| Description |
Dark clouds are condensations of the ISM that are detected as silhouettes
against a bright background and are known to be the cradles of forming stars.
With this proposal, we aim at observing the low-mass filamentary dark cloud
Sandqvist 187/188, also known as the Norma cloud. It hosts a number of low-mass
protostellar objects, among which is a FU Ori star (V346 Nor). 1.2 mm continuum
observations resulted in detecting 6 embedded sources that appear to be
protostellar objects at different evolutionary stages. However additional data,
especially at far-IR wavelengths, that are crucial to derive basic physical
properties like temperature, luminosity, density and mass were insufficient so
far, both in sensitivity and spatial resolution, to construct meaningful source
SEDs. In addition, the global properties of the Norma cloud are also not well
known. Current estimates of its density and mass are mainly based on millimetre
continuum observations assuming a typical and uniform temperature. Therefore,
we want to observe the star forming sites in this cloud with PACS and SPIRE
imaging. The unique combination of sensitivity and spatial resolution at far-IR
wavelengths provided by the Herschel Space Observatory and its instruments will
be the key for determining the still badly constrained properties we are eager
to obtain. With the proposed observations we want to i) fill the gaps in the
SEDs of the embedded objects, ii) constrain their basic properties, iii) derive
their evolutionary stage, and iv) construct a census of the star formation
activity in the Norma cloud. In addition, we want to investigate the properties
of the ISM surrounding these objects. In particular, we are interested in the
temperature and density profiles of the dust around the embedded sources that
we reconstruct from the sensitive mapping with PACS and SPIRE and subsequent SED
modelling. |
