HI gas in the rejuvenated radio galaxy 4C29.30

Abstract

We report the results of our observations of H I absorption towards the central region of the rejuvenated radio galaxy 4C29.30 (J0840+2949) with the Giant Metrewave Radio Telescope. The radio source has diffuse, extended emission with an angular size of ~520 arcsec (639 kpc) within which a compact edge-brightened double-lobed source with a size of 29 arcsec (36 kpc) is embedded. The absorption profile which is seen towards the central component of the inner double is well resolved and consists of six components; all but one of which appears to be redshifted relative to the optical systemic velocity. The neutral hydrogen column density is estimated to be N(HI) = 4.7 × 1021(Ts/100)(fc/1.0) cm-2, where Ts and fc are the spin temperature and covering factor of the background source, respectively. This detection reinforces a strong correlation between the occurrence of H I absorption and rejuve nation of radio activity suggested earlier, with the possibility that the redshifted gas is fuelling the recent activity. © 2010 The Authors. Journal compilation © 2010 RAS.