Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona
Using two-dimensional general relativistic resistive magnetohydrodynamic simulations, we investigate the properties of the sheath separating the black hole jet from the surrounding medium. We find that the electromagnetic power flowing through the jet sheath is comparable to the overall accretion po...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ada385 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832583802381139968 |
|---|---|
| author | Navin Sridhar Bart Ripperda Lorenzo Sironi Jordy Davelaar Andrei M. Beloborodov |
| author_facet | Navin Sridhar Bart Ripperda Lorenzo Sironi Jordy Davelaar Andrei M. Beloborodov |
| author_sort | Navin Sridhar |
| collection | DOAJ |
| description | Using two-dimensional general relativistic resistive magnetohydrodynamic simulations, we investigate the properties of the sheath separating the black hole jet from the surrounding medium. We find that the electromagnetic power flowing through the jet sheath is comparable to the overall accretion power of the black hole. The sheath is an important site of energy dissipation as revealed by the copious appearance of reconnection layers and plasmoid chains. About 20% of the sheath power is dissipated between 2 and 10 gravitational radii. The plasma in the dissipative sheath moves along a nearly paraboloidal surface with transrelativistic bulk motions dominated by the radial component, whose dimensionless 4-velocity is ∼1.2 ± 0.5. In the frame moving with the mean (radially dependent) velocity, the distribution of stochastic bulk motions resembles a Maxwellian with an “effective bulk temperature” of ∼100 keV. Scaling the global simulation to Cygnus X-1 parameters gives a rough estimate of the Thomson optical depth across the jet sheath, ∼0.01–0.1, and it may increase in future magnetohydrodynamic simulations with self-consistent radiative losses. These properties suggest that the dissipative jet sheath may be a viable “coronal” region, capable of upscattering seed soft photons into a hard, nonthermal tail, as seen during the hard states of X-ray binaries and active galactic nuclei. |
| format | Article |
| id | doaj-art-a3b225a5c6ce468485314cfdd133b429 |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-a3b225a5c6ce468485314cfdd133b4292025-01-28T05:57:14ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01979219910.3847/1538-4357/ada385Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing CoronaNavin Sridhar0https://orcid.org/0000-0002-5519-9550Bart Ripperda1https://orcid.org/0000-0002-7301-3908Lorenzo Sironi2https://orcid.org/0000-0002-1227-2754Jordy Davelaar3https://orcid.org/0000-0002-2685-2434Andrei M. Beloborodov4https://orcid.org/0000-0001-5660-3175Department of Astronomy, Columbia University , New York, NY 10027, USA ; nsridhar@stanford.edu; Theoretical High Energy Astrophysics (THEA) Group, Columbia University , New York, NY 10027, USA; Cahill Center for Astronomy and Astrophysics, California Institute of Technology , Pasadena, CA 91106, USA; Department of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA; Kavli Institute for Particle Astrophysics & Cosmology, P. O. Box 2450, Stanford University , Stanford, CA 94305, USACanadian Institute for Theoretical Astrophysics , 60 St. George St., Toronto, ON M5S 3H8, Canada; Department of Physics, University of Toronto , 60 St. George St., Toronto, ON M5S 1A7, Canada; David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George St., Toronto, ON M5S 3H4, Canada; Perimeter Institute for Theoretical Physics , 31 Caroline St. North, Waterloo, ON N2L 2Y5, CanadaDepartment of Astronomy, Columbia University , New York, NY 10027, USA ; nsridhar@stanford.edu; Theoretical High Energy Astrophysics (THEA) Group, Columbia University , New York, NY 10027, USA; Center for Computational Astrophysics , Flatiron Institute, 162 5th Ave., New York, NY 10010, USADepartment of Astrophysical Sciences, Peyton Hall, Princeton University , Princeton, NJ 08544, USATheoretical High Energy Astrophysics (THEA) Group, Columbia University , New York, NY 10027, USA; Department of Physics, Columbia University , New York, NY 10027, USAUsing two-dimensional general relativistic resistive magnetohydrodynamic simulations, we investigate the properties of the sheath separating the black hole jet from the surrounding medium. We find that the electromagnetic power flowing through the jet sheath is comparable to the overall accretion power of the black hole. The sheath is an important site of energy dissipation as revealed by the copious appearance of reconnection layers and plasmoid chains. About 20% of the sheath power is dissipated between 2 and 10 gravitational radii. The plasma in the dissipative sheath moves along a nearly paraboloidal surface with transrelativistic bulk motions dominated by the radial component, whose dimensionless 4-velocity is ∼1.2 ± 0.5. In the frame moving with the mean (radially dependent) velocity, the distribution of stochastic bulk motions resembles a Maxwellian with an “effective bulk temperature” of ∼100 keV. Scaling the global simulation to Cygnus X-1 parameters gives a rough estimate of the Thomson optical depth across the jet sheath, ∼0.01–0.1, and it may increase in future magnetohydrodynamic simulations with self-consistent radiative losses. These properties suggest that the dissipative jet sheath may be a viable “coronal” region, capable of upscattering seed soft photons into a hard, nonthermal tail, as seen during the hard states of X-ray binaries and active galactic nuclei.https://doi.org/10.3847/1538-4357/ada385Black hole physicsHigh energy astrophysicsMagnetohydrodynamical simulationsPlasma astrophysicsX-ray binary starsX-ray active galactic nuclei |
| spellingShingle | Navin Sridhar Bart Ripperda Lorenzo Sironi Jordy Davelaar Andrei M. Beloborodov Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona The Astrophysical Journal Black hole physics High energy astrophysics Magnetohydrodynamical simulations Plasma astrophysics X-ray binary stars X-ray active galactic nuclei |
| title | Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona |
| title_full | Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona |
| title_fullStr | Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona |
| title_full_unstemmed | Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona |
| title_short | Bulk Motions in the Black Hole Jet Sheath as a Candidate for the Comptonizing Corona |
| title_sort | bulk motions in the black hole jet sheath as a candidate for the comptonizing corona |
| topic | Black hole physics High energy astrophysics Magnetohydrodynamical simulations Plasma astrophysics X-ray binary stars X-ray active galactic nuclei |
| url | https://doi.org/10.3847/1538-4357/ada385 |
| work_keys_str_mv | AT navinsridhar bulkmotionsintheblackholejetsheathasacandidateforthecomptonizingcorona AT bartripperda bulkmotionsintheblackholejetsheathasacandidateforthecomptonizingcorona AT lorenzosironi bulkmotionsintheblackholejetsheathasacandidateforthecomptonizingcorona AT jordydavelaar bulkmotionsintheblackholejetsheathasacandidateforthecomptonizingcorona AT andreimbeloborodov bulkmotionsintheblackholejetsheathasacandidateforthecomptonizingcorona |