AGNandGalacticBlackHoleSpectra

TodaysBestAdvertisingforAGN-RyanHickox

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•  Differential Keplerian rotation •  Viscosity : gravity → heat •  Thermal emission: L = AσT4 •  Temperature increases inwards •  GR last stable orbit gives

minimum radius Rms

Spectra of accretion flow: disc- C. Done Review

Log ν

Log

ν f(ν)

Log ν

Log

ν f(ν)

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•  GR last stable orbit gives minimum radius Rms

•  a=0: Tmax = (M/M� )-1/4 (L/LEdd )1/4

•  1 keV (107 K) for 10 M� if L=LEdd

•  10 eV (105 K) for 108 M� " "

•  a=0.998 Tmax ~ 2.2 Tmax (a=0) •  AGN: UV disc, ISM absorption,

mass more uncertain. XRB…

Spectra of accretion flow: disc- C. Done Review

Log ν

Log

ν f(ν)

Log ν

Log

ν f(ν)

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Relativisticeffects-C.Done

Fabian et al. 1989

Energy (keV) flu

x

•  Relativisticeffects(specialandgeneral)affectallemission(Cunningham1975)

•  Hardtoeasilyspotoncontinuumcomponents

•  FeKα linefromirradiateddisc–broadandskewed!(Fabianetal1989)

•  BroadeninggivesanindependentmeasureofRin–sospinifISO(Laor1991)

•  Modelspredictincreasingwidthasgofromlow/hardtohigh/softstates

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WhatDoBroadBandSpectraofBlackHolesLookLike

Log(flu

x)

Log(frequency)

Thermalemissionfromaccretiondisk(softX-raysforGBHC;UVforAGN)

X-ray�tail�- not due to the accretion disk

T~(M/MEdd)1/4M-1/4

How Hot is a Black Hole?? Lets go back to the accretion disk spectrum- Longair 14.52-14.54 T(R)=[3GMM/8πR3]1/4(R/Rin)]-3/4

Temperature at fixed number of Rs decreases as M-1/4

- disks around more massive black holes are cooler at a fixed R/RS and M/MEdd now recasting in terms of the Eddington limit where MEdd is the mass accretion rate for the Eddington limit and we assume that the conversion efficiency of mass into energy is 10% and M8 is the BH mass in units of 108 M¤ T~6.3x105[M/MEdd]1/4[M/M8]-1/4(R/Rin)]-3/4k-UV T~6.3x107[M/MEdd]1/4[M/M!]-1/4(R/Rin)]-3/4k-Xray

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GalacticBlackHoles•  Relativelylowmassandsothe

diskare'hot'

L~ 7x1038 f(M10)2(Tin)4 erg/s Where M10 is the mass in units of 10 M� and Tin is in keV f is a factor taking some complex physics into account !

AdaptedfromMilleretal2003

DiskBB

"Powerlaw"

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GalacticBlackHoles-GBH

•  Relativelylowmassandsothediskare'hot'-mostofthefluxappearinginthex-rays

0.1 1.0 Tin (keV)

L x104

0 ergs/sec

AdaptedfromMilleretal2003

GBHULX

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ReminderofAccretionDiskSpectrum•  Derivationofpreviouseq•  L=2πRin2f(cosi)-1;fisthefluxfromthesurfaceofthedisk,Ristheradius•  Usingtheblackbodylaw L=4πσR2Tin4σ istheStefan-Boltmannconstant

InfittingthespectrumTinisdirectlyobservableWecanthustakethe2equationstogettheinnermostradius

Rin=sqrt(L/4πσTin4)andTin~3M10

-1/4keV T(r)=6.3x105 (M/MEdd)1/4M8

-1/4(r/rs)-3/4(MEdd is the accretion rate in Eddington units, T=Tinforr=rs)

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RealObjects•  Dataforgalactic

blackholesagreeswiththesimpletheory

•  E.gassumethatMBHdoesnotchangeandallchangesluminosityduetochangesinM-ifsothenexpectTin~M 1/4~L1/4

Makishimaetal2000

FittedTin

Diskbolom

etricluminosity

x10

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Miller(2013)

kT(Kev)

Diskflux

blackholetransient

ModificationstoDiskBlackBody

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Miller(2013)

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•  CanFitAGNUV-opticaldatawithaccretiondiskmodels

MalkanandSun1989

Effectsofinclinationondiskspectrumfor5x108M¤BH

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AGN•  AGNareverymassiveand

sothepredictedspectrumoftheaccretiondiskis'cool'-peakinginUV-EUV

•  T~8x104kforaEddingtonlimitedM~108M¤blackhole

•  ProblemswithobservingintheEUVandsodonotobservehighenergyexponentialcutoff

FitofSSADmodelstoAGNspectrum(MalkanandSun1989

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FittedParametersforUVDiskFits

•  Resultsare'reasonable'butnotunique

•  Nowhaveindependentmassestimates-resultscanbechecked–  Findthatvaluesarenotquite

right-needmorecomplexaccretiondiskmodels(surfaceisnotsimpleBB,needtoinclude

relativisticeffects)

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EffectsofStrongGravity(Spin),

InclinationAngleonSpectrumofDisk(Merloni2010)

aisspininGRunits

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RelativisticEffects•  Lightraysarebentbystronggravity-makingthegeometry

rathercomplicated

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•  Possiblestrongeffectoflightbending.

