|TIME VARIABILITY OF THERMAL MOLECULAR LINE EMISSION IN IRC+10216
|We have found during our GT line survey of IRC+10216 and the search for hydrides (OT1 proposal) that some molecular lines present a strong intensity variation with time due to the role of infrared pumping. For some lines the intensity change in six months reaches a factor 3 (CCH). We have checked that the effect is not instrumental and than it arises from physical processes ignored so far in the radiative transfer models. We propose to observe the CCH and HNC lines within bands 1a-5b of HIFI every four months (three observing slots) to allow a detailed study of the variation of thermal molecular emission, and dust emission, in this prototype of AGB C-rich object. The settings will also provide, as a bonus, many lines of SiO, SiS, CS, HCN, CO and 13CO for which intensity variations of up to 30% have been found. In addition, a few specificc settings for HCN and CO will complete the observations. SPIRE and PACS observations will complement, with lower spectral resolution, the whole spectrum of each of these molecules and will provide a global view of the total intensity change of these lines with time. A crude estimate of the distance could be also obtained from the observed time lags between the blue and red parts of the line profiles observed with HIFI.
|Discovery of Time Variation of the Intensity of Molecular Lines in IRC+10216 in the Submillimeter and Far-Infrared Domains . Cernicharo J. et al. . The Astrophysical Journal Letters, Volume 796, Issue 1, article id. L21, 6 pp. (2014). . 796 . 10.1088/2041-8205/796/1/L21 . 2014ApJ...796L..21C ,
|HIFI_HifiPoint_dbs, SPIRE_SpireSpectrometer_, PACS_PacsRangeSpec_point
|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_jcernich_9, SPG v14.2.0. https://doi.org/10.5270/esa-ypjt5sm