2016MNRAS.463.2623H -
Mon. Not. R. Astron. Soc., 463, 2623-2639 (2016/December-2)
The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution.
HUANG Y., LIU X.-W., YUAN H.-B., XIANG M.-S., ZHANG H.-W., CHEN B.-Q., REN J.-J., WANG C., ZHANG Y., HOU Y.-H., WANG Y.-F. and CAO Z.-H.
Abstract (from CDS):
The rotation curve (RC) of the Milky Way out to ∼100 kpc has been constructed using ∼16 000 primary red clump giants (PRCGs) in the outer disc selected from the LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC) and the Sloan Digital Sky Survey (SDSS)-III/APOGEE survey, combined with ∼5700 halo K giants (HKGs) selected from the SDSS/SEGUE survey. To derive the RC, the PRCG sample of the warm disc population and the HKG sample of halo stellar population are, respectively, analysed using a kinematical model allowing for the asymmetric drift corrections and re-analysed using the spherical Jeans equation along with measurements of the anisotropic parameter β currently available. The typical uncertainties of RC derived from the PRCG and HKG samples are, respectively, 5-7 km s–1 and several tens km s–1. We determine a circular velocity at the solar position, Vc(R0) = 240 ± 6 km s–1 and an azimuthal peculiar speed of the Sun, V☉ = 12.1 ± 7.6 km s–1, both in good agreement with the previous determinations. The newly constructed RC has a generally flat value of 240 km s–1 within a Galactocentric distance r of 25 kpc and then decreases steadily to 150 km s–1 at r ∼ 100 kpc. On top of this overall trend, the RC exhibits two prominent localized dips, one at r ∼ 11 kpc and another at r ∼ 19 kpc. From the newly constructed RC, combined with other constraints, we have built a parametrized mass model for the Galaxy, yielding a virial mass of the Milky Way's dark matter halo of 0.90+0.07–0.08 ×1012 M☉ and a local dark matter density, ρ_ ☉, dm_ = 0.32+0.02–0.02 GeV cm–3.
Abstract Copyright:
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Journal keyword(s):
Galaxy: disc - Galaxy: fundamental parameters - Galaxy: halo - Galaxy: kinematics and dynamics - Galaxy: structure - Galaxy: structure
Simbad objects:
4
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