A luminous blue kilonova and an off-axis jet from a compact binary merger at z = 0.1341

E Troja; G Ryan; L Piro; H van Eerten; S B Cenko; Y Yoon; S-K Lee; M Im; T Sakamoto; P Gatkine; A Kutyrev; S Veilleux

doi:10.1038/s41467-018-06558-7

A luminous blue kilonova and an off-axis jet from a compact binary merger at z = 0.1341

Nat Commun. 2018 Oct 16;9(1):4089. doi: 10.1038/s41467-018-06558-7.

Authors

E Troja^{1

2}, G Ryan³, L Piro⁴, H van Eerten⁵, S B Cenko^{6

3}, Y Yoon⁷, S-K Lee⁷, M Im⁷, T Sakamoto⁸, P Gatkine⁹, A Kutyrev^{9

6}, S Veilleux^{9

3}

Affiliations

¹ Department of Astronomy, University of Maryland, College Park, MD, 20742-4111, USA. eleonora.troja@nasa.gov.
² Astrophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, 20771, USA. eleonora.troja@nasa.gov.
³ Joint Space-Science Institute, University of Maryland, College Park, MD, 20742, USA.
⁴ INAF, Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, 00133, Rome, Italy.
⁵ Department of Physics, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
⁶ Astrophysics Science Division, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, 20771, USA.
⁷ Center for the Exploration for the Origin of the Universe, Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
⁸ Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara-shi Kanagawa, 252-5258, Japan.
⁹ Department of Astronomy, University of Maryland, College Park, MD, 20742-4111, USA.

Abstract

The recent discovery of a gamma-ray burst (GRB) coincident with the gravitational-wave (GW) event GW170817 revealed the existence of a population of low-luminosity short duration gamma-ray transients produced by neutron star mergers in the nearby Universe. These events could be routinely detected by existing gamma-ray monitors, yet previous observations failed to identify them without the aid of GW triggers. Here we show that GRB150101B is an analogue of GRB170817A located at a cosmological distance. GRB150101B is a faint short burst characterized by a bright optical counterpart and a long-lived X-ray afterglow. These properties are unusual for standard short GRBs and are instead consistent with an explosion viewed off-axis: the optical light is produced by a luminous kilonova, while the observed X-rays trace the GRB afterglow viewed at an angle of ~13°. Our findings suggest that these properties could be common among future electromagnetic counterparts of GW sources.

Publication types

Research Support, Non-U.S. Gov't