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Related papers: Optically Faint Microjansky Radio Sources

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We present a spectroscopic analysis of 21 galaxies with z=0.2-1.5 drawn from a 25 sq. arcmin ultra-deep 15 micron ISOCAM survey centered in the HDFS. VLT/ISAAC spectra are reported for 18 sources, aimed at detecting the redshifted Ha.…

The faint radio-source population includes sources dominated both by star formation and active galactic nuclei (AGN), encoding the evolution of activity in the Universe. To investigate its nature, we probabilistically classified 4,471 radio…

In order to examine the far-IR/radio correlation at high redshift we have studied the Spitzer 70um/far-infrared (far-IR) properties of sub-mJy radio sources from the 13^H XMM-Newton/Chandra Deep Field by redshift and galaxy type: active…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 N. Seymour , M. Huynh , T. Dwelly , M. Symeonidis , A. Hopkins , I. M. McHardy , M. Page , G. Rieke

From a survey for redshifted HI 21-cm and OH 18-cm absorption in the hosts of a sample of radio galaxies and quasars, we detect HI in three of the ten and OH in none of the fourteen sources for which useful data were obtained. As expected…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 S. J. Curran , M. T. Whiting , M. T. Murphy , J. K. Webb , C. Bignell , A. G. Polatidis , T. Wiklind , P. Francis , G. Langston

We present optical spectroscopy of 62 objects selected from several samples of ultra steep spectrum (USS) radio sources. 46 of these are from our primary catalog, consisting of 669 sources with radio spectral indices alpha < -1.30 (S_nu ~…

We present the mid-infrared spectra of seven of the most powerful radio-galaxies known to exist at 1.5 < z < 2.6. The radio emission of these sources is dominated by the AGN with 500 MHz luminosities in the range 10^27.8 - 10^29.1 W/Hz. The…

We report an ASKAP search for associated HI 21-cm absorption against bright radio sources from the Molonglo Reference Catalogue (MRC) 1-Jy sample. The search uses pilot survey data from the ASKAP First Large Absorption Survey in \hi (FLASH)…

We investigate the relationship between faint X-ray and 1.4 GHz radio source populations detected within 3' of the Hubble Deep Field North using the 1 Ms Chandra and 40 uJy VLA surveys. Within this region, we find that ~42% of the 62 X-ray…

We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field South (Kellermann et al. 2008). Using deep i-band Advanced Camera for Surveys, R-band Wide…

Context. Infrared Faint Radio Sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5 sigma sensitivities as low as 1 uJy. Aims. Recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Peter-Christian Zinn , Enno Middelberg , Edo Ibar

Using a recently completed survey of faint (sub-mJy) radio sources, selected at 1.4 GHz, a dust-free estimate of the local star formation rate (SFR) is carried out. The sample is 50% complete to 0.2 mJy, with over 50% of the radio sources…

Astrophysics · Physics 2009-10-31 B. Mobasher , L. Cram , A. Georgakakis , A. Hopkins

The radio properties of 11 obscured `radio-intermediate' quasars at redshifts z>~2 have been investigated using the European Very-Long-Baseline-Interferometry Network (EVN) at 1.66 GHz. A sensitivity of ~25 micro Jy per 14x17 mas2 beam was…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 H. -R. Kloeckner , A. Martinez-Sansigre , S. Rawlings , M. A. Garrett

We use ultradeep 20 cm data from the Karl G. Jansky Very Large Array and 850 micron data from SCUBA-2 and the Submillimeter Array of an 124 arcmin^2 region of the Chandra Deep Field-north to analyze the high radio power (P_20cm>10^31 erg…

Astrophysics of Galaxies · Physics 2017-02-15 Amy J. Barger , Lennox L. Cowie , Frazer N. Owen , Li-Yen Hsu , Wei-Hao Wang

We study the faint radio population using wide-field very long baseline interferometry (VLBI) observations of 2865 known radio sources in the Cosmic Evolution Survey (COSMOS) field. The main objective of the project was to determine where…

Gigahertz Peaked Spectrum (GPS) radio galaxies are generally thought to be the young counterparts of classical extended radio sources. Statistically complete samples of GPS sources are vital for studying the early evolution of radio-loud…

Astrophysics · Physics 2009-11-13 N. de Vries , I. A. G. Snellen , R. T. Schilizzi , M. D. Lehnert , M. N. Bremer

We present MeerKAT observations searching for HI absorption in a sample of 17 powerful ($L_{\rm 1.4GHz}> 10^{27}$ W Hz$^{-1}$) radio sources at intermediate redshifts ($0.25<z<0.7$). The sample is well characterised at radio and optical…

Astrophysics of Galaxies · Physics 2026-02-11 Raffaella Morganti , Tom Oosterloo , Clive Tadhunter , Suma Murthy

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…

We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. Half of the chosen quasars are bright at mm wavelengths (250 or 350 GHz) while the other half were not detected at…

Astrophysics · Physics 2008-11-26 A. Petric , C. L. Carilli , F. Bertoldi , A. Beelen , P. Cox , A. Omont

Extragalactic sources from the IRAS Faint Source Catalog (FSC) which have the optically faintest magnitudes (E > 18) were selected by spatial coincidence with a source in the FIRST radio survey, and 28 of these sources have been observed…

Astrophysics · Physics 2015-09-08 Lusine Sargsyan , Areg Mickaelian , Daniel Weedman , James Houck

We present a search for associated HI 21 cm absorption in a sample of 29 radio-loud active galactic nuclei (AGNs) at $0.7 < z < 1$, carried out with the upgraded Giant Metrewave Radio Telescope. We detect HI 21 cm absorption against none of…

Astrophysics of Galaxies · Physics 2022-03-30 Suma Murthy , Raffaella Morganti , Nissim Kanekar , Tom Oosterloo
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