2021/10/26 by V. S. Veena, P. Schilke, Á. Sánchez-Monge +11 · 17 citations
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Biology #Classical mechanics #Galaxy #Geometry #Kinematics #Milky Way #Molecular Spectroscopy and Structure #Molecular cloud #Orientation (vector space) #Physics #Protein filament #Scale (ratio) #Spiral (railway) #Spiral galaxy #Stars #astro-ph.GA
paper · pdf · doi:10.3847/2041-8213/ac341f
published in The Astrophysical Journal Letters 921(2), L42 (IOP Publishing) · 10 pages, 7 figures, accepted for publication in ApJ Letters
arxiv created 2021/10/26 · openalex publication_date 2021/11/01 · arxiv updated 2021/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract 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 kiloparsec-scale 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.