W.F. Thi1 - E.F. van Dishoeck1 - D.J. Jansen 1 - M. Spaans 2 - J.H. Black3
1 Leiden Observatory -
We present results from our searches for the pure rotational lines of H2 with
the ISO-SWS from low-density molecular clouds exposed to ultraviolet radiation
which is not much enhanced over the normal interstellar radiation field. Lines
up to S(5) are detected from the IC 63 cloud illuminated by the B0.5 star
Cas, which are compared with the detailed available physical models
for this cloud (Jansen et al. 1995, A&A 302, 223). Results for the S(0)
and/or S(1) lines will be presented for a variety of translucent clouds,
ranging from `cool' PDRs exposed to radiation from late B and A stars to the
outskirts of molecular clouds and isolated translucent clouds. The data form
stringent tests of the temperature structure and heating mechanisms of the
cloud.
Postscript version