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Date and Time of the Query: 2019-08-25 T07:54:14 PDT
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For refcode 2015MNRAS.450.3920B:
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NED Abstract

Copyright by Royal Astronomical Society. 2015MNRAS.450.3920B Expanded haloes, abundance matching and too-big-to-fail in the Local Group Brook, Chris B.; Di Cintio, Arianna Abstract. Observed kinematical data of 40 Local Group (LG) members are used to derive the dark matter halo mass of such galaxies. Haloes are selected from the theoretically expected LG mass function and two different density profiles are assumed, a standard universal cuspy model and a mass-dependent profile which accounts for the effects of baryons in modifying the dark matter distribution within galaxies. The resulting relations between stellar and halo mass are compared with expectations from abundance matching. Using a universal cuspy profile, the ensemble of LG galaxies is fit in relatively low-mass haloes, leaving 'dark' many massive haloes of M_halo_ >~ 10^10^ M_sun_: this reflects the 'too-big-to-fail' problem and results in a M_star_-M_halo_ relation that differs from abundance matching predictions. Moreover, the star formation efficiency of isolated LG galaxies increases with decreasing halo mass when adopting a cuspy model. By contrast, using the mass-dependent density profile, dwarf galaxies with M_star_ >~ 10^6^ M_sun_ are assigned to more massive haloes, which have a central cored distribution of dark matter: the 'too-big-to-fail' problem is alleviated, the resultant M_star_-M_halo_ relation follows abundance matching predictions down to the completeness limit of current surveys, and the star formation efficiency of isolated members decreases with decreasing halo mass, in agreement with theoretical expectations. Finally, the cusp/core space of LG galaxies is presented, providing a framework to understand the non-universality of their density profiles. Key words: galaxies: dwarf, galaxies: formation, galaxies: haloes, Local Group
Retrieve 40 NED objects in this reference.
Please click here for ADS abstract

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