The nearby evolved stars survey – I. JCMT/SCUBA-2 submillimetre detection of the detached shell of U Antliae

van Loon, Jacco Th

Abstract

We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at $450$ and $850\,µ\rm m$ with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at $850\,µ\rm m$ peaks at 40 arcsec with hints of a second peak seen at ~20 arcsec. The emission can be traced out to a radius of 56 arcsec at a 3s level. The outer peak observed at $850\,µ\rm m$ aligns well with the peak observed at Herschel/PACS wavelengths. With the help of spectral energy distribution fitting and radiative transfer calculations of multiple-shell models for the circumstellar envelope, we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope. We determine a total shell dust mass of (2.0 ± 0.3) × 10-5 M? and established that the thermal pulse that gave rise to the detached shell occurred 3500 ± 500 yr ago.

Citation

van Loon, J. T. (2019). The nearby evolved stars survey – I. JCMT/SCUBA-2 submillimetre detection of the detached shell of U Antliae. Monthly Notices of the Royal Astronomical Society, 3218 -3231. https://doi.org/10.1093/mnras/stz2334

• Acceptance Date: Aug 5, 2019
• Publication Date: Nov 1, 2019
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Pages: 3218 -3231
• DOI: https://doi.org/10.1093/mnras/stz2334
• Keywords: stars: AGB and post-AGB – stars: circumstellar matter – stars: massloss – stars: individual: U Ant
• Publisher URL: https://doi.org/10.1093/mnras/stz2334