Search for subsolar-mass ultracompact binaries in advanced LIGO's first observing run

Research output: Contribution to journalArticlepeer-review


  • LIGO Scientific Collaboration
  • Virgo Collaboration

External organisations

  • California Institute of Technology
  • Louisiana State University
  • Universita degli Studi di Salerno
  • Complesso Universitario di Monte S.Angelo
  • Monash University
  • LIGO Livingston Observatory
  • Université Grenoble Alpes
  • University of Sannio at Benevento
  • Max Planck Institute for Gravitational Physics (Albert Einstein Institute) Am Mühlenberg 1, D-14476 Potsdam, Germany
  • Institut für Gravitationsphysik (Albert-Einstein-Institut)
  • University of Illinois at Urbana-Champaign
  • 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, Milwaukee, Wisconsin 53201, USA
  • Università di Pisa
  • Sezione INFN di Pisa
  • Fundació General de la Universitat de Valencia (FGUV)
  • The Australian National University
  • Domaine Scientifique de la Doua
  • IN2P3
  • INFN
  • University of Oregon
  • Canadian Institute for Theoretical Astrophysics
  • University of Strathclyde


We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2 M-1.0 M using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2 M, 0.2 M) ultracompact binaries to be less than 1.0×106 Gpc-3 yr-1 and the coalescence rate of a similar distribution of (1.0 M, 1.0 M) ultracompact binaries to be less than 1.9×104 Gpc-3 yr-1 (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1 M through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2 M to be less than 33% of the total dark matter density and monochromatic populations of 1.0 M to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.


Original languageEnglish
Article number231103
JournalPhysical Review Letters
Issue number23
Publication statusPublished - 7 Dec 2018

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