Please use this identifier to cite or link to this item:
Title: Multi-messenger Observations of a Binary Neutron Star Merger
Authors: Beardmore, Andrew P.
Evans, Philip A.
Osborne, Julian P.
Pagani, Claudio
Page, Kim
Higgins, Adam B.
Starling, Rhaana L.C.
O'Brien, Paul T.
Rosetti, Skye S.
First Published: 3-Oct-2017
Publisher: American Astronomical Society
Citation: Astrophysical Journal Letters, 2017, 848, pp. 12-12 (59)
Abstract: On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40 8 8 - + Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 M. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the OneMeter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.
DOI Link: 10.3847/2041-8213/aa91c9
ISSN: 2041-8205
eISSN: 2041-8213
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © the authors,2017. This is an open-access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

Files in This Item:
File Description SizeFormat 
1710.05833-2.pdfPublished (publisher PDF)2.09 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.