Stability of black hole accretion disks
We discuss the issues of stability of accretion disks that may undergo the limit-cycle oscillations due to the two main types of thermal-viscous instabilities. These are induced either by the domination of radiation pressure in the innermost regions close to the central black hole, or by the partial...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2012-12-01
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| Series: | EPJ Web of Conferences |
| Online Access: | http://dx.doi.org/10.1051/epjconf/20123906004 |
| _version_ | 1819349718341255168 |
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| author | Czerny B. Misra R. Janiuk A. Kunert-Bajraszewska M. |
| author_facet | Czerny B. Misra R. Janiuk A. Kunert-Bajraszewska M. |
| author_sort | Czerny B. |
| collection | DOAJ |
| description | We discuss the issues of stability of accretion disks that may undergo the limit-cycle oscillations due to the two main types of thermal-viscous instabilities. These are induced either by the domination of radiation pressure in the innermost regions close to the central black hole, or by the partial ionization of hydrogen in the zone of appropriate temperatures. These physical processes may lead to the intermittent activity in AGN on timescales between hundreds and millions of years. We list a number of observational facts that support the idea of the cyclic activity in high accretion rate sources. We conclude however that the observed features of quasars may provide only indirect signatures of the underlying instabilities. Also, the support from the sources with stellar mass black holes, whose variability timescales are observationally feasible, is limited to a few cases of the microquasars. Therefore we consider a number of plausible mechanisms of stabilization of the limit cycle oscillations in high accretion rate accretion disks. The newly found is the stabilizing effect of the stochastic viscosity fluctuations. |
| first_indexed | 2024-12-24T19:04:58Z |
| format | Article |
| id | doaj.art-137936c3f913483eb506d3ce585521b4 |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-12-24T19:04:58Z |
| publishDate | 2012-12-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-137936c3f913483eb506d3ce585521b42022-12-21T16:43:07ZengEDP SciencesEPJ Web of Conferences2100-014X2012-12-01390600410.1051/epjconf/20123906004Stability of black hole accretion disksCzerny B.Misra R.Janiuk A.Kunert-Bajraszewska M.We discuss the issues of stability of accretion disks that may undergo the limit-cycle oscillations due to the two main types of thermal-viscous instabilities. These are induced either by the domination of radiation pressure in the innermost regions close to the central black hole, or by the partial ionization of hydrogen in the zone of appropriate temperatures. These physical processes may lead to the intermittent activity in AGN on timescales between hundreds and millions of years. We list a number of observational facts that support the idea of the cyclic activity in high accretion rate sources. We conclude however that the observed features of quasars may provide only indirect signatures of the underlying instabilities. Also, the support from the sources with stellar mass black holes, whose variability timescales are observationally feasible, is limited to a few cases of the microquasars. Therefore we consider a number of plausible mechanisms of stabilization of the limit cycle oscillations in high accretion rate accretion disks. The newly found is the stabilizing effect of the stochastic viscosity fluctuations.http://dx.doi.org/10.1051/epjconf/20123906004 |
| spellingShingle | Czerny B. Misra R. Janiuk A. Kunert-Bajraszewska M. Stability of black hole accretion disks EPJ Web of Conferences |
| title | Stability of black hole accretion disks |
| title_full | Stability of black hole accretion disks |
| title_fullStr | Stability of black hole accretion disks |
| title_full_unstemmed | Stability of black hole accretion disks |
| title_short | Stability of black hole accretion disks |
| title_sort | stability of black hole accretion disks |
| url | http://dx.doi.org/10.1051/epjconf/20123906004 |
| work_keys_str_mv | AT czernyb stabilityofblackholeaccretiondisks AT misrar stabilityofblackholeaccretiondisks AT janiuka stabilityofblackholeaccretiondisks AT kunertbajraszewskam stabilityofblackholeaccretiondisks |