Dynamical Analysis of the Dark Matter and Central Black Hole Mass in the Dwarf Spheroidal Leo I
| Autor: | Maria Jose Bustamante-Rosell, Jens Thomas, Karl Gebhardt, Eva Noyola, Greg Zeimann, X. Mazzalay, Maximilian Fabricius |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Milky Way Dark matter Center (category theory) FOS: Physical sciences Velocity dispersion Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies Dwarf spheroidal galaxy Black hole Dark matter halo Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Earth and Planetary Astrophysics Astrophysics::Galaxy Astrophysics Dwarf galaxy |
| Zdroj: | The Astrophysical Journal. 921:107 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.3847/1538-4357/ac0c79 |
| Popis: | We measure the central kinematics for the dwarf spheroidal galaxy Leo I using integrated-light measurements and previously published data. We find a steady rise in the velocity dispersion from $300^{\prime\prime}$ into the center. The integrated-light kinematics provide a velocity dispersion of $11.76\pm0.66$ km/s inside $75^{\prime\prime}$. After applying appropriate corrections to crowding in the central regions, we achieve consistent velocity dispersion values using velocities from individual stars. Crowding corrections need to be applied when targeting individual stars in high density stellar environments. From integrated light, we measure the surface brightness profile and find a shallow cusp towards the center. Axisymmetric, orbit-based models measure the stellar mass-to-light ratio, black hole mass and parameters for a dark matter halo. At large radii it is important to consider possible tidal effects from the Milky Way so we include a variety of assumptions regarding the tidal radius. For every set of assumptions, models require a central black hole consistent with a mass $(3.3 \pm 2) \times 10^6\, M_\odot$. The no-black-hole case for any of our assumptions is excluded at over 95% significance, with $6.4 |
| Databáze: | OpenAIRE |
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