Microlensing constraints on primordial black holes with Subaru/HSC Andromeda observations

Hiroko Niikura, Masahiro Takada, Naoki Yasuda, Robert H. Lupton, Takahiro Sumi, Surhud More, Toshiki Kurita, Sunao Sugiyama, Anupreeta More, Masamune Oguri, Masashi Chiba

Research output: Contribution to journalArticlepeer-review

327 Scopus citations


Primordial black holes (PBHs) have long been suggested as a viable candidate for the elusive dark matter. The abundance of such PBHs has been constrained using a number of astrophysical observations, except for a hitherto unexplored mass window of MPBH = [10−14, 10−9] solar masses. Here we carry out a dense-cadence, 7-hour-long observation of M31 with the Subaru Hyper Suprime-Cam (HSC) to search for microlensing of stars in M31 by PBHs lying in the halo regions of the Milky Way and M31. Given our simultaneous monitoring of tens of millions of stars in M31, if such light PBHs make up a significant fraction of dark matter, we expect to find many microlensing events. However, we identify only a single candidate event, which translates into stringent upper bounds on the abundance of PBHs in the mass range MPBH ≃ [10−11, 10−6] solar masses.

Original languageEnglish (US)
Pages (from-to)524-534
Number of pages11
JournalNature Astronomy
Issue number6
StatePublished - Jun 1 2019

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics


Dive into the research topics of 'Microlensing constraints on primordial black holes with Subaru/HSC Andromeda observations'. Together they form a unique fingerprint.

Cite this