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Related papers: A Deep 150 MHz GMRT Survey in Eridanus

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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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. H. Ishwara-Chandra , S. K. Sirothia , Y. Wadadekar , S. Pal , R. Windhorst

We present the first full release of a survey of the 150 MHz radio sky, observed with the Giant Metrewave Radio Telescope between April 2010 and March 2012 as part of the TGSS project. Aimed at producing a reliable compact source survey,…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-08 H. T. Intema , P. Jagannathan , K. P. Mooley , D. A. Frail

High red-shift radio galaxies are best searched at low radio frequencies, due to its steep radio spectra. Here we present preliminary results from our programme to search for high red-shift radio galaxies to ~ 10 to 100 times fainter than…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Susanta Kumar Bisoi , C. H. Ishwara-Chandra , S. K. Sirothia , P. Janardhan

Ultra Steep Spectrum (USS) radio sources are one of the efficient tracers of High Redshift Radio Galaxies (HzRGs). To search for HzRGs candidates, we investigate properties of a large sample of faint USS sources derived from our deep 325…

Ultra-steep spectrum (USS) radio sources are good tracers of powerful radio galaxies at $z > 2$. Identification of even a single bright radio galaxy at $z > 6$ can be used to detect redshifted 21cm absorption due to neutral hydrogen in the…

Astrophysics of Galaxies · Physics 2018-01-31 A. Saxena , P. Jagannathan , H. J. A. Röttgering , P. N. Best , H. T. Intema , M. Zhang , K. J. Duncan , C. L. Carilli , G. K. Miley

In this paper we present a wide-area 610 MHz survey of the ELAIS\,N1 field with the GMRT, covering an area of 12.8 deg$^2$ at a resolution of 6 arcsec and with an rms noise of $\sim 40$ $\mu$Jy beam$^{-1}$. This is equivalent to $\sim 20$…

Astrophysics of Galaxies · Physics 2020-08-19 C. H. Ishwara-Chandra , A. R. Taylor , D. A. Green , J. M. Stil , M. Vaccari , E. F. Ocran

We present a 74 MHz survey of a 165 square degree region located near the north galactic pole. This survey has an unprecedented combination of both resolution (25'' FWHM) and sensitivity (RMS noise as low as 24 mJy/beam). We detect 949…

Astrophysics · Physics 2009-11-10 A. S. Cohen , H. J. A. Rottgering , M. J. Jarvis , N. E. Kassim , T. J. W. Lazio

In this paper we present follow-up optical observations of Ultra Steep Spectrum sources that were found by matching 150 MHz GMRT sources with either the 74 MHz VLSS or the 1400 MHz NVSS. These sources are possibly high-redshift radio…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-12 Samuel J. George , Ian R. Stevens

We describe a 325-MHz survey, undertaken with the Giant Metrewave Radio Telescope (GMRT), which covers a large part of the three equatorial fields at 9, 12 and 14.5 h of right ascension from the Herschel-Astrophysical Terahertz Large Area…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 T. Mauch , H. -R. Klöckner , S. Rawlings , M. J. Jarvis , M. J. Hardcastle , D. Obreschkow , D. J. Saikia , M. A. Thompson

We present results of deep 150 MHz observations with the GMRT which show several extended radio sources with a range of morphologies. These sources have then further followed up at higher frequencies (610 and 1400 MHz) with the GMRT. GMRT…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-17 S. J. George , C. H. Ishwara-Chandra

Understanding the low-frequency radio sky in depth is necessary to subtract foregrounds in order to detect the redshifted 21 cm signal of neutral hydrogen from the Cosmic Dawn, Epoch of Reionization (EoR) and post-reionization era. In this…

We report preliminary results of a visual inspection of ~4300 deg$^2$ covered by 4414 images of the 3-GHz VLA Sky Survey (VLASS, epoch 1.1) in search of extended radio structures. Over 7600 positions were registered, and for a subset of 270…

Astrophysics of Galaxies · Physics 2018-08-23 Agueda C. Villarreal Hernández , Heinz Andernach

In our first paper we described three regions of the 9C survey of radio sources with the Ryle telescope at 15.2 GHz, constituting a total area of 520 deg^2 to a completeness limit of approximately 25 mJy. Here we report on a series of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 E. M. Waldram , G. G. Pooley , M. L. Davies , K. J. B. Grainge , P. F. Scott

We present observations of the European Large-Area {\it ISO} Survey-North 1 (ELAIS-N1) at 325 MHz using the Giant Metrewave Radio Telescope (GMRT), with the ultimate objective of identifying active galactic nuclei and starburst galaxies and…

Astrophysics · Physics 2009-11-13 S. K. Sirothia , M . Dennefeld , D. J. Saikia , H. Dole , F. Ricquebourg , J. Roland

We have observed an area of approximatley 27 deg^2 to an rms noise level of less than 0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute the most sensitive radio-source survey of any…

We report the results of a visual inspection of images of the Rapid ASKAP Continuum Survey (RACS) in search of extended radio galaxies (ERG) that reach or exceed linear sizes on the order of one Megaparsec. We searched a contiguous area of…

Astrophysics of Galaxies · Physics 2021-11-18 Heinz Andernach , Eric F. Jiménez-Andrade , Anthony G. Willis

We present the first results from a pilot study to search for distant radio galaxies in the southern hemisphere (delta < -32). Within a 360 deg^2 region of sky, we define a sample of 76 ultra-steep spectrum (USS) radio sources from the 843…

Since radio sources with Ultra Steep Spectra (USS; alpha <~ -1.30; S ~ nu^alpha) are efficient tracers of high redshift radio galaxies (HzRGs), we have defined three samples of such USS sources using the recently completed WENSS, TEXAS,…

Astrophysics · Physics 2011-05-23 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley

We have used the 150 MHz radio continuum survey (TGSS ADR) from the Giant Metrewave Radio Telescope (GMRT) to search for phase-averaged emission toward all well-localized radio pulsars north of -53deg Declination. We detect emission toward…

High Energy Astrophysical Phenomena · Physics 2016-10-05 D. A. Frail , P. Jagannathan , K. P. Mooley , H. T. Intema

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…

Astrophysics · Physics 2016-01-27 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley
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