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arXiv · 1905.07614

Kinematics and Velocity Ellipsoid of Halo Red Giants

Mohamed I. Nouh·Waleed H. Elsanhoury
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Abstract

In the present paper, we aim to determine the kinematical properties, velocity ellipsoid, and Oort constants using a sample of halo red giants. The study is based mainly on the space and radial velocities of about 1583 red giant stars collected from the SEGUE-1 and SEGUE-2 surveys. We divided the sample into three subsamples, the inner halo, the outer halo and the stars near the galactic plane. The fitting of the radial velocity equation gives a the mean of Oort constants, A = 15.6 +- 1.6 km s-1 kpc-1 and B= -13.9 +- 1.8 km s-1 kpc-1, the angular velocity |A-B|= 29.5 +- 0.2 km s-1 kpc-1 implying a rotational velocity of 221.25 +- 26.66 km s-1 if we take the distance to the Galactic center as 7.5 kpc.

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Mohamed I. Nouh, Waleed H. Elsanhoury. 2019-05-18. Kinematics and Velocity Ellipsoid of Halo Red Giants. https://doi.org/10.1007/s10511-020-09624-5

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