One of the early discoveries made with Herschel during the science demonstration phase is the fascinating omnipresence of filamentary structures in the cold interstellar medium and the apparently intimate relationship between the filaments and the formation process of prestellar cloud cores. Our first results from the Gould Belt survey in the Aquila Rift and Polaris Flare regions suggest a picture of core formation according to which filaments form first in the diffuse ISM, probably as a result of interstellar turbulence, and then prestellar cores arise from gravitational fragmentation of the densest filaments. To get further insight into the formation of prestellar cores, it is crucial to clarify the origin and nature of the filaments seen in the wide-field SPIRE/PACS images. Here, we propose follow-up observations of the central parts of two selected filaments with the SPIRE and PACS spectrometers to characterize the physical conditions of thegas and test the hypothesis that the filaments are formed behind low-velocity interstellar shock waves associated with the dissipation of turbulent energy.If this is indeed the case, we expect to detect a number of emission lines such as CII (at 158 microns) andCI (at 609 microns), and several high-J CO lines which are primary coolants of the postshock gas.
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, andre et al., 2012, 'Follow-up spectroscopy of two selected filaments found in the Herschel Gould Belt Survey:A turbulent shock origin ?', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-otwt9r0
