  Cosmological shock waves play a major role in heating baryonic gas in the
large scale structure of the universe. In this contribution we study the
shock-heated gas in connection with shocks themselves. The distributions of
shock speed and temperature of shock-hated gas both should reflect the depth of
gravitational potential of associated nonlinear structures, so their
morphology. From their distributions we find, in addition to hot gas in and
around clusters/groups and warm-hot intergalactic medium (WHIM) with
T=10^5-10^7 K mostly in filaments, there is a significant amount of low
temperature WHIM with T < 10^5 K distributed mostly as sheet-like structures.
Not only the WHIM with T=10^5-10^7 K but also the WHIM with T < 10^5 K make up
a significant fraction of gas mass, implying the low temperature WHIM could be
important in resolving the missing baryon problem. The shock-heated gas in
filaments and sheets are manifested best through emissions and absorptions in
soft X-ray and far UV. We confirm that the WHIM with T=10^5-10^7 K makes
significant contributions to the soft X-ray background, absorptions of highly
ionized species such as OVII and OVIII in AGN spectra, and line emissions from
OVII and OVIII ions, as pointed by previous studies. However, the WHIM with T <
10^5 K is the major contributor to absorptions of lower ionized species such as
OV and OVI, because these photo-ionized ions are most abundant in sheets of low
density and temperature. (abridged)
