Detalles de publicación

PP 020125

Diagonal Ridge pattern of different age populations found in Gaia DR2 with LAMOST Main-Sequence-Turn-Off and OB type Stars

H.-F. Wang (1), Y. Huang (1), H.-W. Zhang (2,3), M. López-Corredoira (4,5,), W.-Y. Cui (6), B.-Q. Chen (1), R. Guo (7), J. Chang (8)
(1) South−Western Institute for Astronomy Research, Yunnan University, Kunming, China; (2) Department of Astronomy, Peking University, Beijing, China; (3) Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, China; (4) IAC; (5) ULL; (6) Department of Physics, Hebei Normal University, Shijiazhuang, China; (7) National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China; (8) Purple Mountain Observatory, the Partner Group of MPI für Astronomie, Nanjing, China
We revisit the diagonal ridge feature (diagonal distributions in the R,vϕ plane) found in Gaia and present timing analysis for it between Galactocentric distances of R=7.5 and 12 kpc, using Main-Sequence-Turn-Off and OB stars selected from the LAMOST Galactic spectroscopic surveys. We recover the ridge pattern in the R-vϕ plane color coded by mean radial velocity and find this feature is presented from very young (OB stars, few hundred Myr) to very old populations (τ = 9−14 \,Gyr). Meanwhile, some ridge features are also revealed in the metallicity [Fe/H], [α/Fe] and vz distributions. In the LZ,vϕ plane, one of the ridge patterns, with constant angular momentum per unit mass, shows variations with different age populations compared. However, the remaining two ones are relatively stable, implying there might have two kinds of ridge patterns with different dynamical origins and evolution.

 
Aceptado para publicación en ApJ | Enviado el 2020-09-04 | Proyecto P/309405