Globular clusters in modified Newtonian dynamics: velocity dispersion profiles from self-consistent models |
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| Authors: | A Sollima C Nipoti |
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| Institution: | Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38205 San Cristobal de La Laguna, Tenerife, Spain;Dipartimento di Astronomia, Universitàdi Bologna, Via Ranzani 1, I-40127 Bologna, Italy |
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| Abstract: | We test the modified Newtonian dynamics (MOND) theory with the velocity dispersion profiles of Galactic globular clusters populating the outermost region of the Milky Way halo, where the Galactic acceleration is lower than the characteristic MOND acceleration a 0. For this purpose, we constructed self-consistent, spherical models of stellar systems in MOND, which are the analogues of the Newtonian King models. The models are spatially limited, reproduce well the surface brightness profiles of globular clusters and have velocity dispersion profiles that differ remarkably in shape from the corresponding Newtonian models. We present dynamical models of six globular clusters, which can be used to efficiently test MOND with the available observing facilities. A comparison with recent spectroscopic data obtained for NGC 2419 suggests that the kinematics of this cluster might be hard to explain in MOND. |
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| Keywords: | gravitation stellar dynamics methods: analytical stars: kinematics globular clusters: general |
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