On the progenitor of binary neutron star merger GW170817

Research output: Contribution to journalArticlepeer-review

Authors

  • LIGO Scientific Collaboration
  • Virgo Collaboration

Colleges, School and Institutes

External organisations

  • California Institute of Technology
  • Louisiana State University
  • University of Salerno
  • Complesso Universitario di Monte S.Angelo
  • University of Florida
  • Monash University
  • LIGO Livingston Observatory
  • IN2P3
  • University of Sannio at Benevento
  • Albert-Einstein-Institut, Max-Planck-Institut für, Gravitationsphysik
  • University of Mississippi
  • University of Illinois
  • University of Cambridge
  • Institution Nikhef National Institute for Subatomic Physics
  • Massachusetts Institute of Technology
  • Instituto Nacional de Pesquisas Espaciais
  • Facebook
  • Laboratori Nazionali del Gran Sasso
  • Inter-University Centre for Astronomy and Astrophysics India
  • Tata Institute of Fundamental Research
  • University of Wisconsin-Milwaukee
  • Università di Pisa
  • Sezione INFN di Pisa
  • Australian National University
  • Domaine Scientifique de la Doua
  • University of the West of Scotland

Abstract

On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just ∼40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of ∼2 kpc away from the galaxy's center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy's star formation history, provided the stellar populations are older than 1 Gyr.

Details

Original languageEnglish
Article numberL40
JournalAstrophysical Journal Letters
Volume850
Issue number2
Publication statusPublished - 1 Dec 2017

Keywords

  • binaries: general, gravitational waves, stars: kinematics and dynamics, stars: neutron