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UniversidadUniversidad dede ValenciaValencia 1515November November2010 2010 PulsarsPulsars asas probesprobes forfor thethe existenceexistence ofof IMBHsIMBHs

ANDREA POSSENTI Layout Layout data analysis of IMBHs from Pulsar searches Pulsar data analysis of IMBHs from Pulsar searches Formation scenarios for the IMBHs Known Black Hole classes IMBH candidates IMBH candidates (?) from Radio Perspectives for the direct observation Formation scenarios for the IMBHs Known Black Hole classes IMBH candidates IMBH candidates (?) from Radio Perspectives for the direct observation ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾ ¾ ) of sun IMBH M 9 10 ≈ to also part of the also also part of the also sun sun sun M [ Maccarone et al. 2007 - ] 2010 in many X-ray binaries: for ss is of order few 10 M 6 10

resulting from evolution ≈ seen in the nucleus of : 100 - 10,000 M 100 - 10,000 M astronomical landscape ? astronomical landscape ? ≈ Classes of Black Holes Classes of Black Holes ≈ masses of order masses mass BH likely in a triple system in a likely BH mass masses Are Intermediate Mass Black Holes (IMBH) of Are Intermediate Mass Black Holes ( solar , the max ma solar metallicity, Black Holes Massive Black Holes are supposed to be contained N.B. ULX in the RZ2109 of NGC of 4472 RZ2109 Globular Cluster N.B. in the ULX stellar be a may in a dense remnants in a dense star cluster remnants in a dense star cluster stars in a dense star cluster – collisions of massive Runaway - segregation of compact Mass 2 – Runaway collisions of massive 1 - Mass segregation of compact 2 Formation mechanisms for IMBHs Formation mechanisms for IMBHs 1 capturing other “ordinary” stars in the cluster ƒ ƒ ƒ ƒ In both cases, the seed IMBH can then grow by In both cases, the [ Colpi et al. 2003 ] al. 2003 [ Colpi et [ Miller & Hamilton 2002 ] 2002 & Hamilton [ Miller [ Miller & Hamilton 2004 ] [ Miller & Hamilton [ Sigurdsson & Hernquist 1993 ] 1993 [ Sigurdsson & Hernquist [ Port.-Zwart & McMillan 2001 ] 2001 & McMillan [ Port.-Zwart [ Kulkarni, Hut & McMillan 1993 ] 1993 & McMillan Hut [ Kulkarni, (or binary IN THE CORE LEFT COMPLETE EVAPORATION ONLY ONE IMBH a] OF ALL THE BHs b] IMBH) Dynamical friction leads to BH confinement in the core, creating a population of BHs in binaries evolving almost in isolation Formation mechanisms for IMBHs -Formation mechanisms for IMBHs - 1 1 Close gravitational encounters btw BHs lead to a hierarchical BH mass growth (via mergers & exchanges) with two outcomes: [ Portegeis-Zwart & McMillan 2002 ] & McMillan [ Portegeis-Zwart then proceed in a runaway explosiona (3 Myr) the [ Freitag, Gurkan & Rasio 2006 ; Gurkan, Fregeau, Rasio 2006 ] Rasio Fregeau, 2006 ; Gurkan, & Rasio Gurkan [ Freitag, growth of a very massive stars growth massive stars: more massive star star massive more (Spitzer instability). speeds core collapse speeds core time scale of the more the more time scale of Core collapse happens Mass segregation of the on the dynamical friction fashion: very massive star collapses directly into a IMBH Formation mechanisms for IMBHs –Formation mechanisms for IMBHs – 1I 1I Collisions between stars can At the onset of [ Freitag et al. 2004 ] 2004 al. et Freitag [ llision” scenario could be [ Glebbek et al. 2009 ] 2009 al. et [ Glebbek star beyond 100 Msun 100 beyond star Moreover, low metallicity seems required for having a low having for required metallicity seems low Moreover, more likely applied to metal poor stellar systems mass loss via wind and an efficient growth of a very mass mass loss via windof and an efficient growth Thus the “runaway star co Special conditions for growing a IMBH in young stellar cluster Formation mechanisms for IMBHs –Formation mechanisms for IMBHs – 1I 1I [Gebhardt, Rich, Ho 2005] Ho Rich, [Gebhardt, 3 /pc G1 in M31 G1 in sun M 6 in the central 0.05 pc sun

