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Active Galactic Nuclei: Laboratory for Gravitational Physics

Active Galactic Nuclei: Laboratory for Gravitational Physics

Talk presented at the 29th Midwest Relativity Meeting, Grand Valley State University, Grand Rapids, MI, USA, October 2019

Ashkbiz Danehkar

October 04, 2019

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  1. Active Galactic Nuclei
    Laboratory for Gravitational Physics
    Image Credit: NASA/JPL-Caltech
    Image Credit: NASA/JPL-Caltech
    Ashkbiz Danehkar
    Department of Astronomy, University of Michigan
    [email protected]
    The 29th Midwest Relativity Meeting, Grand Rapids, Michigan, USA, October 4th, 2019

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  2. 10/04/2019 Midwest Relativity Meeting
    Gravity Timeline
    1687: Newtonian gravity
    1915: General Relativity
    1960-1975: golden age of GR
    (Kip Throne 1995)
    – Cambridge (Sciama’s group)
    – Hamburg GR group (Jordan)
    – Potsdam AEI (Ehlers’ group)
    – Syracuse (Bergmann’s grp)
    – UT Austin (Schild’s group)
    – ...
    local interaction (Einstein field equations)
    non-local long-range interaction (Binanchi identities)
    Trumper 1964, Hawking 1966, Ellis 1971

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  3. 10/04/2019 Midwest Relativity Meeting
    Gravity Timeline
    1992-present: golden age of cosmology
    (Alan Guth 2001)
    2019: EHT imaging of SMBH in M87
    2016: LIGO detection of gravitational waves

    (Weiss+Throne+Barich 2017)
    1995: acceleration expansion of the universe
    (Perlmutter+Schmidt+Riess 2011)
    1974: Test of GR in a binary pulsar (Hulse+Taylor 1993)

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  4. 10/04/2019 Midwest Relativity Meeting
    Active Galactic Nuclei (AGN)
    2019: EHT imaging of SMBH in M87
    First Image of a Supermassive Black Hole
    Credit: Science History Images / Alamy Stock Photo

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  5. 10/04/2019 Midwest Relativity Meeting
    Active Galactic Nuclei (AGN)
    X-ray Observations of AGN (1999-present)
    Chandra X-ray Observatory (1999-present)
    XMM-Newton, X-ray Multi-Mirror Mission (2000-present)
    NuSTAR, Nuclear Spectroscopic Telescope Array (2012-present)
    Gierlinski + 1999
    Lonanov 2007
    Credit: Roen Kelly @ Astronomy

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  6. 10/04/2019 Midwest Relativity Meeting
    Active Galactic Nuclei (AGN)
    AGN Unified Model (radio-loud & -quiet AGN, Seyfert I & II Galaxies)
    Beckmann & Shrader 2012,
    Active Galactic Nuclei
    Unified Models for AFNs
    Antonucci, ARA&A, 1993, 31, 473
    Unified Schemes for AGNs
    Megan Urry & Padovani, 1995, PASP, 107,
    (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)

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  7. 10/04/2019 Midwest Relativity Meeting
    Active Galactic Nuclei (AGN)
    Dermer & Giebles 2016
    AGN Classification (radio-loud & -quiet AGN, Seyfert I & II Galaxies)
    Blandford, Netzer, Woltjer 1990, Active Galactic Nuclei

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  8. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    Detection of relativistic outflows in X-ray

    Seyfert I PG 1211+143
    Ionized outflow at -0.06c and -0.11 c
    Danehkar + 2018
    Pounds + 2003,2006,2009
    Ionized outflow at -0.06c

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  9. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    Detection of relativistic outflows in X-ray

    Seyfert I PDS 456
    Ionized outflow at -0.24c and -0.48 c
    Biossay-Malaquin, Danehkar + 2019

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  10. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    Detection of relativistic outflows in X-ray
    Cappi 2006

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  11. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    Correlation between outflow kinematics and physical conditions
    Tombesi + 2013
    (Ultra-fast outflows)
    (Warm Absorbers)

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  12. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    X-ray Ionized Outflows in AGN
    Ionization parameter
    Gas density
    density Shell thickness
    Luminosity (0.0136-
    13.6 keV)
    King & Pounds 2015; XMM-Newton & Suzaku
    (42 radio-quiet, Tombesi et al 2011; 51 AGN, Gofford et al. 2013)

