Talk presented at American Astronomical Society (AAS) Summer 240th Meeting, Pasadena, CA, USA, June 2022 https://doi.org/10.6084/m9.figshare.25024931

1. Ash Danehkar
Eureka Scientific, Oakland, CA 94602, USA
danehkar@eurekasci.com
Bayesian X-ray Spectral Analysis of
Black Hole Spins in Seyfert I AGN
Image
credit:
NASA/JPL-Caltech

2. 2
240th AAS Summer Meeting
June 14, 2022
Black Hole Spin Implications
Dermer & Giebles 2016

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240th AAS Summer Meeting
June 14, 2022
Black Hole Spin Measurement
Different Methods (see Brenneman 2013):

X-ray Relativistic Reflection Modeling of Innermost Regions
 AGN, Stellar-mass BH, & Neutron Stars

Fitting UV Thermal Continuum
 Suitable for Stellar-mass BH
 Problematic in AGN due to UV absorption lines

High Frequency Quasi-Periodic Oscillations
 AGN + stellar-mass black hole (not yet fully developed)

X-ray Polarimetry
 X-ray polarimeter (in development, e.g. IXPE and XL-Calibur by Henric Krawczynski)

Event Horizon Shadow Imaging
 with Very Long Baseline Interferometry (in development)
 Suitable for Sgr A* and M87

4. 4
240th AAS Summer Meeting
June 14, 2022
Relativistic Reflection Modeling
Credit: Neil Brandt
BH Spin from Reflection Modeling

relline (Dauser + 2010): relativistic line model

xillver (Garcia + 2010,11,13): non-relativistic reflection disk

relline + xillver = relxill (Garcia + 2014)
Fabian + 2000

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240th AAS Summer Meeting
June 14, 2022
Relativistic Reflection Modeling
Image credit: NASA/JPL-Caltech
a = -1
a = 0
a = 1

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240th AAS Summer Meeting
June 14, 2022
Relativistic Reflection Modeling
Image credit: NASA/Dana Berry,SkyWorks Digital
Credit: Javier García
Danehkar + 2022

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240th AAS Summer Meeting
June 14, 2022
Fitting Reflection Model
Relativistic Reflection Modeling of the Innermost Regions
tbnew * warmabs* (diskbb+ relxill[relativistic reflection] + xillver[distant reflection])
Danehkar + 2022

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240th AAS Summer Meeting
June 14, 2022
Bayesian MCMC-based Fitting
Danehkar + 2022
pyBLoCXS “Bayesian Low-Count X-ray Spectral Analysis in Python”
(van Dyk + 2001; Protassov + 2002; Lee + 2011; Xu + 2014)
https://hea-www.harvard.edu/AstroStat/pyBLoCXS/

Sherpa: CIAO's Modeling & Fitting Application
https://cxc.cfa.harvard.edu/sherpa/

pyBLoCXS used for several X-ray spectral modeling
(see e.g. Danehkar + 2021 MNRAS 500, 4801)
Model Parameters:

Black Hole Spin (a)

Inclination (i)

Power-law Photon Index (Γpl)

Innermost Ionization Parameter (log ξrel)

Iron Abundance (AFe)

Distant Ionization Parameter (log ξxil)

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240th AAS Summer Meeting
June 14, 2022
Final Remarks and Future Plan
The best-fitting SMBH spins depends on:

iron abundances (in agreement with Reynolds +2012)

other model parameters e.g. inclination
Future Directions
MCMC-based analysis of other radio-quiet AGN:

Verifying SMBH spins previously found by assuming
the solar composition and fixed inclinations.
Examining other reflection models:

relxill_nk: Testing Einstein’s Gravity
(non-Kerr; Cosimo Bambi + 2018)
Kerr metric: α13 = α22 = 0
(deformation parameters).

relline_lp: coronal and lamp
post geometry:
h : height of the primary source
above the black hole.
Credit: Javier García

10. Thank you for your attention
Supported by the NASA ADAP Grant 80NSSC22K0626.
Image
credit:
NASA/JPL-Caltech