INTEGRAL Upper Limits On Gamma-Ray Emission Associated With The Gravitational Wave Event GW150914
Publication date: 31 March 2016
Authors: Savchenko, V., et al.
Journal: The Astrophysical Journal Letters
Copyright: © 2016. The American Astronomical Society
Using observations of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), we place upper limits on the gamma-ray and hard X-ray prompt emission associated with the gravitational wave event GW150914, which was discovered by the LIGO/Virgo Collaboration. The omnidirectional view of the INTEGRAL/SPI-ACS has allowed us to constrain the fraction of energy emitted in the hard X-ray electromagnetic component for the full high-probability sky region of LIGO triggers. Our upper limits on the hard X-ray fluence at the time of the event range from Fγ = 2 ×10-8 erg cm-2 to Fγ = 10-6 erg cm-2 in the 75 keV–2 MeV energy range for typical spectral models. Our results constrain the ratio of the energy promptly released in gamma-rays in the direction of the observer to the gravitational wave energy Eγ/EGW < 10-6. We discuss the implication of gamma-ray limits for the characteristics of the gravitational wave source, based on the available predictions for prompt electromagnetic emission.Link to publication