Dwarf spheroidals in MOND

    Research output: Contribution to journalArticle

    79 Citations (Scopus)

    Abstract

    We take the line-of-sight velocity dispersions as functions of radius for eight Milky Way dwarf spheroidal galaxies and use Jeans analysis to calculate the mass-to-light ratios (M/L) in Modified Newtonian Dynamics (MOND). Using the latest structural parameters, distances and variable velocity anisotropy, we find six out of eight dwarfs have sensible M/L using only the stellar populations. Sextans and Draco, however, have M/L = 9.2 +5.3 -3.0 and 43.9 +29.0 -19.3 respectively, which poses a problem. Apart from the need for Sextans' integrated magnitude to be reviewed, we propose tidal effects intrinsic to MOND, testable with numerical simulations, but fully orbit dependant, which are disrupting Draco. The creation of the Magellanic Stream is also re-addressed in MOND, the scenario being the stream is ram pressure stripped from the SMC as it crosses the LMC.

    Original languageEnglish
    Pages (from-to)1481-1488
    Number of pages8
    JournalMonthly Notices of the Royal Astronomical Society
    Volume387
    Issue number4
    DOIs
    Publication statusPublished - Jul 2008

    Fingerprint

    Milky Way Galaxy
    disrupting
    mass to light ratios
    ram
    anisotropy
    dwarf galaxies
    line of sight
    simulation
    orbits
    radii
    need
    analysis
    effect
    parameter

    All Science Journal Classification (ASJC) codes

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

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    abstract = "We take the line-of-sight velocity dispersions as functions of radius for eight Milky Way dwarf spheroidal galaxies and use Jeans analysis to calculate the mass-to-light ratios (M/L) in Modified Newtonian Dynamics (MOND). Using the latest structural parameters, distances and variable velocity anisotropy, we find six out of eight dwarfs have sensible M/L using only the stellar populations. Sextans and Draco, however, have M/L = 9.2 +5.3 -3.0 and 43.9 +29.0 -19.3 respectively, which poses a problem. Apart from the need for Sextans' integrated magnitude to be reviewed, we propose tidal effects intrinsic to MOND, testable with numerical simulations, but fully orbit dependant, which are disrupting Draco. The creation of the Magellanic Stream is also re-addressed in MOND, the scenario being the stream is ram pressure stripped from the SMC as it crosses the LMC.",
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    Dwarf spheroidals in MOND. / Angus, G. W.

    In: Monthly Notices of the Royal Astronomical Society, Vol. 387, No. 4, 07.2008, p. 1481-1488.

    Research output: Contribution to journalArticle

    TY - JOUR

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    AU - Angus, G. W.

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