Monolith149 Daily

Another place to see what KG is doing...

LIGO and the GW150914 Discovery

I finally found the paper for the recent LIGO discovery of gravity waves from a black hole merger, event GW150914 at 2015-09-14 09:50:45 +0000 which data implies was the merging of two black holes, one with mass 36 (+5, -4) solar masses and the other 29 (+4, -4) solar masses into an object of 62 (+4, -4) solar masses with 3 (+0.5, -0.5) solar masses radiated away (lost) as emitted gravitational waves.

B.P. Abbot and collaborators say,

Over 0.2 s, the signal increases in frequency and amplitude in about 8 cycles from 35 to 150 Hz, where the amplitude reaches a maximum. The most plausible explanation for this evolution is the inspiral of two orbiting masses, m1 and m2, due to gravitational-wave emission.

The source redshift was measured as z=0.09 (+0.03, -0.04).

One interesting outcome in the conclusions is support for massive black holes.

GW150914 demonstrates the existence of stellar-mass black holes more massive than ≃ 25 solar masses, and establishes that binary black holes can form in nature and merge within a Hubble time. Binary black holes have been predicted to form both in isolated binaries and in dense environments by dynamical interactions. The formation of such massive black holes from stellar evolution requires weak massive-star winds, which are possible in stellar environments with metallicity lower than ≃ ½ the solar value.

The Paper: Observation of Gravitational Waves from a Binary Black Hole Merger by B. P. Abbott et al. (pdf)