(Massive) Black Hole
X-Ray Binaries
Roger Blandford
KIPAC, 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
Lauer et al 2007
• L~1044 (M/1024 gs-1) erg s-1 for L< LEdd ~
1044M6 erg s-1
 M~1.5x1011M6cm~5M6s
 Innermost Stable Circular Orbit
2 xi 2010
KIAA
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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
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Tests of Relativity
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Orbital dynamics
Apsidal motion
LT precession
Disk crossings
2 xi 2010
KIAA
[Dai, Fuerst, RB]
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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
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Close Binary Stars
 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
2 xi 2010
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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~r-1/2 ~m0.8 =>J~m1.3
• J decreases
• Orbit expands
Stable
• Period lengthens
2 xi 2010
KIAA
cf Hameury et al
Mass Transfer
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Relativistic Effects
2 xi 2010
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Relativistic Roche Problem
 Riemann -> local tidal tensor.
 Evaluate volume within critical
equipotential and evaluate
•
•
•
•
r(L1)=0.3m1/3 P2/3 Ro
r(Roche)=90P-2 g cm-3
Good for N, ISCO (all a)
Accurate interpolation
Roche Potential
L1
 Lose mass through L1, L2
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L2
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
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Stellar Evolution
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Differs from close binary case
tdynamical << ttransfer << tKelvin
S[m] will be frozen
Solve:
dP/dm=-Gm/4pr4
dr/dm=1/4pr2r[S(m),P]
=> d log <r>/d log m =h
h=2 for convective low mass star
2 xi 2010
KIAA
dS/dm >=0
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Evolution of solar star
2 xi 2010
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0.3 Mo
h~2
R
Radius-mass relation
for adiabatic stars
M
1Mo
r~ Mh
R~M(1-h)/3
P~M-h/2
2 xi 2010
8Mo
KIAA
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Orbital and stellar evolution
Mass transfer rates
are quite low, making
adiabatic, conservative
assumptions
2 xi 2010
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Period vs mass
2 xi 2010
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Post-Roche Evolution
 After mass transfer orbit expands
• P ~ m-h/2
~ m-1 for low mass star
t-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
2 xi 2010
KIAA
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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[*, r ( L1)]  L K [ rout ]
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X-ray observations
 Maximum efficiency for
a~m
PR ~ PISCO
 Liberal mass loss
• Angular momentum ->Spin
• Wind
 Equatorial viewing
L
a=0.99m
• L ~ D4
• D~2?
2 xi 2010
E
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Observed X-ray emission
a=0
i=5
a=0.998
i=30
a=0
i=30
a=0.998
i=45
2 xi 2010
KIAA
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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
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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
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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”
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