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As a part of the ISOPHOT CIRB (Cosmic Infrared Background Radiation) project we have searched for point-like sources in eight fields mapped at two or three wavelengths between 90 and 180um. Most sources are previously unknown and based on…

Astrophysics · Physics 2007-05-23 M. Juvela , K. Mattila , D. Lemke

We construct empirical models of the diffuse gamma-ray background toward the Galactic Center. Including all known point sources and a template of emission associated with interactions of cosmic rays with molecular gas, we show that the…

High Energy Astrophysical Phenomena · Physics 2014-07-23 Kevork N. Abazajian , Nicolas Canac , Shunsaku Horiuchi , Manoj Kaplinghat

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space…

High Energy Astrophysical Phenomena · Physics 2014-12-15 Yoshiyuki Inoue

Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and the frequency of GRBs in these systems provides an important test of the connection between the gamma-ray burst rate and that of…

High Energy Astrophysical Phenomena · Physics 2016-07-22 D. A. Perley , R. A. Perley , J. Hjorth , M. J. Michałowski , S. B. Cenko , P. Jakobsson , T. Krühler , A. J. Levan , D. Malesani , N. R. Tanvir

We analyze the angular power spectrum (APS) of the unresolved gamma-ray background (UGRB) emission and combine it with the measured properties of the resolved gamma-ray sources of the Fermi-LAT 4FGL catalog. Our goals are to dissect the…

High Energy Astrophysical Phenomena · Physics 2023-07-07 Michael Korsmeier , Elena Pinetti , Michela Negro , Marco Regis , Nicolao Fornengo

A significant fraction (~30%) of the high-energy gamma-ray sources listed in the second Fermi LAT catalog (2FGL) are still of unknown origin, being not yet associated with counterparts at low energies. We recently developed a new…

High Energy Astrophysical Phenomena · Physics 2015-06-15 F. Massaro , R. D'Abrusco , A. Paggi , N. Masetti , M. Giroletti , G. Tosti , Howard A. Smith , S. Funk

We present 5 GHz high resolution VLA observations of 2,127 radio- and X-ray-emitting sources found in both the Green Bank (GB) 5 GHz radio catalog and the ROSAT All-Sky Survey (RASS). We report core flux densities and positions accurate to…

We conduct a stacking analysis using 1.4 GHz NRAO VLA Sky Survey (NVSS) detections and Planck all-sky maps to estimate the differential source counts down to the few 100 $\mu$Jy level at 30, 44, 70 and 100 GHz. Consequently, we are able to…

Astrophysics of Galaxies · Physics 2018-07-11 Eric J. Murphy , Ranga-Ram Chary

We present deep radio maps from the Very Large Array (VLA) for 16 sources detected in a sub-millimeter (submm) survey of the distant Universe. Our deep VLA 1.4-GHz maps allow us to identify radio counterparts or place stringent limits…

Astrophysics · Physics 2009-10-31 Ian Smail , R. J. Ivison , F. N. Owen , A. W. Blain , J. -P. Kneib

In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 John Kehayias , Thomas W. Kephart , Thomas J. Weiler

We report the Fermi Large Area Telescope detection of extended gamma-ray emission from the lobes of the radio galaxy Fornax A using 6.1 years of Pass 8 data. After Centaurus A, this is now the second example of an extended gamma-ray source…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT Collaboration

We use the recent measurement of the isotropic $\gamma$-ray background (IGRB) by Fermi LAT and analysis of the contribution of unresolved point $\gamma$-ray sources to IGRB to build constraints on the models of ultra-high cosmic rays…

High Energy Astrophysical Phenomena · Physics 2016-11-23 Oleg Kalashev

We present constraints on the density of halo dark matter candidates within the solar circle based on the anisotropy in the high energy gamma-ray background. The known galactic components of the gamma-ray background, in particular the…

Astrophysics · Physics 2007-05-23 R. Chary , E. L. Wright

Recent observations of the diffuse Galactic gamma-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the…

High Energy Astrophysical Phenomena · Physics 2017-08-17 G. Morlino , M. D'Angelo , P. Blasi , E. Amato

This Chapter provides a review of $\gamma$-ray sources lying at high Galactic latitudes. Their statistical properties and variability status, as well as studies involving cross correlations with lower frequency catalogs and multiwavelength…

Astrophysics · Physics 2007-05-23 Diego F. Torres

In this letter, we introduce a new method of image stacking to directly study the undetected but possible gamma-ray point sources. Applying the method to the Australia Telescope 20 GHz Survey (AT20G) sources which have not been detected by…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Ming Zhou , Jiancheng Wang , Xiaoyan Gao

Cosmic rays accelerated to ultra-high energies (E>4x10^19 eV) in electric fields in accretion discs around supermassive black holes are discussed. Particle injection spectra are assumed to be harder than those formed in acceleration on…

High Energy Astrophysical Phenomena · Physics 2020-01-08 A. Uryson

Recent studies have found a positive correlation between the star-formation rate of galaxies and their gamma-ray luminosity. Galaxies with a high star-formation rate are expected to produce a large amount of high-energy cosmic rays, which…

High Energy Astrophysical Phenomena · Physics 2016-08-17 Cesar Rojas-Bravo , Miguel Araya

The extragalactic background radiation produced by distant galaxies emitting in the far infrared limits the sensitivity of telescopes operating in this range due to confusion. We have constructed a model of the infrared background based on…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-19 S. V. Pilipenko , M. V. Tkachev , A. A. Ermash , T. I. Larchenkova , E. V. Mikheeva , V. N. Lukash

The discovery of distant sources of very high energy (VHE) gamma-rays with hard energy spectra enabled to derive strong upper limits on the density of the extragalactic background light (EBL). These limits are close to the lower limits…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 M. Raue
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