SUMMARY

1
SUMMARY

• PROBING STRONG GRAVITY IN AGN

Kirpal Nandra Imperial College London
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PROBING STRONG GRAVITY

• The Promise
• The Probes
• The Progress
• The Problems
• The Prospects
• Probably

Paul Reviews Observations (and Theory)
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THE PROMISE

• What are the processes close to the event
  horizon?
• Are black holes in AGN spinning?
• How does BH spin evolve on the Cosmic Scale?
• How does matter behave in the strong field?
• Does it obey the predictions of GR?

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THE PROBES

• Broad emission lines
• Narrow emission lines
• Narrow absorption lines
• Variability/reverb.
• Broadband/disk/reflection spectra
• Polarimetry
• Binary Black Holes
• Microlensing

(Iwasawa, Ballantyne, Guainazzi, de la Calle,
Svoboda, Miniutti)
(Cappi, Reeves,)
(Cappi)
(Zoghbi, de Marco, Ponti, Goosmann)
(Laor, Walton)
(Dovciak)
(Komossa, Liu)
NOBODY!
Nikolajuk TBC
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PROBES MICROLENSING
MICROLENSING!
Chartas et al. 2009 Dai et al. 2009
RX J1131-123116
Direct measurement of size of emission region
X-rays from 10 Rg (Optical 70 Rg)
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THE PROGRESS
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PROGRESS INFLOWS/OUTFLOWS
Cappi
Mrk 509 (long-look, 200ks)
Obs1
Obs2
Obs3
MC et al., 2009 Dadina et al. 05
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PROGRESS HOTSPOTS
Cappi, Iwasawa, Reeves, De Marco
Turner et al. 2005
Iwasawa et al. 2004
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PROGRESS THE INNER FLOW
Iwasawa Nikolajuk
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PROGRESS BROAD LINES
45 of XMM-Newton Seyfert sample with gt30,000
counts
Nandra et al. (2007)
De La Calle, Guainazzi
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PROGRESS BROAD LINES
Zoghbi
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PROGRESS SPIN MEASUREMENT
If ? implies a
Fanidakis et al. arXiv0911.1128
Laor disk continuum fitting
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PROGREES SPIN MEASUREMENT
Miniutti broad emission lines
Fairall-9
SWIFT J1247
Implications for black hole accretion/merger
history through cosmic time (also Ballantyne)
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PROGRESS STRONG GRAVITY
Iwasawa Walton Svoboda
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THE PROBLEMS

• Broad lines
• Predicted to be universal, but not always
  observed
• Degenerate with complex absorption
• Lines are much weaker than we might have hoped
• Sometimes variable, sometimes now
• Narrow lines
• NOT predicted unless extreme anisotropic effects.
  
• Limited statistical significance (Vaughan
  Uttley)
• Spallation of Fe
• Non-repeatable observations -gt cannot test models
• Should be transient (Kepler timescale) is this
  too convenient?
• QPOs
• Finally one decent AGN example (RE 1034
  Middleton)
• Ooops it went away (Middleton)
• Which QPO to associate with GBHC?
• Interpretation in GBHC not clear despite vastly
  better data

• Overall, two major problems
• Repeatability of observations
• Prediction and testing of models

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PROBLEMS BROAD LINES
Zoghbi
Absorption highly unlikely to be sole
explanation, but details (e.g. spin) very hard to
disentangle
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PROBLEMS BROAD LINES
30 of Sample
Why are broad lines absent? (Almost) unavoidable
prediction of accreting systems Ionization, Fe
abundance, Extreme blurring?
Criteria lt99 significance for blurred
reflection 12 total IC4329A (1) NGC 5506(1), NGC
5548(1) NGC 7469(1)
Disk line upper limits typically 50-100 eV
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PROBLEMS S/N RATIO
De la Calle
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PROBLEMS NARROW FEATURES

• Lines statistical significance? (transient
  features, number of trials in time and energy,
  etc)
• Identifications of edges/lines energies? (Kallman
  et al. 2005, Kaspi et al. for PG1211)
• Local contamination? (PDS456 at risk? McKernan
  et al. 04, 05)
• Publication bias? Only positive detection, low
  signif., Vaughan Uttley 08)

Outflow v (km/s)
Solutions Large Samples, Systematic
analysis Cappi, de Marco, de la Calle, Ponti
cz (km/s)
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PROBLEMS NARROW LINES
Obs 1 vs Obs2
Reeves
Strong narrow K? line at 6.4 keV. Constant flux
over 3 years. However redshifted but relatively
narrow line emission is observed at 5.4 keV and
5.9 keV in 2005 low state.
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PROBLEMS NARROW LINES
Mostly S. Vaughan
Suzaku
All XMM co-add
5.4 keV
Reeves
If 5.4 keV is real, it is variable (thus not
spallation)
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PROBLEMS LINE VARIABILITY
Bhayani Nandra (2010)
Variability key to break degeneracies Iwasawa,
Zoghbi, Reeves, de Marco, Ponti, Goosmann
BUT source behaviour not predictable with
current models
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PROSPECTS REVERBERATION
Zoghbi
Reeves
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PROSPECTS POLARIZATION
X-ray polarimetry a new window to be opened by
GEMS, NHXM, IXO
Dovciak
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PROSPECTS BH SPIN
ASTRO-H First high resolution, high throughput
spectroscopy at 6 keV
IXO ULTRA-HIGH THROUGHPUT
ASTRO-H
IXO
IXO XMS
MCG-6-30-15 100ks
NGC 3783 300ks
IXO
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PROSPECTS TRACING HOTSPOTS
IXO high throughput
C. Reynolds
Flux constraint 20
400s exposure 1/10 tKeplerian at 6 rg
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PROSPECTS TESTING GR?
Testing the no-hair theorem e0
GR correct
e0.0 (GR)
0.2
?0.5
C. Reynolds
Johanssen Psaltis (2009)
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PROGNOSIS

• Strong gravity effects in AGN can be probed
• For example, mlensing shows X-rays arise within
  10 Rg
• Major issues
• Model degeneracies
• Unrepeatable observations
• Lack of testable model framework
• Major progress
• Large samples, systematic analysis
• Variability studies, reverberation
• Huge future potential
• High resolution spectroscopy
• High throughput spectroscopy
• Polarimetry

Promising Prospects for Proactive Promotion of
Proposed Projects
IXO
See you in Progue 2020!