Physical conditions in the ultraviolet absorbers of IRAS F22456-5125


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IOP Publishing Ltd.


We present the ultraviolet (UV) and X-ray spectra observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) and the XMM-Newton satellite, respectively, of the low-z Seyfert 1 galaxy IRAS F22456-5125. This object shows absorption from five distinct, narrow kinematic components that span a significant range in velocity (similar to 0 to -700 km s(-1)) and ionization (Lyman series, C III, N III, and O VI). We also show that three of the five kinematic components in these lines appear to be saturated in Ly beta lambda 1026 and that all five components show evidence of saturation in the O vi doublet lines lambda lambda 1032, 1038. Further, all five components show evidence for partial covering due to the absorption seen in the O VI doublet. This object is peculiar because it shows no evidence for corresponding X-ray absorption to the UV absorption in the X-ray spectrum, which violates the 1: 1 correlation known for low-z active galactic nuclei (AGNs). We perform photoionization modeling of the UV absorption lines and predict that the O VII column density should be small, which would produce little to no absorption in agreement with the X-ray observation. We also examine the UV variability of the continuum flux for this object (an increase of a factor of 6). As the absorption components lack variability, we find a lower limit of similar to 20 kpc for the distance for the absorbers from the central AGN.



galaxies: seyfert, ultraviolet: galaxies, intrinsic absorption-lines, all-sky survey, active galaxies, spectroscopic-explorer, seyfert-galaxies, galactic nuclei, spectra, agn, telescope, continuum


Jay P. Dunn et al. 2010. "Physical conditions in the ultraviolet absorbers of IRAS F22456-5125," ApJ 713 900 doi:10.1088/0004-637X/713/2/900