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相关论文: Radio spectral index distribution of SDSS-FIRST so…

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[Abridged] We study the evolution of the radio spectral index and far-infrared/radio correlation (FRC) across the star-formation rate-stellar masse (i.e. SFR-M*) plane up to z 2. We start from a M*-selected sample of galaxies with reliable…

It has been known for nearly three decades that high redshift radio galaxies exhibit steep radio spectra, and hence ultra-steep spectrum radio sources provide candidates for high-redshift radio galaxies. Nearly all radio galaxies with z > 3…

宇宙学与河外天体物理 · 物理学 2015-05-18 C. H. Ishwara-Chandra , S. K. Sirothia , Y. Wadadekar , S. Pal , R. Windhorst

We are conducting a large observing program with the Spitzer Space Telescope to determine the mid-to-far infrared spectral energy distributions of a well-defined sample of 87 nearby, 12 micron-selected Seyfert galaxies. In this paper we…

We discuss the optical and radio properties of 30,000 FIRST sources positionally associated with an SDSS source in 1230 deg$^2$ of sky. The majority (83%) of the FIRST sources identified with an SDSS source brighter than r=21 are optically…

The vast majority of extragalactic compact continuum radio sources are associated with star formation or jets from (super)massive black holes and, as such, are more likely to be found in association with starburst galaxies or early-type…

高能天体物理现象 · 物理学 2023-12-20 D. Vohl , H. K. Vedantham , J. W. T. Hessels , C. G. Bassa , D. O. Cook , D. L. Kaplan , T. W. Shimwell , C. Zhang

We use the Expanded Very Large Array to image radio continuum emission from local luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in 1 GHz windows centered at 4.7, 7.2, 29, and 36 GHz. This allows us to probe the integrated…

Extra-galactic radio sources are a significant contaminant in cosmic microwave background and Sunyaev-Zel'dovich effect experiments. Deep interferometric observations with the BIMA and OVRO arrays are used to characterize the spatial,…

The flux density spectra of radio pulsars are known to be steep and, to first order, described by a power-law relationship of the form S_{\nu} \propto \nu^{\alpha}, where S_{\nu} is the flux density at some frequency \nu and \alpha is the…

太阳与恒星天体物理 · 物理学 2015-06-15 Samuel D. Bates , Duncan R. Lorimer , Joris P. W. Verbiest

We analyze radio continuum emission of early-type galaxies with dynamical measurements of central super-massive black hole (SMBH) masses, and well-characterized large-scale environments, but regardless on the exact level of the nuclear…

星系天体物理 · 物理学 2023-03-08 Anna Wójtowicz , Łukasz Stawarz , C. C. Cheung , Norbert Werner , Dominik Rudka

We present 0.5 -160 micron Spectral Energy Distributions (SEDs) of galaxies, detected at 70microns with the Multiband Imaging Photometer for Spitzer (MIPS), using broadband imaging data from Spitzer and ground-based telescopes.…

We have started a search for High Redshift Radio Galaxies (HZRGs) in an area covering 7 sr by selecting a sample of Ultra Steep Spectrum (USS) sources with a low flux density cut-off S(1400 MHz) > 10 mJy and a steep spectral index cut-off…

天体物理学 · 物理学 2016-01-27 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley

We separate the extragalactic radio source population above ~50 uJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed…

Seyfert and LINER galaxies are known to exhibit compact radio emission on $\sim$ 10 to 100 parsec scales, but larger Kiloparsec-Scale Radio structures (KSRs) often remain undetected in sub-arcsec high resolution observations. We investigate…

星系天体物理 · 物理学 2014-10-13 Veeresh Singh , C. H. Ishwara-Chandra , Yogesh Wadadekar , Alexandre Beelen , Preeti Kharb

In the next few years the classification of radio sources observed by the large surveys will be a challenging problem, and spectral index is a powerful tool for addressing it. Here we present an algorithm to estimate the spectral index of…

We present the results of the flux density measurements at 4.85 GHz and 10.45 GHz of a sample of 5998 NVSS radio sources with the Effelsberg 100 m telescope. The initial motivation was the need to identify the NVSS radio sources that could…

宇宙学与河外天体物理 · 物理学 2015-05-13 E. Angelakis , A. Kraus , A. C. S. Readhead , J. A. Zensus , R. Bustos , T. P. Krichbaum , A. Witzel , T. J. Pearson

We present a sample of 1317 Infrared-Faint Radio Sources (IFRSs) that, for the first time, are reliably detected in the infrared, generated by cross-correlating the Wide-Field Infrared Survey Explorer (WISE) all-sky survey with major radio…

This is the third in a series of papers that present observations and results for a sample of 76 ultra-steep-spectrum radio sources designed to find galaxies at high redshift. Here we present multi-frequency radio observations, from the…

天体物理学 · 物理学 2009-11-11 I. J. Klamer , R. D. Ekers , J. J. Bryant , R. W. Hunstead , E. M. Sadler , C. De Breuck

The problems of using the spectral index of radio galaxies in various tests, in particular, in selecting distant radio sources are considered. The history of the question of choosing a criterion of searching for distant radio galaxies based…

宇宙学与河外天体物理 · 物理学 2010-03-03 O. V. Verkhodanov , M. L. Khabibullina

The Westerbork Northern Sky Survey (WENSS) has been used to select a sample of Gigahertz Peaked Spectrum (GPS) radio sources at flux densities one to two orders of magnitude lower than bright GPS sources investigated in earlier studies.…

We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al.…

天体物理学 · 物理学 2009-11-06 C. L. Carilli , F. Bertoldi , A. Omont , P. Cox , R. G. McMahon , K. G. Isaak