|When twins are not identical: a HIFI scan of IRAS15194-5115, the stellar twin of IRC+10216
|de beck, e.
|Currently, our knowledge of the chemistry occurring in the stellar atmospheres and circumstellar envelopes of AGB stars is far from being complete. A most powerful method to study the circumstellar chemistry is broadband spectral scans of individual sources. We propose here to perform a spectral scan of the high mass-loss rate carbon star IRAS15194-5115 in selected HIFI bands. Lines will be identified and radiative transfer modelling will be performed for most of the detected species to provide circumstellar abundances and isotope ratios. The results will be compared with those of similar spectral scans of other types of evolved objects, in particular IRC+10216, to address the efficiency of various chemical processes and their dependence on the evolution of the object. A comparison between isotope ratios determined for IRAS15194-5115 and IRC+10216 will be of special interest since these stars have most likely taken different evolutionary paths along the AGB. The proposed observations will improve our understanding of AGB stars and their role in the chemical evolution of galaxies.
|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.
|Publisher And Registrant
|European Space Agency
|European Space Agency, 2013, OT2_edebeck_2, SPG v14.1.0. https://doi.org/10.5270/esa-ttrm6vy