Steady models of magnetically supported black hole accretion disks

Hiroshi Oda, Mami Machida, Kenji E. Nakamura, Ryoji Matsumoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We obtained steady solutions of magnetized black hole accretion disks taking into account the gas pressure, magnetic pressure, and radiation pressure.We assumed the bremsstrahlung cooling in the optically thin limit and the black body cooling in the optically thick limit.Wassumed that magnetic fields inside the disk are turbulent and dominated by azimuthal component and that the azimuthally averaged Maxwell stress is proportional to the total pressure. We found that when accretion rate exceeds the threshold for the onset of the thermal instability for optically thin disks, a magnetic pressure dominated, cool branch appears in the thermal equilibrium curve. This disk corresponds to the "Bright/Hard" state in black hole candidates observed during the transition from a Low/Hard state to a High/Soft state.

Original languageEnglish
Title of host publicationAstrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects
Pages408-410
Number of pages3
DOIs
Publication statusPublished - Dec 1 2008
Externally publishedYes
EventInternational Conference on Astrophysics of Compact Objects - Huangshan City, China
Duration: Jul 1 2007Jul 7 2007

Publication series

NameAIP Conference Proceedings
Volume968
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

OtherInternational Conference on Astrophysics of Compact Objects
CountryChina
CityHuangshan City
Period7/1/077/7/07

Fingerprint

accretion disks
cooling
thermal instability
radiation pressure
bremsstrahlung
gas pressure
thresholds
curves
magnetic fields

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Oda, H., Machida, M., Nakamura, K. E., & Matsumoto, R. (2008). Steady models of magnetically supported black hole accretion disks. In Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects (pp. 408-410). (AIP Conference Proceedings; Vol. 968). https://doi.org/10.1063/1.2840442

Steady models of magnetically supported black hole accretion disks. / Oda, Hiroshi; Machida, Mami; Nakamura, Kenji E.; Matsumoto, Ryoji.

Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects. 2008. p. 408-410 (AIP Conference Proceedings; Vol. 968).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oda, H, Machida, M, Nakamura, KE & Matsumoto, R 2008, Steady models of magnetically supported black hole accretion disks. in Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects. AIP Conference Proceedings, vol. 968, pp. 408-410, International Conference on Astrophysics of Compact Objects, Huangshan City, China, 7/1/07. https://doi.org/10.1063/1.2840442
Oda H, Machida M, Nakamura KE, Matsumoto R. Steady models of magnetically supported black hole accretion disks. In Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects. 2008. p. 408-410. (AIP Conference Proceedings). https://doi.org/10.1063/1.2840442
Oda, Hiroshi ; Machida, Mami ; Nakamura, Kenji E. ; Matsumoto, Ryoji. / Steady models of magnetically supported black hole accretion disks. Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects. 2008. pp. 408-410 (AIP Conference Proceedings).
@inproceedings{67cb965d5e8a40b5bee0b3d96de3da12,
title = "Steady models of magnetically supported black hole accretion disks",
abstract = "We obtained steady solutions of magnetized black hole accretion disks taking into account the gas pressure, magnetic pressure, and radiation pressure.We assumed the bremsstrahlung cooling in the optically thin limit and the black body cooling in the optically thick limit.Wassumed that magnetic fields inside the disk are turbulent and dominated by azimuthal component and that the azimuthally averaged Maxwell stress is proportional to the total pressure. We found that when accretion rate exceeds the threshold for the onset of the thermal instability for optically thin disks, a magnetic pressure dominated, cool branch appears in the thermal equilibrium curve. This disk corresponds to the {"}Bright/Hard{"} state in black hole candidates observed during the transition from a Low/Hard state to a High/Soft state.",
author = "Hiroshi Oda and Mami Machida and Nakamura, {Kenji E.} and Ryoji Matsumoto",
year = "2008",
month = "12",
day = "1",
doi = "10.1063/1.2840442",
language = "English",
isbn = "9780735404854",
series = "AIP Conference Proceedings",
pages = "408--410",
booktitle = "Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects",

}

TY - GEN

T1 - Steady models of magnetically supported black hole accretion disks

AU - Oda, Hiroshi

AU - Machida, Mami

AU - Nakamura, Kenji E.

AU - Matsumoto, Ryoji

PY - 2008/12/1

Y1 - 2008/12/1

N2 - We obtained steady solutions of magnetized black hole accretion disks taking into account the gas pressure, magnetic pressure, and radiation pressure.We assumed the bremsstrahlung cooling in the optically thin limit and the black body cooling in the optically thick limit.Wassumed that magnetic fields inside the disk are turbulent and dominated by azimuthal component and that the azimuthally averaged Maxwell stress is proportional to the total pressure. We found that when accretion rate exceeds the threshold for the onset of the thermal instability for optically thin disks, a magnetic pressure dominated, cool branch appears in the thermal equilibrium curve. This disk corresponds to the "Bright/Hard" state in black hole candidates observed during the transition from a Low/Hard state to a High/Soft state.

AB - We obtained steady solutions of magnetized black hole accretion disks taking into account the gas pressure, magnetic pressure, and radiation pressure.We assumed the bremsstrahlung cooling in the optically thin limit and the black body cooling in the optically thick limit.Wassumed that magnetic fields inside the disk are turbulent and dominated by azimuthal component and that the azimuthally averaged Maxwell stress is proportional to the total pressure. We found that when accretion rate exceeds the threshold for the onset of the thermal instability for optically thin disks, a magnetic pressure dominated, cool branch appears in the thermal equilibrium curve. This disk corresponds to the "Bright/Hard" state in black hole candidates observed during the transition from a Low/Hard state to a High/Soft state.

UR - http://www.scopus.com/inward/record.url?scp=72349086827&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=72349086827&partnerID=8YFLogxK

U2 - 10.1063/1.2840442

DO - 10.1063/1.2840442

M3 - Conference contribution

AN - SCOPUS:72349086827

SN - 9780735404854

T3 - AIP Conference Proceedings

SP - 408

EP - 410

BT - Astrophysics of Compact Objects - International Conference on Astrophysics of Compact Objects

ER -