منابع مشابه
Hot coronae in nearby radio galaxies
We present Rosat X-ray observations (with PSPC and HRI instruments) of a sample of radio galaxies belonging to the B2 catalog (3C31, 0206+35, 1113+29 and 1553+24). The source 3C31 (B2 0104+32) belongs to the group Arp 331 which shows emission from a diffuse hot intra-group gas and from the brightest members of the group. We discuss both the morphological and spectral features of this extended r...
متن کاملAccretion disc coronae as magnetic reservoirs
Most astrophysical sources powered by accretion onto a black hole, either of stellar mass or supermassive, when observed with hard X-rays show signs of a hot Comptonizing component in the flow, the so-called corona, with observed temperatures and optical depths lying in a narrow range (0.1τ1 and 1×109KT 3×109 K). Here we argue that these facts constitute strong supporting evidence for a magneti...
متن کاملVertical Structure of Accretion Discs with Hot Coronae in AGN
We study vertical structure of radiation pressure dominated disc with a hot corona. We include all the relevant processes like bound–free opacity and convection. We show that the presence of the corona modifies considerably the density and the opacity of the disc surface layers which are important from the point of view of spectrum formation. The surface of the disc with a corona is much denser...
متن کاملQuantum carpets, carpets of light
In 1836 Henry Fox Talbot, an inventor of photography, published the results of some experiments in optics that he had previously demonstrated at a British Association meeting in Bristol. "It was very curious to observe that though the grating was greatly out of the focus of the lens...the appearance of the bands was perfectly distinct and well defined...the experiments are communicated in the h...
متن کاملMagnetic Flares and Outflows from Structured Accretion Disc Coronae
We present a model for magnetic structured coronae above accretion discs. On the shortest timescales, spatially and temporally correlated coronal flares can explain Xray temporal and spectral variability observed in Seyfert galaxies. In particular, power density spectra, flux-spectral index and flux-variance correlations are naturally accounted for by the model. More dramatic spectral variation...
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ژورنال
عنوان ژورنال: Astronomy and Geophysics
سال: 2002
ISSN: 1366-8781,1468-4004
DOI: 10.1046/j.1468-4004.2002.43416.x