Browsing by Author "Ishwara-Chandra, C. H."

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    J1615+5452: a remnant radio galaxy in the ELAIS-N1 field
    (Oxford University Press, 2020) Taylor, A. R.; Randriamanakoto, Z.; Ishwara-Chandra, C. H.
    We report the discovery of a remnant radio active galactic nucleus (AGN) J1615+5452 in the field of ELAIS-N1. GMRT continuum observations at 150, 325, and 610 MHz combined with archival data from the 1.4 GHz NVSS survey were used to derive the radio spectrum of the source. At a redshift z ∼ 0.33, J1615+5452 has a linear size of ∼100 kpc and spectral indices ranging between α1400610<−1.5 and α325150=−0.61±0.12⁠. While the source has a diffuse radio emission at low frequencies, we do not find evidence of core, jets, or hotspots in the 1.4 GHz VLA data of ∼5 arcsec angular resolution.
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    A wide-area GMRT 610-MHz survey of ELAIS N1 field
    (Oxford University Press, 2020) Taylor, A. R.; Ishwara-Chandra, C. H.; Green, D. A.
    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 deg2 at a resolution of 6 arcsec and with an rms noise of ∼40 μJy beam−1. This is equivalent to ∼20 μJy beam−1 rms noise at 1.4 GHz for a spectral index of −0.75. The primary goal of the survey was to study the polarized sky at sub-mJy flux densities at < GHz frequencies, alongwith a range of other science goals such as investigations into the nature of the low-frequency μJy source populations and alignments of radio jets. A total of 6400 sources were found in this region, the vast majority of them compact.