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TAPIR Theore�Cal Astrophysics Including Rela�Vity & Cosmology H�P TAPIR Theore&cal AstroPhysics Including Relavity & Cosmology hp://www.tapir.caltech.edu Chrisan O [email protected], Cahill Center for Astronomy and Astrophysics, Office 338 TAPIR: Third Floor of Cahill, around offices 316-370 ∼20 graduate students 5 senior researchers ∼15 postdocs 5 professors 2 professors emeritus lots visitors TAPIR Research TAPIR Research Topics • Cosmology, Star Forma&on, Galaxy Evolu&on, Par&cle Astrophysics • Theore&cal Astrophysics • Computa&onal Astrophysics • Numerical Rela&vity • Gravitaonal Wave Science: LIGO/eLISA design and source physics TAPIR – Theore&cal AstroPhysics Including Rela&vity 3 TAPIR Research Professors: Sterl Phinney – gravitaonal waves, interacHng black holes, neutron stars, white dwarfs, stellar dynamics Yanbei Chen – general relavity, gravitaonal wave detecHon, LIGO Phil Hopkins – cosmology, galaxy evoluHon, star formaon. Chrisan O – supernovae, neutron stars, computaonal modeling and numerical relavity, LIGO data analysis/astrophysics. Ac&ve Emeritus Professors: Peter Goldreich & Kip Thorne Senior Researchers (Research Professors)/Associates: Sean Carroll – cosmology, extra dimensions, quantum gravity, DM, DE Curt Cutler (JPL) – gravitaonal waves, neutron stars, LISA Lee Lindblom – neutron stars, numerical relavity Mark Scheel – numerical relavity Bela Szilagyi – numerical relavity Elena Pierpaoli (USC,visiHng associate) – cosmology Asantha Cooray (UC Irvine,visiHng associate) – cosmology TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 4 Cosmology & Structure Formation Today - HOW DO WE GO FROM BIG BANG TO MILKY WAY? Phil Hopkins, 330 Cahill z~1090 (t~400,000 yr) ? Ø Formaon of structure in the Universe (just gravity?) Ø Probes of dark maer & dark energy Ø How can we make progress in the “next generaon” of cosmology experiments? LMC The Interstellar & Intergalactic Medium - TURBULENCE & PHYSICS ON SCALES ~ 1012 - 1028 cm Phil Hopkins, 330 Cahill Ø Gravity Ø Turbulence (super-sonic up to Mach~100) Ø MagneHc Fields Ø Cosmic Rays & relavisHc parHcles Ø Radiaon Ø Cooling processes & molecular chemistry Ø Star & black Hole Formaon/Growth Inter-stellar medium phases: Ø “Feedback”: Stars, supernovae, black holes “cold” (blue), “warm” (pink) and “hot” yellow Galaxy Formation & Evolution Phil Hopkins, - WHY DO OUR MODELS FAIL SO BADLY ? 330 Cahill Ø How do galaxies grow? What happens when they hit each other (collisional & collisionless dynamics)? Ø What physics are we missing that explains why galaxies are so “under-massive”? Ø Can their structure constrain the nature of dark maer? Star & Planet Formation - WHAT’S HAPPENING ON SCALES CLOSER TO OUR OWN? Collapse of a disk around a young star to form a giant planet by gravitaonal instability see Phil Hopkins, 330 Cahill Ø How do stars actually form? Why do they have the masses they do? (radiaon vs. gravity?) Ø How do massive stars impact galaxies: supernova explosions, ionizing radiaon, super-winds? Ø How can we form the diversity of planets we are seeing? Is there more than one way to do it? Super-Massive Black Holes - THE “MONSTERS” AT GALAXY CENTERS “Jet” of relativistic particles from black hole Gas disk in galaxy center sees the “photon wind” from black hole see Phil Hopkins, 330 Cahill Gas in Perseus Cluster ~ millions of light years Ø How do they form? Are exoHc physics involved? “blown out” by a single black hole! Ø How do they accrete material? How does this radiate and “shine”? How can we observe it? Ø How does the black hole (and its relavisHc jets, accreHon disks) interact with the galaxy? TAPIR Research High Energy Astrophysics (Theory) ● Subjects of research at Caltech ● White dwarfs with binary companions – Tides, accretion – Make supernovae (Ia, 0.1a), pulsars (AIC), AM-CVn gravitational waves – Explosive pace of recent observational discoveries ● Neutron stars with binary companions – Accretion, irradiation, evaporation – Make X-ray binaries, Pulsars, Gamma-ray bursts, neutrinos, ultra-high energy cosmic rays, gravitational waves ● Black holes with companions – Tidal disruption events, circumbinary disks – Make radio-X-ray flares, gravitational waves, galaxy feedback... ● Close connection with observational programs at Caltech (Profs. Harrison, Prince, Kulkarni, Hallinan): – X-rays (NuSTAR), Optical (Palomar Transient Factory, Keck), LIGO See Prof. Sterl Phinney, 316 Cahill TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 10 TAPIR Research Textbook story TIME 1) Old, dead, field-decayed pulsar + <1Msun main sequence star 2) Magnetic braking 3) Low Mass X-ray binary (LMXB) -spinup of neutron star 4) Accreting Millisecond X-ray Pulsar (AMXP) 5) Millisecond Radio Pulsar (MSP) -now also brought to you on your gamma-ray dial (Fermi). X-ray