Radial Velocities

VELOCITY FLUCTUATIONS IN THE MILKY WAY USING RED CLUMP GIANTS

Context: If the Galaxy is axisymmetric and in dynamical equilibrium, we expect negligible fluctuations in the residual line-of-sight velocity field. However, non-axisymmetric structures like a bar, spiral arms and merger events can generate velocity fluctuations. Recent results using the APOGEE survey claim significant fluctuations in velocity for stars in the mid plane (|z|<0.25 kpc) out to 5 kpc and suggest that the dynamical influence of the Milky Way's bar extends out to the Solar neighborhood.

Paper PDF: 

Confirmation of co-moving star pairs identified in Gaia DR1

Recently, Oh et al published "Co-moving stars in Gaia DR1" (http://arxiv.org/abs/1612.02440) which identified over 13000 co-moving star pairs in Gaia DR1 based upon their proper motions and parallaxes. Some of the pairs form larger groups (e.g., they recovered the Pleiades).

About 350 of these pairs of stars are also in the Cannon 1.3 table. Oh et al found a similar sized overlap with RAVE. We would be able to use the GALAH results to investigate the 3D space motions and chemistry of these stars to identify those stars which true binaries and clusters.

Syndicate content