Variability: who cares? or…. Photometric redshift for XMM-COSMOS sources. M.Salvato, G. Hasinger, O. Ilbert, G. Zamorani, M.Brusa + COSMOS collaboration. Salvato et al. 2009,ApJ, accepted. In order to better understand the role (if any) of the
M.Salvato, G. Hasinger, O. Ilbert, G. Zamorani, M.Brusa
Salvato et al. 2009,ApJ, accepted
AGN phase in Galaxy evolution, a complete CENSUS of AGN is crucial.
get them all : Due to the interplay between host and
Active Nucleous, No criterion can exist
that can identify all AGN using a single
waveband (i.e. see talks at this conference).
get the right redshift: most of the sources are faint and we
must rely on photometric redshifts.
not better than 0.06 (after removing 20% of outliers ...)
…or, in other words,
something linke this…
WHAT IS MORE IMPORTANT ?
XMM sample has
long term variability
Additional ~1000 non X-ray detected
galaxies are varying and there are
currently under investigation
Both factors are crucial to reducing the number of outliers.
Siana et al. 2008
Ilbert et al Salvato et al.
Variability effects your work more than you think…