lated observational lated observational -based axi-symmetric models fit Orbit-based axi-symmetric ground and HST l.o.s velocities and proper motions (a) to constrain the ratio as M/L a function of radius and (b) to infer a limit on the mass of 3400 M The central 4” appears to rotate --> a density of 7x10 IMBH on the basis sun M of axi-symmetric models of axi-symmetric 4 M15 in M15 in

evidences for IMBH candidates evidences for IMBH candidates

Non radio pulsar re Non radio pulsar re HST surface brightness profile and the ] 2006 al. et Bosch den [Van 1.8 (±0. 5) x 10 velocity profile (Keck spectra) suggest a NonNon radioradio pulsarpulsar rere

evidencesevidences forfor IMBHIMBH candidatescandidates HLX-1 in the spiral ESO243-49 latedlated observationalobservational [ Farrell et al. 2009, 2010 ] Hyper-luminous X-ray source with a of up to 1042 erg/s

X-ray, UV, optical and radio obs

suggest it is an IMBH of > 500 Msun ] [Tremaine [Tremaine : relation σ - on BH half-light / R [ Maccarone & Servillat 2010 ] ] [ Noyola et al 2008; Sollima imbh core of GCs in the Milky Way 2008 ][ Umbreit et al 2009 ] of the IMBH : on M54 imbh of the globular clusters :

for IMBH candidates for IMBH candidates radio [ Ibata et al. 2009 seen for the central BHs in Galaxies and L and x Revised mass constraints et al 2009; van der Marel & Anderson 2010 e.g. recently now roughly compatible with the M [ Baumgardt et al. 2005 ] [ Trenti [ Baumgardt N.B. from L et al 2002] difficult to test due small R GCs showing a large ratio R Keplerian rising velocity dispersion close to the sphere of influence R Other non radio pulsar related signatures Other non radio pulsar related signatures compatible with about 30% | (dP/dt) (dP/dt)/P | and two with negative GC center of mass 3 MSPs close to the all with high value of

NGC 6752 NGC 6752

5 MSPs GC NGC 6752 the in Parkes @ timed and discovered [ D’Amico et al 2002 ] 2002 al et D’Amico [

Interesting cases from radio pulsar data: Interesting cases from radio pulsar data: …one can derive …one ratio M/L ...ascribing thenegativedP/dt ...ascribing oteefc ftheclusterpotentialwell… theeffectof to – for the central region of the globular cluster… region ofthe for thecentral a lower bound totheMass-to-Luminosity - as itisusuallyassumed as -

[ Phinney 1992 ] The case of the 3 MSPs in the core of NGC 6752

a unusually high M/L>6-7 in the central regions of the cluster

≈ 3400 Msun of low-luminosity matter in the inner 0.076 pc

[ D’Amico et al 2002 ] [ Ferraro et al 2003 ] moreover…PSR-A in NGC 6752 is the most offset pulsar ever detected in a globular cluster and PSR-C is also a very offset one…

both probably ejected in the halo by a dynamical encounter in the cluster core occurred less than ≈ 1.0 Gyr ago [Colpi, Possenti & Gualandris 2002]

a binary IMBH of mass [10-50 Msun] appears the most probable center of scattering if the MSP has been recycled before the scattering

a single IMBH of 500 Msun is viable if the MSP [Sigurdsson 2003, Mar] has been reycled after the scattering [Colpi, Mapelli, Possenti 2004] ..but is PSR-A really belonging to the globular cluster ? The of the binary “could” be compatible with a MSP+WD(of 0.2 Msun) system at the cluster distance [Cocozza et al 2006, Bassa et al 2006 ] … what about MSPs’ proper motions? [Corongiu al 2011, in preparation] et

The projected velocity vectors of PSR-A and PSR-C are consistent with each other and with that of PSR-D (one of the inner MSPs), but unconsistent wrt the optical determination of the cluster , and with the proper motion of the two inner MSPs with a negative dP/dt InterestingInteresting casescases fromfrom radioradio pulsarpulsar data:data:

After 19 years of timing @ Jodrell Bank of the

isolated MSP PSR B1820-30A (Pspin = 5.44 ms) [LyneNGCNGC at al, in 66246624preparation]

the combination of the measured values of dP/dt d2P/dt2 & upper limits on d3P/dt3

a unusually high M/L > 30-300 in the central regions of the cluster ?

