Gravitationalwave GW detectors in the nexus of multimessenger

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Gravitational-wave (GW) detectors in the nexus of multi-messenger astrophysics Isabel Leonor (University of Oregon)

Gravitational-wave (GW) detectors in the nexus of multi-messenger astrophysics Isabel Leonor (University of Oregon) For the LIGO Scientific Collaboration and the Virgo Collaboration LIGO-G 0900682

Overview: LIGO-Virgo is fully engaged in multi-messenger astrophysics optical gamma rays, x-rays neutrinos radio

Overview: LIGO-Virgo is fully engaged in multi-messenger astrophysics optical gamma rays, x-rays neutrinos radio July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 2

The GRB sample for the LIGO-Virgo GRB triggers were mostly from Swift; S 5/VSR

The GRB sample for the LIGO-Virgo GRB triggers were mostly from Swift; S 5/VSR 1 run v during S 6/VSR 2 run, GRB triggers will be mostly from Fermi+Swift factor of ~3 increase in trigger rate July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 Virgo average antenna factor 212 GRB triggers from Nov. 4, 2005 to Oct. 1, 2007 v ~70% with double-IFO coincidence LIGO data v ~45% with triple-IFO coincidence LIGO data v ~15% short-duration GRBs v ~25% with redshift LIGO Hanford average antenna factor v some were from IPN 3, INTEGRAL, HETE-2 3

Search for gravitational-wave burst (GWB) counterparts to GRBs (S 5/VSR 1 run) v v

Search for gravitational-wave burst (GWB) counterparts to GRBs (S 5/VSR 1 run) v v v used to search for GW counterpart to both long and short GRBs burst search is model-independent targets GW signals less than ~few seconds fully coherent search which cross-correlates data streams from different interferometers set 90% upper limits on strain for each GRB assuming energy emitted in GW results for 137 GRBs (paper due soon) for Advanced LIGO-Virgo D ~ 150 Mpc July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 4

Search for GW inspiral signals from GRBs v used to search for GW counterpart

Search for GW inspiral signals from GRBs v used to search for GW counterpart to short GRBs v v v there is evidence that short GRBs are nearer search makes use of inspiral templates target GW inspiral signals from coalescing masses in the range 1 M < m 1 < 3 M , 1 M < m 2 < 40 M v v v during S 5 run, inspiral search range for NS merger event was ~15 Mpc (SNR=8) for S 5 run, 21 short GRBs have been analyzed; no candidate events found set lower limit on distance for each GRB (paper due out soon) July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 NS-NS merger simulation Price and Rosswog 5

GRB 070201: In M 31 or beyond? GRB or soft gamma repeater (SGR)? v

GRB 070201: In M 31 or beyond? GRB or soft gamma repeater (SGR)? v v (ar. Xiv: 0712. 1502) short GRB whose position error box overlapped with spiral arms of Andromeda galaxy (M 31, ~770 kpc) occurred during LIGO S 5 run; two Hanford interferometers were in science mode inspiral search analysis excludes binary merger event at M 31 with >99% confidence; larger distances also excluded with high confidence burst search analysis gives upper limits on GW energy released; these limits do not exclude a model of a soft gamma repeater in M 31 (Ap. J, 2008, 681, 1419) July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 6

Search for GW bursts coincident with soft gamma repeater (SGR) bursts v v v

Search for GW bursts coincident with soft gamma repeater (SGR) bursts v v v SGRs thought to be highly magnetized neutron stars (~1 E+15 G) most observed SGRs are Galactic SGR bursts from crustal deformations and catastrophic cracking may be accompanied by GW burst emission search for excess power from GW burst relies on SGR lightcurves from Interplanetary Network (IPN 3), including Swift, Konus-Wind, etc. 191 bursts from SGR 1806 -20 and SGR 1900+14 have been analyzed for coincident GW emission using LIGO some of the upper limits set on GW energy emission already explore some SGR models 90% UL on energy of GW emission coincident with 215 SGR bursts (PRL, 2008, 101, 211102) Robert Mallozzi (UAH, MSFC)

