The Arecibo Galaxy Environment Survey - II. A H i view of the Abell cluster 1367 and its outskirts

Abstract

We present 21 cm H I line observations of 5 1 deg 2 centred on the local Abell cluster 1367 obtained as part of the Arecibo Galaxy Environment Survey. One hundred sources are detected (79 new H I measurements and 50 new redshifts), more than half belonging to the cluster core and its infalling region. Combining the H I data with Sloan Digital Sky Survey (SDSS) optical imaging, we show that our H I selected sample follows scaling relations similar to the ones usually observed in optically selected samples. Interestingly, all galaxies in our sample appear to have nearly the same baryon fraction independently of their size, surface brightness and luminosity. The most striking difference between H I and optically selected samples resides in their large-scale distribution: whereas optical and X-ray observations trace the cluster core very well, in H I there is almost no evidence of the presence of the cluster. Some implications on the determination of the cluster luminosity function and H I distribution for samples selected at different wavelength are also discussed.