(Massive) Black Hole X-Ray Binaries

Roger BlandfordKIPAC, Stanford

+Jane Dai, Steven Fuerst, Peter Eggleton

Massive Black Holes in AGN

Ubiquitous in normal galaxies (not dwarfs)

Hole mass related to mass of bulge and velocity dispersion

Most local black holes are dormant

When fueled through an accretion disk

• L~1044 (M/1024 gs-1) erg s-1 for L< LEdd ~ 1044M6 erg s-1

M~1.5x1011M6cm~5M6s Innermost Stable Circular Orbit

KIAA2 xi 2010

Lauer et al 2007

2

AGN Stars Stellar dynamical mass Sgr A* (Ghez, Genzel)

• 106.6Mo; ~100 OB stars (6Myr) • S2: 15 yr, e~0.87, rmin~1015.3cm~ 3000m~70 rtid • Disk distributions?? Invisible stars?

Tidal disruption (Komossa)• X-ray flares• Fall back emission • Fe line reverberation

2 xi 2010 KIAA 3

Tests of Relativity Orbital dynamics Apsidal motion LT precession Disk crossings

2 xi 2010 KIAA

[Dai, Fuerst, RB]

4

RE J1034+396•z=0.042 Seyfert galaxy•Lbol ~ 1044.7 erg s-1

•FUV-SX•XMM-Newton observations•1 hr QPO in ~1 d observing•Best example to date in AGN of a phenomenon quite common in stellar XRB•<Q> ~ 16 overall but much higher for section of data •~7% sinusoidal profile•Interpreted as diskoseismic mode•Could it be an EMRI mass transfer binary?•Planetars???

2 xi 2010 KIAA 5

Close Binary Stars

2 xi 2010 KIAA

Cataclysmic variables• WD + “red” star• ~2000 P>80min

Low Mass X-ray Binaries • BH/NS + lower mass companion • ~200 P>11min, LX ~1036-38 erg s-1

Ultra Compact X-ray Binaries• WD+Ns• P>5min

Evolve to overflow Roche Lobe through L1• Accretion disk + hot spot• Orbits evolve by gravitational, magnetic braking• Outbursts due to unstable supply, transfer and burning

6

Conservative Mass transfer

Transfer m -> M at constant m+M, J J ~ mMP1/3

If M>>m and gravitational radiation wins,• dJ/dt~-m2M4/3P-7/3

If m fills Roche lobe, P~-1/2 ~m0.8 =>J~m1.3

• J decreases• Orbit expands• Period lengthens

2 xi 2010 KIAA

Stable Mass Transfer

7

cf Hameury et al

Relativistic Effects

2 xi 2010 KIAA 8

Relativistic Roche Problem

Riemann -> local tidal tensor. Evaluate volume within critical

equipotential and evaluate• r(L1)=0.3m1/3 P2/3 Ro • (Roche)=90P-2 g cm-3

• Good for N, ISCO (all a)• Accurate interpolation

Lose mass through L1, L22 xi 2010 KIAA

Roche Potential

L1 L2

9

Pre-Roche evolution Gravitational radiation dominates

• Need PPN corrections to torque Low mass star fills Roche lobe when

P=PR=8m0.8hr [ => m < 0.1 Mo ]

Outside ISCO• P > PISCO ~ M [=>M<3x107Mo]

Time to overflow tR-t=2x105M6

-2/3m1.3[(P/PR)8/3-1] yr

2 xi 2010 KIAA 10

Stellar Evolution Differs from close binary

case tdynamical << ttransfer << tKelvin S[m] will be frozen Solve:

dP/dm=-Gm/4r4

dr/dm=1/4r2[S(m),P]=> d log </d log m = =2 for convective low mass star

2 xi 2010 KIAA

dS/dm >=0

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Evolution of solar star

2 xi 2010 KIAA 12

Radius-mass relation for

adiabatic stars

2 xi 2010 KIAA

0.3 Mo

~ 2

1Mo

8Mo

~ M

R~M(1-)/3

P~M-/2

RM

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Orbital and stellar evolution

2 xi 2010 KIAA

Mass transfer ratesare quite low, makingadiabatic, conservative assumptions

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Period vs mass

2 xi 2010 KIAA 15

Post-Roche Evolution After mass transfer orbit expands

• P ~ m-/2

~ m-1 for low mass start-tR=1400M6

-2/3m-1 P8/3 [(P/PR)11/3-1] yr; [~ 5000yr] Conservative Mass loss

dm/dt = (dm/dt)R = -1.3x1020M0.7P-0.3 g s-1 [~ 1021g s-1] ~ -m8.3 eventually till ttransfer > tKelvin

Dynamical complications• Holding pattern?• Interactions, drag

KIAA2 xi 2010 16

Mass transfer Mass flows from L1 onto

relativistic disk forming hotspot

Gas spirals in to rms before plunging into hole

Inclined orbits are more complex as streams may not self-intersect

Disk flow may have complex gaps and resonances

Hot spot Doppler beams emission

Also spiral shocks, eccentricity

2 xi 2010 KIAA

€

L[Ω*,r(L1)] = LK [rout ]

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X-ray observations Maximum efficiency for

a ~ mPR ~ PISCO

Liberal mass loss• Angular momentum ->Spin • Wind

Equatorial viewing• L ~ D4

• D~2?

2 xi 2010 KIAA

L

E

a=0.99m

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Observed X-ray emission

2 xi 2010 KIAA

a=0 a=0.998i=5

i=30 i=45a=0 a=0.998

i=30

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AGN QPOs: other mechanisms Passage of star through an accretion

disk orbiting a spinning black hole (Zentsova; Nyakshin; Dai, Fuerst & RB)

• Inclined stellar orbit, apsidal motion, precession• Inelastic collisions -> beamed X-ray emission• Ray tracing Star moving through sub-Keplerian

disk Diskoseismic modes• Trapped g-modes

2 xi 2010 KIAA 20

Other observations 17 min IR QPO frm SgrA* (Genzel) 12yr period in OJ287??

• Binary black holes??? (Lehto & Valtonen) LISA harbingers

• Discover incipient EMRI, coalescence • Predictable evolution with degree position!• Seek electromagnetic signal in phase with ~10-9

power- eg LSST.

2 xi 2010 KIAA 21

Summary Observations of quasi-periodic X-ray

emission from stars orbiting black holes in AGN is a potential probe of general relativity

RE J1034+396 may not be an example Reasonable to search AGN X-ray

database for QPO’s with P~5-20hr AGN black holes could have many

“planetars” 2 xi 2010 KIAA 22