Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer

Details Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer

Oct 1996

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996ssrv...78..277v&link_type=abstract

Space Science Reviews, Volume 78, Issue 1-2, pp. 277-288

Physics

41

Ism: General, Abundances, Clouds, Radiation Field, Solar Neighborhood

Scientific paper

Because of the strong absorption of extreme ultraviolet radiation by hydrogen and helium, almost every observation with the Extreme Ultraviolet Explorer (EUVE) satellite is affected by the diffuse clouds of neutral gas in the local interstellar medium (LISM). This paper reviews some of the highlights of the EUVE results on the distribution and physical state of the LISM and the implications of these results with respect to the interface of the LISM and the heliosphere. The distribution of sources found with the EUVE all-sky surveys shows an enhancement in absorption toward the galactic center. Individual spectra toward nearby continuum sources provide evidence of a greater ionization of helium than hydrogen in the Local Cloud with an mean ratio of H I/He I of 14.7. The spectral distribution of the EUV stellar radiation field has been measured, which provides a lower limit to local H II and He II densities, but this radiation field alone cannot explain the local helium ionization. A combination of EUVE measurements of H I, He I, and He II columns plus the measurement of the local He I density with interplanetary probes can place constraints on the local values of the H I density outside the heliosphere to lie between 0.15 and 0.34 cm-3 while the H II density ranges between 0.0 and 0.14 cm-3. The thermal pressure (P/k = nT) of the Local Cloud is derived to be between 1700 and 2300 cm-3 K, a factor of 2 to 3 above previous estimates.

Affiliated with

Also associated with

No associations

Rating

Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations of the Local Interstellar Medium with the Extreme Ultraviolet Explorer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1144076