The properties of very young star-forming cores are difficult to trace. Many of their physical parameters still need to be refined observationally, before a meaningful modelling can advance. The Herschel satellite provides access to the wavelength regime where the bulk of emission arises for such objects. We plan to employ the two versatile spectrographs SPIRE-FTS and PACS-Spec in order to scrutinise ^en very young protostars comprising a larger range of masses and luminosities. The selected objects have been revealed as promisinging targets within our Herschel GT project EPoS. Our goals are three-fold: (1) We want to recover emission from molecular species like CO and HCO+ with SPIRE-FTS, which in combination with ground-based data enables an excitation analysis and constraints for line transfer and structure modelling. (2) We want to reveal the slope of the sub-mm continuum emission with FTS low-res spectra, which gives us a handle on the related dust emissivities. This is crucial to lift the degeneracy between column density, temperature, and dust emissivity, which usually renders an interpretation of sub-mm continuum maps ambiguous. (3) With the PACS spectroscopy for a sub-sample of two objects we want to trace the most important cooling lines of oxygen, carbon, and water to assess the thermal budget for these object stages. Of special importance is the measurement of the OI 63.2 micron line strength. This line gives a more direct access to the true outflow rate than common CO observations and is thus an important tool to characterise our targets which all are known to drive outflows.
Publication
The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder - II. Estimating radial velocity of SPIRE spectral observation sources | Scott Jeremy P. et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2020MNRAS.496.4894S |
Herschel was launched on 14 May 2009! It is the fourth cornerstone mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
European Space Agency, linz et al., 2013, 'Herschel spectroscopy for very young star-forming cores: excitation, outflows, and dust emissivity', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-g5rwiv2