•  ifweonlyknewwherethex-rayscomefrom(hs~rs)fromtimevariabilityarguments

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EffectsofStrongGravity(Spin),InclinationAngleonSpectrumofDisk(Merloni2010)

ToppanelisADspectrumvsenergyforfixedinclinationangle,spinvariesBottompanelfixedspin,inclinationanglevaries.

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Next...

•  AccretionDiskfitstoAGNspectra

•  Broadbandspectraarenotsosimple-what'sthereinadditiontotheaccretiondisk–  thegeometryoftheinnermostregions–  briefreviewofComptonization

•  Effectsof'reprocessing'-thedisk'sees'thehardx-rayradiationandtherearemeasurableeffects

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LifeisNotSoSimple

•  ThebroadbandspectraofbothAGNandGalacticblackholeshavemajordeviationsfromdiskspectra

AdaptedfromPolettaetal2007

Emissionfromdust?

diskemission

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AGN•  Ahugeamountofwork

hasgoneintoobservingAGNacrosstheentireelectromagneticspectrum

•  Thereisastrongrelationshipbetweentheoptical-UVandthex-ray

Brusaetal2009

diskemission

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X-raytoUVRelationship•  Over103in

luminositytheUVandx-raytrackeachintypeIAGN

•  Directconnectionofdiskemission(seeninUV)tox-rays

Lussoetal2010LUV

L xray

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•  AverageSpectralEnergyDistributionsfor2ClassesofObjectsSelectedasX-rayEmittingAGNinagivenx-rayluminositybin(Pollettaetal2007)

Effectofreddeningbydust

x-ray

GeneralShapeoftheOptical-X-

raySED

•  Astheluminosityofthesourceincreasestheratioofx-raytoopticalluminosity(αox)decreasesslightly

•  e.gmoreluminousAGNarex-ray'quieter"

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Coffeyetal2019

αox=[log(Fx)-log(FUV)]/2.605

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EffectsofDustCanBeDominant•  RememberfortheM~108

T~5x105Kso'rollover'isintheFUV–effectsofdustaremaximumintheUV

•  Emax~3kT~1016hz•  Theeffectsofdust(Reddening)

goatλ-2

•  muchbiggereffectsatshorter(UV)wavelengths-majoreffectondeterminationoftemperatureofaccretiondiskfitstoquasars.

Laor1990

averageamountofreddeningintheMilkywayatb=500

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AGN-SummaryofSpectralComponents•  3Broadbandsofenergy•  Diskdominatesinoptical-UV•  ComptonizationinX-ray•  ReprocessedradiationinIR

Magdziarz et al 1998

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AGN•  AGNareverymassiveand

sothepredictedspectrumoftheaccretiondiskis'cool'-peakinginUV-EUV

•  T~8x104kforaEddingtonlimitedM~108M¤blackhole

•  ProblemswithobservingintheEUVandsodonotobservehighenergyexponentialcutoff

FitofSSADmodelstoAGNspectrum(MalkanandSun1989

ConnectionofFeKlineandtheReprocessingRegions•  Themostprominentspectral

featuresinmostx-rayAGNspectraare–  theFeKlinecomplex–  TheComptonreflection�hump�

•  Wherearetheseregions•  Howaretheyconnected•  Whatdowelearnaboutthegeometryandchemicalabundanceofthecentralregions?

•  Whatisthephysicalstateofthegasandhowisitconnectedtoother�places�-e.gtheregionsresponsibleforproducingtheoptical/UV/IRradiation

•  Whatcanwelearnaboutaccretion

X-ray source

reflection

MCG-5-23-16Suzakudata(Reevesetal2006

Cartoonorreality??

Comptonhump

FeKcomplex

MoreComplexity•  ComptonizationandX-rayAGNSpectra

•  X-raySpectralComponentsandreprocessing

•  Directevidencefordisksandsmallx-raysizefromgravlensing

•  BroadFeKLinesandSpin

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Optically-thickpartoftheaccretiondiskemitsthermalspectrum…blackbodyradiationwith

X-ray�tail�probablycomesfromahotcoronax-raysproducedbyinverseComptonscatteringofthermaldiskemissionbyelectronswithT~109K

WheredotheSpectralComponentsArise?

