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The End of the MACHO Era: Limits on Halo Dark Matter from Stellar Halo Wide Binaries

Jaiyul Yoo·Julio Chaname·Andrew Gould
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Abstract

We simulate the evolution of halo wide binaries in the presence of MAssive Compact Halo Objects (MACHOs) and compare our results to the sample of wide binaries of Chaname & Gould (2003). The observed distribution is well fit by a single power law for angular separation, 3.5" < theta < 900", whereas the simulated distributions show a break in the power law whose location depends on the MACHO mass and density. This allows us to place upper limits on MACHO density as a function of their assumed mass. At the 95% confidence level, we exclude MACHOs with mass M > 43Msun at the standard local halo density rho_H. This all but removes the last permitted window for a full MACHO halo for masses M > 10^{-7.5}Msun.

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Jaiyul Yoo, Julio Chaname, Andrew Gould. 2003-10-08. The End of the MACHO Era: Limits on Halo Dark Matter from Stellar Halo Wide Binaries. https://doi.org/10.1086/380562

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