2010MNRAS.403..269C

We report the results of our observations of Hi 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) = 4.7x10²¹(T_s/100)(f_c/1.0)/cm2, where T_sand f_c are the spin temperature and covering factor of the background source, respectively. This detection reinforces a strong correlation between the occurrence of Hi absorption and rejuvenation of radio activity suggested earlier, with the possibility that the redshifted gas is fuelling the recent activity.