Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-11-02
Astronomy and Astrophysics
Astrophysics
20 pages with 4 EPS figures. Accepted for publication in ApJ
Scientific paper
10.1086/338422
Deep hard X-ray and near infrared observations of a type-2 radio-quiet QSO candidate at z=0.9, AXJ08494+4454, are reported. The 0.5-10keV Chandra X-ray Observatory spectrum of AXJ08494+4454 is hard, and is explained well with a power-law continuum absorbed by a hydrogen column density of 2x10^23 cm^-2. The 2-10keV luminosity of the object reaches hard X-ray luminosity of QSOs. The large X-ray absorption and the large intrinsic luminosity support the original identification of AXJ08494+4454 as a type-2 radio-quiet QSO. Nevertheless, the deep Subaru/IRCS J-band spectroscopic observation suggests the presence of a strong broad H-alpha emission line from AXJ08494+4454. If real, the broad H-alpha emission line has a velocity width of 9400+-1000 km/s, which corresponds to a typical broad-Balmer line velocity width of a luminous QSO. The existence of the strong broad H-alpha line means that the object is not a type-2 QSO, but a luminous cousin of a Seyfert 1.9 galaxy in the source-frame optical spectrum. The Balmer decrement of broad lines, and the broad H-alpha emission to the hard X-ray luminosity ratio suggest that the nucleus is affected by dust extinction with A_V of 1-3 mag in the optical wavelength. The estimated amount of dust extinction is much smaller than that expected from the X-ray column density.
Akiyama Masayuki
Ohta Kouji
Ueda Yoshihiro
No associations
LandOfFree
A candidate of a type-2 QSO at z=0.9: Large X-ray absorption with a strong broad-H-alpha emission line 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 candidate of a type-2 QSO at z=0.9: Large X-ray absorption with a strong broad-H-alpha emission line, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A candidate of a type-2 QSO at z=0.9: Large X-ray absorption with a strong broad-H-alpha emission line will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-481158