Observational constraints on the distribution of AGN BH spin in the - - PowerPoint PPT Presentation

▶
observational constraints on the distribution of agn bh
SMART_READER_LITE
LIVE PREVIEW

Observational constraints on the distribution of AGN BH spin in the - - PowerPoint PPT Presentation

May 21, 2023 162 likes •601 views

Observational constraints on the distribution of AGN BH spin in the 5 1 0 2 h c r a local Universe M h t 0 3 , i a h g n a h S , N G A n i n i p s H B Matteo Guainazzi g n i r u s a e M , i

slide-1
SLIDE 1

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Observational constraints on the distribution of AGN BH spin in the local Universe

Matteo Guainazzi ASTRO-H Science Operation Team ISAS/JAXA & ESA/ESAC

slide-2
SLIDE 2

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-3
SLIDE 3

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-4
SLIDE 4

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Measuring spin in BHs

Astrophysical black holes are characterized by three quantities: mass (measurable through gas and/or stellar dynamics), charge (assumed 0), spin

Method XRB? SgrA* AGN?

Thermal emission from the accretion disk

YESa NO NO

X-ray spectroscopy

  • f the disk reflection

spectrum

YESb NO YESb

Measurement of GR frequencies in the precession modele

YESc YESd NO

X-ray polarimetry

NO NO NO

(aMcClintock et al., 2011, arXiv:1101:0811; bthis talk; cMotta et al., 2013, arXiv:1309.3652; dAschenbach, 2004, A&A, 425,1075; eStella & Vietri, 1999, PhRvL, 82, 17)

slide-5
SLIDE 5

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5 (Bardeen et al., 1972, ApJ, 178, 347)

What we really measure is the ISCO=rms

slide-6
SLIDE 6

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Optically thick accretion disk reflection

(Reynolds, 2013, SSRv, 81)) (Fabian et al., 2000, PASP, 12, 1145)

= Hard component Reflection component Astrophysical scenario underlying the “disk reflection method” in AGN (ad XRB)

slide-7
SLIDE 7

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

The disk reflection method: monochromatic case

(Fabian et al., 2000, PASP, 112, 1145) (Brenneman & Reynolds, 2006, ApJ, 652, 1028)

slide-8
SLIDE 8

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

The disk reflection method: reality

(based on Ross & Fabian, 2007, MNRAS, 381, 1697; Brenneman & Reynolds, 2006, ApJ, 652, 1028)

The whole disk reflection spectrum is blurred

“Pure” reflection spectrum Blurred with a Schwarzschild (a=0) kernel Blurred with a Kerr (a=0.998) kernel a=0 a=0.998

slide-9
SLIDE 9

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-10
SLIDE 10

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Why do we care?

The distribution of super-massive BH spins in the local Universe carries the imprinting of the host galaxy history (=evolution)

(Courtesy Dr. Giovanni Miniutti, LAEX; based on Berti & Volonteri, 2008, ApJ, 684, 822)

slide-11
SLIDE 11

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

BH spin as tracer of BH-galaxy evolution

The BH spin could drive the evolution of radio-loud galaxies into radio-quiet

(Garofalo et al., 2010, MNRAS, 409, 975)

BZ = Blandford-Znajek BP = Blandford-Payne

slide-12
SLIDE 12

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

BH spin (possibly) powering jets

Power of ballistic jets in transient XRBs

(McClintock et al., 2013, arXiv:1302.1583; see a different view in: Russell et al., 2013, MNRAS, 2013, 431, 405)

slide-13
SLIDE 13

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-14
SLIDE 14

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Early results

(Tanaka et al, 1995, Nat, 375, 659)

Discovery: ASCA/SIS CCD resolution Confirmation:Chandra/HETG Grating resolution The archetypal case: MCG-6-30-15 Most of our current measurements are still at CCD resolution

(Young et al., 2005, ApJ, 631, 733)

slide-15
SLIDE 15

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Summary of AGN BH spin measurements

(Reynolds, 2013, SSRv, 183, 277)

slide-16
SLIDE 16

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Comparison with AGN evolution models Pure “coherent”/”chaotic” evolutionary models predicts distributions clustered towards too high/low BH spin values

