Interstellar absorption of the lowenergy X-rays from the Crab Nebula
Abstract
Observations of the soft X-ray emission from the Crab Nebula, made with the MSSL X-ray telescopes on board the satellite Copernicus, require a review of the currently accepted interstellar abundances of light elements. The soft X-ray data imply a gas column density of ( i o ) x 1021 atoms cm-2 using Brown & Gould X-ray absorption cross-sections. Results obtained from 21 cm radio measurements indicate a lower value of the column density. Better agreement between the X-ray and radio values can be obtained by increasing the abundances of helium and neon over those assumed by Brown & Gould.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- 1973
- DOI:
- 10.1093/mnras/165.4.355
- Bibcode:
- 1973MNRAS.165..355C