Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Model for the X-Ray and UV Emission from Seyfert Galaxies and Galactic
  Black Holes   We propose that the X--ray emission from radio quiet AGN and galactic black
holes is due to Comptonization of soft thermal photons emitted by the
underlying accretion disk in localized structures (blobs). The power per unit
area produced by the blobs, impinging on the disk, can easily dominate the
radiation internally produced by the disk. In this case the electron
temperature and the high energy spectrum can be determined in a similar way as
in the previously studied homogeneous model (Haardt \& Maraschi 1991). However
in the present model: a) the emitted spectrum is largely independent of the
{\it fraction} of gravitational power dissipated in the blobs; b) the X--ray
spectrum can be harder depending on a form factor of the blobs; c) the UV (or
soft X--ray for galactic objects) luminosity that is not intercepted by the
blobs can be larger than the X--ray luminosity. In the framework of a
simplified accretion disk $\alpha-\Omega$ dynamo model, we make order of
magnitude estimates of the number of active blobs, their size, luminosity and
hence their compactness, finding values in agreement with what is observed. The
expected UV to X--ray spectra and correlations of X--ray and UV light curves
are discussed.

36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th