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Earth-mass dark halos are torn into dark mini-streams by stars

HongSheng Zhao·James E. Taylor·Joseph Silk·Dan Hooper
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Abstract

The promising neutralino dark matter particles generically condense into numerous earth-mass dark halos with smaller substructures suppressed by free streaming\cite{berezinsky}. The recent {\it Letter to Nature}\cite{moore} claims that these 0.01pc-sized dense halos emerged at redshifts 60--26 are rarely destructed inside galaxies, hence the nearest halos at about 0.1pc from Earth are bright in annihilation-powered gamma-rays, but are inaccessible to direct detections. However, most mini-halos reaching solar neighbourhood should experience strong impulses by individual stars in the Galactic disk and bulge, and have been torn into pc-long tidal streams over a Hubble time with only modest overdensity, reducing indirect annihilation signals. Sweeping across the solar system per century, mini-streams leave directional and temporal signatures for direct searches of neutralinos.

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HongSheng Zhao, James E. Taylor, Joseph Silk, Dan Hooper. 2005-02-09. Earth-mass dark halos are torn into dark mini-streams by stars. https://arxiv.org/abs/astro-ph/0502049

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