• DOI:10.1038/s41550-019-0723-1
• Corpus ID: 118986293

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

@article{Niikura2019MicrolensingCO,
  title={Microlensing constraints on primordial black holes with Subaru/HSC Andromeda observations},
  author={Hiroko Niikura and Masahiro Takada and Naoki Yasuda and Robert H. Lupton and Takahiro Sumi and Surhud More and Toshiki Kurita and Sunao Sugiyama and Anupreeta More and Masamune Oguri and Masashi Chiba},
  journal={Nature Astronomy},
  year={2019},
  volume={3},
  pages={524-534}
}

• H. Niikura, M. Takada, +8 authors M. Chiba
• Published 9 January 2017
• Physics
• Nature Astronomy

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.The abundance of primordial black holes in the Galactic halo is constrained through their microlensing of stars in M31. Despite monitoring tens of millions of stars, only a single candidate event is found, providing stringent upper bounds on their abundance.