On Disk Formation around Isolated Black Holes via Stream Accretion

We investigate accretion onto an isolated black hole from uniform winds. If the winds are directed toward the black hole, then the accretion process can be well described by the classical Bondi–Hoyle–Lyttleton or BHL accretion. If the wind is not directed toward the black hole and flows past it, the...

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Main Authors: Priyesh Kumar Tripathi, Indranil Chattopadhyay, Raj Kishor Joshi
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/ad9b96
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author Priyesh Kumar Tripathi
Indranil Chattopadhyay
Raj Kishor Joshi
author_facet Priyesh Kumar Tripathi
Indranil Chattopadhyay
Raj Kishor Joshi
author_sort Priyesh Kumar Tripathi
collection DOAJ
description We investigate accretion onto an isolated black hole from uniform winds. If the winds are directed toward the black hole, then the accretion process can be well described by the classical Bondi–Hoyle–Lyttleton or BHL accretion. If the wind is not directed toward the black hole and flows past it, then a smaller fraction of the flow can be attracted by the black hole, and this type of accretion cannot be described by the classical BHL, and we coin the second kind as the lateral BHL. We show that the classical BHL cannot form an accretion disk, while lateral BHL can form transient accretion disks. To describe the thermodynamics of the flow, we have used a variable adiabatic index equation of state which depends on the temperature of the flow as well as the composition of the gas. We show that the electron-proton gas forms an accretion disk, which disappears and forms a shock cone, only to form the disk again at a later time, while for flows with fewer protons, the accretion disk, once lost, does not reappear again. Only when the flow is pair-dominated does it form a persistent accretion disk. We also show that a shock cone is less luminous than the accretion disk.
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spelling doaj-art-16a07a90d7b94c9280d96f1b122d413b2025-01-20T14:59:35ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0197916110.3847/1538-4357/ad9b96On Disk Formation around Isolated Black Holes via Stream AccretionPriyesh Kumar Tripathi0https://orcid.org/0009-0002-7498-6899Indranil Chattopadhyay1https://orcid.org/0000-0002-2133-9324Raj Kishor Joshi2https://orcid.org/0000-0002-9036-681XAryabhatta Research Institute of Observational Sciences (ARIES) , Manora Peak, Nainital 263001, India; Department of Applied Physics, Mahatma Jyotiba Phule Rohilkhand University , Bareilly 243006, IndiaAryabhatta Research Institute of Observational Sciences (ARIES) , Manora Peak, Nainital 263001, IndiaAryabhatta Research Institute of Observational Sciences (ARIES) , Manora Peak, Nainital 263001, IndiaWe investigate accretion onto an isolated black hole from uniform winds. If the winds are directed toward the black hole, then the accretion process can be well described by the classical Bondi–Hoyle–Lyttleton or BHL accretion. If the wind is not directed toward the black hole and flows past it, then a smaller fraction of the flow can be attracted by the black hole, and this type of accretion cannot be described by the classical BHL, and we coin the second kind as the lateral BHL. We show that the classical BHL cannot form an accretion disk, while lateral BHL can form transient accretion disks. To describe the thermodynamics of the flow, we have used a variable adiabatic index equation of state which depends on the temperature of the flow as well as the composition of the gas. We show that the electron-proton gas forms an accretion disk, which disappears and forms a shock cone, only to form the disk again at a later time, while for flows with fewer protons, the accretion disk, once lost, does not reappear again. Only when the flow is pair-dominated does it form a persistent accretion disk. We also show that a shock cone is less luminous than the accretion disk.https://doi.org/10.3847/1538-4357/ad9b96AccretionAstrophysical black holesHydrodynamical simulationsShocks
spellingShingle Priyesh Kumar Tripathi
Indranil Chattopadhyay
Raj Kishor Joshi
On Disk Formation around Isolated Black Holes via Stream Accretion
The Astrophysical Journal
Accretion
Astrophysical black holes
Hydrodynamical simulations
Shocks
title On Disk Formation around Isolated Black Holes via Stream Accretion
title_full On Disk Formation around Isolated Black Holes via Stream Accretion
title_fullStr On Disk Formation around Isolated Black Holes via Stream Accretion
title_full_unstemmed On Disk Formation around Isolated Black Holes via Stream Accretion
title_short On Disk Formation around Isolated Black Holes via Stream Accretion
title_sort on disk formation around isolated black holes via stream accretion
topic Accretion
Astrophysical black holes
Hydrodynamical simulations
Shocks
url https://doi.org/10.3847/1538-4357/ad9b96
work_keys_str_mv AT priyeshkumartripathi ondiskformationaroundisolatedblackholesviastreamaccretion
AT indranilchattopadhyay ondiskformationaroundisolatedblackholesviastreamaccretion
AT rajkishorjoshi ondiskformationaroundisolatedblackholesviastreamaccretion