NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-24 T07:57:04 PDT
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For refcode 2000A&A...355..113G:
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NED Abstract

Copyright by European Southern Observatory (ESO). Reproduced by permission
2000A&A...355..113G A direct view of the AGN powering IRAS 12393+3520. GUAINAZZI M., DENNEFELD M., PIRO L., BOLLER T., RAFANELLI P., YAMAUCHI M. Received 10 November 1999/Accepted 21 December 1999 Abstract: We report the first direct X-ray evidence that an AGN is hidden in the center of IRAS 12393+3520. An ASCA observation of this target unveiled a bright (0.5-10keV luminosity 3.9 x 10^42^erg/s) and variable source, with minimum observed doubling/halving time scale comprised in the range 30-75ks. A model composed by a simple power-law, with photon index =~1.8 and an absorption edge, whose threshold energy is consistent with K- shell photoionization of OVII, provides an adequate fit of the spectrum. This suggests that we are observing the emission from the nuclear region through a warm absorber of N_H_=~ a few 1021cm^-2^. If it has internal dust with Galactic gas-to-dust ratio, it could explain the lack of broad H{beta} emission, even in the episodic presence of a broad H{alpha} emission line. Optical spectra obtained over several years show indeed variations in the strength of this broad H{alpha} component. A distribution of dusty, optically thick matter on spatial scales a few hundreds parsec, which does not intercept the line of sight towards the nucleus, is probably required to account simultaneously for the relative [OIII] luminosity deficit in comparison to the X-rays. The high IR to X-ray luminosity ratio is most likely due to intense star formation in the circumnuclear region. IRAS 12393+3520 might thus exhibit simultaneously nuclear activity and remarkable star formation. Key words: X-rays: galaxies - galaxies: active - galaxies: Seyfert - galaxies: individual: IRAS 12393+3520 - galaxies: ISM - galaxies: nuclei
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