Observability of the virialization phase of spheroidal galaxies with radio arrays
Massardi, M ; Lapi, A ; Zotti, G De ; et al. ; - ASI Sponsor
Jan - 2008

journal : Mon. Not. R. Astron. Soc.
type: Article Journal

Abstract
In the standard galaxy formation scenario plasma clouds with a high thermal ener gy content must e xist at high redshifts since the protogalactic gas i s shock heated to the virial temperature, and e xtensi v e cooling, leading to ef ficient star formation, must a w ait the collapse of massi v e haloes (as indicated by the massi v e body of e vidence, referred to as downsizing ). Massi v e plasma clouds are potentially observ able through the thermal and kinetic Sun yae v–Zel’ do vich ef fects and their free–free emission. W e find that the detection of substantial numbers of galaxy- scale thermal Sun yae v–Zel’ do vich signals is achie v able by blind surv e y s with ne xt generation radio telescope arrays such as EVLA, ALMA and SKA. This population is e v en detectable with the 10 per cent SKA, and wide field of vie w options at high frequenc y on a ny of these arrays w ould greatly increase surv e y speed. An analysis of confusion ef fects and of the contamination by radio and dust emissions sho ws that the optimal frequencies are those in the range 10– 35 GHz. Predictions for the redshift distrib utions of detected sources are also w ork ed out.

keywords : formation,galaxies,high-redshift,instrumentation,interferometers