BlackHoleWeather -- Spin-coupled chaotic cold accretion across the meso-scale: Morphology and thermodynamics

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Piana, Olmo, Gaspari, Massimo, Barbani, Filippo, Cammelli, Vieri, Stel, Giovanni, Brustio, Davide M., Olivares, Valeria, Salvestrini, Francesco, Danehkar, Ashkbiz, Tombesi, Francesco, Temi, Pasquale, Maccagni, Filippo M., Fournier, Martin
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910263481991168
author Piana, Olmo
Gaspari, Massimo
Barbani, Filippo
Cammelli, Vieri
Stel, Giovanni
Brustio, Davide M.
Olivares, Valeria
Salvestrini, Francesco
Danehkar, Ashkbiz
Tombesi, Francesco
Temi, Pasquale
Maccagni, Filippo M.
Fournier, Martin
author_facet Piana, Olmo
Gaspari, Massimo
Barbani, Filippo
Cammelli, Vieri
Stel, Giovanni
Brustio, Davide M.
Olivares, Valeria
Salvestrini, Francesco
Danehkar, Ashkbiz
Tombesi, Francesco
Temi, Pasquale
Maccagni, Filippo M.
Fournier, Martin
contents Supermassive black hole (SMBH) spin is a key but poorly constrained ingredient of the feeding-feedback loop. Chaotic cold accretion (CCA) of cold gas clouds delivers rapidly varying three-dimensional torques that drive spin evolution and jet-axis reorientation, and in turn spin regulates jet power. We introduce a time-dependent SMBH spin model linking resolved multiphase feeding at meso scales to unresolved relativistic angular-momentum transfer at the innermost stable circular orbit (ISCO). We perform GPU-accelerated hydrodynamical simulations of a group atmosphere with jet feedback and SMBH spin evolution, resolving multiphase inflow and angular-momentum direction below parsec scales. We compare fixed-axis, direct, and hybrid prescriptions, with the latter preserving the resolved torque direction while filtering its magnitude through a Kerr ISCO closure. We then apply the hybrid model to low- and high-turbulence group setups. The cold-gas reservoir is nearly independent of whether the jet is fixed, spin-coupled, or rapidly reorienting. The spin prescription instead controls the inner feeding-feedback coupling, modulating central accretion, jet efficiency, and feedback geometry. The hybrid model is bracketed by analytic limits, whereas the direct model overestimates spin variability and jet-axis wandering, showing that an ISCO closure is required. Low-spin SMBHs are easier to reorient because a misaligned torque acts on a smaller angular-momentum reservoir. The decisive quantity is the coherence of the delivered angular momentum: the low-turbulence run preserves longer feeding bridges and faster spin evolution, whereas stronger turbulence fragments the inflow and enhances torque cancellation. In CCA, turbulence regulates whether the cold reservoir remains connected, how the angular momentum reaches the SMBH, where the next jet points, and how feedback is imprinted onto the halo.
format Preprint
id arxiv_https___arxiv_org_abs_2605_27502
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle BlackHoleWeather -- Spin-coupled chaotic cold accretion across the meso-scale: Morphology and thermodynamics
Piana, Olmo
Gaspari, Massimo
Barbani, Filippo
Cammelli, Vieri
Stel, Giovanni
Brustio, Davide M.
Olivares, Valeria
Salvestrini, Francesco
Danehkar, Ashkbiz
Tombesi, Francesco
Temi, Pasquale
Maccagni, Filippo M.
Fournier, Martin
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
Supermassive black hole (SMBH) spin is a key but poorly constrained ingredient of the feeding-feedback loop. Chaotic cold accretion (CCA) of cold gas clouds delivers rapidly varying three-dimensional torques that drive spin evolution and jet-axis reorientation, and in turn spin regulates jet power. We introduce a time-dependent SMBH spin model linking resolved multiphase feeding at meso scales to unresolved relativistic angular-momentum transfer at the innermost stable circular orbit (ISCO). We perform GPU-accelerated hydrodynamical simulations of a group atmosphere with jet feedback and SMBH spin evolution, resolving multiphase inflow and angular-momentum direction below parsec scales. We compare fixed-axis, direct, and hybrid prescriptions, with the latter preserving the resolved torque direction while filtering its magnitude through a Kerr ISCO closure. We then apply the hybrid model to low- and high-turbulence group setups. The cold-gas reservoir is nearly independent of whether the jet is fixed, spin-coupled, or rapidly reorienting. The spin prescription instead controls the inner feeding-feedback coupling, modulating central accretion, jet efficiency, and feedback geometry. The hybrid model is bracketed by analytic limits, whereas the direct model overestimates spin variability and jet-axis wandering, showing that an ISCO closure is required. Low-spin SMBHs are easier to reorient because a misaligned torque acts on a smaller angular-momentum reservoir. The decisive quantity is the coherence of the delivered angular momentum: the low-turbulence run preserves longer feeding bridges and faster spin evolution, whereas stronger turbulence fragments the inflow and enhances torque cancellation. In CCA, turbulence regulates whether the cold reservoir remains connected, how the angular momentum reaches the SMBH, where the next jet points, and how feedback is imprinted onto the halo.
title BlackHoleWeather -- Spin-coupled chaotic cold accretion across the meso-scale: Morphology and thermodynamics
topic Astrophysics of Galaxies
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2605.27502