Overview talk : The growth of BHs and the fueling of AGN

23 Pages·2015·14.02 MB·English

Growth
 of
 Black
 Holes
 &
 Fueling
 of
 AGN

Ayçin Aykutalp
TCAN Meeting, 3 March 2015,
Atlanta
Journey
 to
 the
 Unknown

Ayçin Aykutalp
TCAN Meeting, 3 March 2015,
Atlanta
How Do Black Holes Grow?
Accretion of Gas Via Mergers Tidal
 Capture
 of
 Stars

Efficiency of these channels depends on:

§  black hole seed masses and cosmic time

§  occurrence of merger events

Large dyn. range
§  properties of the central region and of the host galaxy
10 kpc - <0.01 pc

§  larger scale environment of the host dark matter halo

§  stellar and black hole feedback processes
Observations of High-z Quasars
4-8 orders of magnitude in mass
in only ~700 Myr!!!

ULAS J1120+0641, Mortlock et al. 11
SDSS J010013.02+280225.8, Wu et al. 15
Seed
BH

M =102-106 M M = 2 x 109 M M = 1.2 x 1010 M
BH ¤ BH ¤ BH ¤
z = 20-15 z = 7.085 z = 6.3

4
Eddington Luminosity & Accretion
Eddington Luminosity Salpeter Time
σ c
GMm Lσ t
  T
=

p T Sal
=
  4πcGm
r2 4πr2c p

t = 45 (ε /0.1) (L/L ) Myr
Sal r Edd
4πcGMm
L
  p
=

Edd
σ
T

L = 1.26×1038 (M/M ) erg/s
Edd ¤
Eddington Limited Accretion
.

4πGM m
M
  BH p
=

Edd
ε σ c

.
  r T
M = 2.26 (M/M )(ε /0.1) M /yr
In order to grow 1010 M SMBH by z=6.3,
Edd ¤ r ¤
!
assuming Edd. Accretion, the seed BH
should be at least 104 M @ z=20 !!!
!
Angular Momentum Problem
How cosmic gas from large scales fall into accretion disks and feed BHs?
Angular momentum acts as an ‘accretion barrier’: Gas parcel starts out at ~10 kpc
needs to lose ~99.9% of its angular momentum, without forming stars!

For
 rapid
 BH
 growth,
 an
 efficient
 mechanism
 is
 needed
 to
 transport
 angular

momentum.
Angular Momentum Transport
Mechanisms
Major
 Galaxy
 Mergers:
 gravitaDonal
 Ddal
 forces
 during
 mergers
 can
 efficiently
 extract

angular
 momentum
 from
 gas
 and
 drive
 it
 towards
 the
 center

Internal
 Disk
 Instabili=es:
 e.g.
 “bars-­‐within-­‐bars”,
 t =
 T /|W|>0.14-­‐0.26
 (Shlosman

crit rot
et
 al.
 ‘89)

Hydrodynamical
 Turbulence:
 e.g.
 “supernovae”,
 convergent
 turbulent
 flows
 create

dens
 filaments
 which
 is
 not
 affected
 by
 the
 hydro.
 drag

MHD
 Turbulence:
 at
 small
 scales
 ???
letters to nature
observations point to the existence of strong outflows in bright interval of time, the object would be a bright quasar with a specific
quasars18–20.Inthispicture,blackholeaccretionisexpectedtohave lifetime.
a crucial effect on the evolution of the host galaxy. However, the Differences persist as the remnants settle into a relaxed state
couplingofstarformationwithblackholegrowthinthecontextof (fourthpairof images inFig.1,t 2.5Gyr).Theremnantwithout
¼
galaxy evolution is difficult to treat on the basis of analytical blackholes(bottomimage)retainsalargeamountofdensecoldgas,

