Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Home
Search
Quick Search
Advanced
Fulltext
Browse
Collections
Persons
My eDoc
Session History
Login
Name:
Password:
Documentation
Help
Support Wiki
Direct access to
document ID:


          Display Documents



ID: 5539.0, MPI für Astrophysik / High Energy Astrophysics at MPA
X-ray spectra from accretion disks illuminated by protons
Authors:Deufel, B.; Dullemond, C. P.; Spruit, H. C.
Language:English
Date of Publication (YYYY-MM-DD):2002
Title of Journal:Astronomy & Astrophysics
Journal Abbrev.:Astron. Astrophys.
Volume:387
Issue / Number:3
Start Page:907
End Page:917
Review Status:Peer-review
Audience:Experts Only
Abstract / Description:The X-ray spectrum from a cool accretion disk heated by virialized protons is computed. The cool disk is either embedded in a magnetically heated accretion disk corona or partly extends into an ion supported torus (or ADAF). We calculate the stationary equilibrium between proton heating, electron thermal conduction and the radiative losses by bremsstrahlung and Compton scattering. A heated surface layer on top of the accretion disk is produced with temperatures between 60-90 keV above a cool layer with temperatures of 0.01 keV (AGN) and 1 keV (galactic black hole candidates). The spectra produced by the surface layer are reminiscent of hard state spectra, but a bit too steep, especially for AGN's. Near the inner edge of the disk, where the optical depth of the disk tau less than or similar to 1, we find that the cool component of the disk disappears. Instead, the hot protons from the corona/ADAF heat the disk, on a dynamical time-scale, to temperatures of several 100 keV, limited by pair production. This region, here called a "warm disk", could contribute significantly to the hard X-ray spectra and could be important for feeding material into an ADAF.
Free Keywords:accretion; accretion disks; black hole physics; X-rays : galaxies; X-rays : stars
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astrophysik
External Affiliations:Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85740; Garching, Germany; Max Planck Inst Astrophys, D-85740 Garching, Germany
Identifiers:ISI:000175901300013
ISSN:1432-0746
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.