Issue |
A&A
Volume 391, Number 2, August IV 2002
|
|
---|---|---|
Page(s) | L11 - L15 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20021003 | |
Published online | 02 August 2002 |
Letter to the Editor
A high-resolution study of the evolution of the
Lyman α forest in the redshift interval
*
Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: [ejanknecht,rbaade,dreimers]@hs.uni-hamburg.de
Corresponding author: E. Janknecht, ejanknecht@hs.uni-hamburg.de
Received:
15
April
2002
Accepted:
6
July
2002
Spectroscopy with HST/STIS Echelle and VLT/UVES
of the bright QSO HE 0515-4414 ()
offers for the first time the opportunity to study the Lyman α forest
in the redshift range
at a resolution ≤
10 km s-1.
The number density evolution of the Lyman α lines is well described
by the power law approach d
. We derive
for the strong lines
(
),
in agreement with the Lyman α forest evolution for
.
The expected slow-down in their evolution does not appear
earlier than
. For the weak lines
(
) we find
that the HE 0515-4414 data for
follow the trend with
known from
observations, i.e. we confirm the difference in evolution
between weak and strong lines.
We use the two-point velocity correlation function (TPCF)
to search for clustering of the Lyman α lines,
yet we detect no excess in the TPCF on scales up to 10 000 km s-1.
Key words: cosmology: observations / intergalactic medium / quasars: Ly α forest / quasars: individual: HE 0515-4414
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.