Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams
| dc.creator | SOFUE, Yoshiaki | |
| dc.date | 1995-08-24 | |
| dc.date | 1995-10-25 | |
| dc.date.accessioned | 2026-07-07T08:58:19Z | |
| dc.date.available | 2026-07-07T08:58:19Z | |
| dc.description | Analyzing the (l, b, Vlsr) data cube of 13CO(J=1-0) line emission obtained by Bally et al, we have investigated the molecular gas distribution and kinematics in the central +/-1 deg (150 pc) region of the Galaxy. We have applied the pressing method to remove the local- and foreground-gas components at low velocities in order to estimate the intensity more quantitatively. Two major dense molecular arms have been identified in longitude-radial velocity diagrams as apparently rigidly-rotating ridges. The ridges are spatially identified as two arms, which we call the Galactic Center molecular Arms (GCA). The arms compose a rotating ring of radius 120 pc (the 120-pc Molecular Ring), whose inclination is about 85 deg. The Sgr B molecular complex is associated with GCA I, and Sgr C complex is located on GCA II. These arms are as thin as 13 to 15 pc, except for vertically extended massive complexes around Sgr B and C. The LV behavior of the arms can be qualitatively reproduced by a model which assumes spiral arms of gas. Assuming a small pitch angle for the arms, we tried to deconvolve the LV diagram to a projection on the galactic plane, and present a possible face-on CO map as seen from the galactic pole, which also reveals a molecular ring and arms. We have estimated masses of these molecular features, using the most recent value of the CO-to-H2 conversion factor taking into account its metallicity dependency and radial gradient in the Galaxy. The estimated molecular masses and kinetic energy are about a factor of three smaller than those reported in the literature using the conventional conversion factor. | |
| dc.description | Plain Tex, 19pages, Figures upon request | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9508110 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9508110 | |
| dc.identifier | Publ.Astron.Soc.Jap. 47 (1995) 527 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/147282 | |
| dc.subject | Astrophysics | |
| dc.title | Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams | |
| dc.type | text |