Paths to a Unified AGN Outflow Model via Computational Relativity

Paths to
a Unified AGN Outflow Model
via Computational Relativity
Ashkbiz Danehkar, Postdoc
Department of Astronomy, University of Michigan
danehkar@umich.edu
Challenges and Innovations in Computational Astrophysics - II, November 20, 2020
Image
Credit:
J.
Bergeron,
Sky
&
Telescope
Magazine
Image
Credit:
J.
Bergeron,
Sky
&
Telescope
Magazine

20/11/2020 Computational Astrophysics II
2
Outline

Observational Background
 AGN Classification
 Ultra-Fast Outflow (UFO)
 Evidence for a Unified AGN Outflow Model
 Implication of Black Hole Spins

Black Hole Spin Surveys
 Relativistically broadened Fluorescence K-shell Iron Line
 Compton continuum above 7 keV
 Relativistic Reflection Model (relxill + xillver)

Numerical Relativity
 Visualization of Gravitational Physical Lines: Tendex and Vortex
 Einstein Cactus Computational Toolkit

3
AGN Classification
AGN Unified Model (radio-loud & -quiet AGN, Seyfert I & II Galaxies)
Beckmann & Shrader 2012,
Active Galactic Nuclei
Unified Models for AGNs
Antonucci, ARA&A, 1993, 31, 473
Unified Schemes for AGNs
Megan Urry & Padovani, 1995, PASP, 107, 803
(Bernie Fanaroff &
Julia Riley 1974)
AGN Unified Model
• Radio-Quiet AGN
 Seyfert I (BLR+NLR,
compact outflows)
 Seyfert II (NLR)
• Radio-Loud AGN
 FR I (compact radio jets)
 FR II (extended radio jets)
 Blazar (relativistic beams)
(Carl Seyfert 1942)

4
Ultra-fast Outflows
Disk
Black-
body
Hot Corona
Warm
Absorbers
K-shell Iron
Beckmann & Shrader 2012
Risaliti & Elvis 2004
(bbody + powerlaw + ∑ emis) x ∏ abs

5
Evidence for Unified AGN Outflow
Correlation between outflow kinematics and physical conditions
Tombesi + 2013
(Ultra-fast outflows)
(Warm Absorbers)

6
Problems
Radio-quiet and radio-loud AGN
Garofalo + 2010
●
Radio-quiet AGN
– Compact Outflows
– Weak Radio Source
●
Radio-loud AGN
– Extended Jets
– Strong Radio Source
– Typically in elliptical massive
galaxies evolved from recent mergers (binary SMBH?)

7
AGN Classification: Radio-loud & Radio-quiet AGN
Dermer & Giebles 2016

8
Implication of Black Hole Spins
Correlation between SMBH Angular Momentum with Uktra-fast Outflows
Danehkar +

9
Measurements of Black Hole Spins
Black Hole Spin Measurement (see Brenneman 2013)
●
Thermal Continuum Fitting (UV observation)
– stellar-mass black hole
– AGN (may problematic due to UV absorption lines!)
●
Inner Disk Reflection Modeling
– AGN (X-ray)
●
High Frequency Quasi-Periodic Oscillations
– AGN + stellar-mass black hole (fully not developed)
●
X-ray Polarimetry
– Need sensitive X-ray polarimter (not available now!)
●
Imaging the Event Horizon Shadow
– Need Very Long Baseline Interferometry (in development)
– Suitable only for Sgr A* and M87
a = J c / G M2
(a: BH spin, J: angular momentum, M: BH mass, G: gravitational constant, c: speed of light)

10
Relativistically broadened Kα iron line (6.4 keV)
Compton hump (> 10keV)
Black Hole Spin Measurement from X-ray
a = - 1
a = 0
a = 1
Image credit: NASA/JPL-Caltech

11
BH Spin from Reflection Modeling
●
kerrconv (Brenneman & Reynold 2006)
●
relline (Dauser + 2010)
●
xillver (Garcia + 2010,11,13)
●
relxill (Garcia + 2014)
Dauser & Garcia + 2014

12
Supermassive Black Hole Spin

13
Weyl (Vacuum Riemann) Tensor
Einstein’s 70th birthday, Institute for Advanced Study, 1949
Weyl, Mathematische Zeitschrift, 2, 384, 1918

