| タイトル | [New Determination of the Abundances of Oxygen, Nitrogen and Sulfur as a Function of Galactocentric Distance |
| 著者（英） | Churchwell, E. B. |
| 著者所属（英） | Wisconsin Univ. |
| 発行日 | 1997-01-01 |
| 言語 | eng |
| 内容記述 | The goals of this program were to obtain data which could provide the basis for a new determination of the abundances of Oxygen, Nitrogen, and Sulfur as a function of galactocentric distance. This program was preceded by a detailed VLA high resolution radio study of the ultracompact (UC) HII region G29.96 to demonstrate that reliable electron temperatures could be obtained with nonLTE modeling of the line intensities for a few radio recombination lines distributed over a reasonable range of principle quantum numbers. These results were published. Having demonstrated the technique, a survey of 28 UC HII regions located in the galactocentric distance range of 0- 17 kpc was undertaken. The lines of H42(alpha), H66(alpha), H76(alpha), and H93(alpha) were observed with spatial resolutions of 3.7 to 6.7 arc secs. The nonLTE models constrained by the new data produced a well-defined temperature gradient. This study provided an entirely independent check on direct measurements of abundances via the measurement of spectral lines from atomic coolants. |
| NASA分類 | Astronomy |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/539682 |
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