Observations of 3C273 with the Goddard High Resolution Spectrograph on the Hubble Space Telescope. II.
Abstract
Observations of the quasar 3C 273 taken with the Goddard High Resolution Spectrograph in November and December 1993 are presented here. We have included both the fully-reduced spectra, and spectra combined with our earlier (1991) observations. There are a total of 10 new medium resolution exposures covering four wavelength regions: 1164-1201 Angstroms, 1214-1251 Angstroms, 1537-1573 Angstroms, and 1633-1670 Angstroms. We confirm the suggestion of Morris et al. (1991) that the galactic Si IV lambda 1393 line is blended with an extragalactic lya line by observing the lyb counterpart to this extragalactic line. We obtain an improved upper limit on the C IV/H I ratio in these weak low redshift lya absorption systems by coadding the corresponding C IV spectral regions. Improved line profiles for the galactic C IV and N V absorption are also presented and discussed. The improved measurements lead to a downward revision of the galactic C IV column density, log N (C IV) = 14.46+/- 0.04.
- Publication:
-
The Astronomical Journal
- Pub Date:
- August 1997
- DOI:
- 10.1086/118492
- Bibcode:
- 1997AJ....114..554B
- Keywords:
-
- QUASARS: INDIVIDUAL: 3C 273;
- QUASARS: EMISSION LINES