Observing the strong gravity regime of accreting black holes with Simbol-X

0.15 MB·English

by  R. W. Goosmann

Mem.S.A.It.Vol.75,282
(cid:13)c SAIt 2004 Memoriedella
Observing the strong gravity regime of
a

reting bla
k holes with Simbol-X
R.W.Goosmann1,2,M.Dovcˇiak1,andV.Karas1
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1 AstronomicalInstitute,AcademyofSciences,Bocˇn´ıII1401a,CZ–14131Praha4,
0
0 CzechRepublic,e-mail:[email protected]
2 2 ObservatoiredeParis,SectiondeMeudon,5pl.JulesJanssen,F–92190Meudon,France

n
a
J Abstract. The X-ray reflection features of irradiated accretion disks around black holes
enableustoprobetheeffectsofstronggravity.Weinvestigatetowhichprecisionthereflec-
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tionsigns,i.e.theironK-lineandtheComptonizedhump,canbeobservedwithSimbol-X
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fornearbySeyfertgalaxies.Thesimulationspresentedincludeaccuratecomputationsofthe

localreprocessedspectraandmodificationsduetogeneralrelativisticeffectsinthevicinity
]
h oftheblackhole.Wediscusstheimpactofglobalblackholeparametersandoftheirradi-
p ationpatternofthediskontheresultingspectraastheywillbedetectedbytheSimbol-X
- mission.
o
r
Keywords.Blackholephysics–X-rays:galaxies–Spacevehicles:instruments
t
s
a
[
TheX-rayspectraofmanyaccretingblack and Noar (Dumont,Abrassart,&Collin 2000;
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holesareknowntorevealrelativisticallymod- Dumontetal. 2003) and the relativistic ef-
v
ified reflection features, notably a fluores- fectsareaddedapplyingtheray-tracingmodel
0
cent iron K-line complex (for a review see KY (Dovcˇiaketal. 2004) inside XSPEC. Our
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4 Reynolds&Nowak2003)andaComptonized modeling procedure is described in detail in
2 hump(e.g.Lightman&White 1988).Withits Goosmannetal. (2007). We assume a black
1. broad photon energy coverage the Simbol-X hole with M = 3×107M⊙ that is maximally
satellite is particularly suited to observe such spinningandthatcarriesanaccretiondiskbe-
0
X-ray reflection spectra. In this proceedings inginhydrostaticbalance(beforetheflaregoes
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0 note, we show that Simbol-X will be able to off).Weconsiderorbitingspotsatthediskradii
v: distinguishX-raysbeingre-emittedatdifferent R = 4Rg and R = 21Rg (Rg = GM/c2).
radiioftheinnermostaccretiondisk. Simulateddataareobtainedforthe“observed”
i
X We assume that the X-rays are produced spot emission at both radii using a modified
r by magnetic flares co-orbiting with the disk versionofthekyl1crmodelinXSPECandthe
a so that the reflection features originate in currently available response matrices for the
underlying orbiting spots. Detailed reflec- MPDandCZDdetectorsofSimbol-X.Theob-
tion spectra of such spots are modeled us- servation time is set to one Keplerian orbit in
ing the coupled radiative transfer codes Titan both cases and the flux rates are adjusted to
an XMM-Newton observation of the Seyfert
galaxyNGC3516(Iwasawaetal.2004).
Sendoffprintrequeststo:R.W.Goosmann
Goosmann,Dovcˇiak,&Karas:Stronggravityregimeofaccretingblackholes 283
-4
10
MPD CZT
V
e
k
s
2 -5
m10
c
s /
n
o
ot
h
P
R = 21 R
g
R = 4 R
g
-6
10
1 3 5 10 30 50
Photon energy [keV]
Fig.1.SimulatedMPDandCZDspectraofanorbitingflarespotatR=4R (top)andR=21R (bottom).
g g
TheunderlyingXSPECmodelsareshownassolidlines.Thedatasetscontainaverticaloffsetforclarity.
In Fig. 1 the time-integrated spectra for Simbol-Xobservesbothreflectionfeaturessi-
both orbiting flares are plotted over the spec- multaneouslyputsimportantconstraintsonthe
tralrangecoveredbythetwodetectors.While emissionradiusandalsoontheappliedrepro-
theoverallspectralshapeissimilarforspotsat cessingmodels.
both disk radii, the position and the shape of
Acknowledgements. Wethanktheorganizersofthe
thereflectionfeaturesdiffersignificantly.
Simbol-Xworkshopforaninterestingconference.
At R = 4R the impact of the gravi-
g
tational redshift pushes the maximum of the
References
Comptonized hump below 15 keV and the
strongprojectedvelocitygradientalongtheor- Dovcˇiak M., Karas V., & Yaqoob T. 2004a,
bit almost entirely flattens the profile of the ApJS,153,205
iron line complex. At R = 21Rg, on the Dumont A.-M., Abrassart A., & Collin S.
otherhand,the Comptonhumpiscenteredon 2000,A&A,357,823
20keV andtheironlineprofileisclearlyvis- DumontA.-M.,CollinS.,PaletouF.,Coupe´S.,
ible showing a double horn. The data further GodetO.,&PelatD.2003,A&A,407,13
suggeststheappearanceofseparatesoftX-ray Goosmann R. W., Mouchet M., Czerny B.,
emissionlinesbelow3keV. Dovcˇiak M., Karas V., Ro´z˙an´ska A., &
For rapidly spinning black holes, it might DumontA.-M.2007,A&A,475,155
thusbeimpossibletodetectreprocessedemis- IwasawaK.,MiniuttiG.,&FabianA.C.2004,
sionfromtheinnermostaccretiondisk(below MNRAS,355,1073
R = 6R ) in the iron line band, but the po- Lightman, A. P., & White, T. R. 1988, ApJ,
g
sition of the Comptonized hump can give an 335,57
alternativehandleonthelocationoftherepro- Reynolds, C. S., & Nowak, M. A. 2003,
cessing site. Forlargerdiskradii,the factthat Phys.Rep.,377,389