| Description |
Dark clouds are condensations of the ISM that are detected as silhouettesagainst 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 cloudSandqvist 187/188, also known as the Norma cloud. It hosts a number of low-massprotostellar objects, among which is a FU Ori star (V346 Nor). 1.2 mm continuumobservations resulted in detecting 6 embedded sources that appear to beprotostellar objects at different evolutionary stages. However additional data,especially at far-IR wavelengths, that are crucial to derive basic physicalproperties like temperature, luminosity, density and mass were insufficient sofar, both in sensitivity and spatial resolution, to construct meaningful sourceSEDs. In addition, the global properties of the Norma cloud are also not wellknown. Current estimates of its density and mass are mainly based on millimetrecontinuum observations assuming a typical and uniform temperature. Therefore,we want to observe the star forming sites in this cloud with PACS and SPIREimaging. The unique combination of sensitivity and spatial resolution at far-IRwavelengths provided by the Herschel Space Observatory and its instruments willbe the key for determining the still badly constrained properties we are eagerto obtain. With the proposed observations we want to i) fill the gaps in theSEDs of the embedded objects, ii) constrain their basic properties, iii) derivetheir evolutionary stage, and iv) construct a census of the star formationactivity in the Norma cloud. In addition, we want to investigate the propertiesof the ISM surrounding these objects. In particular, we are interested in thetemperature and density profiles of the dust around the embedded sources thatwe reconstruct from the sensitive mapping with PACS and SPIRE and subsequent SEDmodelling. |