Search for GW burst emission from an SGR storm (SGR 1900+14) 30 seconds SGR

Search for GW burst emission from an SGR storm (SGR 1900+14) 30 seconds SGR 1900+14 lightcurve (Mar 29, 2006) from Swift-BAT telescope v v v assume GW signal accompanies each storm episode “stacking” power from different storm episodes leads to increased GW search sensitivity requires precise timing from SGR lightcurve for start time of each storm episode resulting upper limits on GW energy emission ~order of magnitude lower than non-stacked analysis (ar. Xiv: 0905. 0005) July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 8

Search for periodic GW signals from known pulsars v target signal: monochromatic signals emitted

Search for periodic GW signals from known pulsars v target signal: monochromatic signals emitted by pulsars v most likely mechanism for production of detectable GW is small distortions of the NS shape away from axisymmetry v search at GW frequency twice the pulsar rotation frequency v search method makes use of a signal template for each pulsar requires updated ephemeris data to model phase evolution of pulsar signal requires collaboration with radio pulsar astronomers v v S 5 best limit: h 0=2. 3 E-26 at the sweet spot (paper due soon) best ellipticity limit of 7 E-8 Jodrell Bank Parkes Telescope Green Bank 116 known pulsars 95% upper limits (preliminary)

Crab pulsar: beating the spin-down limit v v v spin-down limit assumes all the

Crab pulsar: beating the spin-down limit v v v spin-down limit assumes all the pulsars rotational energy loss is radiated by gravitational wave we know some energy is emitted electromagnetically and is powering the expansion of the Crab nebula this is poorly constrained and allows room for gravitational wave emission search method depends on data from Jodrell Bank Crab Pulsar monthly ephemeris to track the phase using first nine months of LIGO S 5 data, obtain 95% upper limit on strain amplitude of h 0=2. 7 E-25 lower than classical spin-down limit by a factor of ~5 (Ap. J, 2008, 683, L 45) v using entire S 5 data gives UL which beats spin-down limit by ~7 Jodrell Bank Credits: X-ray: NASA/CXC/ASU/ J. Hester et al. ; Optical: NASA/HST/ASU/ J. Hester et al.

Swift target of opportunity (To. O) v v v during S 6/VSR 2, possible

Swift target of opportunity (To. O) v v v during S 6/VSR 2, possible GW candidates from all-sky burst and inspiral searches will be verified by requesting electromagnetic follow-up observations X-ray follow-up will be requested from Swift LIGO-Virgo error box will be ~few degrees verification of astrophysical object by an EM counterpart will further probe nature of object anticipates era of regular GW detections using more sensitive detectors, i. e. Advanced LIGO, Advanced Virgo July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 11

Swift target of opportunity (To. O) v v v during S 6/VSR 2, possible

Swift target of opportunity (To. O) v v v during S 6/VSR 2, possible GW candidates from all-sky burst and inspiral searches will be verified by requesting electromagnetic follow-up observations X-ray follow-up will be requested from Swift LIGO-Virgo error box will be ~few degrees verification of astrophysical object by an EM counterpart will further probe nature of object anticipates era of regular GW detections using more sensitive detectors, i. e. Advanced LIGO, Advanced Virgo July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 12

LOOC UP Locating and Observing Optical Counterparts to Unmodeled Pulses in gravitational waves v

LOOC UP Locating and Observing Optical Counterparts to Unmodeled Pulses in gravitational waves v v for S 6/VSR 2 run, position information of GW triggers from all-sky burst search will be sent to available optical telescopes via automated interface imaging/follow-up will be requested from telescopes expect initial latency of ~30 -60 minutes from GW trigger to imaging LOOC UP currently pursuing MOU’s with telescopes (Sky. Mapper, ROTSE, TAROT, etc. ) July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 13

Gravitational waves and neutrinos (nascent collaborations) LVD Borexino Super-K Ice. Cube ANTARES July 15,

Gravitational waves and neutrinos (nascent collaborations) LVD Borexino Super-K Ice. Cube ANTARES July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 14

Supernova early warning system (SNEWS) http: //snews. bnl. gov v v alert system which

