GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

Abstract

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4 −0.04 . All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Supernovae from Massive Stars

“…Since the first (and only) two direct detections of gravitational waves are associated with the merger of double black hole binaries with masses 36 − 29 M ⊙ (GW150914 [51]) and 14 − 7 M ⊙ (GW151226 [52]), before closing this chapter it is worth showing the final remnant masses expected for all the models as a function of the initial metallicity for the three initial rotation velocities (Figures 25, 26, 27). The figures show that, in the non rotating case, only low metallicity models (with [Fe/H] ≤ −1 and with initial masses in the range 50 M/M ⊙ 80) can produce black holes as massive as those associated to GW150914.…”

The Polarizations of Gravitational Waves

“…Similarly to Einstein-aether theory, it is also constrained by the solar system test (i.e., the constraints on α 1 and α 2 2 ), the absence of the gravitational Cherenkov radiation, and the recent GW speed bound [45], etc. Taking all the constraints into account, it was found that the speed of the one 2 The expressions for α 1 and α 2 in generalized TeVeS theory are even more complicated, so they are not presented here, either. of scalar d.o.f.…”

“…The gravitational wave (GW) was detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific and Virgo collaborations, which further supports General Relativity (GR) [1][2][3][4][5][6]. It is also a new tool to probe gravitational physics in the high speed, strong field regime.…”

Bowen-York-type initial data for binaries with neutron stars

“…If object 1(2) is a BH, set its puncture bare mass m 1(2) = M 1 (2) . If object 1(2) is a NS, construct a spherically symmetric stellar model with ADM mass M ADM 1 (2) . Compute also its rest mass M 0…”

“…GWs from binary black holes (BBHs) have been recently detected by the Laser Interferometer Gravitational Wave Observatory (LIGO), first detection in the transient event GW150914 [1] and second detection in the transient event GW151226 [2]. As advanced LIGO reaches designed sensitivity, GWs from double neutron star (DNS) and black hole -neutron star (BH-NS) binaries will very likely also be detected.…”