a IMBH of 100-5000 Msun orbited by the MSP ? NeededNeeded thethe measurementmeasurement ofof dd33P/dtP/dt33 forfor confirmation…confirmation… oscillations oscillations Calculated the expected induced TOA fluctuations by space-time lying IMBH binary a to due line-of-sightclose to the Earth the and PSR btw a

of pulsars in GCs of pulsars in GCs ions, the Shapiro delay effects ions, the Shapiro components and a 10 year orbital period: orbital year 10 and a components [ Larchenkova1 & Lutovinov 2009] & Lutovinov [ Larchenkova1 [ Jenet et al. 2005 ] sun M 3 For the case of a binary IMBH consisting case of a binary IMBH the For and 10 sun of 10M In similar geometrical configurat IMBH effects on timing IMBH effects on timing are also verysmall Needed the measurement of the effects on at least TWO MSPs Needed the measurement of the effects on at least TWO MSPs ) in a globular cluster eccentricity > 0.8 sun and 0.5-1.5 AU ≈ [ DeVecchi, Colpi, Mapelli, Possenti 2007] Possenti Mapelli, Colpi, [ DeVecchi,

Recycled Pulsar + IMBH Recycled Pulsar + IMBH

binary in globular clusters ? binary in globular clusters ? Typical orbitalTypical parameters of the captured MSP are orbital separation by a single or binary IMBH (100-300 M Statistical study of the capture of process of a MSP dynamical RecycledRecycled PulsarPulsar ++ IMBHIMBH binarybinary inin globularglobular clustersclusters ??

Given the orbital parameters, the formed [MSP+IMBH] have relatively short lifetime before coalescence: of order ≈ 108 -109 yr The formation rate of [MSP+IMBH] is quite low: of order ≈ 10-11 yr

Given the number of known MSPs in GCs of the Galaxy (≈ 150) , the expected number of observable [MSP+IMBH] is

of order NMSP+IMBH ≈ 0. 1 if all the GCs with a known MSP would contain a IMBH If SKA will unveil a 10 times larger population of MSPs in GCs then

NMSP+IMBH >≈ 1 i.e. SKA will discover a MSP+IMBH

if 100-300 Msun IMBHs are common in the GCs [ DeVecchi, Colpi, Mapelli, Possenti 2007-2008] while orbital orbital P.Zwart et et P.Zwart erg/sec) are survives survives e.g. e.g. 0 - 1 [ 40 1-10 AU 1-10 span the whole ≈ even including range ) star ) star strong kicks span sun for the X-ray binary to to binary X-ray the for The binary the case, Supernova in the 99%Supernova in of separation eccentricity Post Supernova and Post of of a Young (<10 Myr) PSR in one

technically possible in the PM Survey

c

c e detection

super star clusters ? super star clusters ? become a [IMBH+YoungPSR] binary [IMBH+YoungPSR] a become

one may study the conditions e Young PSR+IMBH in dense r Young PSR+IMBH in dense p a / t s o p a al. 2004] Assuming that the very bright ULX sources (> 10 ULX(> Assuming sourcesthe very bright that IMBHs accreting from a massive (> 15 M [ Patruno, Colpi, Faulkner, Possenti 2005 ] Possenti 2005 Colpi, Faulkner, [ Patruno, Given those parameters, such systemsuch wouldhave been ULX

N

ULX ULX

f N f N ) = ) = >> 1 ) ?

ULX A (sensitive to PSR to PSR A (sensitive = thebeaming factor

b (observedPMSurvey in (observedPMSurvey in = characteristic oflife-time the PSR at distances where N where at distances

super star clusters ? super star clusters ? So why no detection ? Assuming: PSR = characteristic oflife-time the X-ray phase τ IMBH+PSR binary and the # of bright ULX X τ

Young PSR+IMBH in dense Young PSR+IMBH in dense SK and LOFAR for Chances IMBH-PSR IMBH-PSR the ratio btw the # of bright ULX and the total # of ULX the ratio btw the # of [IMBH+massiveMS] binary ending as a N N = =

f R [ Patruno et al 2005 ] et al [ Patruno Assumingno additional wrt bias forisolated detection YoungPSRs:

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