Components of the Local Interstellar Medium
Abstract
HST, EUVE, and optical Ca II spectra are providing the critical velocity and column density data needed to identify individual structures (clouds) of warm gas in the local ISM near the Sun. We determine the shape and physical properties of the Local Interstellar Cloud (LIC) from 43 lines of sight. The Sun is located very close to the edge of and will soon leave the LIC. Analysis of UV and optical spectra for another 20 lines of sight permit us to determine preliminary sizes and properties of other clouds located within about 50 pc of the Sun. We will show new results for the G, NGP, SGP, and other clouds. These nearby clouds appear to have the same D/H ratio as the LIC, but they have different velocity vectors, temperatures, and metal depletions. We will also discuss their ionization equilibria and relation to the Scorpio-Centaurus Association and the Local Bubble.
- Publication:
-
Recent Insights into the Physics of the Sun and Heliosphere: Highlights from SOHO and Other Space Missions
- Pub Date:
- 2001
- Bibcode:
- 2001IAUS..203..595L