Survival of Dwarf Spheroidal Galaxies: Effects of Mass Loss after Collapse in a Non-Baryonic Gravitational Potential

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Session 108 -- Dwarf and Irregular Galaxies
Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[108.13] Survival of Dwarf Spheroidal Galaxies: Effects of Mass Loss after Collapse in a Non-Baryonic Gravitational Potential

D.E. Potter (Maria Mitchel Observatory & U. of Colorado, Boulder), A.Noriega-Crespo (Maria Mitchel Observatory)

Direct summation N-Body simulations are used to test the stability of dwarf spheroidal galaxies throughout their presumed evolution. Mass loss ranging between 10-90 percent is suspected to occur at the time of initial star formation. The disruptive effects of this mass loss are simulated on systems with and without an underlying non-baryonic matter potential and the two cases are compared. This comparison reveals the effectiveness of systems containing a non-baryonic dark matter potential to survive after extreme mass loss relative to systems free of non-baryonic matter which undergo the same mass loss. Interpretation of the number of particles escaped beyond a tidal radius after the different simulations reveal the critical ratio between the initial non-barionic matter density and the mass loss ejected by the initial star formation above which results in a recognizable remaining relaxed system. These results are applied to the known population of dwarf spheroidal galaxies and an estimated limit is plac

ed on their pre-star formation non-baryonic to baryonic matter ratio.

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