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The Seyfert 1.9 galaxy MCG-05-23-016 has been shown to exhibit a complex X-ray spectrum. This source has moderate X-ray luminosity, hosts a comparably low-mass black hole, but accretes at a high Eddington rate, and allows us to study a super massive black hole in an early stage. Three observations of the INTEGRAL satellite simultaneous with pointed Swift/XRT observations performed from December 2006 to June 2007 are used in combination with public data from the INTEGRAL archive to study the variability of the hard X-ray components and to generate a high-quality spectrum from 1 to 150 keV. The AGN shows little variability in the hard X-ray spectrum, with some indication of a variation in the high-energy cut-off energy ranging from 50 keV to >>100 keV, with an electron plasma temperature in the 10 - 90 keV range. The reflection component is not evident and, if present, the reflected fraction can be constrained to R < 0.3 for the combined data set. Comparison to previous observations shows that the reflection component has to be variable. No variability in the UV and optical range is observed on a time scale of 1.5 years. The hard X-ray spectrum of MCG-05-23-016 appears to be stable with the luminosity and underlying power law varying moderately and the optical/UV flux staying constant. The spectral energy distribution appears to be similar to that of Galactic black hole systems, e.g. XTE 1118+480 in the low state. The AGN exhibits a remarkably high Eddington ratio of L(bol)/L(Edd)> 0.8 (or L(bol)/L(Edd) > 0.1, if we consider a higher mass of the central engine) and, at the same time, a low cut-off energy around 70 keV. Objects like MCG-05-23-016 might indicate the early stages of super massive black holes, in which a strong accretion flow feeds the central engine.
We present the results of the simultaneous deep XMM and Chandra observations of the bright Seyfert 1.9 galaxy MCG-5-23-16, which is thought to have one of the best known examples of a relativistically broadened iron K-alpha line. The time averaged sp
We report on a 100 ks Suzaku observation of the bright, nearby (z=0.008486) Seyfert 1.9 galaxy MCG -5-23-16. The broad-band (0.4-100 keV) X-ray spectrum allows us to determine the nature of the high energy emission with little ambiguity. The X-ray co
We present a detailed X-ray spectral analysis of the nearby Seyfert 2 galaxy MCG-01-24-12 based on a multi-epoch data set. Data have been taken with different X-ray satellites, namely XMM-Newton, NuSTAR, Swift and Chandra and cover different time int
Systems of shells and polar rings in early-type galaxies are considered bona fide tracers of mass accretion and/or mergers. Their high frequency in low density environments suggests that such episodes could drive the evolution of at least a fraction
(Abridged) We describe a sample of low-mass Seyfert 2 galaxies selected from the Sloan Digital Sky Survey, having a median absolute magnitude of M_g = -19.0 mag. These galaxies are Type 2 counterparts to the Seyfert 1 galaxies with intermediate-mass