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相关论文: Diffuse steep-spectrum sources from the 74 MHz VLS…

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We present serendipitous detections of radio sources at 28.5 GHz (1 cm), which resulted from our program to image thermal Sunyaev-Zeldovich (SZ) effect in 56 galaxy clusters. We find 64 radio sources with fluxes down to 0.4 mJy, and within…

天体物理学 · 物理学 2009-10-30 Asantha R. Cooray , Laura Grego , William L. Holzapfel , Marshall Joy , John E. Carlstrom

Diffuse radio emission in galaxy clusters is known to be related to cluster mass and cluster dynamical state. We collect the observed fluxes of radio halos, relics, and mini-halos for a sample of galaxy clusters from the literature, and…

宇宙学与河外天体物理 · 物理学 2015-11-24 Z. S. Yuan , J. L. Han , Z. L. Wen

Several problems regarding the process of galaxy formation are still open. One of them is the role played by AGN phenomena in contributing to galaxy build-up and to Star Formation (SF) quenching. On the other hand, the theory of AGN…

星系天体物理 · 物理学 2015-04-15 Nicola Malavasi , Sandro Bardelli , Paolo Ciliegi , Olivier Ilbert , Lucia Pozzetti , Elena Zucca

I extract the radio spectral index, $\alpha$, from 541,195 common sources observed in the 150 MHz TIFR GMRT Sky Survey (TGSS) and the 1.4 GHz NRAO VLA Sky Survey (NVSS). This large common source catalogue covers about $80\%$ of the sky. The…

星系天体物理 · 物理学 2019-07-26 Prabhakar Tiwari

We present a multifrequency radio continuum study of seven giant low surface brightness (GLSB) galaxies using the Giant Metrewave Radio Telescope (GMRT). GLSB galaxies are optically faint, dark-matter dominated systems that are poorly…

星系天体物理 · 物理学 2015-06-23 Alka Mishra , N. G. Kantharia , M. Das , D. C. Srivastava , S. N. Vogel

Using Chandra imaging spectroscopy and VLA L-band maps, we have identified radio galaxies at P(1.4 GHz) >= 3x10^{23} W Hz^{-1} and X-ray point sources (XPSs) at L(0.3-8 keV) >= 10^{42} ergs s^{-1} in 11 moderate redshift (0.2<z<0.4)…

宇宙学与河外天体物理 · 物理学 2009-10-16 Quyen N. Hart , John T. Stocke , Eric J. Hallman

We investigate the properties of the environment around 20 powerful radio galaxies and quasars at redshifts between 0.45 and 1. Using XMM-Newton and Chandra observations we probe the spatial distribution and the temperature of the cluster…

天体物理学 · 物理学 2009-11-13 Elena Belsole , Diana M. Worrall , Martin J. Hardcastle , Judith H. Croston

We present high sensitivity radio observations of the merging cluster A521, at a mean redsfhit z=0.247. The observations were carried out with the GMRT at 610 MHz and cover a region of $\sim$1 square degree, with a sensitivity limit of…

天体物理学 · 物理学 2009-11-11 S. Giacintucci , T. Venturi , S. Bardelli , G. Brunetti , R. Cassano , D. Dallacasa

Cosmological shocks are a critical part of large-scale structure formation, and are responsible for heating the intracluster medium in galaxy clusters. In addition, they are also capable of accelerating non-thermal electrons and protons. In…

宇宙学与河外天体物理 · 物理学 2015-05-19 Samuel W. Skillman , Eric J. Hallman , Brian W. O'Shea , Jack O. Burns , Britton D. Smith , Matthew J. Turk

High-resolution radio observations of nearby starburst galaxies have shown that the distribution of their radio emission consists of a compact (<150 pc), high surface brightness, central radio source immersed in a low surface brightness…

天体物理学 · 物理学 2008-04-29 Miguel A. Perez-Torres , Antonio Alberdi

We used archival very long baseline interferometry (VLBI) data of active galactic nuclei (AGN) observed from 1.4 GHz to 86 GHz to measure the angular size of VLBI radio cores in 8959 AGNs. We analysed their sky distributions, frequency…

星系天体物理 · 物理学 2022-08-15 T. A. Koryukova , A. B. Pushkarev , A. V. Plavin , Y. Y. Kovalev

Many galaxy clusters host Mpc scale diffuse radio sources called radio halos. Their origin is connected to the processes that lead to the formation of clusters themselves. In order to unveil this connection, statistical studies of radio…

宇宙学与河外天体物理 · 物理学 2021-03-10 V. Cuciti , R. Cassano , G. Brunetti , D. Dallacasa , F. de Gasperin , S. Ettori , S. Giacintucci , R. Kale , G. W. Pratt , R. J. van Weeren , T. Venturi

Galaxy clusters grow by mergers with other clusters and galaxy groups. These mergers create shocks within the intracluster medium (ICM). It is proposed that within the shocks particles can be accelerated to extreme energies. In the presence…

宇宙学与河外天体物理 · 物理学 2015-05-28 R. J. van Weeren , M. Bruggen , H. J. A. Rottgering , M. Hoeft

Some galaxy clusters contain non-thermal synchrotron emitting plasma permeating the intracluster medium (ICM). The spectral properties of this radio emission are not well characterized at decameter wavelengths ({\nu} < 30 MHz), primarily…

宇宙学与河外天体物理 · 物理学 2024-12-10 C. Groeneveld , R. J. van Weeren , A. Botteon , R. Cassano , F. de Gasperin , E. Osinga , G. Brunetti , H. J. A. Röttgering

We use deep Herschel observations of the complete 2Jy sample of powerful radio AGNs in the local universe (0.05 < z < 0.7) to probe their cool interstellar medium (ISM) contents and star-forming properties, comparing them against other…

星系天体物理 · 物理学 2022-03-02 E. Bernhard , C. N. Tadhunter , J. C. S. Pierce , D. Dicken , R. Morganti , C. Ramos Almeida , E. Daddi

Aims. We investigate the radio loudness ($\mathcal{R}$) distribution in a large, homogeneous sample of radio galaxies. Methods. The sample is composed of galaxies from the ROGUE I/II catalogue belonging to the SDSS MGS and is divided into…

星系天体物理 · 物理学 2026-04-01 A. Wójtowicz , N. Vale Asari , Ł. Stawarz , G. Stasinska , D. Kozieł-Wierzbowska

Compact Steep Spectrum (CSS) radio sources are active galactic nuclei that have radio jets propagating only on galactic scales, defined as having projected linear sizes (LS) of up to $20\,$kpc. CSS sources are generally hosted by massive…

星系天体物理 · 物理学 2023-05-10 Yjan A. Gordon , Christopher P. O'Dea , Stefi A. Baum , Keith Bechtol , Chetna Duggal , Peter S. Ferguson

Feedback by radio-loud active galactic nuclei (AGN) in galaxy groups is not fully understood. Open questions include the duty cycle of the AGN, the spatial extent of the radio lobes, the effect they have on the intragroup medium, and the…

We report on new 1.41 GHz Green Bank Telescope and 352 MHz Westerbork Synthesis Radio Telescope observations of the Coma cluster and its environs. At 1.41 GHz we tentatively detect an extension to the Coma cluster radio relic source…

宇宙学与河外天体物理 · 物理学 2015-05-20 Shea Brown , Lawrence Rudnick

The organization of this paper is as follows: the basic formulae used to derive the age of synchrotron sources and the equipartition parameters are presented in Section 2, while the observational properties of diffuse radio sources (Radio…

天体物理学 · 物理学 2015-06-24 Luigina Feretti , Gabriele Giovannini
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