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
Publication
Deconvolution of Images from BLAST 2005: Insight into the K3-50 and IC 5146 Star-forming Regions . Roy Arabindo et al. . The Astrophysical Journal, Volume 730, Issue 2, article id. 142, 12 pp. (2011). . 730 . 10.1088/0004-637X/730/2/142 . 2011ApJ...730..142R , Interstellar and Ejecta Dust in the Cas A Supernova Remnant . Arendt Richard G. et al. . The Astrophysical Journal, Volume 786, Issue 1, article id. 55, 22 pp. (2014). . 786 . 10.1088/0004-637X/786/1/55 . 2014ApJ...786...55A , The dust mass in Cassiopeia A from a spatially resolved Herschel analysis . De Looze I. et al. . Monthly Notices of the Royal Astronomical Society, Volume 465, Issue 3, p.3309-3342 . 465 . 10.1093/mnras/stw2837 . 2017MNRAS.465.3309D , The dust budget crisis in high-redshift submillimetre galaxies . Rowlands K. et al. . Monthly Notices of the Royal Astronomical Society, Volume 441, Issue 2, p.1040-1058 . 441 . 10.1093/mnras/stu605 . 2014MNRAS.441.1040R , The Footprint Database and Web Services of the Herschel Space Observatory . Dobos László et al. . Experimental Astronomy, Volume 42, Issue 2, pp.139-164 . 42 . 10.1007/s10686-016-9502-5 . 2016ExA....42..139D , Near-infrared Extinction due to Cool Supernova Dust in Cassiopeia A . Lee Yong-Hyun et al. . The Astrophysical Journal, Volume 808, Issue 1, article id. 98, 14 pp. (2015). . 808 . 10.1088/0004-637X/808/1/98 . 2015ApJ...808...98L , A Herschel PACS and SPIRE study of the dust content of the Cassiopeia A supernova remnant . Barlow M. J. et al. . As...tronomy and Astrophysics, Volume 518, id.L138, 5 pp. . 518 . 10.1051/0004-6361/201014585 . 2010A&A...518L.138B ,
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.
