Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams

Details Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams

1995-08-24

arxiv.org/abs/astro-ph/9508110v2

Publ.Astron.Soc.Jap. 47 (1995) 527

Astronomy and Astrophysics

Astrophysics

Plain Tex, 19pages, Figures upon request

Scientific paper

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.

Affiliated with

Also associated with

No associations

Rating

Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Galactic Center Molecular Arms, Ring and Expanding Shells.I. Kinematical Structures in Longitude-Velocity Diagrams will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-677545