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arXiv · 1003.4268

Kinematics of Milky Way Satellites in a Lambda Cold Dark Matter Universe

Louis E. Strigari·Carlos S. Frenk·Simon D. M. White
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Abstract

We investigate whether the subhalos of Lambda-CDM galaxy halos have potentials consistent with the observed properties of Milky Way satellites, particularly those with high-quality photometric and kinematic data: Fornax, Leo I, Sculptor, Sextans, and Carina. We compare spherical models with isotropic velocity dispersion tensors to the observed, circularly averaged star counts, line-of-sight velocity dispersion profiles and line-of-sight velocity distributions. We identify subhalos within the six high-resolution dark matter halos of the Aquarius Project for which the spherically averaged potentials result in excellent fits to each of the five galaxies. In particular, our simple one-integral models reproduce the observations in the inner regions, proving that these data are fully consistent with Lambda-CDM expectations and do not require cored dark matter distributions. For four of the five satellites the fits require moderately cusped {\it stellar} density profiles. The star count data for Leo I, however, do require a cored distribution of star counts. Current data suggest that these five satellites may be hosted by Lambda-CDM subhalos with maximum circular velocities in the range 10 to 30 km/s.

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Louis E. Strigari, Carlos S. Frenk, Simon D. M. White. 2010-03-22. Kinematics of Milky Way Satellites in a Lambda Cold Dark Matter Universe. https://doi.org/10.1111/j.1365-2966.2010.17287.x

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