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Related papers: The extragalactic radio-source population at 95 GH…

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We have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($\alpha…

Astrophysics of Galaxies · Physics 2011-02-11 K. S. Dwarakanath , Ruta Kale

We present initial results from a follow-up of the 9C survey, complete to 25 mJy at 15 GHz, designed to assemble and investigate a sample of young radiosources. We have made radio continuum maps of 111 sources at frequencies spanning 1.4-43…

I describe an observational program aimed at understanding the radio emission from distant, rapidly evolving galaxy populations. These observations were carried out at 1.4 and 8.5 GHz with the VLA centered on the Hubble Deep Field. Further…

Astrophysics · Physics 2009-10-31 E. A. Richards

We have studied the optical, near-IR and radio properties of a complete sample of 43 sources detected at 15-micron in one of the deeper ELAIS repeatedly observed region. The extragalactic objects in this sample have 15-micron flux densities…

This paper analyses the radio properties of a subsample of optically obscured (R>25.5) galaxies observed at 24um by the Spitzer Space Telescope within the First Look Survey. 96 F[24um]>0.35 mJy objects out of 510 are found to have a radio…

Astrophysics · Physics 2009-11-13 M. Magliocchetti , P. Andreani , M. A. Zwaan

Using the JVLA, we explored the Galactic center (GC) with a resolution of 0.05" at 33.0 and 44.6 GHz. We detected 64 hyper-compact radio sources (HCRs) in the central parsec. The dense group of HCRs can be divided into three spectral types:…

Astrophysics of Galaxies · Physics 2022-03-09 Jun-Hui Zhao , Mark R. Morris , W. M. Goss

We tested the effectiveness of radio selection to discover heavily obscured AGNs, particularly at high-z, and we measured their abundance for the first time from a radio perspective. We consider the radio sources detected in the J1030…

The Planck-ATCA Co-eval Observations (PACO) project has yielded observations of 464 sources with the Australia Telescope Compact Array (ATCA) between 4.5 and 40 GHz. The main purpose of the project was to investigate the spectral properties…

We identified 15,658 NVSS radio sources among the 55,288 2MASX galaxies brighter than $k_\mathrm{20fe} = 12.25$ at $\lambda = 2.16\,\mu\mathrm{m}$ and covering the $\Omega =7.016$ sr of sky defined by J2000 $\delta > -40^\circ$ and $\vert b…

Astrophysics of Galaxies · Physics 2019-02-27 J. J. Condon , A. M. Matthews , J. J. Broderick

We present the first results of a systematic search for the rare extragalactic radio sources showing an inverted (integrated) spectrum, with spectral index $\alpha \ge +2.0$, a previously unexplored spectral domain. The search is expected…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Gopal-Krishna , S. K. Sirothia , Mukul Mhaskey , Pritesh Ranadive , Paul J. Wiita , A. Goyal , N. G. Kantharia , C. H. Ishwara-Chandra

We follow up on a report by Vacca et al. (2018) of 28 candidate large-scale diffuse synchrotron sources in an 8{\deg}$\times$8{\deg} area of the sky (centred at RA 5h0m0s Dec 5{\deg}48'0''). These sources were originally observed at 1.4 GHz…

Astrophysics of Galaxies · Physics 2022-05-27 Torrance Hodgson , Melanie Johnston-Hollitt , Benajmin McKinley , Tessa Vernstrom , Valentina Vacca

We present 1.4 and 5 GHz observations taken with the Very Large Array (VLA), and observations at 250 GHz obtained with the Max-Planck millimeter bolometer (MAMBO) at the IRAM 30~m telescope, of ten optically selected Quasi-stellar Objects…

We review estimates of small scale fluctuations due to extragalactic point sources in the Planck Surveyor frequency bands. While our undestanding of the spectral and evolutionary properties of these sources is far from complete,…

Astrophysics · Physics 2007-05-23 G. De Zotti , L. Toffolatti , G. L. Granato

We present very long baseline interferometry (VLBI) observations of 179 radio sources in the COSMOS field with extremely high sensitivity using the Green Bank Telescope (GBT) together with the Very Long Baseline Array (VLBA) (VLBA+GBT) at…

We present measurements of the clustering properties of galaxies in the field of redshift range $0.5 \lesssim z \lesssim 1.5$ Ultra Steep Spectrum (USS) radio sources selected from Sydney University Molonglo Sky Survey and NRAO VLA Sky…

Astrophysics · Physics 2009-11-11 Carlos G. Bornancini , Nelson Padilla , Diego G. Lambas , Carlos De Breuck

We present a new image of the 5.5 GHz radio emission from the extended Chandra Deep Field South. Deep radio observations at 5.5 GHz were obtained in 2010 and presented in the first data release. A further 76 hours of integration has since…

Astrophysics of Galaxies · Physics 2015-10-07 M. T. Huynh , M. E. Bell , A. M. Hopkins , R. P. Norris , N. Seymour

Extragalactic peaked-spectrum radio sources are thought to be the progenitors of larger, radio-loud active galactic nuclei (AGN). Synchrotron self-absorption (SSA) has often been identified as the cause of their spectral peak. The…

Astrophysics of Galaxies · Physics 2019-08-07 M. A. Keim , J. R. Callingham , H. J. A. Röttgering

We use the recent releases of sensitive VLA/LOFAR large-area surveys at 340 MHz and 54 MHz, in conjunction with the 1.4 GHz NVSS, to accurately determine the `spectral index - flux density relation' ($\alpha$ - S) for extragalactic radio…

Astrophysics of Galaxies · Physics 2023-07-05 Pratik Dabhade , Gopal-Krishna

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…

Astrophysics of Galaxies · Physics 2019-07-26 Prabhakar Tiwari

From an on-going survey of the Galactic bulge, we have discovered a number of compact, steep spectrum radio sources. In this present study we have carried out more detailed observations for two of these sources, located 43 arcmin and 12.7…

High Energy Astrophysical Phenomena · Physics 2021-07-21 S. D. Hyman , D. A. Frail , J. S. Deneva , N. E. Kassim , S. Giacintucci , J. E. Kooi , T. J. W. Lazio , I. Joyner , W. M. Peters , V. Gajjar , A. P. V. Siemion
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