Title:	Serendipitous discovery of a dying giant radio galaxy associated with NGC 1534, using the Murchison Widefield array
Authors:	Hurley-Walker, N. Deshpande, A.A. Prabu, T. Udaya Shankar, N. Srivani, K.S. Subrahmanyan, Ravi +25 Co-authors
Keywords:	techniques interferometric Radio continuum
Issue Date:	1-Mar-2015
Publisher:	Oxford University Press for The Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2015, Vol. 447, p2468-2478
Abstract:	Recent observations with the Murchison Widefield Array at 185 MHz have serendipitously unveiled a heretofore unknown giant and relatively nearby (z = 0.0178) radio galaxy associated with NGC 1534. The diffuse emission presented here is the first indication that NGC 1534 is one of a rare class of objects (along with NGC 5128 and NGC 612) in which a galaxy with a prominent dust lane hosts radio emission on scales of ∼700 kpc. We present details of the radio emission along with a detailed comparison with other radio galaxies with discs. NGC 1534 is the lowest surface brightness radio galaxy known with an estimated scaled 1.4-GHz surface brightness of just 0.2 mJy arcmin−2. The radio lobes have one of the steepest spectral indices yet observed: α = −2.1 ± 0.1, and the core to lobe luminosity ratio is <0.1 per cent. We estimate the space density of this low brightness (dying) phase of radio galaxy evolution as 7 × 10−7 Mpc−3 and argue that normal AGN cannot spend more than 6 per cent of their lifetime in this phase if they all go through the same cycle.
Description:	Open Access
URI:	http://hdl.handle.net/2289/6190
ISSN:	0035-8711 1365-2966 - (online)
Alternative Location:	http://adsabs.harvard.edu/abs/2015MNRAS.447.2468H http://arxiv.org/abs/1412.3856 http://dx.doi.org/10.1093/mnras/stu2570
Copyright:	2015 The authors & the Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.