|Stellar Disk Evolution
|AbstractIn a collaboration between the HSC, P. Harvey (Mission Scientist) and the three instrument consortia we propose to apply the full power of Herschel to investigate the properties of circum-stellar disks. The versatility of Herschel allows us to address several key questions: How do the disks evolve with time? Planets clearly form out of circum-stellar disks and there is growing evidence that the time scale is short, 1 - 10 Myr, for the main accretion phase. During this time period, the stellar radiation and stellar winds clean the disks from most of their dust and gas, eventually making them transparent. However, collisions and evaporation from comet- like bodies will continue to produce dust and gas. This activity declines with time, and we will pursue this scenario by observing a sample of IR excess stars of known age, ranging from a few million years to the age of the sun. Are there analogues to our Kuiper belt around nearby stars? The Kuiper belt is a dust belt surrounding the Sun, located outside the orbit of Neptune, which has a key role in stabilizing orbits of the KE-objects and this dynamical aspect makes it particularly interesting to search for stars that may host KE-belt analogues. Herschel offers a unique sensitivity beyond 100 m and we propose an extensive survey of nearby stars seeking cold dust emission. What will a closer IR look at the Fabulous Four (and some other resolved disks) reveal? Several nearby MS stars with IR excesses have circumstellar dust structures that can be resolved by Herschel. Imaging these structures in the six PACS+SPIRE bands will enable us to explore the dust properties, notably the size distribution and albedo. What is the composition of young disks? We propose a detailed spectroscopic investigation of four bright disks, including a full spectral scan with PACS, an FTS scan at full resolution and HIFI observations of selected frequencies. The ai...m is to constrain the properties of both the dust and gas components.
|Herschel-PACS observations of far-IR lines in young stellar objects. I. [OI] and H2O at 63 μm . Riviere-Marichalar P. et al. . Astronomy & Astrophysics, Volume 594, id.A59, 25 pp. . 594 . 10.1051/0004-6361/201527829 . 2016A&A...594A..59R ,
Stellar multiplicity and debris discs: an unbiased sample . Rodriguez David R. et al. . Monthly Notices of the Royal Astronomical Society, Volume 449, Issue 3, p.3160-3170 . 449 . 10.1093/mnras/stv483 . 2015MNRAS.449.3160R ,
|HIFI_HifiPoint_fs, SPIRE_SpireSpectrometer_, PACS_PacsRangeSpec_point, SPIRE_SpirePhoto_large, PACS_PacsLineSpec_point, PACS_PacsPhoto_largeScan
|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, KPGT_golofs01_1, SPG v14.2.0. https://doi.org/10.5270/esa-pkzl4xe