English

EXPERIMENTAL LIMITS ON THE DARK MATTER HALO OF THE GALAXY FROM GRAVITATIONAL MICROLENSING.

Astrophysics 2016-08-30 v1 High Energy Physics - Phenomenology

Abstract

We have monitored 8.6 million stars in the Large Magellanic Cloud for 1.1 years and have found 3 events consistent with gravitational microlensing. We place strong constraints on the Galactic halo content in the form of compact lensing objects in the mass range 104\msun10^{-4} \msun to 101\msun10^{-1} \msun. Three events is fewer than expected for a standard spherical halo of objects in this mass range, but appears to exceed the number expected from known Galactic populations. Fitting a naive spherical halo model to our data yields a MACHO fraction f=0.200.14+0.33f = 0.20^{+0.33}_{-0.14}, which implies a total MACHO mass (inside 50 kpc) of 8.06+14\ten10\msun8.0^{+14}_{-6}\ten{10} \msun, and a microlensing optical depth 97+15\ten89^{+15}_{-7} \ten{-8} (68\sim 68\% CL).

Keywords

Cite

@article{arxiv.astro-ph/9501091,
  title  = {EXPERIMENTAL LIMITS ON THE DARK MATTER HALO OF THE GALAXY FROM GRAVITATIONAL MICROLENSING.},
  author = {C. Alcock and R. A. Allsman and T. S. Axelrod and D. P. Bennett and K. H. Cook and K. C. Freeman and K. Griest and J. A. Guern and M. J. Lehner and S. L. Marshall and H. -S. Park and S. Perlmutter and B. A. Peterson and M. R. Pratt and P. J. Quinn and A. W. Rodgers and C. W. Stubbs and W. Sutherland and .},
  journal= {arXiv preprint arXiv:astro-ph/9501091},
  year   = {2016}
}

Comments

8 pages, uuencoded compressed PostScript, 4 figures included (400kB). Submitted to Phys Rev Lett.