Discovery of the Pigtail Molecular Cloud in the Galactic Center

The Astrophysical Journal (Impact Factor: 5.99). 09/2012; 756(1):87. DOI: 10.1088/0004-637X/756/1/87
Source: arXiv


This paper reports the discovery of a helical molecular cloud in the central
molecular zone (CMZ) of our Galaxy. This "pigtail" molecular cloud appears at
(l, b, V_LSR) ~ (-0.7deg, +0.0deg, -70 to -30 km/s), with a spatial size of ~
(20 pc)^2 and a mass of (2-6) 10^5 solar masses. This is the third helical
gaseous nebula found in the Galactic center region to date. Line intensity
ratios indicate that the pigtail molecular cloud has slightly higher
temperature and/or density than the other normal clouds in the CMZ. We also
found a high-velocity wing emission near the footpoint of this cloud. We
propose a formation model of the pigtail molecular cloud. It might be
associated with a magnetic tube that is twisted and coiled because of the
interaction between clouds in the innermost x_1 orbit and ones in the outermost
x_2 orbit.

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Available from: Tetsuo Hasegawa, Oct 10, 2015
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