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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evolution from AGB to planetary nebula in the MSX survey

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Author(s):
Ortiz, R. ; Lorenz-Martins, S. ; Rangel, E. M. ; Maciel, W. J. [4]
Total Authors: 4
Document type: Journal article
Source: Astronomy & Astrophysics; v. 431, n. 2, p. 565-574, 2005.
Field of knowledge: Physical Sciences and Mathematics - Astronomy
Location: ARQUIVO FAPESP
Abstract

We investigate the evolution of oxygen- and carbon-rich AGB stars, post-AGB objects, and planetary nebulae using data collected mainly from the MSX catalogue. Magnitudes and colour indices are compared with those calculated from a grid of synthetic spectra that describe the post-AGB evolution beginning at the onset of the superwind. We find that carbon stars and OH/IR objects form two distinct sequences in the ( K-[8.3] [8.3]-[14.7]) MSX colour diagram. OH/IR objects are distributed in two groups: the bluest ones are crowded near [14.7]-[ 21.3 and [8.3]-[ 14.7 , and a second, redder group is spread over a large area in the diagram, where post-AGB objects and planetary nebulae are also found. High mass-loss rate OH/IR objects, post-AGB stars, and planetary nebulae share the same region in the ( K-[8.3] [8.3]-[14.7]) and [14.7]-[ 21.3 [8.3]-[14.7]) colour-colour diagrams. This region in the diagram is clearly separated from a bluer one where most OH/IR stars are found. We use a grid of models of post-AGB evolution, which are compared with the data. The gap in the colour-colour diagrams is interpreted as the result of the rapid trajectory in the diagram of the stars that have just left the AGB. (AU)

FAPESP's process: 02/08816-5 - Photoionized nebulae, stars and the chemical evolution of galaxies
Grantee:Walter Junqueira Maciel
Support type: Research Projects - Thematic Grants