A dataset provided by the European Space Agency

Name OT2_rsahai_6
Title Probing the molecular disk in Y Gem: an AGB star with variable UV emission signifying accretion onto a binary companion


DOI 10.5270/esa-ebt3cs7
Author sahai, r.
Description We propose to observe CO J=6-5 and 9-8 line emission from a cool AGB star, Y Gem, which, in dramatic contrast to most objects in its class, has relatively strong and variable FUV and NUV fluxes - evidence of variable accretion of matter onto an accretion disk in a binary system. We found Y Gem as a UV source serendipitously, while combing the GALEX archive as part of a project to look for hot binary companions to cool AGB stars. This object may represent the earliest phases of an AGB star with a growing accretion disk which will produce collimated jets that are widely believed to sculpt the round circumstellar envelopes of AGB stars into bipolar planetary nebulae. It may evolve into a member of the class of post-AGB objects which show no extended outflows, but only circumbinary disks. HIFI observations of high-J CO lines are needed to probe the warmest and innermost circumstellar regions where the hypothesized accretion disk resides and jet launching may occur. Furthermore, the proposed CO observations, together with our existing CO J=2-1 data, will allow us to accurately constrain the CO excitation temperature, and the optical depths of the CO lines and thus the total mass of the emitting region. The disk or torus mass will provide an important constraint on its formation process (e.g., common envelope evolution or Bondi-Hoyle wind-accretion- Roche lobe overflow.)
Instrument HIFI_HifiPoint_dbs
Temporal Coverage 2012-09-20T19:40:36Z/2013-03-23T10:43:10Z
Version SPG v14.1.0
Mission Description 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 ┬Ám range, bridging the gap between earlier infrared space missions and groundbased facilities.
Creator Contact https://support.cosmos.esa.int/herschel/
Date Published 2013-09-23T09:06:18Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, 2013-09-23T09:06:18Z, OT2_rsahai_6, SPG v14.1.0. https://doi.org/10.5270/esa-ebt3cs7