estimates alone. yielding prolonged star formation at a steady rate. However, in the
Wehave,therefore,performeddetailednumericalsimulationsof simulationwithsupermassiveblackholes(topimage),nearlyallthe
galaxy mergers thatinclude radiativecooling, starformation, black gasisexpelledfromthecentre,quenchingstarformationandblack
hole growth, energetic feedback from supernovae and accretion hole accretion itself. Consequently, the black hole mass saturates,
onto black holes, as well as the gravitational dynamics of gas, stars quasar activity stops, and star formation is inhibited, so that the
and dark matter (see Supplementary Information and further remnantresemblesa‘dead’ellipticalgalaxywhosestellarpopulation
details in ref. 21). As described in the Supplementary Information, quickly reddens24. In the particular example we show, the remnant
we include a novel treatment of gas accretion onto supermassive ofthismajormergerisanellipticalgalaxy.Inthehierarchicalmodel
black holes and its associated feedback in the centres of merging of galaxy formation, a new disk can grow around this spheroid,
lettegraslatxoiens.aWtueredescribe black holes using collisionless ‘sink’ particles turning it into the bulge component of a spiral galaxy. Invery gas-
........t.h..a..t..c..a..n...g..r..o..w...i..n...m...a..s..s..b..y...a..c..c.r..e..t.i.n. ggasfromtheirsurroundings.The rich mergers, a disk component may even survive directly25 (an
haveremainedunclear.Herewereportsimulationsthatsimul-
Eneragcycrinetpiuotnfrroamteqisuaessatirmsaretegdulbaytesrelatatnienougslytfohlleowsstmarafolrml-asticonaalned,thuengrrowetshoolfvbeladckholesexample of this is shown in the Supplementary Figure). We there-
during galaxy–galaxy collisions. We find that, in addition to
thegflroowwtahroaundndacthtievibtylaocfkbhlaoclekthootlehselagrengeera-tisncgaalebu,rrsteosfosltavrefdormgaatisonp10r,oapmeerrgetrielesads toforeexpectblackholesinbulgesofspiralgalaxiestobeassembledin
stronginflowsthatfeedgastothesupermassiveblackholeand
anduthseinirghaosstphgaerlaicxaielsBondi–Hoyle22 mtheoredbyeplo.wWertehefquuarsatrh.Tehreeanesrsguyrmeleaesedthbyattheaquasaramannersimilartothoseinellipticals.Ourresultsshouldalsoapply
small fraction, f, of the radiateedxpellsuenmougihngoasstiotqyuencchobuotphlsetasrfotrmhaetiornmanod-furtherfor cases involving minor mergers.
TizianaDiMatteo1*,VolkerSpringel1&LarsHernquist2 blackholegrowth.Thisdeterminesthelifetimeofthequasar
dynamically to the surrounding gphaasse.(aTpphroiaschi‘nfge1e00dmbillaiocnkyeaersn)aendrgexypl’aingsithveereslation- Theevolutionofstarformationrate,blackholeaccretionrateand
81M57a4x0-PGlaaarnccnhki-nIgnesbteiftiufMtefu¨u¨cnrcAthesitnrv,oGpeherymsfikae,nKeyadrl-Sbchawacrzkschield-nStreasrseg1,y heatinsdhigsipperrbaseiottwne.eeEn_the blackfLhole mfashsMa_ndc2th,ewstehllaerrveelocityblack hole mass for mergers when the progenitor galaxy mass is
2AstronomyDepartment,HarvardUniversity,60GardenStreet,Cambridge, Alargefractiofeneodfth¼eblackh¼olemassingalaxiestodayisthought
Massachuwsettes02fi138x,UStAhe radiative efficiency, h, ttoohav0e.b1ee,natshsemebltedydpuiricngatlhevpaealkuoefqudasearraicvtiveitdyinthevaried (including the model shown in Fig. 1) are shown in Fig. 2.
earlyUniverse11,12,whenlargeamountsofmatterwereavailablefor
*Presentadfdrresso:DempartmenStofhPhyasicks,Cuarnergiae-M–elloSnUunivnersiyty,a500e0Fvorb2es3Avenauec,Picttsbruerght,ion models onto a non-rotating Modelswithdifferent massqualitatively reproducethekey features
Pennsylvania15213,USA accretion onto central black holes. Interactions and mergers
