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(Massive) Black Hole X-Ray Binaries. Roger Blandford KIPAC, Stanford +Jane Dai, Steven Fuerst, Peter Eggleton. Massive Black Holes in AGN. Lauer et al 2007. Ubiquitous in normal galaxies (not dwarfs) Hole mass related to mass of bulge and velocity dispersion
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(Massive) Black Hole X-Ray Binaries Roger Blandford KIPAC, Stanford +Jane Dai, Steven Fuerst, Peter Eggleton
Massive Black Holes in AGN Lauer et al 2007 • 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 KIAA
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 KIAA
Tests of Relativity [Dai, Fuerst, RB] • Orbital dynamics • Apsidal motion • LT precession • Disk crossings KIAA
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??? KIAA
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 KIAA
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 • Period lengthens cf Hameury et al Stable Mass Transfer KIAA
Relativistic Effects KIAA
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 • Lose mass through L1, L2 Roche Potential L1 L2 KIAA
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 KIAA
Stellar Evolution • 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 dS/dm >=0 KIAA
0.3 Mo h ~ 2 Radius-mass relation for adiabatic stars R M 1Mo • ~ Mh • R~M(1-h)/3 • P~M-h/2 8Mo KIAA
Orbital and stellar evolution Mass transfer rates are quite low, making adiabatic, conservative assumptions KIAA
Period vs mass KIAA
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 KIAA
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 KIAA
X-ray observations • Maximum efficiency for a ~ m PR ~ PISCO • Liberal mass loss • Angular momentum ->Spin • Wind • Equatorial viewing • L ~ D4 • D~2? L a=0.99m E KIAA
Observed X-ray emission a=0 i=5 i=30 a=0.998 a=0 i=30 i=45 a=0.998 KIAA
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 KIAA
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. KIAA
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” KIAA