State transitions in black hole X-ray binaries are likely caused by gas evaporation from a thin accretion disk into a hot corona. We present a height-integrated version of this process, which is suitable for analytical and numerical studies. With radius
We develop a Newtonian model of a deep tidal disruption event (TDE), for which the pericenter distance of the star,
- Award ID(s):
- 2006684
- NSF-PAR ID:
- 10362619
- Publisher / Repository:
- DOI PREFIX: 10.3847
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 926
- Issue:
- 1
- ISSN:
- 0004-637X
- Format(s):
- Medium: X Size: Article No. 47
- Size(s):
- ["Article No. 47"]
- Sponsoring Org:
- National Science Foundation
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Abstract r scaled to Schwarzschild units and coronal mass accretion rate to Eddington units, the results of the model are independent of black hole mass. State transitions should thus be similar in X-ray binaries and an active galactic nucleus. The corona solution consists of two power-law segments separated at a break radiusr b ∼ 103(α /0.3)−2, whereα is the viscosity parameter. Gas evaporates from the disk to the corona forr >r b , and condenses back forr <r b . Atr b , reaches its maximum, . If atr ≫r b the thin disk accretes with , then the disk evaporates fully before reachingr b , giving the hard state. Otherwise, the disk survives at all radii, giving the thermal state. While the basic model considers only bremsstrahlung cooling and viscous heating, we also discuss a more realistic model that includes Compton cooling and direct coronal heating by energy transport from the disk. Solutions are again independent of black hole mass, andr b remains unchanged. This model predicts strong coronal winds forr >r b , and aT ∼ 5 × 108K Compton-cooled corona forr <r b . Two-temperature effects are ignored, but may be important at small radii. -
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