| 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. |
