Implications for dwarf spheroidal mass content from interloper removal

A. L. Serra, G. W. Angus, A. Diaferio

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Using the caustic method, we identify the member stars of five dwarf spheroidal (dSph) galaxies of the Milky Way, the smallest dark matter (DM) dominated systems in the Universe. After our interloper rejection, we compute line-of-sight velocity dispersion profiles that are substantially smoother than previous results. Moreover, two dSphs have line-of-sight velocity dispersions 20% smaller than previous calculations suggested. Our Jeans modelling confirms that the DM content interior to 300 pc is roughly constant with satellite luminosity. Finally, if we assume that MOND provides the true law of gravity, our identification of interlopers implies that four dSphs have mass-to-light ratios in agreement with stellar population synthesis models, whereas Carina still has a mass-to-light ratio a factor of two too large and remains a problem for MOND.

Original languageEnglish
Article numberA16
JournalAstronomy and Astrophysics
Volume524
Issue number1
DOIs
Publication statusPublished - Nov 19 2010

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mass to light ratios
line of sight
dark matter
dwarf galaxies
rejection
alkalies
universe
luminosity
gravity
gravitation
stars
synthesis
profiles
modeling
removal
calculation
method

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

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abstract = "Using the caustic method, we identify the member stars of five dwarf spheroidal (dSph) galaxies of the Milky Way, the smallest dark matter (DM) dominated systems in the Universe. After our interloper rejection, we compute line-of-sight velocity dispersion profiles that are substantially smoother than previous results. Moreover, two dSphs have line-of-sight velocity dispersions 20{\%} smaller than previous calculations suggested. Our Jeans modelling confirms that the DM content interior to 300 pc is roughly constant with satellite luminosity. Finally, if we assume that MOND provides the true law of gravity, our identification of interlopers implies that four dSphs have mass-to-light ratios in agreement with stellar population synthesis models, whereas Carina still has a mass-to-light ratio a factor of two too large and remains a problem for MOND.",
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Implications for dwarf spheroidal mass content from interloper removal. / Serra, A. L.; Angus, G. W.; Diaferio, A.

In: Astronomy and Astrophysics, Vol. 524, No. 1, A16, 19.11.2010.

Research output: Contribution to journalArticle

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