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EvenMorePossibleGeometries

FromC.Done

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RealDataForGalacticBH

Wheredothehighenergyphotonsarise?InbothAGNandBlackHolebinariesitisthoughtthatthisspectralcomponentisduetoComptonizationofa'seedphoton'populationoffofhighlyenergeticelectronsproduced'above'thedisk

disknotdisk

Possiblegeometries-blueisx-rayemittingregion

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ComptonizedSpectraLongair9.4.1

Done2007

n y~4kT/mec2(maxτ,τ2)n slopeα~-3/2+(9/4+y)1/2

•  Thefreeparameterforthepowerlawslopeisywhichcontrolsthespectralslope

•  Howeverthesmallerτis,thelargerThastobetogetthesameslope-the'bumpier'thespectraare

•  spectrumsteepsathighE(maxT)

•  y~1istheusualcase•  seeUnwrappingtheX-ray

SpectraofActiveGalacticNucleiC.ReynoldsarXiv:1510.07638

• 

ThermalComptonizedContinuum•  Thedetailedsolutionisabitmessy

(Zdziarski,Johnson&Magdziarz(1996)butfory>1oneformsaspectrumwhichcanbeapproximatedbyapowerlawofslopeΓwithahighenergycutoffrelatedtothetemperatureofthehotelectrons.

•  power-lawindexofthephotoncountrateasafunctionof

energy,dN(E)/dE � E−Γ,

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ThermalComptonizedContinuum•  Thedetailed

solutionisabitmessy(Zdziarski,Johnson&Magdziarz(1996)butfory>1oneformsaspectrumwhichcanbeapproximatedbyapowerlawofslopeΓwithahighenergycutoffrelatedtothetemperatureofthehotelectrons.

•  , 37

Typicalslopesare~-2whichgivesτe~1andy =3/4y=4kTemec2max(τe,τ2e)typicaltemperaturesare50-300keV

ThermalComptonizedSpectra•  Typicalslopesare~-2

•  whichgivesτe~1andy =3/4

y=4kTemec2max(τe,τ2e)•  typicaltemperaturesare50-300keV

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NumericalcalculationsofComptonizedspectrafordifferentT,τ combinations

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AGN-SummaryofSpectralComponents

Hickok & Alexander 2018

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MoreOnBHSpectra•  Relationshipofcomponents•  Whydowethinkdiskexists•  Geometryofcentralregions•  Reprocessing-howcanwelearnaboutthe

materialinandaroundtheblackholefromspectralandtemporalsignaturesinthespectra

•  Spinanditsinfluence

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Howdoweknowthattherereallyisadisk??

•  RecentmicrolensingobservationsofafewQSOshave'resolved'thex-rayandopticalsources

•  Theopticalsourcesizeanddependenceofluminosityonwavelengthareconsistentwithstandarddisktheory-e.g.

•  Microlensingperturbationstothefluxratiosofgravitationallylensedquasarimagescanvarywithwavelengthbecauseofthechromaticdependenceofthesourcesapparentsize.

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MicroLensing•  AswesawlasttimeinadiskT(r)~Tmaxr-3/4

•  Writingitoutinfull•  Teff(r)={(3G2MBH

2mpfEdd)/2cσSBεr3)}1/4(1-rin/r)1/4–  fEddistheEddingtonratio,MBHistheBHmass,σSBtheStefanBoltzman

constant,ε istheefficiency

•  Thusthediskemitsmostofitsshortwavelengthlightatsmallradiiandlongwavelengthlightatlargeradii

•  Integratingthedisktemperatureprofile(Blackburneetal2010)onegetsthatthehalflightradiusasafunctionofsizeis

r1/2~1.7x1016cm(MBH/109M�)2/3(fEdd/ε)1/3 (λ/µ)4/3•  Inotherwordstheeffectivesize~λ4/3

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•  ThesizeofthediskisinEinsteinradiusunitswhichareconvertedtocgsunitswithamodelofthegravpotentialofthelensinggalaxy

•  Sourceisbiggeratlongerwavelengths-lineiswhataSSdiskshouldbe

•  Tocomparetomodeldisks,havetoassumeMBH,fEdd/ε

SizeofPG1115inEinsteinradiusunits

logr(cm

)

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X-rayMicroLensingAlso

•  Probabilitydistributionofopticalandx-raysourcesize(Zimmeretal2010,Chartasetal2008)-x-rayisMUCHsmaller

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ResultsareInRoughAgreementWithTheory•  X-raysareemittingnear

theSchwarzschildradius

•  Optical~10xfurtherout

Chartas2008