....................b......l...a.....c.....k.........h......o.......l...e...........(.....H.........e.....r....e........c.......i...s.......t....h......e........v.....e.....l...o......c.....i...t....y.. obfetwliegenhgta,laxLies arehkMno_wcn2toistritghgerelaargcec-srcaeletinoucnlear gasof the evolution shown in Fig. 1: the star formation and black hole
IntheearlyUniverse,whilegalaxieswerestillforming,black inflows13,14, which are required for the growth of central black
holes alsummassiivneoassaitbyil,lioannsodlarMm_asisess tpohweeremd qauasssarsa.cchorleestbiyoanccrertiaon¼t.eA)ls.o,Whierearcfhuicarltmhodeerlsoafsgaslauxymfoermationaccretion rates are both quenched in the remnant, and black hole
Supermassive black holes are found at the centres of most implythatmergersofgalaxiesformellipticalorspheroidalcom-
galaxiesthtodaaty1–3f,where0t.h0ei5rm,asssoesatrehraeltate,dto0th.5ev%elociotyf tpohneeMntsaicncgraelaxtieeasd, byrdeesjsttroyomingasstesllarrednisek srganyMd triisggeringgreowthrsatguratees owirng sto feedback provided by accretion energy.
dispersionsofstars¼intheirhostgalaxiesandhencetothemassof nuclearstarbursts.
thecentaravlbauillgaeobftlheegtaolaxyh4,5e.Tahtistsuhggeestgsaalsin.kbetweenthe ThishasledtosuggestionsthattheMBH–jrelation(whereMBHHowever, the damping of star formation and black hole activity is
growthoftheblackholesandtheirhostgalaxies6–9,whichhas istheblackholemass,andjisthevelocitydispersionofstarsinthe
indeedbeenTasosumieldluforsatrnuamtbeertohfyeearse.Bfufettchetoroigfinocfethnetrbaullg,e osfugpalaexiresm) caousldsiavrisee inblgaalacxky mherogerlse,sproovidned that
observedrelationbetweenblackholemassandstellarvelocity strong outflows are produced in response to major phases of
mergersoftwodiskgalaxies,wecomparethegasevolutionbetween
dispersion,anditsconnectionwiththeevolutionofgalaxies, accretion,capableofhaltingfurtherblackholegrowth8,15–17.Indeed,
two simulations involving galaxies that are roughly the size of the
Milky Way (Fig. 1). Star formation and supernova feedback are
includedinbothsimulations,butweaddourblackholegrowthand
feedback model in one (top four panels of Fig. 1; see also Sup-
plementaryVideo)andneglectitintheother(bottomfourpanels).
Thefirstpairofimages(attimet 1.1Gyr)showsthegalaxiessoon
¼
after their first encounter, when strong gravitational forces have
spawned extended tidal tails. At this time, the black holes in the
Di Matteo et al ‘05
centres of each galaxy (top panel) have already grown significantly
from their initial masses and are accreting at a moderate level.
However,theoverall starformation rate isessentially unaffected by
thepresenceoftheblackholes,asindicatedbyFig.2,whichplotsthe
starformationrate(inbothcases),theblackholeaccretionrateand
black hole mass (for the top panels of Fig. 1) as a function of time.
The second snapshot (t 1.4Gyr) in Fig. 1 shows the galaxies
Figure1Snapshotsofthesimulatedtimeevolutionofmergersoftwogalaxieswithand particle-hydrodynamicsimulationcode.Thefirstsnapshot(t 1.1Gyr)showsthe
¼ ¼
withoutblawckhholees.nThetfuhllteimyesebqueengceifonrthitsosimuclaotionaclanebsecvieewe.dHintheere,styhstemesatftiedrthaefilrsitnpastsaegeroafthcettwiooganlaxiehs.aThsesedcoindsstnoapsrhotte(td1.4Gyr)
¼
SupplementaryVideo.Topandbottompanelsshowrespectivelythemodelswithand depictsthegalaxiesdistortedbytheirmutualtidalinteraction,justbeforetheymerge.The
withouAtthetihn clmuesiondoafbilasjckkohsolers(iB nH)m.tInobothecaasrespg,foauerisnrarps hooctsfaatdbiffueiresnytstimmeesimsn ebpetakroiincthteshtsarpfo rimsratationlaasn,drblaabcknhuodlearccgrsetaiotns (se&eiaslso Fsigrh.2a)oiscrpeakchieedddatth etime
thesimulationsareshown.Theimagesvisualizetheprojectedgasdistributioninthetwo ofthethirdsnapshot(t 1.6Gyr),whenthegalaxiesfinallycoalesce.Atthistime,a
galaxies,cboloeur-tcwodedebeytnempertahturee(blutetworeod).Thgecaolllidaingxgailaexises.havTethheseametidstroanglwinrdedrisvepnboyfene¼dbsaeckendergryfirovmethseaccgreationsexpienlsmtuochoftthehgaesfromthe