(Sesana et al., 2014, ApJ. 2014. 794, 104)

slide-17
SLIDE 17

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

First attempt on lensed QSOs

RXJ1131-1231 (z=0.658) a=0.87+0.15

  • 0.08

(Reis et al., Nat, 507, 207; Reynolds et al., 2014, ApJ, 792, L41; Walton et al., 2015, arXiv:1503.05255)

slide-18
SLIDE 18

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-19
SLIDE 19

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to the disk physics

(Reynolds & Fabian, 2008, ApJ, 675, 1048)

slide-20
SLIDE 20

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to the disk structure

(Svoboda et al., 2012, A&A, 545, 106)

Physics: lamppost over a disk with radially stratified ionisation Model: single-ionisation reflection [ε(r) ~ r-q] Test case: MCG-6-30-15

slide-21
SLIDE 21

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to parameter degeneracies

(Reynolds et al., 2012, ApJ, 755, 88)

Probability for the BH spin in NGC3783 (Suzaku observation) free abundance Solar abundance free (disk)/Solar (torus) abundance

slide-22
SLIDE 22

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to data modeling

Fairall 9 – Suzaku data

slide-23
SLIDE 23

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to data modeling

Fairall 9 – Suzaku data Model “A”: a≈0.52, i≈48º, Z/Zsolar>8.3 Model “B”: a≈0.96, i≈36º, Z/Zsolar>0.75

Same data, same analysers, different models

(Lohfink et al., 2012, ApJ, 758, 67)

slide-24
SLIDE 24

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Explaining MCG-6-30-15 without relativistic blurring

The Fe Kα can be fit without any relativistic broadening, with layers

  • f ionised, partial covering

absorbers

(Miller et al., 2009, MNRAS, 399, 69)

slide-25
SLIDE 25

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Core question If the same spectrum can be fit with two models:

  • one requires relativistic broadening, and

yields a=0.96±0.01,

  • the other does not require relativistic

broadening: Which is the best estimate for the BH spin?

slide-26
SLIDE 26

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Why so difficult? Spectral complexity

(Risaliti & Elvis, 2004, ASSL, 308, 187)

slide-27
SLIDE 27

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Why so difficult? Spectral complexity + variability

  • Fe Kα line photons: ≈3%

total

  • Variability timescale, τ:

≈1 h

  • Number of EPIC-pn Fe Kα

line photons in τ:

– ≈50 in τ – ≈1200 in 1 day Spectral complexity: Variability:

(Risaliti & Elvis, 2004, ASSL, 308, 187) (Vaughan & Fabian, 2004, MNRAS, 348. 1415)

slide-28
SLIDE 28

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Outline

  • How to measure spin in accreting Super-

Massive Black Holes (SMBH)

  • Why measuring spin in accreting SMBH
  • Where do we stand now?
  • Why is it such a difficult (and controversial)

measurement?

  • How we can put these measurements on

more robust ground?

slide-29
SLIDE 29

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

break frequency scales ~with mass

Unification of accreting black holes in Fourier space

(McHardy et al., 2004, MNRAS, 348, 783)

slide-30
SLIDE 30

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Variability as an opportunity

(line profiles from the calculations by Dovčiak et al., 2004, ApJS, 153, 205))

slide-31
SLIDE 31

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Reverberation lags

Discovery of “soft lags” in 1H0707-495 → an energy band dominated by disk reflection lags another energy band dominated by the primary emission Energy spectrum Lags spectrum

(Zoghbi et al., 2011, MNRAS, 412, 59)

slide-32
SLIDE 32

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

These “reverberation lags” scale with the BH mass

(de Marco et al., 2013, MNRAS, 431, 2441)

[Alternative interpretation: X-ray scattering by an absorbing

medium whose opacity decreases with increasing energy with a high covering fraction, and that partially covers the source (cf. Miller et al., 2010, MNRAS, 408, 1928)]

slide-33
SLIDE 33

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

This is not the “killer argument” yet

Both interpretation require reprocessing

  • n scales <20 rg (Miller at al., 2010, MNRAS, 408, 1928)

20

(de Marco et al., 2013, MNRAS, 431, 2441)

slide-34
SLIDE 34

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Fe Kα riverberation in NGC4151

ν<2x105 Hz ν=[5-50]x105 Hz The Fe Kα red wing lags peak at a higher time frequency (=shorter timescales) This is consistent with a disk reverberation scenario whereby the red wing is produced closer to the BH event horizon, where the gravitational redshift is stronger

(Zoghbi et al., 2012, MNRAS, 422, 129)

slide-35
SLIDE 35

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to data modeling

Fairall 9 – Suzaku data Model “A”: a≈0.52, i≈48º, Z/Zsolar>8.3 Model “B”: a≈0.96, i≈36º, Z/Zsolar>0.75

Same data, same analysers, different models

slide-36
SLIDE 36

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Systematics due to data modeling

Fairall 9 – Suzaku data Model “A”: a≈0.52, i≈48º, Z/Zsolar>8.3 Model “B”: a≈0.96, i≈36º, Z/Zsolar>0.75

Same data, same analysers, different models

slide-37
SLIDE 37

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

The broad band helps ...

