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The influence of binary stars on the kinematics of low-mass galaxies

Sven De Rijcke·Herwig Dejonghe
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Abstract

In this paper, the influence of binary stars on the measured kinematics of dwarf galaxies is investigated. Using realistic distributions of the orbital parameters (semi-major axis, eccentricity, ...), analytical expressions are derived for the changes induced by the presence of binary stars in the measured velocity moments of low-mass galaxies (such as the projected velocity dispersion and the 4th order Gauss-Hermite coefficient h4). It is shown that there is a noticeable change in the observed velocity dispersion if the intrinsic velocity dispersion of a galaxy is of the same order as the binary velocity dispersion. The kurtosis of the line-of-sight velocity distribution (LOSVD) is affected even at higher values of the intrinsic velocity dispersion.

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Sven De Rijcke, Herwig Dejonghe. 2002-01-24. The influence of binary stars on the kinematics of low-mass galaxies. https://doi.org/10.1046/j.1365-8711.2002.05075.x

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