Supernova early warning system (SNEWS) http: //snews. bnl. gov v v alert system which would send out notification of high-confidence SN to astronomical community a few minutes after detection of neutrino burst by multiple detectors LIGO-Virgo is signed up to get these alerts in the control rooms low-latency search for a GW signal coincident with a SNEWS trigger is planned for the LIGO-Virgo S 6/VSR 2 run there is a proposed joint GW-neutrino search which will complement the existing infrastructure and procedures which are in place in the event of a SNEWS alert July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 15

Estimates of Galactic and nearby core-collapse supernova rate v v v estimated Galactic rate

Estimates of Galactic and nearby core-collapse supernova rate v v v estimated Galactic rate is a few (~3) per century estimated rate in Local Group (out to ~1 Mpc) ~twice the Galactic rate ~1 per year out to the Virgo cluster observations indicate that the true nearby SN core-collapse rates could be higher than these estimates (e. g. ~3 times higher, using observed SN in 20022005) electromagnetically dark or obscured SN would also bring uncertainties to these rates July 15, 2009 SLAC Ando, S. et al. 2005, PRL, 95, 171101 Te. V Particle Astrophysics, LIGO-G 0900682 16

LIGO sensitivity and expected improvement with joint neutrino search in contrast to neutrino signal,

LIGO sensitivity and expected improvement with joint neutrino search in contrast to neutrino signal, energy emitted as GW radiation is expected to be small v currently, there are large uncertainties in models of corecollapse SN, e. g. simulations have difficulty making a SN explode v like neutrino signal, GW signal would probe the innermost region of SN core v requiring coincidence of GW and neutrino signals to within a short time window of ~few seconds would allow lower detection thresholds improvement in sensitivity 153 Hz v July 15, 2009 SLAC Energy into GW (solar masses) LMC Models for GW emission (from Ott, C. 2009, CQG, 26, 063001) A: PNS pulsations B: rotational instability C: rotating collapse and bounce D: convection and SASI Te. V Particle Astrophysics, LIGO-G 0900682 Andromeda Distance (kpc) 17

Joint search could benefit neutrino search as well v v v criterion for neutrino

Joint search could benefit neutrino search as well v v v criterion for neutrino search can be relaxed example: for Super-K distant SN search, criterion is at least 2 neutrino events per 20 seconds and high energy threshold of 17 Me. V if coincidence with GW signal is used, then criterion can be relaxed to a single neutrino event; odds will increase that distant core-collapse will satisfy this criterion energy threshold could also be lowered July 15, 2009 SLAC Probability of satisfying criterion v Detection probability LMC Andromeda standard criterion relaxed criterion Te. V Particle Astrophysics, LIGO-G 0900682 Distance to supernova (kpc) 18

Gravitational waves and high-energy neutrinos v v v ANTARES (Mediterranean Sea) currently a collaborative

Gravitational waves and high-energy neutrinos v v v ANTARES (Mediterranean Sea) currently a collaborative effort between LIGO, Virgo, Ice. Cube, ANTARES joint GW and high-energy neutrino search will lower background rate both GW and high-energy neutrino signals travel long distances without absorption possible sources: long and short GRBs, low-luminosity GRBs, failed GRBs, soft gamma repeaters overlapping GW and neutrino data is available from past runs (S 5/VSR 1) and will be available from future runs (S 6/VSR 2 and beyond) Ice. Cube (South Pole) July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 19

Other current or future multi-messenger activities v analysis of Swift data to extract sub-threshold

Other current or future multi-messenger activities v analysis of Swift data to extract sub-threshold events (possible GRBs) which can increase GRB sample which serve as triggers to GW analysis v v v analysis is currently ongoing (E. Harstad, University of Oregon) search for GW bursts coincident with pulsar glitches search for GW signal associated with RXTE observations of Sco X-1 radio-triggered searches for GW bursts … July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 20

Summary v LIGO and Virgo are fully engaged in multi-messenger astrophysics v These multi-messenger

Summary v LIGO and Virgo are fully engaged in multi-messenger astrophysics v These multi-messenger analyses continue to be pursued during the current S 6/VSR 2 run v These activities and the nascent collaborations serve as a strong foundation for analyses of future, more sensitive data as an era of regular GW detections is anticipated with Advanced LIGO-Virgo July 15, 2009 SLAC Te. V Particle Astrophysics, LIGO-G 0900682 21