FUSE observations of the HeII Lyman alpha forest towards HS1700+6416
Abstract
We present FUSE observations of the HeII Lyman alpha forest in the redshift range 2.3 < z < 2.7 towards HS1700+6416. Between October 2002 and February 2003, the brightness of the QSO increased by a factor 2. Therefore, with an exposure time of 203 ks during orbital night, the quality of the resulting spectrum is comparable to the HE2347-4342 data. This second line of sight with a resolved HeII Lyman alpha forest reveals a similar variation of several orders of magnitude of the column density ratio eta = N(HeII)/N(HI) and confirms the results of previous studies. The well-known metal line spectrum of HS1700+6416 permits to examine the influence of metal line absorption on the HeII column densities.
Cite
@article{arxiv.astro-ph/0410588,
title = {FUSE observations of the HeII Lyman alpha forest towards HS1700+6416},
author = {D. Reimers and C. Fechner and G. Kriss and M. Shull and R. Baade and W. Moos and A. Songaila and R. Simcoe},
journal= {arXiv preprint arXiv:astro-ph/0410588},
year = {2007}
}
Comments
3 pages, 3 figures, to appear in Astrophysics in the Far Ultraviolet: Five Years of Discovery with FUSE, ASP Conf. series, eds. G. Sonneborn, W. Moos & B-G Andersson