Mass estimators in the Gaia era

Abstract

Forthcoming astrometric missions such as the Gaia satellite will bring to the fore the problem of estimating the enclosed mass from a set of positions, radial velocities and proper motions of tracer stars. Here, we show how to construct the tracer mass estimator when the proper motion data are available in addition to the usual line-of-sight velocity data. Notably, the mass estimators do not require any assumption on the anisotropy, as it is naturally incorporated through the different components of proper motions. In addition, the separate treatment of the proper motions and the line-of-sight velocities is desirable because they are observationally independent and thus the propagation of the combined uncertainties is rather straightforward. The extension to projected data is also sketched, together with a possible application of measuring the masses of Galactic globular clusters.

submitted to MNRAS, including 7 journal pages, 4 figures, 3 tables

References in corpus (5)

• Mismatch and Misalignment: Dark Haloes and Satellites of Disc Galaxies
• Systemic Proper Motions of Milky Way Satellites from Stellar Redshifts: the Carina, Fornax, Sculptor and Sextans Dwarf Spheroidals
• A first measurement of the Proper Motion of the Leo II dwarf spheroidal galaxy
• Modified Virial Formulae and the Theory of Mass Estimators
• Accurate Masses for Navarro-Frenk-White Dark Matter Haloes

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• Applying scale-free mass estimators to the Local Group in Constrained Local Universe Simulations
• Plan beta: Core or Cusp?
• Jeans that fit: weighing the mass of the Milky Way analogues in the $\Lambda \mathrm{CDM}$ universe