A Classic Type 2 QSO

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0


24 LaTeX pages including 6 postscript figures. Revised version, accepted by ApJ

Scientific paper


In the Chandra Deep Field South 1Msec exposure we have found, at redshift 3.700 +- 0.005, the most distant Type 2 AGN ever detected. It is the source with the hardest X-ray spectrum with redshift z>3. The optical spectrum has no detected continuum emission to a 3sigma detection limit of ~3 10^{-19} ergs/s/cm^2/AA and shows narrow lines of Ly_alpha, CIV, NV, HeII, OVI, [OIII], and CIII]. Their FWHM line widths have a range of ~700-2300 km/s with an average of approximately ~1500 km/s. The emitting gas is metal rich (Z ~2.5-3 Z_solar). In the X-ray spectrum of 130 counts in the 0.5-7 keV band there is evidence for intrinsic absorption with N_H > 10^{24} cm^{-2}. An iron K_alpha line with rest frame energy and equivalent width of ~6.4 keV and ~1 keV, respectively, in agreement with the obscuration scenario, is detected at a 2sigma level. If confirmed by our forthcoming XMM observations this would be the highest redshift detection of FeK_alpha. Depending on the assumed cosmology and the X-ray transfer model, the 2-10 keV rest frame luminosity corrected for absorption is ~10^{45 +- 0.5} ergs/s, which makes our source a classic example of the long sought Type 2 QSOs. From standard population synthesis models, these sources are expected to account for a relevant fraction of the black-hole-powered QSO distribution at high redshift.

No associations


Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.


A Classic Type 2 QSO 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 A Classic Type 2 QSO, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Classic Type 2 QSO will most certainly appreciate the feedback.

Rate now


Profile ID: LFWR-SCP-O-175789

All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.