The Astrophysics of Gravitational Wave Sources Conference Summary: Ground-Based Detectors ( Hz) Kimberly New, LANL

Detection & Data Analysis: LIGO & GEO’s science runs Brady & Mavalvala high sensitivity, large bandwidth, hours of coincident operation searches – NS/NS chirps, bursts, known pulsars, stochastic bkgd. techniques used science implications

Detection & Data Analysis: Detectors in 2012 Finn interferometers - sensitivity improvements –<50 Hz: improve seismic isolation active isolation multiple levels of suspension – Hz: mitigate thermal noise suspension system (increase mass, used fused silica ribbon) test masses (sapphire) –>200 Hz: reduce shot noise increase laser power

Detection & Data Analysis: Detectors in 2012 Finn resonant acoustic detectors –current sensitivity near 900 Hz (1 Hz bandwidth) –future spheres, spheres within spheres 100 Hz bandwidth near 1 KHz (with improved amplifiers) gravitational wave astronomy –NS/NS coalescence to 400 Mpc –stellar BH/BH coalescence to z=0.5 –pulsars (  ~ at 10 2 Hz)

Sources: Binaries Schutz, Centrella, Bulik, Heyl BH/BH Coalescence (Centrella, Schutz) –LIGO: stellar mass BH/BH binary final coalescence –signal will contain astrophysically rich info: spins, strong field GR –simulations of vacuum field eqns. scale w/ mass & spin –evolve single BHs for 10 3 M ! –binary BHs for 10 2 M (~orbital period) ! –“Discovery Channel” simulation of merger (AEI) –simulation of ringdown w/Lazarus perturbative code –remaining numerical issues stability (formalism, gauge choices, boundary conditions) physical initial data waveform extraction

Sources: Binaries Schutz, Centrella, Bulik, Heyl chirp mass measurement could constrain binary evolution –parameter studies with population synthesis code (Bulik, Kalogera) –compact binary mass distribution: “fingerprints” –most evolution input parameters could be constrained with ~100 chirp mass observations effects of r-mode instability on LMXBs (Heyl) –r-mode saturation –detection with LIGO? –EM signatures?

Sources: Intermediate-Mass Black Holes Mushotzky, van der Marel, Miller observations suggest existence formation channels: Pop III stars, cluster interactions GWs –10-50 M , 10s of LIGO II detections per year –> 100 M , frequency generally too low for LIGO (ringdown?)

Sources: Collapse Mezzacappa, Fryer Core collapse supernovae –precision modeling of macro & micro physics is the goal –steps along the way indicate sensitivities (e.g., neutrino transport, EOS, general relativity) –multi-D simulations with multi-frequency neutrino transport don’t yet yield explosions –GW characteristics sensitive to EOS/GR (not as sensitive to neutrino transport) –new 3D SPH simulations of 15 M  stars (Fryer & Warren) GWs from bar instability detectable with LIGO II (100 cycles, 10Mpc) GWs from proto-NS convection detectable for Galactic SNe

Sources: Collapse Mezzacappa, Fryer Pop III, first generation stars –massive (no metallicity driven winds) –SPH collapse simulation of 300 M  rotating star (Fryer et al.) core rotating fast enough to develop dynamical bar instability high redshift puts GWs from bars & BH ringing out of LIGO II range fragmentation could be detectable with LIGO II (but does it occur?)

Sources: GRBs Mészáros, Norris GWs from GRBs –long GRBs, strong association with collapse –short GRBs, binary merger? –GW and GRB emission polarized; observations with third generation detector could measure 1% polarization in a year (Kobayashi & Mészáros) Nearby GRB/GW sources? (Norris) –class of nearby GRBs associated with Type Ic SNe? (long pulses, long lags, soft spectra, subluminous) –ex.: GRB / SN 1998bw (38 Mpc); GRB (680 Mpc) –concentrated near Supergalactic Plane; observed asymmetries –temporal separation of GRB and SNe? separate GW signatures? –could see 4 per year with LIGO II (50 Mpc, 100 cycle bar)

Sources: unexpected –dark matter? 30% of universe couple to gravitational radiation GW observations could determine if distribution is smooth

In Summary What information can we provide along the way to self- consistent simulations? (timing info, etc.) Observation Informs - Finn Is study of GWs from marginal sources worthwhile? –have “guaranteed” sources, “luxury” of studying others –often other drivers for study (SNe, GRBs, etc) –today’s marginal source can become tomorrow’s observed source (galactic supernova)