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Far-ultraviolet observations of the Crab Nebula using the Hopkins Ultraviolet Telescope
- Source :
- Astrophysical Journal, Part 1. 399(2)
- Publication Year :
- 1992
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 1992.
-
Abstract
- Observations of the FUV spectrum of the central portion of the Crab Nebula SNR using the Hopkins Ultraviolet Telescope (HUT) aboard the Astro-1 space shuttle mission in December 1990 are reported. The C IV 1549-A emission line shows two resolved components representing the front and back sides of the shell expanding at roughly +/- 1100 km/s. The He II 1640-A emission line shows only a blueshifted component corresponding to the near side of the shell. The HUT observation is compared to optical emission-line imagery and to archival IUE observations. This comparison indicates that a distribution emission component, consisting of either a number of individually faint filaments or a diffuse component, produces the bulk of the emission seen by HUT. A grid of photoionization models for the Crab Nebula filaments is calculated to infer the range of limits. The differing UV line ratios observed for these components indicates that varying carbon and/or He abundances are present in the observed material.
- Subjects :
- Astrophysics
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 399
- Issue :
- 2
- Database :
- NASA Technical Reports
- Journal :
- Astrophysical Journal, Part 1
- Notes :
- NAS5-27000, , NAG5-988
- Publication Type :
- Report
- Accession number :
- edsnas.19930031001
- Document Type :
- Report
- Full Text :
- https://doi.org/10.1086/171952