ainnitdiacliomnanssiscstcoefofrarnlenseoptxotrnednawidnegldtodrasarek‘v migriaaotlitveoerlfhoncailto y,s’agVsvotirea¼llafr(Mbseutlog ate£,oca1nh0dGnaHd0gis)t1k/a3mo¼lada1e 6xu0tpkyohmf.sst2aAer1s, l tSisnhynseteorMmresugaiofgtnesrBhitnhethgoeHaslainmxieulsla.ythio anv ewwmitheerbgaleadckk(tholse2st..5FaGinyrar)l,lbyl,etauhveinrlgassbtetshnsinapdsqahuoantssih-dsotwatsicthe
¼
and20%gaasc(hcerreeMttotiiosthnetotealvhaelonmastss,Gaistrheegratvirtaitiognaglceonrstaentdandat thspihseroitdailmgalaxeies,.Inittheisismulaatiolnrweithabdlackyholeesv(toipd),theenremtnantthisvaerytgaspoor
H0¼100hkms21Mpc21istheHubbleconstantwherewetaketheconstanth¼0.7). andhaslittlegasleftthatisdenseenoughtosupportongoingstarformation.This
Eachindivbidulalagaclaxkyinthheosimluelatiofnseiseredprebsenatecdwkith3a0,0l0t0eparrtsiclestfohrtheedatrkhehrigmhlighotstdheyfacntthaatmthepirecsencsetoafstupeermaossfivebtlahckeholegs,awhsich,acacrsetematter
matter,20,000forthestellardisk,20,000forthegaseousdisk,and10,000forthebulge fromthesurroundinggasandheatitwiththeassociatedfeedbackenergy,dramatically
componenit.nTwdosiucchagaltaxeiedswerbesyetuptohnaeparrabeollica,ptroigrvadeecloyllisiolnocowursee,arnddealtnerssthietmyergearrnemdnanth.Thiegschaleebarrshtoewsmthepdimeenrsiaontinuunritseofokpcfh21
thenevolvedforwardintimenumericallywithGADGET-2(ref.29),aparalleltree-smooth- (1pc 3.26lightyears).
¼
thegassurroundingthegalaxiesinthesimulationwithblackholes.
604 © 2005 Nature Publishing Group NATURE|VOL433|10FEBRUARY2005|www.nature.com/nature
EInnhfaactn, acseigsn itfihcaen tqwuinadshaars satacrtteidvitotyfl oawnodu ttohfeth eecnenetrregsy.
When the galaxies finally merge, as shown in the third pair of
released by the SMBH expels the gas from the
images inFig.1(t 1.6Gyr),much ofthegas isquicklyconverted
¼
into stars in intense bursts of star formation10. Owing to the
inner region thus quenching further star formation
enhanced gas density, the black holes, which also merge to form Figure2Blackholeactivity,starformationandblackholegrowthplottedasafunctionof
and the growth of the SMBH.
one object, experience a rapid phase of accretion close to the timeduringagalaxy–galaxymerger.Thestarformationrate(SFR),blackholeaccretion
Eddington rate, resulting in significant mass growth. Also, the rate(BHAR)andblackholemassareshowninthetop,middleandbottompanels,
morphologies of the remnants in the two simulations begin to respectively.Thethreelinesineachpanel(black,redandorange)correspondtomodels
differsignificantly.Inthemodelwithoutblackholes,mostofthegas withgalaxiesofvirialvelocityV 80,160and320kms21,respectively.For
vir
¼
is still inflowing in a comparatively cool phase. In contrast, the comparison,wealsoshow(toppanel,dashedline)theevolutionofthestarformationrate
simulations with black holes exhibit a significant change in the forthemodelwithoutablackholethatisshowninFig.1(fortheV 160kms21
vir
¼
thermodynamic state of the circumnuclear gas, which is heated by galaxy).Wenote,inparticular,thatowingtoAGNfeedback,thepeakamplitudeofthe
thefeedbackenergyprovidedbytheaccretionandpartlyexpelledin starburstduringthemergerisloweredbyasignificantfactor.Theblackfilledcirclesinthe
a powerful wind. During this strong accretion phase and for this individualpanelsidentifythetimesofthecorrespondingsnapshotsshowninFig.1.
NATURE|VOL433|10FEBRUARY2005|www.nature.com/nature 605
© 2005 Nature Publishing Group
BH Growth vs Star Formation
AA50CH13-Kennicutt ARI 19July2012 14:3
When gas is moved down to a few pc scale the surface density of gas will go up
(Σ > 103-4 M pc-2), which can lead to high star formation rates
gas ¤
M51 (Kennicutt et al. 2007) – Apertures

