended Groth Strip International Survey we obtain stacked X-ray maps of galaxies at 0.7 < z < 1.0 as a function of stellar mass. We compute the total X-ray counts of…

We provide a highly concise overview of what X-ray surveys and their multiwavelength follow-up have revealed about the nature of the cosmic X-ray background (CXRB) and its constituent sources. We first describe early global studies of the…

High Energy Astrophysical Phenomena · Physics 2023-04-05 W. N. Brandt , G. Yang

[Abbreviated] Upcoming large area sky surveys like EUCLID and eROSITA crucially depend on accurate photometric redshifts (photo-z). The identification of variable sources, such as AGNs, and the achievable redshift accuracy for varying…

We study the spatial distribution of a 95% complete sample of 508 X-ray point sources (XPS) detected in the 0.5-2.0 keV band in Chandra ACIS-I observations of 51 massive galaxy clusters found in the MACS survey. Covering the redshift range…

Astrophysics · Physics 2009-11-10 Joshua T. Ruderman , Harald Ebeling

X-ray reflection generates much of the spectral complexity in the X-ray spectra of AGN. It is argued that strong relativistic blurring of the reflection spectrum should commonly be expected from objects accreting at a high Eddington rate.…

Astrophysics · Physics 2007-05-23 A. C. Fabian

As an evolutionary phase of galaxies, active galactic nuclei (AGN) over a large range of redshift have been utilized for understanding cosmic evolution. In particular, the population and evolution of AGNs have been investigated through the…

Astrophysics of Galaxies · Physics 2019-01-02 Jaejin Shin , Richard. M. Plotkin , Jong-Hak Woo , Elena Gallo , John S. Mulchaey

We undertake a spectral study of a sample of bright X-ray sources taken from six XMM-Newton fields at high galactic latitudes, where AGN are the most populous class. These six fields were chosen such that the observation had an exposure…

High Energy Astrophysical Phenomena · Physics 2015-05-30 M. A. Hassan , B. A. Korany , R. Misra , I. A. M. Issa , M. K. Ahmed , F. A. Abdel-Salam

We present an analysis of the X-ray point source populations in 182 Chandra images of galaxy clusters at z>0.1 with exposure time >10 ksec, as well as 44 non-cluster fields. Analysis of the number and flux of these sources, using a detailed…

Astrophysics of Galaxies · Physics 2010-04-29 R. Gilmour , P. Best , O. Almaini

The information content of the autocorrelation function (ACF) of intensity fluctuations of the X-ray background (XRB) is analyzed. The tight upper limits set by ROSAT deep survey data on the ACF at arcmin scales imply strong constraints on…

Astrophysics · Physics 2009-10-22 L. Danese , L. Toffolatti , A. Franceschini , J. M. Martin-Mirones , G. De Zotti

Compton Thick (CT) AGN are a key ingredient of Cosmic X-ray Background (CXB) synthesis models, but are still an elusive component of the AGN population beyond the local Universe. Multi-wavelength surveys are the only way to find them at z >…

Astrophysics of Galaxies · Physics 2017-05-10 G. Lanzuisi

We present results of optical identification of the ASCA Large Sky Survey. X-ray sources which have hard X-ray spectra were identified with type-2 AGN at redshifts smaller than 0.5. It is supported that the absorbed X-ray spectrum of type-2…

Astrophysics · Physics 2021-07-14 M. Akiyama , K. Ohta , T. Yamada , Y. Ueda , T. Takahashi , M. Sakano , T. Tsuru , I. Lehmann , G. Hasinger

We present a detailed interpretation of the spectrum of the cosmic infrared background longwards of 5 microns and of galaxy counts from various surveys at mid-infrared, far-infrared and submillimeter wavelengths by evolving the mid-infrared…

Astrophysics · Physics 2009-11-06 R. Chary , D. Elbaz

Hot intergalactic gas in clusters, groups, and filaments emanates a continuous background of 0.5-2.0 keV X-rays that ought to be detectable with the new generation of X-ray observatories. Here we present selected results from a program to…

Astrophysics · Physics 2009-11-06 G. Mark Voit , Greg L. Bryan

We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log N - log S relation in the 2-10 keV energy band to a form close to…

X-rays offer a reliable method to identify Active Galactic Nuclei (AGN). However, in the high-redshift Universe X-ray AGN are poorly sampled due to their relatively low space density and the small areas covered by X-ray surveys. In addition…

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