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X-ray emission from dark clusters of MACHOs

F. De Paolis·G. Ingrosso·Ph. Jetzer·M. Roncadelli
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Abstract

MACHOs (Massive Astrophysical Compact Halo Objects) - as discovered by microlensing experiments towards the LMC - provide a natural explanation for the galactic halo dark matter. A realistic possibility is that MACHOs are brown dwarfs of mass $\sim 0.1 M_{\odot}$. Various arguments suggest that brown dwarfs should have a coronal X-ray emission of $\sim 10^{27}$ erg s$^{-1}$. As MACHOs are presumably clumped into dark clusters (DCs), each DC is expected to have a total X-ray luminosity of $\sim 10^{29}-10^{32}$ erg s$^{-1}$. We discuss the possibility that dark clusters contribute to the diffuse X-ray background (XRB) or show up as discrete sources in very deep field X-ray satellite observations. Moreover, from the observed diffuse XRB we infer that the amount of virialized diffuse gas present in the galactic halo can at most make up 5% of the halo dark matter.

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F. De Paolis, G. Ingrosso, Ph. Jetzer, M. Roncadelli. 1997-09-05. X-ray emission from dark clusters of MACHOs. https://arxiv.org/abs/astro-ph/9709052

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