SIMBAD references

We estimate the solar peculiar velocities and Oort constants using a sample of 5627 A-type stars with d< 0.6 kpc and |z|< 0.1 kpc, selected from the LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) surveys. The radial and tangential velocities of these A-type stars are fitted by using a non-axisymmetric model. The best-fitting result yields the solar peculiar velocities (U_☉,V_☉,W_{☉)=(11.69±}0.68,_10.16±0.51,_7.67±0.10)km_s^–1 and Oort constants A=16.31±0.89 km s^–1 kpc^–1, B=-11.99±0.79 km s^–1 kpc^–1, C=-3.10±0.48 km s^–1 kpc^–1, and K=-1.25±1.04 km s^–1 kpc^–1. |K+C|> 4 km s^–1 kpc^–1 means that there is a radial velocity gradient in the extended local disc, implying that the local disc is in a non-asymmetric potential. Using the derived Oort constants, we derive the local angular velocity Ω~A-B=28.30±1.19 km s^–1 kpc^–1. By using A-type star sample of different volumes, we further try to evaluate the impacts of the ridge pattern in the R-V_ph plane on constraining the solar motions and Oort constants. As the volume becomes larger towards the anticentre direction, the values of A and B become larger (implying a steeper slope of the local rotation curve) and the value of V_☉ becomes smaller probably caused by the ridge structure and its signal increasing with distance.