1st of November 2016 |
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ATCA detections of massive molecular gas reservoirs in dusty, high-z radio galaxies |
by Ian Heywood (CASS) |
Today's ATNF Daily Astronomy Picture (ADAP)
shows ATCA 7 mm spectra of
two optically-faint, narrow-line radio galaxies with redshifts > 2 (left
panels), corresponding to a lookback time of about ten billion years. Strong
detections of 12CO are found in both systems, with line profiles
that are probably indicative of on-going mergers. The mass of molecular
hydrogen inferred from these spectra is 100 billion solar masses in each
system. Modelling the far-infrared data from
Herschel-ATLAS implies a billion solar
masses of dust, and a correspondingly large amount of on-going obscured star
formation, approximately 1000 solar masses per year. The right hand panels
show composite H-ATLAS images using the 500, 350 and 250 micron data. Despite
the targets being `typical' high-z radio sources in terms of their 1.4 GHz
radio luminosities, they have gas and dust properties similar to those of the
most extreme sub-mm galaxies and quasars at high redshift. The question is,
how typical is this? Credit: Heywood et al., MNRAS 2016, in press. |