Abstract

Poster - Splinter 4MOST   (MW-0337)

Dynamics at the bar-spiral interface

Léa Marques
AIP

Bars and spirals have both long been known to drive galaxy evolution. Recently, several numerical works have studied how their interaction in particular impacts both dynamics and star formation processes. Notably, the periodic overlap of the bar and inner spiral structure, caused by their different pattern speed, was shown to correlate with fluctuations in bar parameters, bursts in radial migration and star formation at the bar ends, and bursts of star formation in the nuclear stellar disk. However, observations of the bar-spiral interface in the Milky Way have been lacking, due to a lack of spectroscopic data. In that context, I will present ‘Dynamics at the bar-spiral interface’, a 4MOST supplementary target program that aims to get detailed kinematic information of stars at the interface between the near end of the bar and the Scutum-Centaurus spiral arm. Combined with S3/4MIDABLE-LR, this program will allow a detailed exploration of the velocity space at the interface region, as well as Tremaine-Weinberg pattern speed measurements across it.