Daftar Isi: On the dust and gas content of high-redshift galaxies hosting obscured AGN in the CDF-S

Daftar Isi:

Submillimeter Galaxies (SMGs) at high redshift are among the best targets to investigate the early evolutionary phases in the lifetime of massive systems, during which large gas reservoirs sustain vigorous star formation and efficiently feed the central, buried Super Massive Black Hole (SMBH), until it enters into luminous Quasar (QSO) phase, quenching the star formation. I will present the analysis of new ALMA band 4 (1.8-2.4 mm) data of six obscured QSOs (log(N_H) from X-ray spactra > 23) hosted by SMGs at redshift > 2.5 in the 7 Ms Chandra Deep Field South (CDF-S), and I will show their properties in terms of continuum emission and high-J CO transitions. Sizes and masses of the galaxies are measured to estimate whether and to which extent the host ISM may contribute to the nuclear absorption, under different geometry assumption. We found that these galaxies are massive (log(M_gas) ~ 10, log(M_dust) ~ 8) and compact (< 3 kpc) systems and that the ISM has column densities up to log(N_H) =24-25, comparable with those derived from the X-ray spectra, concluding that the galaxy ISM can substantially contribute to the AGN obscuration.