(Risaliti et al;, 2013, Nat, 494, 449)

slide-38
SLIDE 38

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

… and will help even more with ASTRO-H

ionised outflow

slide-39
SLIDE 39

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Conclusions

  • Are BH spin measurement in AGN possible in principle? Yes

–

Fe Kα reverberation results can be explained only in the corona+relativistic disk scenarios

  • Are the errors on current (i.e., XMM-Newton, Suzaku) measurements

under control? No

–

They rely on fitting the not understood spectrum in the soft X-ray band

–

The statistical weight of the high-energy (i.e. E>10 keV) spectrum is too small (or inexistent)

  • Will we be able to measure some AGN BH spins? Yes

–

NuSTAR and (better) Astro-H address the shortcomings of current

  • bservatories. However, variability, and uncertainties in the

models will dominate the error budget

  • What would we need to transform this in a solid science?

–

[use only sources with] ~103-4 net counts per unit variability time

–

Disk reflection models treating illumination, ionization radial structure and vertical structure self-consistently

slide-40
SLIDE 40

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Conclusions

  • Are BH spin measurement in AGN possible in principle? Yes

–

Fe Kα reverberation results can be explained only in the corona+relativistic disk scenarios

  • Are the errors on current (i.e., XMM-Newton, Suzaku) measurements

under control? No

–

They rely on fitting the not understood spectrum in the soft X-ray band

–

The statistical weight of the high-energy (i.e. E>10 keV) spectrum is too small (or inexistent)

  • Will we be able to measure some AGN BH spins? Yes

–

NuSTAR and (better) Astro-H address the shortcomings of current

  • bservatories. However, variability, and uncertainties in the

models will dominate the error budget

  • What would we need to transform this in a solid science?

–

[use only sources with] ~103-4 net counts per unit variability time

–

Disk reflection models treating illumination, ionization radial structure and vertical structure self-consistently

slide-41
SLIDE 41

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Conclusions

  • Are BH spin measurement in AGN possible in principle? Yes

–

Fe Kα reverberation results can be explained only in the corona+relativistic disk scenarios

  • Are the errors on current (i.e., XMM-Newton, Suzaku) measurements

under control? No

–

They rely on fitting the not understood spectrum in the soft X-ray band

–

The statistical weight of the high-energy (i.e. E>10 keV) spectrum is too small (or inexistent)

  • Will we be able to measure some AGN BH spins? Yes

–

NuSTAR and (better) Astro-H address the shortcomings of current

  • bservatories. However, variability, and uncertainties in the

models will dominate the error budget

  • What would we need to transform this in a solid science?

–

[use only sources with] ~103-4 net counts per unit variability time

–

Disk reflection models treating illumination, ionization radial structure and vertical structure self-consistently

slide-42
SLIDE 42

M a t t e

  • G

u a i n a z z i , “ M e a s u r i n g B H s p i n i n A G N ” , S h a n g h a i , 3

t h

M a r c h 2 1 5

Conclusions

  • Are BH spin measurement in AGN possible in principle? Yes

–

Fe Kα reverberation results can be explained only in the corona+relativistic disk scenarios

  • Are the errors on current (i.e., XMM-Newton, Suzaku) measurements

under control? No

–

They rely on fitting the not understood spectrum in the soft X-ray band

–

The statistical weight of the high-energy (i.e. E>10 keV) spectrum is too small (or inexistent)

  • Will we be able to measure some AGN BH spins? Yes

–

NuSTAR and (better) Astro-H address the shortcomings of current

  • bservatories. However, variability, and uncertainties in the

models will dominate the error budget

  • What would we need to transform this in a solid science?

–

[use only sources with] ~103-4 net counts per unit variability time

–

Disk reflection models treating illumination, ionization radial structure and vertical structure self-consistently