Abstract

VERBENA, J. L.; JEYAKUMAR, S.; SCHRODER, K.-P.  and  WACHTER, A.. Probing the cool outer envelope of NGC 6826 and its previous mass-loss history. Rev. mex. astron. astrofis [online]. 2016, vol.52, n.2, pp.271-282. ISSN 0185-1101.

We made a direct, quantitative comparison between theoretical and observed density profiles of the planetary nebula NGC 6826. For this, we observed the optically thin 13CO(J=1-0) and 13CO(J=2-1) rotational transition lines at a projected radial distance from the central star of 60′′ and 75′′. The line strengths and ratios observed at the inner point, and the upper limits observed at the outer point, are consistent with density profiles predicted by mass-loss histories computed from our evolution models when non-LTE radiative transfer and the conditions of collisional excitation in the envelope are taken into account.

Keywords : planetary nebulae: individual (NGC 6826); stars: AGB and post-AGB; stars: mass-loss.

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