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Measuring the Spins of Stellar-Mass Black Holes by Fitting the X-ray Continuum Spectrum Jeff McClintock. Credit: A. Broderick & E. Mer. Probing Strong Gravity Near Black Holes Prague: 2010 February 15-18. Our Team. Jeff McClintock Ramesh Narayan
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Measuring the Spins of Stellar-Mass Black Holesby Fitting the X-ray Continuum SpectrumJeff McClintock Credit: A. Broderick & E. Mer Probing Strong Gravity Near Black Holes Prague: 2010 February 15-18
Our Team Jeff McClintock Ramesh Narayan Charles Bailyn Andy Cantrell Shane Davis Vivek Dhawan Ken Ebisawa Lijun Gou Li-Xin Li Jifeng Liu Jon McKinney Jerry Orosz Bob Penna Mark Reid Ron Remillard Rebecca Shafee Danny Steeghs Jack Steiner Manuel Torres
Black Holes are Extremely Simple • Mass: M • Spin: a* = J/(M2G/c) (-1 a* 1) • (Electric Charge: Q)
Innermost Stable Circular Orbit (ISCO) a* = 0 RISCO = 6MG/c2= 90 km a* = 1 RISCO = 1MG/c2= 15 km Extreme Kerr for M = 10 M
Innermost Stable Circular Orbit (ISCO)Dependence on Spin Parameter a* a* = 0 RISCO = 6MG/c2= 90 km a* = 1 RISCO = 1MG/c2= 15 km for M = 10 M
Radius of ISCO vs. Spin 6 90 km 4 RISCO/M(G/c2) (for 10 M) RISCO/M a* 2 15 km 0 0 0.2 0.4 0.6 0.8 1 Spin a*
Measuring RISCO is Analogous to Measuring the Radius of a Star R R RISCO Bottom Line: RISCO & M a*
Measuring RISCO is Analogous to Measuring the Radius of a Star R R Require accurate values of M, i, D RISCO F(R)? RISCO Bottom Line: RISCO / M a*
Novikov & Thorne Thin-Disk Model:F(R) 0.10 dF/d(lnR) 0.05 a* = 0 Novikov & Thorne 1973 Li et al. 2005 (kerrbb2) 0 R/M(G/c2)
Novikov & Thorne Thin-Disk Model: F(R)Four Identical Black Holes Differing Only in Spin 0.10 a* = 0.98 dF/d(lnR) a* = 0.9 0.05 Testing NT model via GRMHD simulations Narayan, Shafee, Penna, McKinney… a* = 0.7 a* = 0 0 R/M(G/c2)
3D GRMHD Simulation Results for Thin Disks Shafee, McKinney, Narayan+ 2008 Penna et al. 2010 Angular momentum profiles agree closely with NT (within (within 2-3% ) NT Model R/(MG/c2)
3D GRMHD Simulation Results for Thin Disks Shafee, McKinney, Narayan+ 2008 Penna et al. 2010 Angular momentum profiles agree closely with NT (within (within 2-3% ) Very little torque at the ISCO (few%) NT Model R/(MG/c2)
3D GRMHD Simulation Results for Thin Disks Shafee, McKinney, Narayan+ 2008 Penna et al. 2010 Angular momentum profiles agree closely with NT (within (within 2-3% ) Very little torque at the ISCO (few%) Luminosity inside ISCO modest (4-11% ) NT Model R/(MG/c2)
Requirements for the Continuum Fitting MethodZhang, Cui & Chen 1997 • Theoretical profile of disk flux F(R) • Disk atmosphere model of spectral hardening Davis et al. 2005, 2006, 2009; Davis & Hubeny 2006; Blaes et al. 2006 • Spectrum dominated by strong thermal component • Thin disk: H/R < 0.1 equivalent to L/Ledd < 0.3 McClintock et al. 2006 • Accurate estimates of M, D, i
New Results for LMC X-3 The Constant Inner-Disk Radius of LMC X-3: A Basis for Measuring Black Hole Spin James F. Steiner, Jeffrey E. McClintock, Ronald A. Remillard, Lijun Gou, Ramesh Narayan Submitted to ApJL on 25 January 2010 Adopt M = 10 M, i = 67, D = 48 kpc XSPEC model = phabs(simplkerrbb2)
LMC X-3: 1983 - 2009 Steiner et al. 2010 LD / LEdd
LMC X-3: 1983 - 2009 Steiner et al. 2010 LD / LEdd
LMC X-3: 1983 - 2009 Steiner et al. 2010 LD / LEdd Rin (GM/c2)
LMC X-3: 1983 - 2009 Steiner et al. 2010 Rin (GM/c2) L / LEdd
LMC X-3: 1983 - 2009 Steiner et al. 2010 Rin (GM/c2) Rin = 3.85 0.12 GM/c2( 3%) L / LEdd
Microquasar GRS 1915+105: a* = 0.98 - 1 McClintock et al. 2006 VLA 3.5 cm Vjet = (0.92 0.08)c 1 month Mirabel & Rodriguez 1994 1 arcsec
Soft X-ray Transient A0620-00: a* = 0.12 0.18a* < 0.61 a* > -0.56 (3) Gou et al. 2010 50 2 - 18 keV Intensity (Crab) 25 August 1975 50 Crab! 0 0 10 20 30 Time (days)
Soft X-ray Transient A0620-00: a* = 0.12 0.18a* < 0.61 a* > -0.56 (3) _ 200 Gou et al. 2010 50 Strong evidence for a relativistic jet 2 - 18 keV 2 - 18 keV Intensity (Crab) Flux density (mJy) Multiple jet ejections Arcsec scale Initially optically thick _ 100 25 940 MHz 0 0 Kuulkers, Fender, Spencer, Davis & Morrison 1999 0 10 20 30 Time (days)
Three Spin Measurements in the Works for 2010 • XTE J1550-564 • Dynamical model (Orosz et al.) • Spin (Steiner et al.) • Cygnus X-1 • VLBA parallax (Reid et al.) • Dynamical model (Orosz et al.) • Spin (Gou et al.) • LMC X-3 • Dynamical model (Orosz et al). • Spin (Steiner et al.)
Conclusions • LMC X-3 is a confidence builder: Rin is constant to 3% over 26 years and for 7 missions • 3D GRMHD tests to date indicate NT model is sound • Six spins measured -- three more in 2010 • A0620-00 with a* ~ 0.1 indicates high spin not required to drive microquasar jets -- jets are likely disk driven