A New Spin on Black Holes in a MAD Universe

Seminar
AstroPhysics Seminar
QUEST Center event
No
Speaker
Angelo Ricarte, Harvard University
Date
02/04/2025 - 17:30 - 16:00Add to Calendar 2025-04-02 16:00:00 2025-04-02 17:30:00 A New Spin on Black Holes in a MAD Universe We can now spatially resolve accreting black holes with the Event Horizon Telescope (EHT), leading to advances in our understanding of accretion and jet launching.  So far, these studies prefer Magnetically Arrested Disk (MAD) accretion flows over their more weakly magnetized Standard and Normal Evolution (SANE) counterparts.  Such models produce efficient jets via the Blandford-Znajek (BZ) mechanism, which extracts the spin-energy of the black hole.  In this talk, we explore the cosmological implications of MAD accretion flows.  First, using general relativistic radiative magnetohydrodynamics (GRRMHD) simulations, we develop new "sub-grid" formulae for BZ jet feedback and spin evolution, appropriate for both semi-analytic models and cosmological simulations, for arbitrary spins and accretion rates.  Then, we implement these formulae in the semi-analytic model Serotina, which evolves a cosmological population of supermassive black holes from the seeding epoch (z~20) to the present day.  We demonstrate that spin-down in a MAD universe due to BZ jets has an observable effect moderating SMBH spins across cosmic time.  Forward modeling different selection effects, we make predictions for spin measurements via X-ray reflection spectroscopy, extensions to the EHT, and the Laser Interferometer Space Antenna (LISA).  Note the change in time (4 pm). The seminar will be given on Zoom.https://zoom.us/j/9290951953 https://zoom.us/j/9290951953 המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
https://zoom.us/j/9290951953
Abstract

We can now spatially resolve accreting black holes with the Event Horizon Telescope (EHT), leading to advances in our understanding of accretion and jet launching.  So far, these studies prefer Magnetically Arrested Disk (MAD) accretion flows over their more weakly magnetized Standard and Normal Evolution (SANE) counterparts.  Such models produce efficient jets via the Blandford-Znajek (BZ) mechanism, which extracts the spin-energy of the black hole.  In this talk, we explore the cosmological implications of MAD accretion flows.  First, using general relativistic radiative magnetohydrodynamics (GRRMHD) simulations, we develop new "sub-grid" formulae for BZ jet feedback and spin evolution, appropriate for both semi-analytic models and cosmological simulations, for arbitrary spins and accretion rates.  Then, we implement these formulae in the semi-analytic model Serotina, which evolves a cosmological population of supermassive black holes from the seeding epoch (z~20) to the present day.  We demonstrate that spin-down in a MAD universe due to BZ jets has an observable effect moderating SMBH spins across cosmic time.  Forward modeling different selection effects, we make predictions for spin measurements via X-ray reflection spectroscopy, extensions to the EHT, and the Laser Interferometer Space Antenna (LISA). 
 


Note the change in time (4 pm). The seminar will be given on Zoom.

https://zoom.us/j/9290951953

תאריך עדכון אחרון : 26/03/2025