Abstract
ABSTRACT The circular rotation speed of the Milky Way at the solar radius, Θ0, has been estimated to be 220 km s−1 by fitting the maximum velocity of H i emission as a function of Galactic longitude. This result is in tension with a recent estimate of Θ0 = 240 km s−1, based on Very Long Baseline Interferometry (VLBI) parallaxes and proper motions from the BeSSeL and VERA surveys for large numbers of high-mass star-forming regions across the Milky Way. We find that the rotation curve best fitted to the VLBI data is slightly curved, and that this curvature results in a biased estimate of Θ0 from the H i data when a flat rotation curve is assumed. This relieves the tension between the methods and favors Θ0 = 240 km s−1.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
