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We present the first targeted measurement of the power spectrum of anisotropies of the radio synchrotron background, at 140 MHz where it is the overwhelmingly dominant photon background. This measurement is important for understanding the…

宇宙学与河外天体物理 · 物理学 2023-07-06 A. R. Offringa , J. Singal , S. Heston , S. Horiuchi , D. M. Lucero

The faint radio point sources that are unresolved in cosmic microwave background (CMB) anisotropy maps are likely to be a biased tracer of the large-scale structure dark matter distribution. While the shot-noise contribution to the angular…

天体物理学 · 物理学 2008-11-26 Paolo Serra , Asantha Cooray , Alexandre Amblard , Luca Pagano , Alessandro Melchiorri

We report a measurement of anisotropy in the cosmic microwave background radiation (CMBR) on 7-22 arcminute scales. Observations of 36 fields near the North Celestial Pole (NCP) were made at 31.7 and 14.5 GHz, using the 5.5-meter and…

天体物理学 · 物理学 2007-05-23 E. M. Leitch , A. C. S. Readhead , T. J. Pearson , S. T. Myers , S. Gulkis , C. R. Lawrence

Dusty, starforming galaxies and active galactic nuclei that contribute to the integrated background intensity at far-infrared wavelengths trace the large-scale structure. Below the point source detection limit, correlations in the…

天体物理学 · 物理学 2008-11-26 Alexandre Amblard , Asantha Cooray

The origin of the radio synchrotron background (RSB) is currently unknown. Its understanding might have profound implications in fundamental physics or might reveal a new class of radio emitters. In this work, we consider the scenario in…

We estimate the contribution of extragalactic radio sources to fluctuations in sky temperature over the range of frequencies (10-300 GHz) used for Cosmic Microwave Background (CMB) anisotropy measurements. CMB anisotropy observations at…

天体物理学 · 物理学 2007-05-23 Aaron Sokasian , Eric Gawiser , George F. Smoot

Galactic foreground emission is a limiting factor for precise cosmic microwave background (CMB) anisotropy measurements. We perform an angular power spectrum analysis (APS) of all-sky total intensity maps at 408 MHz and 1420 MHz, which are…

天体物理学 · 物理学 2009-11-13 L. La Porta , C. Burigana , W. Reich , P. Reich

The existence of a radio synchrotron background (RSB) excess is implied by a number of measurements, including excess emission seen by the ARCADE~2 and LWA experiments. Highly sensitive wideband radio arrays, of the kind used to measure the…

宇宙学与河外天体物理 · 物理学 2026-03-16 Zheng Zhang , Philip Bull , Katrine A. Glasscock

We present predictions on the angular power spectrum of CMB fluctuations due to extragalactic point sources (EPS) by using a method for simulating realistic 2D distributions of clustered EPS. Both radio and far--IR selected source…

天体物理学 · 物理学 2009-11-10 J. González-Nuevo , L. Toffolatti , F. Argüeso

We explore the possibility of detecting the excess of the cosmic radio background (CRB) toward galaxy clusters due to its Compton scattering by electrons of the hot intergalactic gas. When mapping the background fluctuations at frequencies…

高能天体物理现象 · 物理学 2024-08-06 S. A. Grebenev , R. A. Sunyaev

We explore the large to moderate scale anisotropy in distant radio sources using the TGSS ADR1 catalog. We use different measures, i.e. number counts, sky brightness and flux per source, for this study. In agreement with earlier results, we…

宇宙学与河外天体物理 · 物理学 2019-12-20 Prabhakar Tiwari , Shamik Ghosh , Pankaj Jain

We present a study of the environments of extended radio sources in the Australia Telescope Low Brightness Survey (ATLBS). The radio sources were selected from the Extended Source Sample (ATLBS-ESS), which is a well defined sample…

宇宙学与河外天体物理 · 物理学 2015-06-16 K. Thorat , L. Saripalli , R. Subrahmanyan

Confusion noise due to extragalactic sources is a fundamental astrophysical limitation for experiments aimed at accurately determining the power spectrum of the Cosmic Microwave Background (CMB) down to arcmin angular scales and with a…

天体物理学 · 物理学 2007-05-23 L. Toffolatti , G. De Zotti , F. Argüeso , C. Burigana

Applying basic physical principles to recent observational results, we derive upper and lower limits on microwave anisotropy from point sources over the range of frequencies 10-1000 GHz. We examine the level of noise in the observations as…

天体物理学 · 物理学 2007-05-23 Eric Gawiser , Andrew Jaffe , Joseph Silk

Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this non-thermal emission component significantly exceeds the…

高能天体物理现象 · 物理学 2016-07-05 Ke Fang , Tim Linden

Anisotropies in the nanohertz gravitational-wave background are a compelling next target for pulsar timing arrays (PTAs). Measurements or informative upper limits to the anisotropies are expected in the near future and can offer important…

宇宙学与河外天体物理 · 物理学 2025-08-26 Gabriela Sato-Polito , Marc Kamionkowski

Recently, a new measurement of the auto- and cross-correlation angular power spectrum (APS) of the isotropic gamma-ray background was performed, based on 81 months of data of the Fermi Large-Area Telescope (LAT). Here, we fit, for the first…

高能天体物理现象 · 物理学 2017-06-21 Shin'ichiro Ando , Mattia Fornasa , Nicolao Fornengo , Marco Regis , Hannes-S. Zechlin

The small angular scale fluctuations of the (on large scale) isotropic gamma-ray background (IGRB) carry information about the presence of unresolved source classes. A guaranteed contribution to the IGRB is expected from the unresolved…

高能天体物理现象 · 物理学 2019-08-15 A. Cuoco , T. Linden , M. N. Mazziotta , J. M. Siegal-Gaskins , Vincenzo Vitale , E. Komatsu

While the arcminute-scale Cosmic Microwave Background (CMB) anisotropies are due to secondary effects, point sources dominate the total anisotropy power spectrum. At high frequencies the point sources are primarily in the form of dusty,…

We present a measurement of the angular power spectrum of the cosmic far-infrared background (CFIRB) anisotropies in one of the extragalactic fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) at 250, 350 and 500 \mu…

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