| タイトル | New observations with the HST Goddard High Resolution Spectrograph of the low-redshift Lyman-Alpha clouds in the 3C 273 line of sight |
| 著者（英） | Weymann, Ray; Morris, Simon; Heap, Sally; Rauch, Michael; Williams, Robert |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 1995-01-10 |
| 言語 | eng |
| 内容記述 | We presenty spectra of 3C 273 between 1216 and 1250 A obtained in the (pre-COSTAR (Corrective Optics Space Telescope Axial Replacement instrument)) configuration of the Goddard High Resolution Spectrograph (GHRS) taken with the G160M grating with a resolution approximately = 20 km/s. The two strong Ly alpha lines at velocities of approximately 1000 and approximately 1600 km/s are well fitted with Voigt profiles and yield column densities, Doppler parameters and redshifts of log N(H I)=14.19 +/- 0.04 V(sub Dop)=40.7 +/- 3.0 km/s, V = 1012.4 +/- 2.0 km/s, and log N(H I)=14.22 +/- 0.07, V(sub Dop)=34.2 +/- 3.3 km/s and V = 1582.0 +/- 2.0 km/s, respectively. Motivated by the initial announcement by Williams and Schommer of detectable H alpha emission associated with the approximately 1600 km/s cloud, we discuss the difficulty of finding models which can account for emission of that magnitude given the observed neutral hydrogen column density, though a recent reobservation by these authors has shown the initial detection to be spurious. The C/H abundance ratio is probably less than about one-fourth of the solar abundance in these clouds, although this result is very uncertain and model dependent. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 95A68565 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/309762 |
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