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  13. 10/04/2019 Midwest Relativity Meeting
    Ultra-fast Outflow in AGN
    Theories for Relativistic Outflows in AGN

    strong magnetic field in accretion flow/disk
    of rotating BH
    – Blandford-Znajek process (1977) for strong jets from flow
    – Blandford-Payne process (1982) for slow winds from disk

    frame dragging (gravitomagnetism indirectly)
    – Penrose process (1971)
    – Kerr spacetime of rotating BH
    – extracting black-hole rotational energy

    frame dragging + magnetic field
    (e.g. Narayan & Quataert 2005)

    gravitomagnetism (directly)?
    Frame dragging+magnetic
    (Narayan & Quataert 2005)
    Blandford-Znajek process
    (Thorne 1995)

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  14. 10/04/2019 Midwest Relativity Meeting
    Supermassive Black Hole Spin
    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)

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  15. 10/04/2019 Midwest Relativity Meeting
    Supermassive Black Hole Spin
    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

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  16. 10/04/2019 Midwest Relativity Meeting
    Supermassive Black Hole Spin
    BH Spin from Reflection Modeling

    kerrconv (Brenneman & Reynold 2006)

    relline (Dauser + 2010)

    xillver (Garcia + 2010,11,13)

    relxill (Garcia + 2014)
    Dauser & Garcia + 2014

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  17. 10/04/2019 Midwest Relativity Meeting
    Supermassive Black Hole Mass
    BH Mass from Reverberation Mapping Technique (Kaspi + 2000)

    Variation in light curves of broad emission line region (BLR) in Seyfert I AGN

    Time delay in variation of BLR luminosity (Hb 4861A) relative to
    variation of accretion disk luminosity (continuum 5100A)
    Bentz + 2006

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  18. 10/04/2019 Midwest Relativity Meeting
    SMBH Spin Implication
    Black Hole Spin Implication for a Unified AGN Model?
    Garofalo + 2010
    Beckmann & Shrader 2012,
    Active Galactic Nuclei
    AGN Unified Model
    - Radio-Quiet AGN: Seyfert I, Seyfert II
    - Radio-Loud AGN: FR I, FR II (extended radio jets)

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  19. 10/04/2019 Midwest Relativity Meeting
    SMBH Spin Implication
    Black Hole Spin Implication for a Unified AGN Model?
    Danehkar +

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  20. 10/04/2019 Midwest Relativity Meeting
    Future Direction for X-ray Astronomy

    XRISM, X-Ray Imaging and Spectroscopy Mission (2022)
    – Japan Aerospace Exploration Agency (JAXA)
    – Replacement for Hitomi, ASTRO-H (2016, failed)

    ATHENA, Advanced Telescope for High Energy Astrophysics (2031)
    – European Space Agency (ESA)

    Lynx X-ray Observatory (proposed 2035)
    – National Aeronautics and Space Administration (NASA)

    Arcus X-ray observatory (proposed 2023)
    – NASA

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  21. 10/04/2019 Midwest Relativity Meeting
    Proposed Direction for Numerical GR

    Finite-difference Time-domain (FDTD; 1980)

    Discontinuous Time-domain Method (FETD; 2000)

    Finite Element Method (FEM; 1973)

    Finite Integration Technique (FIT, 1977)

    For Maxwell EM equations, there are several numerical methods:
    For Einstein field equations (local gravitational interaction), there are several
    numerical methods (see review by Font 2003 for numerical GR; Fornt 2008 for
    For example, for Bianchi dynamical formulas of non-local (Weyl) gravitational fields:
    Newtonian Tidal force
    Non-Newtonian effect
    Gravitational waves
    shear induction?
    hydrodynamics simulation
    not fully developed
    angular momentum

    Finite Difference Method (FDM; 1988)

    Smoothed Particle Hydrodynamics (SPH; 1977)

    Spectral Methods (1988)

    Flow Field-dependent Variation Method (FDV; 2002)

    One of reference books for mathematics of Weyl fields

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  22. 10/04/2019 Midwest Relativity Meeting
    Implication of Supermassive Black Hole Angular Momentum for AGN Outflows?

    Relativistic Outflows in AGN measured from
    – blue-shifted highly-ionized absorption lines in X-ray spectra

    AGN Outflow Physical conditions from
    – photo-ionization modeling of absorbers

    Black Hole Spin measured from
    – relativistic Fe Kα line (6.4 keV)
    – Compton hump (> 10keV)

    Black Hole Mass measured from
    – time delay in BLR vs. disk light curves in
    Seyfert I AGN (Reverberation-mapping)

    Physical Mechanism behind
    relativistic outflows in AGN?
    – Need for larger sample and
    future X-ray observations (XRISM 2022, ATHENA 2031, Lynx 2035)
    – Future developments in numerical methods & simulations of GR hydrodynamics
    Credit: Roen Kelly @ Astronomy

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  23. Image Credit: NASA/JPL-Caltech
    Image Credit: NASA/JPL-Caltech
    Thank you for your attention
    Thank you for your attention

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