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)

Comments

Fermi Bubbles

Image: A giant gamma-ray structure was discovered in 2010 by processing Fermi all-sky data at energies from 1 to 10 billion electron volts, shown here. The dumbbell-shaped feature (center) emerges from the galactic center and extends 50 degrees north and south from the plane of the Milky Way, spanning the sky from the constellation Virgo to the constellation Grus. Credits: NASA/DOE/Fermi LAT/D. Finkbeiner et al. At a time when our earliest human ancestors mastered walking upright the heart of our Milky Way galaxy underwent a titanic eruption, driving gases and other material outward at 2 million miles per hour.

CONTAMINATION BY SUPERNOVAE IN GLOBULAR CLUSTERS

Credit: ALMA (ESO/NAOJ/NRAO)/Alexandra Angelich (NRAO/AUI/NSF) Only a small amount of the supernovae products remains trapped within globular clusters and this "catch" only occurs in the most massive cases (mass cluster ≥ 10^6 solar masses).

SUPER-EDDINGTON ACCRETION IN ACTIVE GALACTIC NUCLEI

Supermassive black holes at the cores of galaxies blast radiation and ultra-fast winds outward, as illustrated in this artist's conception. Credit: NASA/JPL-Caltech Broad emission lines are a hallmark feature of type 1 active galactic nuclei (AGNs) and quasars. Many basic properties of the broad-line region (BLR), such as its basic geometry, dynamics, and physical connection to the accretion disk around the supermassive black hole (BH), remain illdefined. AGN spectra exhibit both tremendous diversity as well as discernable patterns of systematic regularity.

SpaceTime

Search This Blog