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A Distant Extended Spiral Arm in the Fourth Quadrant of the Milky Way


McClure-Griffiths, NM and Dickey, JM and Gaensler, BM and Green, AJ, A Distant Extended Spiral Arm in the Fourth Quadrant of the Milky Way, The Astrophysical Journal, 607, (2 II) pp. L127-L130. ISSN 0004-637X (2004) [Refereed Article]

DOI: doi:10.1086/422031


Using data from the Southern Galactic Plane Survey, we present a possible distant spiral arm in the fourth quadrant of the Milky Way. The very distinct and cohesive feature can be traced for over 70° as the most extreme positive velocity feature in the longitude-velocity diagram. The feature is at a Galactic radius between 18 and 24 kpc and appears to be the last major structure before the end of the H I disk. We compare the feature with a Galactic spiral model and show that it is well reproduced by a spiral arm of pitch angle i ∼ 9°. The arm is quite well confined to the Galactic plane, dropping at most 1 kpc below the Galactic equator. Over most of its length, the arm is 1-2 kpc thick.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Galactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Dickey, JM (Professor John Dickey)
ID Code:46593
Year Published:2004
Web of Science® Times Cited:49
Deposited By:Physics
Deposited On:2007-08-28
Last Modified:2007-08-28

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