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A Kiloparsec-scale Molecular Wave in the Inner Galaxy: Feather of the Milky Way?

Veena, V. S., Schilke, P., Sánchez-Monge, Á., Sormani, M. C., Klessen, R. S., Schuller, F., Colombo, D., Csengeri, T., Mattern, M., Urquhart, J.S. and others. (2021) A Kiloparsec-scale Molecular Wave in the Inner Galaxy: Feather of the Milky Way? The Astrophysical Journal Letters, 921 . Article Number L42. ISSN 2041-8205. E-ISSN 2041-8213. (doi:10.3847/2041-8213/ac341f) (KAR id:91603)

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We report the discovery of a velocity coherent, kiloparsec-scale molecular structure toward the Galactic center region with an angular extent of 30° and an aspect ratio of 60:1. The kinematic distance of the CO structure ranges between 4.4 and 6.5 kpc. Analysis of the velocity data and comparison with the existing spiral arm models support that a major portion of this structure is either a subbranch of the Norma arm or an interarm giant molecular filament, likely to be a kiloparsec-scale feather (or spur) of the Milky Way, similar to those observed in nearby spiral galaxies. The filamentary cloud is at least 2.0 kpc in extent, considering the uncertainties in the kinematic distances, and it could be as long as 4 kpc. The vertical distribution of this highly elongated structure reveals a pattern similar to that of a sinusoidal wave. The exact mechanisms responsible for the origin of such a kiloparsecscale filament and its wavy morphology remains unclear. The distinct wave-like shape and its peculiar orientation makes this cloud, named as the Gangotri wave, one of the largest and most intriguing structures identified in the Milky Way.

Item Type: Article
DOI/Identification number: 10.3847/2041-8213/ac341f
Uncontrolled keywords: Unified Astronomy Thesaurus concepts: Milky Way Galaxy (1054); Galaxy kinematics (602); Galaxy structure (622); Interstellar medium (847); Giant molecular clouds (653); Submillimeter astronomy (1647)
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: James Urquhart
Date Deposited: 16 Nov 2021 10:29 UTC
Last Modified: 10 Dec 2022 22:50 UTC
Resource URI: (The current URI for this page, for reference purposes)
Urquhart, J.S.:
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