Transition between Atomic and Molecular Hydrogen in the Galaxy: Vertical Variation of the Molecular Fraction
| dc.creator | Imamura, K. | |
| dc.creator | Sofue, Y. | |
| dc.date | 1996-07-08 | |
| dc.date.accessioned | 2026-07-07T02:21:27Z | |
| dc.date.available | 2026-07-07T02:21:27Z | |
| dc.description | We derive radial and vertical distributions of HI and H2 gas densities in our Galaxy by using the terminal velocity method. We calculate the molecular fraction (f_mol) defined as the ratio of the molecular hydrogen to total hydrogen gas density at galactic longitude l= 33 to 64 deg and galactic latitude b=-2 to +2 deg. The thickness of the molecular dominant region f_mol > 0.8 is approximately constant (109 +/- 12 pc) at galactocentric distance R = 4.7 to 7.2 kpc. The molecular fraction decreases suddenly at a critical height from the galactic plane, below which the gas disk is almost totally molecular, while it is almost atomic beyond this height. We show that the vertical f_mol variation can be reproduced by a model which takes into account the phase transition between HI and H2 gases in the interstellar matter. Key words: Atomic Hydrogen --- the Galaxy --- Interstellar Matter --- Molecular Hydrogen | |
| dc.description | To appear in A&Ap, Latex 11 pages, 9 figures in 11 ps files | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9607044 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9607044 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/10555 | |
| dc.subject | Astrophysics | |
| dc.title | Transition between Atomic and Molecular Hydrogen in the Galaxy: Vertical Variation of the Molecular Fraction | |
| dc.type | text |