) M51 (Schuster et al. 2007), NGC 4736 and NGC 5055 (Wong & Blitz 2002), and
3
- NGC 6946 (Crosthwaite & Turner 2007) – Radial profiles
c
p 2 Non-starburst spirals (Kennicutt 1998b) – Global
k Starburst galaxies (Kennicutt 1998b) – Global
/
LSB galaxies (Wyder et al. 2009) – Global
r
y
1
/

!
M
(2)] 0
–c
ep
Σgas <
 cπsκG

 , m www.annualreviews.orgQ5. For personal use only.<1
  ormation Rat–1log [ (M year kΣSFR☉ ––12 100 %
wnloaded frogy on 03/02/1 Star F –3 10 %
Doolo g –4
50:531-608. ute of Techn lo –5 1 %
12.stit –1 0 1 2 3 4
BHs grow onAstrophys. 20 aby Georgia In fixeFRideglau triSoen1ab2eltwpeeensttaer-Lfror motaigtimo nS-reautesr(ScfFaaRc)lseuerl fo aGgwce [ΣdaHehIns +s eiH t2di e(rMseea☉n npadcst–so2i)t]a tlsy(att oa(mMricsan! dfm opolrcec-mu2la)r)
  goasnsur faace dynamical timescale!!
o. ed densitiesforvarioussetsofmeasurements(fromBigieletal.2008).Regionscoloredgray,green,yellow,and
Astrovid redshowthedistributionofvaluesfrommeasurementsofsubregionsofSINGSgalaxies.Overplottedas
v. pr lightbluedotsaredatafrommeasurementsinindividualaperturesinM51(Kennicuttetal.2007).Datafrom
Ress radialprofilesfromM51(Schusteretal.2007),NGC4736andNGC5055(Wong&Blitz2002),andNGC
Annu. Acce 6fr9o4m6(6C1rnoostrhmwaalistpei&ralTgualranxeiers2(0d0a7r)kabrleueshstoawrsn)aansdda3r6ksbtalurbeufirlsltedgacliarxcileess.(oTrahnegdeitsrkia-anvgelersa)gferdommeKaesnurneicmuetntts
(1998b)arealsoshown.Themagenta-filleddiamondsshowglobalmeasurementsfrom20low-surface-
brightness(LSB)galaxies(Wyderetal.2009).Inallcases,calibrationsofinitialmassfunction(IMF),X(CO),
etc.,wereplacedonacommonscale.Thethreedottedgraydiagonallinesextendingfromlowerleftto
upperrightreflectaconstantglobalstar-formationefficiency.Thetwoverticallinesdenoteregimesthat
correspondroughlytothosediscussedinSection6ofthisreview.FiguretakenfromBigieletal.(2008).
ReproducedbypermissionoftheAAS.
alsoshowthattheUV-basedSFRfallsoffmuchmorerapidlythanthecold-gassurfacedensity,
withglobalstar-formationefficiencies(ϵ′)anorderofmagnitudeormorelowerthanthoseinthe
innerdisks(Bigieletal.2010).Takentogether,theserecentresultsandstudiesoftheouterMW
(Section5.1)confirmthepresenceofapronouncedturnoverintheSchmidtlawfortotalgasat
surfacedensitiesoforderafewM pc−2(Figure12).
⊙
www.annualreviews.org StarFormation 583
•
Accretion Disc Particle (ADP) Method
Any gas that crosses the accretion radius R is removed from the computational
acc
domain and added to the accretion disc. Gas is added to the accretion disc after a
time that is of order the dynamical time-scale t at R
dyn acc

Gas is transported through the accretion disc and is added to the black hole with a
time delay which is of the order of the disc viscous time, t = 10-100 Myr
visc