Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-02-24
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication in A&A
Scientific paper
We present the observed-frame optical, near- and mid-infrared properties of X-ray selected AGN in the Lockman Hole. Using a likelihood ratio method on optical, near-infrared or mid-infrared catalogues, we assigned counterparts to 401 out of the 409 X-ray sources of the XMM-Newton catalogue. Accurate photometry was collected for all the sources from U to 24um. We used X-ray and optical criteria to remove any normal galaxies, galactic stars, or X-ray clusters among them and studied the multi-wavelength properties of the remaining 377 AGN. We used a mid-IR colour-colour selection to understand the AGN contribution to the optical and infrared emission. Using this selection, we identified different behaviours of AGN-dominated and host-dominated sources in X-ray-optical-infrared colour-colour diagrams. More specifically, the AGN dominated sources show a clear trend in the f_x/f_R vs. R-K and f_24um/f_R vs. R-K diagrams, while the hosts follow the behaviour of non X-ray detected galaxies. In the optical-near-infrared colour-magnitude diagram we see that the known trend of redder objects being more obscured in X-rays is stronger for AGN-dominated than for host-dominated systems. This is an indication that the trend is more related to the AGN contaminating the overall colours than any evolutionary effects. Finally, we find that a significant fraction (~30%) of the reddest AGN are not obscured in X-rays.
Burwitz Vadim
Egami Eiichi E.
Fotopoulou Sotiria
Hasinger Guenter
Rovilos Emmanouel
No associations
LandOfFree
Optical and infrared properties of active galactic nuclei in the Lockman Hole does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Optical and infrared properties of active galactic nuclei in the Lockman Hole, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical and infrared properties of active galactic nuclei in the Lockman Hole will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-709062