What is this MESS?

MESS is a Guaranteed Time Key Programme for the Herschel Space Observatory.

"The circumstellar environment in post-main-sequence objects"

Proposal ID: KPGT_mgroen01_1

Martin Groenewegen, K.U. Leuven, Mike Barlow, University College London, Franz Kerschbaum, University of Vienna, Joris Blommaert, Institute for Astronomy, KU Leuven, Pedro Garcia Lario, ESA-ESAC, J. Cernicharo, CSIC, Spain, Oliver Krause , Max-Planck-Institut fuer Astronomie, Angela Baier, Univ. Vienna, Jeroen Bouwman, Max-Planck-Institut fuer Astronomie, Martin Cohen, Berkeley, USA, Leen Decin, K.U. Leuven, Thomas Henning, Max-Planck-Institut fuer Astronomie, Damien Hutsemekers, IAGL, Rob Iveson, UK ATC, Royal Observatory, Edinburgh, Djazia Ladjal, K.U. Leuven, Tanya Lim, Rutherford Appleton Laboratory, Goeran Olofsson, Stockholm University, Thomas Posch, Univ. Vienna, Gregor Rauw, IAGL, Pierre Royer, K.U. Leuven, Bruce Sibthorpe, Cardiff University, Bruce Swinyard, Rutherford Appleton Laboratory, Toshiya Ueta, Univ. Denver, Bart Vandenbussche, K.U. Leuven, Griet Van de Steene, Royal Observatory Brussels, Hans Van Winckel, K.U. Leuven, Eva Verdugo, ESA-ESAC, Christoffel Waelkens, K.U. Leuven

Mass-loss is one of the most fundamental properties of post-main sequence evolution. The mass-loss process leads to the formation of circumstellar shells containing dust and molecules. Although the mass-loss phenomenon has been studied since the 1960s, and important results have been obtained with the IRAS, ISO and Spitzer space missions, the details of the mass-loss process and the formation and evolution of the circumstellar shells are still not well understood. With its improved spatial resolution compared to ISO and Spitzer, better sensitivity, the extension to longer and unexplored wavelength regions, and medium resolution spectrometers, the combination of PACS and SPIRE observations will lead to a significant improvement in our understanding of the phenomena of mass-loss and dust formation. The main aims of this programme are three-fold: (1) to study the time dependence of the mass-loss process, via a search for shells and multiple shells around a wide range of evolved objects, in order to quantify the total amounts of mass lost at the various evolutionary stages of low to high-mass stars, (2) to study the dust and gas chemistry as a function of progenitor mass, and (3) to study the properties and asymmetries of evolved star envelopes. To this end, a sample of 103 Asymptotic Giant Branch and Red Super Giants, post-AGB and Planetary Nebulae, Luminous Blue Variables and Wolf-Rayet stars, and 5 Supernovae remnants will be imaged with PACS at 70+170 micron, and a sub-set of 32 stars will be imaged at all 3 wavelengths with SPIRE. In spectroscopy, a sample of 55 stars will be observed over the full wavelength range of PACS and, 23 stars will be observed with the SPIRE FTS. The sample of AGB stars has been selected to cover all chemical types (M-, S-, C-stars), variability types (irregular, semi-regular, Miras) and periods, and mass-loss rates. Stars have been selected to have high IRAS fluxes and low background levels. The spectroscopic targets are typically the brightest of the mapping targets.

Read the project proposal to see what it's all about. Enjoy!
     
University of Vienna, Department of Astronomy, A-1180 Wien