|Molecular complexity of the O-rich pre-Planetary Nebula OH231.8
|sanchez contreras, c.
|Envelopes around evolved stars are extraordinarily efficient factories of complex molecules and dust particles that will eventually enrich the ISM. To date, most chemistry studies have focused on C-rich envelopes, expected to show the largest molecular variety and abundances. Recent observations suggest that O-rich shells may be as chemically diverse as their Carbon counterparts, however, no serious attempt has been made yet to perform a full frequency scan of such objects. We propose to carry out a line survey with HIFI of the well known, O-rich pre-PN OH 231.8, which displays fast (&amp;gt;400 km-s), bipolar outflows and a molecular richness unparalleled amongst O-rich AGB and post-AGB stars. Results from our exploratory mm line survey with the IRAM 30 m antenna of this object has led to the detection of hundreds of lines from different species that clearly point to non-equilibrium-shock-induced molecule formation processes in the fast flow. The HIFI could be potentially effective to reveal the dense and warm regions near the centre, which is strongly affected by shocks. At its completion, this project will provide the sorely needed molecular inventory and abundance measurements in O-rich CSEs, which are required to obtain a better understanding of the intricate, non-equilibrium molecule formation processes in O-rich environments. We will use our radiative transfer and chemistry models to reproduce the observed spectra and empirically derived abundances, respectively, and constrain the nebular physical and chemical conditions in the envelope of OH231.
|Molecular ions in the O-rich evolved star OH231.8+4.2: HCO+, H13CO+ and first detection of SO+, N2H+, and H3O+ . Sánchez Contreras C. et al. . Astronomy & Astrophysics, Volume 577, id.A52, 22 pp. . 577 . 10.1051/0004-6361/201525652 . 2015A&A...577A..52S ,
|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, 2012, OT1_csanch01_1, SPG v14.1.0. https://doi.org/10.5270/esa-0mlcgeb