heating Sterl Phinney, 316 Cahill Possible heating by relativistic pulsar wind 2 TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 11 TAPIR Research Textbook story -2 Millisecond Radio Pulsar (MSP) Companion remnants can be: ● White dwarf (0.15-1.3Msun) ● M-star (~0.3Msun) “Redbacks” ● Brown Dwarf (~0.02Msun) “Black Widows” Possible heating by relativistic ● Planet[s] (Earth mass -Jupiter mass) pulsar wind ● Nothing (Isolated recycled MSP) Last 2 years: Textbook story is wrong! Some big questions: ● Are Redbacks progenitors/descendants/cyclical phase of X-ray binaries? ● How does physics of heating of companions to LMXB, MSPs work? ● Tidal heating Sterl Phinney, ● X-ray heating 316 Cahill ● Pulsar wind/cosmic ray heating ●Can the heating cause (observed) bloating, evaporation of companion? ● What causes the (observed) orbital period changes, eccentricities? 3 TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 12 TAPIR Research Black Widow Pulsars (Neutron Star+ Brown Dwarf): Pulsar-facing Side of companioN Heated (most of Examples: INcident pulsar wind PSR B1957+20 Flux) PSR J2051-0827 PSR J2214+3000 Radio eclipses: wind PSR J2241-5236 From brown dwarf PSR J1719-1438 (Jupiter, C) 0FGL J2239.8-0530 (weak radio) Sterl Phinney , 316 Cahill TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 13 TAPIR Research One example: How does a pulsar's ultrarelativistic wind actually heat its companion? Sterl Phinney, 316 Cahill Pulsar wind particles Photosphere at 4000K Photosphere At 6000K Interior of companion star GEANT-4 airshower MonteCarlo 5 To determine heating vs depth; model atmosphere to determine radiated spectrum. TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 14 TAPIR Research Theore&cal Rela&vity (Chen, Thorne) • Predict and understand numerical relavity discoveries. • Perturbaon theory: Extreme-mass-rao inspiral into Kerr bHs. • Development of analyHcal gravitaonal wave templates. • LIGO data analysis techniques. • Tidal interacHons of black holes. • Tests of relavity and alternave theories of relavity. • Design of 3rd-generaon gravitaonal wave detectors (LIGO 3, quantum non-demoliHon, macroscopic quantum mechanics, bbO=Big bang Observatory) -> See Yanbei Chen, postdocs and grad students on Friday! TAPIR – Theore&cal AstroPhysics Including Rela&vity and Cosmology 15 2 Visualizaon/AnalyHcal Modeling of black-Hole Mergers Visualization/Analytical Modeling of Black-Hole Mergers • How• How should we best should we best visualizevisualize the space-time numerical relavity obtained by spaceHmesnumerical relativity?? • What• What is the is the qualitativestructure structure of the binary black-hole merger space-Hme? of the binary black-hole merger space-time? 17 • How• How can we be"er can we better understandunderstand the waveforms the waveforms these binaries emit? these binaries emit? 3 II. A DETAILED DESCRIPTION OF THE # METHOD 300 C # mostly tail transition A. Further Motivation !ringdown !merger 250 # Before going into the details of our procedure, it is D mostly worth spending some time discussing why our specific inspiral implementation of PN and BHP theories will help avoid 200 direct part" some of the difficulties that arose in other methods in the !infall t g introduction and noting the limitations and assumptions f that underlie our approach. 150 B It is certainly hard to argue that existing orders of e PN (up to v6 in the metric, for near-zone dynamics [22]) 100 See Prof. Yanbei Chen and BHP (up to second order for Schwarzschild, see [23] for details! 318 Cahill for a gauge-invariant formulation) theories are accurate in the whole space, simultaneously. Nevertheless, it is Newtonian interior ! plausible to argue that these approximation techniques 50 exterior cover different spatial regions at different times in a way Post BH perturbation such that each theory is either valid to a reasonable level A of accuracy or occupying a portion of spacetime that will 0 !50 0 50 100 150 200 not influence physical observables where it fails. Using an approach of this type, we aim to get the most out of r" the approximation methods. space-Hme vortexvortex curves depicHng the spaceHmeFIG. diagram of a head-on bH collision and 11: Tendex lines in the equatorial plane for a rotating FIG. 10: Samespace-time as Fig. 9 but zoomedcurves depicting out to show the the wave Specifically, we find that the following procedure gives FIG. 1: (Colorcurrent online)space-time quadrupole This figure diagram in depicts linearized a of spacetime a theory. dia- The curves shown zone. In the“frame-dragging“frame-dragging” wave zone, the” lines effect of a binary effect generically of a binary collect into span interpretaon of the waveform i- 16 good agreement with the waveform of a numerical- gram of aare black-hole lineshead-on
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