Study of the stellar orbital eccentricity based on LAMOST survey

doi:10.7523/j.issn.2095-6134.2019.03.005

Abstract

Abstract: Based on A/F/G/K giant stars from LAMOST data,we pick out halo sample stars according to the space and metallicity distribution to study the orbital eccentricity distribution of the halo stars in the Galaxy. We find that the observed halo stellar orbital eccentricity distribution has the peak of 0.8 and it does not change with the distance in the 5<|z|<15 kpc range. In addition, the inner-halo stars and outer-halo stars have different eccentricity distributions in the 5<|z|<25 kpc range. The peak eccentricity of inner-halo is about 0.65, and that of outer-halo is about 0.8. Compared to the inner-halo stars, the outer-halo stars are more concentrated in the area beyond e~0.6. Maybe this different kinematics represents different formation mechanisms of inner-halo and outer-halo.

Key words: inner-halo, outer-halo, eccentricity

CLC Number:

P156.5

LIU Shuai, DU Cuihua. Study of the stellar orbital eccentricity based on LAMOST survey[J]. , 2019, 36(3): 326-330.

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