Detection of an Iron Emission Feature from the Lensed Broad Absorption Line QSO H1413+117 at z = 2.56
Abstract
We present the X-ray energy spectrum of the lensed broad absorption line QSO H1413+117 (the Cloverleaf) at z=2.56 observed with the Chandra X-ray observatory. We detected 293 photons in a 40 ks Advanced CCD Imaging Spectrometer (ACIS-S) observation. The X-ray image consists of four lensed image components, thus the photons are from the lensed QSO itself. The overall spectrum can be described with a power-law function heavily absorbed by neutral matter at a redshift consistent with the QSO redshift. This supports the idea that intrinsic absorption is significant for BAL QSOs. The spectral fit significantly (99% confidence) improves when we include an emission line. The centroid energy and intrinsic width (Gaussian σ) of the line are 6.21+/-0.16 keV and 220+270-130 eV (90% errors), respectively, in the QSO rest frame, assuming the absorbed power law as the continuum. The equivalent width of the line in the QSO rest frame is 960+1400-480 eV. We suggest that the large equivalent width, the centroid energy, and the line broadness can be explained by iron K emission arising from X-ray reprocessing in the BAL flow, assuming it has a conical thin-sheet structure.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2001
- DOI:
- 10.1086/338653
- arXiv:
- arXiv:astro-ph/0111410
- Bibcode:
- 2001ApJ...563L.103O
- Keywords:
-
- Cosmology: Gravitational Lensing;
- Galaxies: Quasars: Emission Lines;
- Galaxies: Quasars: Individual: Alphanumeric: H1413+117;
- X-Rays: Galaxies;
- Astrophysics
- E-Print:
- 3 figures, Accepted for publication in ApJ Letters