ISOCAM covers 2 - 18 
m, using a Short Wave (SW, 2 - 5.5 m) InSb
detector and a Long Wave (LW, 5 - 18 m) Si:Ga array. In spite of its
small array ( 
pixels), the LW turned out to compete
successfully with larger groundbased arrays, mainly due to the very small
local background of ISOCAM and the absence of atmospheric absorption bands.
The group has focused its efforts on an extensive survey of nearby star
formation regions lasting for the full mission (Jan 1996 - Apr 1998). Most
of the data reductions were performed during 1997-98. The aim is to
improve our knowledge on the mass distribution of young stars (the Initial
Mass Function, IMF) and the star formation efficiency in clouds with
different physical properties. It is found that the number of stars in the
regions studied so far increases steeply with decreasing mass. Typically
25% of the detected young stars have masses below 0.1M 
and most of
these will fade away as brown dwarfs. The observed mass distributions were
found to have a power law exponent of -1.4, which is close to the power
law for the ``clumps'' identified by radio observations of molecular
clouds. This implies that only 25% of the mass of all objects below
1M would reside in objects below 0.1M . This conclusion on the
total brown dwarf mass is, however, very sensitive to the details.
The LWS (Long Wavelength Spectrometer) aboard ISO has successfully collected science data during February 1996 through May 1998. Through LWS science team membership, the group has obtained data within the Guaranteed Time programme. In addition, as the PI of Open Time observations, the group is organising the reduction and analysis of these data sets (see http://isowww.estec.esa.nl:80/). Below, a brief account is given of the first results:
Detection of molecular line-emission from shocked flows. In addition
to H 
O-vapour, molecular line emission from OH and high-J CO has been
discovered. The emission originates in regions of interaction between mass
outflows from a (proto-)stellar object and the ambient molecular cloud.
The emitting gas is heated to modest temperatures by relatively mild
shocks, and detailed model fitting of the far-infrared line spectrum led to
estimates of the order of room-temperature. This `luke-warm' molecular gas
represents a previously unseen phase of the interstellar medium in low-mass
(solar type) star forming regions with properties different from that
observed in the optical and in the near-infrared.
Mass loss from young stellar objects: relation to the central mass.
After this initial discovery, it came therefore as a surprise to find, from
a spectroscopic LWS-survey of 17 Herbig-Haro objects in 7 different star
forming regions, that detectable molecular line emission appears to be a
rare event. Instead, the far-infrared spectra of such flows are dominated
by fine-structure emission from neutral atomic oxygen, [OI]63 m . This is
indicative of the presence of considerably stronger shocks, dissociating
most of the molecules.