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Related papers: Nearby Galaxies and the Ginga X-ray Background

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We have cross-correlated the galaxies from the IRAS 2 Jy redshift survey sample and the 0.7 Jy projected sample with the all-sky cosmic X-ray background (CXB) map obtained from the HEAO-1 A2 experiment. We have developed a formulation to…

Astrophysics · Physics 2009-10-22 Takamitsu Miyaji , Ofer Lahav , Keith Jahoda , Elihu Boldt

The intensity of the soft X-Ray background is correlated with the distribution of galaxies. To demonstrate this, magnitude limited galaxy samples extracted from bright galaxy catalogues and the Lick counts are utilized. Significant…

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…

Recent ROSAT surveys suggest that galaxies constitute the new class of X-ray sources required to explain the full phenomenology of the cosmic X-Ray Background (XRB). To test this hypothesis, we compute the two-point cross-correlation…

Astrophysics · Physics 2016-08-30 A. Refregier , D. J. Helfand , R. G. McMahon

We report the identification of a positive cross-correlation signal between the unresolved $\gamma$-ray emission, measured by the \emph{Fermi} Large Area Telescope, and four different galaxy cluster catalogues. The selected catalogues peak…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-07 Manuel Colavincenzo , Xiuhui Tan , Simone Ammazzalorso , Stefano Camera , Marco Regis , Jun-Qing Xia , Nicolao Fornengo

Large-scale fluctuations of the X-ray background are investigated using the ROSAT All-Sky Survey. The autocorrelation function of the extragalactic background at 1 keV is determined at separations 0.1 - 40 deg. We detect a significant…

The foreground component of the X-ray Background (XRB) can be studied by cross-correlating its intensity with galaxy catalogs. We computed the two-point cross-correlation function $W_{xg}$ between 67 {\em Einstein} X-ray fields and the APM…

Astrophysics · Physics 2007-05-23 A. Refregier , D. J. Helfand , R. G. McMahon

A significant cross-correlation between the unresolved X-ray background (XRB) at soft energies (0.5 to 2 keV) and foreground bright galaxies has now been reported in several studies. This cross-correlation has been interpreted in terms of a…

Astrophysics · Physics 2011-05-23 Asantha R. Cooray

We use Chandra deep observations of the Galactic Center (GC) region to improve the constraints on the unresolved fraction of the Galactic X-ray background (also known as the Galactic ridge X-ray emission). We emphasize the importance of…

Astrophysics · Physics 2009-11-11 M. Revnivtsev , A. Vikhlinin , S. Sazonov

A careful analysis of the HEAO1 A2 2-10 keV full-sky map of the X-ray background (XRB) reveals clustering on the scale of several degrees. After removing the contribution due to beam smearing, the intrinsic clustering of the background is…

Astrophysics · Physics 2009-11-07 S. P. Boughn , R. G. Crittenden , G. P. Koehrsen

The X-ray background is generated by various classes of objects and variety of emission mechanisms. Relative contribution of individual components depends on energy. The goal is to assess the integral emission of the major components of the…

Astrophysics · Physics 2009-11-13 A. M. Soltan

We present a formalism describing the physical content of cross-correlation functions between a diffuse background and a population of discrete sources. The formalism is used to interpret cross-correlation signals between the unresolved…

Astrophysics · Physics 2015-06-24 M. A. Treyer , O. Lahav

At the faint end of the deepest X-ray surveys, a population of X-ray luminous galaxies is seen. In this paper, we present the results of a cross-correlation between the residual, unresolved X-ray photons in a very deep X-ray survey and the…

Astrophysics · Physics 2009-10-31 A. M. Newsam , I. M. McHardy , L. Jones , K. Mason

We compute the real-space cluster-galaxy cross-correlation xi_cg(r) using the ROSAT-ESO Flux Limited X-ray (REFLEX) cluster survey, a group catalogue constructed from the final version of the 2dFGRS, and galaxies extracted from 2MASS and…

Astrophysics · Physics 2009-11-10 Ariel G. Sanchez , Diego G. Lambas , Hans Boehringer , Peter Schuecker

With a decade of gamma-ray data from the Fermi-LAT telescope, we can now hope to answer how well we know the local Universe at gamma-ray frequencies. On the other hand, with gamma-ray data alone it is not possible to directly access the…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-27 Simone Ammazzalorso , Nicolao Fornengo , Shunsaku Horiuchi , Marco Regis

We have incorporated the description of the X-ray properties of Active Galactic Nuclei (AGNs) into a semi-analytic model of galaxy formation, adopting physically motivated scaling laws for accretion triggered by galaxy encounters. Our model…

Astrophysics · Physics 2009-11-10 N. Menci , F. Fiore , G. C. Perola , A. Cavaliere

The study of the magnification bias produced on high-redshift sub-millimetre galaxies by foreground galaxies through the analysis of the cross-correlation function was recently demonstrated as an interesting independent alternative to the…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 J. Gonzalez-Nuevo , M. M. Cueli , L. Bonavera , A. Lapi , M. Migliaccio , F. Argüeso , L. Toffolatti

The correlation between distant Gamma-Ray Bursts (GRBs) and foreground galaxy clusters is re-examined by using the well localized (with an accuracy down to a few arcseconds) Swift/XRT GRBs. The galaxy clusters are compiled from both X-ray…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 J. Wang , J. Y. Wei

Our understanding of the $\gamma$-ray sky has greatly advanced, yet studying the unresolved $\gamma$-ray background (UGRB) can unveil the nature of the faintest $\gamma$-ray source populations in the Universe. Statistical cross-correlations…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 B. Thakore , M. Regis , M. Negro , S. Camera , D. Gruen , N. Fornengo , A. Roodman

The synthesis model for the cosmic X-ray background (XRB) -based on the integrated emission of Active Galactic Nuclei (AGNs)- is complemented with new observational results. We adopt the most recent estimates of the AGN X-ray luminosity…

Astrophysics · Physics 2007-05-23 R. Gilli , G. Risaliti , M. Salvati
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