Evidence for an ionization gradient in the local interstellar medium : EUVE observations of white dwarfs

@inproceedings{Wolff1999EvidenceFA,
  title={Evidence for an ionization gradient in the local interstellar medium : EUVE observations of white dwarfs},
  author={Burkhard Wolff and D. Koester and Rosine Lallement},
  year={1999}
}
We present an enlarged and homogeneous set of interstellar hydrogen and helium column densities obtained through continuum and ionization edges fitting of nearby hot white dwarfs observed with the Extreme Ultraviolet Explorer (EUVE). We compare the HI columns towards the targets and their locations relative to the soft X-ray cavity contours drawn by Snowden et al. (1998). We then use the inferred ionization degrees of hydrogen and helium (available towards 17 objects) as a database for a search… CONTINUE READING