English

New limits from microlensing on Galactic Black Holes in the mass range $10M_{\odot}<M<1000M_{\odot}$

Astrophysics of Galaxies 2022-08-10 v3 Cosmology and Nongalactic Astrophysics

Abstract

We have searched for long duration microlensing events originating from intermediate mass Black Holes (BH) in the halo of the Milky Way, using archival data from EROS-2 and MACHO photometric surveys towards the Large Magellanic Cloud. We combined data from these two surveys to create a common database of light curves for 14.1 million objects in LMC, covering a total duration of 10.6 years, with flux series measured through four wide passbands. We have carried out a microlensing search on these light curves, complemented by the light curves of 22.7 million objects, observed by EROS-2 only or MACHO only over about 7 years, with flux series measured through only two passbands. A likelihood analysis, taking into account LMC self lensing and Milky Way disk contributions allows us to conclude that compact objects with masses in the range 10100M10 - 100 M_{\odot} cannot make up more than 15%\sim 15\% of a standard halo total mass (at 95%95\% confidence level). Our analysis sensitivity weakens for heavier objects, although we still exclude that 50%\sim 50\% of the halo be made of 1000M\sim 1000 M_{\odot} BHs. Combined with previous EROS results, an upper limit of 15%\sim 15\% of the total halo mass can be obtained for the contribution of compact halo objects in the mass range 106102M10^{-6} - 10^2 M_{\odot}.

Keywords

Cite

@article{arxiv.2202.13819,
  title  = {New limits from microlensing on Galactic Black Holes in the mass range $10M_{\odot}<M<1000M_{\odot}$},
  author = {T. Blaineau and M. Moniez and C. Afonso and J. -N. Albert and R. Ansari and E. Aubourg and C. Coutures and J. -F. Glicenstein and B. Goldman and C. Hamadache and T. Lasserre and L. LeGuillou and E. Lesquoy and C. Magneville and J. -B. Marquette and N. Palanque-Delabrouille and O. Perdereau and J. Rich and M. Spiro and P. Tisserand},
  journal= {arXiv preprint arXiv:2202.13819},
  year   = {2022}
}

Comments

9 pages, 5 figures, accepted for publication in Astronomy and Astrophysics