14
Gravitoelectric and Gravitomagnetic Tensors
●
Gravitoelectric & Gravitomagnetic fields
– Names coined by Kip Thorne (IAU, 97, 255, 1982)
– Thorne et al. Black holes: The membrane paradigm (Yale
University, 1986)
●
Gravitoelectric Tensor
– Newtonian Tidal Force
●
Gravitomagnetic Tensor
– Frame-dragging vortex & Gravitational Waves
●
Bianchi Identities
– Constraints for gravitoelectric & gravitomagnetic
(see e.g. Relativistic Cosmology, Ellis, Maartens, &
MacCallum, Cambridge, 2012)
Kip Thorne’s 60th birthday, Caltech, 2000

15
Tendex and Vortex Lines
●
Visualization of Gravitoelectric & Gravitomagnetic tensors
– Nichols et al. PRD 84, 124012, 2011; PRD 86, 104028, 2012
●
Tidal Tendex Line
– Tendex coined by David Nichols (tendere: ‘to stretch’)
– integral curves of eigenvectors of gravitoeletric tensor
– Owen el al. PRL 106, 151101, 2011
– Zhang et al. PRD 86, 084049, 2012
●
Frame-dragging Vortex Line
– integral curves of eigenvectors of gravitomagnetic tensor
eigenvector eigenvalue
eigenvector eigenvalue
Owen el al. PRL 106, 151101, 2011

16
Tendex and Vortex Lines of Slowly Spinning SMBH
Danehkar, IJMPD, 2020, arXiv:2006.13287 [gr-qc]
●
Visualization of Eab & Hab around a slow Kerr BH
– slow Kerr metric (Zhang et al. PRD 86, 084049, 2012)
– gravitoelectric tensor
– gravitomagnetic tensor (Zhang et al. PRD 86, 084049, 2012)

17
Tendex and Vortex Lines of Fast Spinning BH
●
Visualization of Eab & Hab around a fast Kerr BH
Tidal Tendex Line Frame-dragging Vortex Line
Zhang et al. PRD 86, 084049, 2012

18
Tendex and Vortex Lines of Merging Binary BH
●
Visualization of Eab & Hab around binary BHs
Tidal Tendex Line Frame-dragging Vortex Line
●
Spectral Einstein Code (SpEC)
– https://www.black-holes.org/code/SpEC.html
– SpEC is not publicity available
●
New version: SpECTRE
– https://github.com/sxs-collaboration/spectre
– SpECTRE is still under development by the SXS (Simulating eXtreme Spacetimes) Collaboration, and not yet ready
– Updates on SpECTRE code: https://icerm.brown.edu/programs/sp-f20/w3/ (see talk, Oct 28)
Owen el al. PRL 106, 151101, 2011

19
Gravitational Waves
●
Visualization of Eab & Hab around binary BHs
– Gravitational Wave Simulations by SpEC
Owen el al. PRL 106, 151101, 2011
LIGO detection of gravitational waves, 2016

20
Einstein Cactus Computational Toolkit
●
The Einstein Toolkit (https://einsteintoolkit.org/)
– Cactus Thorns (http://svn.einsteintoolkit.org/cactus/)
– Recent Tutorial: https://icerm.brown.edu/programs/sp-f20/w1/
●
Einstein Toolkit Thorn: EinsteinAnalysis/WeylScal4
– calculates Weyl scalars in the Einstein Toolkit
– converted to Thorn using Kranc (http://kranccode.org/)
●
New Module for gravitoelectric and gravitomagnetic tensors in the Einstein
Toolkit
– can be made by Mathemtica scripts and converted to Thorn using Kranc
●
Kranc: Mathematica program turns tensorial equations into a thorn for the Cactus
Computational Toolkit
transverse wave component for GW simulations of mergers

21
Summary
Unified AGN Outflow Model via BH Spin Survey
& Numerical Relativity
●
– Observational Evidence for a Unified AGN Outflow Model
– Possible correlation between SMBH angular momentum and AGN outflows
– Physical mechanism behind radio-loud AGN: binary SMBH in radio-loud?
●
Black Hole Spin Surveys
 Relativistically broadened Fluorescence Iron Line + Compton continuum
 Relativistic Reflection Model (relxill + xillver)
●
– Gravitoelectric and Gravitiomagnetic tensors
visualized using their Tidal Tendex and Frame-dragging Vortex Lines.
– Visualization of Tendex and Vortex lines for exact solutions and binary BHs are very
complex, but can be done using a new module made by either Kranc or NRPy+ for the
Einstein Toolkit. These simulations are computationally expensive (need HPC)

22
Image
Credit:
J.
Bergeron,
Sky
&
Telescope
Magazine
Image
Credit:
J.
Bergeron,
Sky
&
Telescope
Magazine
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Paths to a Unified AGN Outflow Model via Computational Relativity

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