Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lost Baryons at Low Redshift   We review our attempts to discover lost baryons at low redshift with ``X-ray
forest'' of absorption lines from the warm-hot intergalactic medium. We discuss
the best evidence to date along the Mrk 421 sightline. We then discuss the
missing baryons in the Local Group and the significance of the z=0 absorption
systems in X-ray spectra. We argue that the debate over the Galactic vs.
extragalactic origin of the z=0 systems is premature as these systems likely
contain both components. Observations with next generation X-ray missions such
as Constellation-X and XEUS will be crucial to map out the warm-hot
intergalactic medium.

32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg