Bayesian X-ray Spectral Analysis of Black Hole Spins in Seyfert I AGN

Talk presented at American Astronomical Society (AAS) Summer 240th Meeting (in-person), Pasadena, CA, USA, June 2022

Transcript

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
3. 3 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
5. 5 240th AAS Summer Meeting June 14, 2022 Relativistic Reflection Modeling Image credit: NASA/JPL-Caltech a = -1 a = 0 a = 1
6. 6 240th AAS Summer Meeting June 14, 2022 Relativistic Reflection Modeling Image credit: NASA/Dana Berry,SkyWorks Digital Credit: Javier García Danehkar + 2022
7. 7 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
8. 8 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)
9. 9 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