Accurate Distances of Massive Young Stars in the Scutum Spiral Arm

Abstract As part of the BeSSeL Survey, we have used Very Long Baseline Array to measure 16 trigonometric parallaxes and proper motions molecular masers associated with 14 high-mass star-forming regions in Scutum arm first quadrant Milky Way. This increases number maser sources accurate distances this 42. The can now be traced over a length ≈8 kpc spanning ≈100° Galactic azimuth. We find that large inward peculiar noted by Immer et al. are concentrated near end bar, while away from bar modest more typical spiral arms seen, strengthening suggestion induced bar.