Tidal disruption of the first dark microhalos

HongSheng Zhao, Dan Hooper, Garry W. Angus, James E. Taylor, Joseph Silk

    Research output: Contribution to journalArticle

    39 Citations (Scopus)

    Abstract

    We point out that the usual self-similarity in cold dark matter models is broken by encounters with individual normal galactic stars on a subparsec scale. Tidal heating and stripping must have redefined the density and velocity structures of the population of the Earth-mass dark matter halos, which are likely to have been the first bound structures to form in the universe. The disruption rate depends strongly on galaxy types and the orbital distribution of the microhalos; in the Milky Way, stochastic radial orbits are destroyed first by stars in the triaxial bulge, and microhalos on nonplanar retrograde orbits with large pericenters and/or apocenters survive the longest. The final microhalo distribution in the solar neighborhood is better described as a superposition of filamentary microstreams rather than as a set of discrete spherical clumps in an otherwise homogeneous medium. This has important consequences to our detections of microhalos by direct recoil signal and indirect annihilation signal.

    Original languageEnglish
    Pages (from-to)697-701
    Number of pages5
    JournalAstrophysical Journal
    Volume654
    Issue number2 I
    DOIs
    Publication statusPublished - Jan 10 2007

    Fingerprint

    dark matter
    retrograde orbits
    stars
    homogeneous medium
    solar neighborhood
    clumps
    stripping
    velocity structure
    encounters
    halos
    universe
    galaxies
    heating
    orbits
    orbitals
    distribution
    rate
    cold
    detection

    All Science Journal Classification (ASJC) codes

    • Space and Planetary Science
    • Nuclear and High Energy Physics

    Cite this

    Zhao, H., Hooper, D., Angus, G. W., Taylor, J. E., & Silk, J. (2007). Tidal disruption of the first dark microhalos. Astrophysical Journal, 654(2 I), 697-701. https://doi.org/10.1086/509649
    Zhao, HongSheng ; Hooper, Dan ; Angus, Garry W. ; Taylor, James E. ; Silk, Joseph. / Tidal disruption of the first dark microhalos. In: Astrophysical Journal. 2007 ; Vol. 654, No. 2 I. pp. 697-701.
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    Zhao, H, Hooper, D, Angus, GW, Taylor, JE & Silk, J 2007, 'Tidal disruption of the first dark microhalos', Astrophysical Journal, vol. 654, no. 2 I, pp. 697-701. https://doi.org/10.1086/509649

    Tidal disruption of the first dark microhalos. / Zhao, HongSheng; Hooper, Dan; Angus, Garry W.; Taylor, James E.; Silk, Joseph.

    In: Astrophysical Journal, Vol. 654, No. 2 I, 10.01.2007, p. 697-701.

    Research output: Contribution to journalArticle

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    Zhao H, Hooper D, Angus GW, Taylor JE, Silk J. Tidal disruption of the first dark microhalos. Astrophysical Journal. 2007 Jan 10;654(2 I):697-701. https://doi.org/10.1086/509649