A Possible Ultra Strong and Broad Fe Kα Emission Line in Seyfert 2 Galaxy IRAS 00521-7054
Abstract
We present XMM-Newton spectra of the Seyfert 2 Galaxy IRAS 00521-7054. A strong feature at ~6 keV (observer's frame) can be formally fitted with a strong (EW = 1.3 ± 0.3 keV in the rest frame) and broad Fe Kα line, extending down to 3 keV. The underlying X-ray continuum could be fitted with an absorbed power law (with Γ = 1.8 ± 0.2 and N H = 5.9+0.6 -0.7 × 1022 cm-2) plus a soft component. If due to relativistically smeared reflection by an X-ray illuminated accretion disk, the spin of the supermassive black hole (SMBH) is constrained to be 0.97+0.03 -0.13 (errors at 90% confidence level for one interesting parameter), and the accretion system is viewed at an inclination angle of 37° ± 4°. This would be the first type 2 active galactic nucleus reported with strong red Fe Kα wing detected which demands a fast rotating SMBH. The unusually large EW would suggest that the light bending effect is strong in this source. Alternatively, the spectra could be fitted by a dual-absorber model (though with a global χ2 higher by ~6 for 283 dof) with N H1 = 7.0 ± 0.8 × 1022 cm-2 covering 100% of the X-ray source, and N H2 = 21.7+5.6 -5.4 × 1022 cm-2 covering 71%, which does not require an extra broad Fe Kα line.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2012
- DOI:
- 10.1088/2041-8205/747/1/L11
- arXiv:
- arXiv:1202.0400
- Bibcode:
- 2012ApJ...747L..11T
- Keywords:
-
- galaxies: active;
- galaxies: Seyfert;
- X-rays: individual: IRAS 00521-7054;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 14 pages, 4 figures, accepted to ApJ Letters