A candidate of a type - 2 QSO at z = 0 . 9 : Large X - ray absorption with a strong broad - H α emission line 1

Deep hard X-ray and near infrared observations of a type-2 radio-quiet QSO candidate at z = 0.9, AX J08494+4454, are reported. The 0.5–10 keV Chandra X-ray Observatory spectrum of AX J08494+4454 is hard, and is explained well with a power-law continuum absorbed by a hydrogen column density of (2.3± 1.1)× 10 cm. The 2–10 keV luminosity of the object is estimated to be 7.2 −2.0× 10 44 erg s, after correcting the absorption, and reaches hard X-ray luminosities of QSOs. The large X-ray absorption and the large intrinsic luminosity support the original identification of AX J08494+4454 as a type-2 radio-quiet QSO. Nevertheless, the deep Subaru/IRCS J-band spectroscopic observation suggests the presence of a strong broad Hα emission line from AX J08494+4454. If Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and University of Hawaii 2.2m Telescope, HI.