DETAILED MOLECULAR OBSERVATIONS TOWARD THE DOUBLE HELIX NEBULA

Journal Article · Tue Jul 01 04:00:00 EDT 2014 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/213/1/8· OSTI ID:22340202

Torii, K.; Enokiya, R.; Hasegawa, K.; Kudo, N.; Fukui, Y. ^[1]

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1. Department of Physics and Astrophysics, Nagoya University, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)

The Double Helix Nebula (DHN), located 100 pc above Sgr A* in the Galactic center (GC), is a unique structure whose morphology suggests it is a magnetic feature. Recent molecular observations toward the DHN revealed two candidate molecular counterparts of the DHN at radial velocities of –35 km s{sup –1} and 0 km s{sup –1} and discussed the model in which the DHN has its origin at the circumnuclear disk in the GC. In this paper, new CO observations toward the DHN using the Caltech Submillimeter Observatory and Mopra telescopes are presented. The higher-resolution observations of ∼1 pc scale reveal the detailed distributions and kinematics of the two CO counterparts (the 0 km s{sup –1} and –35 km s{sup –1} features) and provide new information on their physical conditions. As a result, we find that the 0 km s{sup –1} feature with a mass of 3.3 × 10{sup 4} M {sub ☉} coincides with the infrared emission of the DHN, indicating clear association with the DHN. The association of the –35 km s{sup –1} feature, with a mass of 0.8 × 10{sup 4} M {sub ☉}, is less clear compared with the 0 km s{sup –1} feature, but the complementary distribution between the molecular gas and the DHN and velocity variation along the DHN support its association with the DHN. The two molecular features are highly excited, as shown by the relatively high CO J = 2-1/J = 1-0 intensity ratios of ∼1.0, and have kinetic temperatures of ∼30 K, consistent with the typical molecular clouds in the GC.

• OSTI ID: 22340202
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 213; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CLOUDS
GALAXIES
NEBULAE
RESOLUTION
TELESCOPES