Universe Colloquium - Part 2: Spectral energy distribution of heavily obscured AGN beyond the local Universe

by Italo Balestra (INAF - Osservatorio Astronomico di Tieste)

Wednesday 15 Feb 2012, 17:00 → 17:30 Europe/Berlin

seminar room (basement) (Cluster building, Garching)

We present a multi-wavelength study of a sample of active galaxies (AGN) in the Chandra Deep-Field South (CDFS). We aimed at investigating the properties of the spectral energy distribution (SED) of heavily obscured AGN and their evolution with redshift, as well as with properties of their host galaxies, such as stellar mass, star-formation rate, morphology, etc. We select data from recent 4Ms Chandra observations of the CDFS. Exploiting all the publicly available photometric data and extensive spectroscopic coverage of the CDFS and Extended-CDFS, we investigate the properties of the SED of our sample of heavily-obscured AGN, by performing SED fitting of all the available photometry from the UV to the sub-millimeter bands. We fit the SEDs both using libraries of empirical templates and with synthetic SED models, making use of decomposition technique to disentangle host galaxy and AGN contribution. The SEDs of the host galaxies of the highly-obscured AGN of our sample are very heterogeneous and show a dependency with redshift, but in general always present evidences of enhanced star formation. They can be broadly subdivided into three main categories correlated to their AGN/starburst activity: 1) ULIRG and QSO, 2) strong star-forming galaxies (starburst), and 3) Seyfert 2 and "normal" galaxies.

The winter term of the Universe Colloquium ends with a double feature talk (30min each).
This is the second talk followed by a social gathering with wine & cheese.