Major structures of the inner galaxy delineated by 6.7 GHz methanol masers

Date

2011

Authors

Green, J A
Caswell, J.L.
McClure-Griffiths, Naomi
Avison, A
Breen, S.L.
Burton, Michael Graham
Ellingson, S
Fuller, G.A.
Gray, M.D.
Pestalozzi, M.

Journal Title

Journal ISSN

Volume Title

Publisher

IOP Publishing

Abstract

We explore the longitude-velocity distribution of 6.7–GHz methanol masers in the context of the inner structure of our Galaxy. We analyse the correlation in velocities within this distribution and identify density enhancements indicating large-scale regions of enhanced star formation. These are interpreted as the starting points of the spiral arms and the interaction of the Galactic bar with the 3–kpc arms. The methanol masers support the presence of a long thin bar with a 45◦ orientation. Signatures of the full 3–kpc arm structure are seen, including a prominent tangent at approximately −22◦ Galactic longitude. We compare this distribution with existing models of the gas dynamics of our Galaxy. The 3–kpc arm structure appears likely to correspond to the radius of corotation resonance of the bar, with the bar on its inner surface and the starting points of the spiral arms on its outer surface.

Description

Keywords

Keywords: Galaxy: kinematics and dynamics; Galaxy: structure; ISM: kinematics and dynamics; masers; stars: massive

Citation

Source

The Astrophysical Journal

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1088/0004-637X/733/1/27

Restricted until