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arXiv · 0902.2410

Total mass distributions of Sersic galaxies from photometry $&$ cent\ ral velocity dispersion

Dalia Chakrabarty·Brendan Jackson
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Abstract

We develop a novel way of finding total mass density profiles in Sersic ellipticals, to about 3 times the major axis effective radius, using no other information other than what is typically available for distant galaxies, namely the observed surface brightness distribution and the central velocity dispersion $σ_0$. The luminosity density profile of the observed galaxy is extracted by deprojecting the measured brightness distribution and scaling it by a fiduciary, step-function shaped, $raw$ mass-to-light ratio profile ($M/L$). The resulting raw, discontinuous, total, 3-D mass density profile is then smoothed according to a proposed smoothing prescription. The parameters of this raw $M/L$ are characterised by implementing the observables in a model-based study. The complete characterisation of the formalism is provided as a function of the measurements of the brightness distribution and $σ_0$. The formalism, thus specified, is demonstrated to yield the mass density profiles of a suite of test galaxies and is successfully applied to extract the gravitational mass distribution in NGC 3379 and NGC 4499, out to about 3 effective radii.

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Dalia Chakrabarty, Brendan Jackson. 2009-02-13. Total mass distributions of Sersic galaxies from photometry $&$ cent\ ral velocity dispersion. https://doi.org/10.1051/0004-6361%2F200809965

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