X-rays from Compact Stars: Probing Fundamental PhysicsCompact Stars: Nature’s Extreme Physics LabsDid Einstein have the last word on Gravity?QCD phase diagram: New states of matterFundamental Physics: The Equation of State (EOS) of ultra-dense matterBlack Holes and Neutron Stars: Fun FactsAccreting X-ray BinariesBlack Hole X-ray Novae How Do You “Weigh” a Black HoleV4641 Sgr; a “naked eye” Black HoleGalactic Black Hole Binaries Black Hole Accretion “States” Accretion States: High/Soft (Thermal Dominant) Accretion States: Very High or steep power law (SPL) state Black Hole Event Horizons? Black Hole Event Horizons? X-ray Timing: “Black Hole Microscopy”RXTE Revolutionized Black Hole Studies Black Hole High Frequency QPOs High Frequency QPOs in XTE J1550-564 Black Hole space-time: Black Holes have no “hair”General Relativistic Frequencies in Black Hole Accretion Disks Evidence for Black Hole Spin in a Microquasar (GRO J1655-40)450 Hz QPO in GRO J1655-40Constraining Black Hole Spin Evidence for Black Hole Spin in GRO J1655-40 Models of X-ray Variability: Relativistic Precession Models of X-ray Variability: “Diskoseismology”Constraining Black Hole Spin: X-ray SpectraRelativistic Fe Ka Lines from Galactic Black Hole Binaries Sources of Thermonuclear X-ray Bursts: LMXBs Containing Neutron StarsX-ray Bursting Neutron Stars and Black hole event horizons?Accreting Neutron Star binaries: What do we see?EXO 0748-676 SummaryWhy Study Bursting Neutron Stars?Hi-res X-ray Spectroscopy of Neutron Stars: Recent ResultsEXO 0748-676: Search for Burst OscillationsRotational Doppler Broadening of LinesSpectral Line Profiles: Probing Frame Dragging Around a Neutron StarEOS of Neutron Stars: Future with Constellation-XOscillations during X-ray Bursts Discovery of Neutron Star Spin Rates in Bursting LMXBsSource SummaryHow Fast Can Neutron Stars Spin?Burst Oscillations Probe the Structure of Neutron StarsRotational Modulation of Neutron Star Emission: The ModelMass – Radius Constraints: Recent Results: XTE J1814-338 Compactness limits from pulse fitting in XTE J1814-338Sources of Thermonuclear X-ray Bursts: LMXBs Containing Neutron StarsNASA’s Rossi X-ray Timing Explorer (RXTE)X-ray Bursts from Accreting ms Pulsars: SAX J1808 and XTE J1814Puzzle # 1: Frequency Evolution of Burst OscillationsInside Neutron Stars Mass Estimates From Power Spectral Measurements Burst Oscillations: Ignition and Spreading.What Breaks the Symmetry?Rotational Modulation of Neutron Star Emission: The ModelOscillations at Burst Onset (4U 1636-53) Simulated Lightcurve: 10x PCAFitting of Pulsations During Burst Rise: SimulationsSGR 1806-20: RHESSI Confirmation of the Oscillations Burst Modeling: A Theoretical OpportunityRXTE/PCA Observes Superburst from 4U 1636-53EXO Absorption Lines: CaveatsRotational Broadening of Surface LinesRXTE Observes Three Hour Thermonuclear Burst from a Neutron Star (4U 1820-30) Line Spectroscopy and M - R Constraints for Neutron Stars *SAX J1808.4-3658 (401 Hz Pulsar)45 Hz Signal: SummaryBurst Oscillations and Source StatePulse Phase Spectroscopy: XTE J1814-338Pulse Phase Spectroscopy: Seeing the Surface Velocity.Outline“Normal” Thermonuclear Bursts Properties of Burst OscillationsMass – Radius Constraints: Persistent Pulse Profiles Nuclear flows during X-ray Bursts: With Hydrogen Superburst from 4U 1820-30: Spectral Modelling Fundamental Physics: Existence of New States of Matter?Future: Simulated Lightcurve: 10x RXTE/PCAFirst Superburst from 4U 1735-44 (BeppoSAX/WFC) New Superburst from 4U 1608-522 (RXTE/ASM) Probing the Accretion disk in 4U 1820-30: Reflection Spectra Superbursts observed with RXTE/PCA Superburst Sources Superburst from 4U 1820-30: Carbon Production A Carbon “bomb” on a Neutron Star Carbon Flashes on Neutron Stars: Mixed Accretors RXTE Observes Three Hour Burst from a Neutron Star (4U 1820-30) Superburst from 4U 1820-30: Disk Reflection Superburst from 4U 1820-30: Evolution of the Disk Pulsations During the Superburst from 4U 1636-53Time Dependence of the Pulsation Frequency Predicted Orbital Modulation from Optical Ephemeris for 4U 1636-53 Phase Coherent Timing with Circular Orbit Model EXO 0748-676 Burst Oscillations: The MovieM - R Constraints for Neutron Stars: The Future Fundamental Physics: The Neutron Star Equation of State (EOS)Goddard Space Flight CenterX-rays from Compact Stars: ProbingFundamental PhysicsTod Strohmayer, NASA’s Goddard Space Flight CenterGoddard Space Flight CenterCompact Stars: Nature’s Extreme Physics Labs• Neutron stars, ~1.5 Solar masses compressed inside a sphere ~20 km in diameter.• Highest density matter observable in universe.• Highest magnetic field strengths observable in the universe.• Black holes have the strongest gravitational fields accessible to study.• General Relativity (GR) required to describe structure. Complex Physics!!Goddard Space Flight CenterDid Einstein have the last word on Gravity?• Speculations about the existence of “Dark Stars” preceded Einstein.• Einstein’s Theory of General Relativity predicted existence of black holes (event horizons).• Strong field gravity effects still untested.• Existence of event horizons• Existence of unstable circular orbits• Dragging of inertial frames.• Need black holes, NSs to test.Fritz ZwickyAlbert EinsteinGoddard Space Flight CenterQCD phase diagram: New states of matterRho 2000, thanks to David Kaplan• Theory of QCD still largely unconstrained.• Recent theoretical work has explored QCD phase diagram (Alford, Wilczek, Reddy, Rajagopal, et al.)• Exotic states of Quark matter postulated, CFL, color superconducting states.• Neutron star interiors could contain such states. Can we infer its presence??Goddard Space Flight CenterFundamental Physics: The Equation of State (EOS) of ultra-dense matterdP/dr = -ρ G M(r) / r2• Mass measurements, limits softening of EOS from hyperons, quarks, other exotic stuff.• Radius provides direct information on nuclear interactions (nuclear symmetry energy).• Other observables, such as global oscillations might also be crucial.Lattimer & Prakash 2001Goddard Space Flight CenterBlack Holes and Neutron Stars: Fun Facts•Egrav = GMm/R = (GM/c2R) mc2 ~ 0.2 mc2 !!• Orbital Period (near “surface”): 2π (R3/GM)1/2~1 ms• Stellar Pulsation periods: 0.01 ms < Ppuls< 100 ms• Spin Periods: Pspin> 0.5 ms• Dynamical timescale: Tdyn = 1 / (G ρavg )1/2< 1