NO CORRELATION BETWEEN FERMI GBM SIGNAL AND GW150914

Image: Merging black holes. Credit: NASA

Recently it has been suggested that electromagnetic signals detected by Fermi GBM could be associated with the merger of the two black holes detected by LIGO (GW150914).

In a recent paper (Lyutikov 2016) the author assesses that the physical constraints required by the association of the Fermi GBM signal contemporaneous with GW150914 - radiative power of 10⁴⁹ erg s⁻¹, and corresponding magnetic fields on the black hole of the order of 10¹² Gauss - are astrophysically highly implausible.

Combined with the relatively high random probability of coincidence of 0.22 percents, he concludes that the electromagnetic signal is likely unrelated to the BH merger.

Lyutikov 2016 (preprint) - Fermi GBM signal contemporaneous with GW150914 - an unlikely association (arXiv)

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For orbital period generally we refer to the sidereal period, that is the temporal cycle that it takes an object to make a full orbit, relative to the stars. This is the orbital period in an inertial (non-rotating) frame of reference (365,25 days for the earth).

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