TY - JOUR
T1 - Determining the local dark matter density with LAMOST data
AU - Xia, Qiran
AU - Liu, Chao
AU - Mao, Shude
AU - Song, Yingyi
AU - Zhang, Lan
AU - Long, R. J.
AU - Zhang, Yong
AU - Hou, Yonghui
AU - Wang, Yuefei
AU - Wu, Yue
PY - 2016/3/10
Y1 - 2016/3/10
N2 - Measurement of the local dark matter density plays an important role in both Galactic dynamics and dark matter direct detection experiments. However, the estimated values from previous works are far from agreeing with each other. In this work, we provide a well-defined observed sample with 1427G-and K-type main-sequence stars from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope spectroscopic survey, taking into account selection effects, volume completeness, and the stellar populations. We apply a vertical Jeans equation method containing a single exponential stellar disc, a razor thin gas disc, and a constant dark matter density distribution to the sample, and obtain a total surface mass density of 78.7+3.9 -4.7 M⊙ pc-2 up to 1 kpc and a local dark matter density of 0.018 ±0.0054 M⊙ pc-3We find that the sampling density (i.e. number of stars per unit volume) of the spectroscopic data contributes to about two-third of the uncertainty in the estimated values. We discuss the effect of the tilt term in the Jeans equation and find it has little impact on our measurement. Other issues, such as a non-equilibrium component due to perturbations and contamination by the thick-disc population, are also discussed.
AB - Measurement of the local dark matter density plays an important role in both Galactic dynamics and dark matter direct detection experiments. However, the estimated values from previous works are far from agreeing with each other. In this work, we provide a well-defined observed sample with 1427G-and K-type main-sequence stars from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope spectroscopic survey, taking into account selection effects, volume completeness, and the stellar populations. We apply a vertical Jeans equation method containing a single exponential stellar disc, a razor thin gas disc, and a constant dark matter density distribution to the sample, and obtain a total surface mass density of 78.7+3.9 -4.7 M⊙ pc-2 up to 1 kpc and a local dark matter density of 0.018 ±0.0054 M⊙ pc-3We find that the sampling density (i.e. number of stars per unit volume) of the spectroscopic data contributes to about two-third of the uncertainty in the estimated values. We discuss the effect of the tilt term in the Jeans equation and find it has little impact on our measurement. Other issues, such as a non-equilibrium component due to perturbations and contamination by the thick-disc population, are also discussed.
KW - Dark matter
KW - Galaxy: Disc
KW - Galaxy: Kinematics and dynamics
UR - http://www.scopus.com/inward/record.url?scp=84965053930&partnerID=8YFLogxK
U2 - 10.1093/mnras/stw565
DO - 10.1093/mnras/stw565
M3 - Article
AN - SCOPUS:84965053930
SN - 1365-2966
VL - 458
SP - 3839
EP - 3850
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -