(FermiFermi) GBM observations of LIGO gravitational-wave event GW150914

Journal Article · Wed Jul 20 00:00:00 EDT 2016 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8205/826/1/L6· OSTI ID:22868830

Connaughton, V.; Littenberg, T.; Cleveland, W. ^[1]; Burns, E. ^[2]; Goldstein, A.; Hui, C. M.; Wilson-Hodge, C. A. ^[3]; Blackburn, L. ^[4]; Briggs, M. S. ^[5]; Zhang, B. -B.; Jenke, P.; Bhat, P. N. ^[6]; Camp, J.; McEnery, J. E.; Racusin, J.; Singer, L. ^[7]; Christensen, N. ^[8]; Shawhan, P. ^[9]; Veitch, J. ^[10]; others, and

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1. Universities Space Research Association, 320 Sparkman Drive, Huntsville, AL 35806 (United States)
2. Physics Department, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States)
3. Astrophysics Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States)
4. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
5. Department of Space Science, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States)
6. CSPAR, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States)
7. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
8. Physics and Astronomy, Carleton College, MN 55057 (United States)
9. Department of Physics, University of Maryland, College Park, MD 20742 (United States)
10. University of Birmingham, Birmingham B15 2TT (United Kingdom)

With an instantaneous view of 70% of the sky, the Fermi Gamma-ray Burst Monitor (GBM) is an excellent partner in the search for electromagnetic counterparts to gravitational-wave (GW) events. GBM observations at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) event GW150914 reveal the presence of a weak transient above 50 keV, 0.4 s after the GW event, with a false-alarm probability of 0.0022 (2.9σ). This weak transient lasting 1 s was not detected by any other instrument and does not appear to be connected with other previously known astrophysical, solar, terrestrial, or magnetospheric activity. Its localization is ill-constrained but consistent with the direction of GW150914. The duration and spectrum of the transient event are consistent with a weak short gamma-ray burst (GRB) arriving at a large angle to the direction in which Fermi was pointing where the GBM detector response is not optimal. If the GBM transient is associated with GW150914, then this electromagnetic signal from a stellar mass black hole binary merger is unexpected. We calculate a luminosity in hard X-ray emission between 1 keV and 10 MeV of 1.8{sub −1.0}{sup +1.5}×10{sup 49} erg s{sup −1}. Future joint observations of GW events by LIGO/Virgo and Fermi GBM could reveal whether the weak transient reported here is a plausible counterpart to GW150914 or a chance coincidence, and will further probe the connection between compact binary mergers and short GRBs.

• OSTI ID: 22868830
• Journal Information: Astrophysical Journal Letters, Vol. 826, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BLACK HOLES
COSMIC GAMMA BURSTS
GRAVITATIONAL WAVE DETECTORS
GRAVITATIONAL WAVES
HARD X RADIATION
INTERFEROMETERS
KEV RANGE
LUMINOSITY
MEV RANGE
SOLAR ACTIVITY
SPECTRA
STELLAR MAGNETOSPHERES
TRANSIENTS