other query modes : |
Identifier query |
Coordinate query |
Criteria query |
Reference query |
Basic query |
Script submission |
TAP |
Output options |
Object types |
Help |
2012MNRAS.419.1254R - Mon. Not. R. Astron. Soc., 419, 1254-1270 (2012/January-2)
Chemical composition of a sample of candidate post-asymptotic giant branch stars.
RAO S.S., GIRIDHAR S. and LAMBERT D.L.
Abstract (from CDS):
We have also made a contemporary abundance analysis of the high Galactic latitude supergiants BD+39°4926 and HD 107369. The former is heavily depleted in refractories and estimated [Zn/H] of -0.7 dex most likely gives initial metallicity of the star. For HD 107369 the abundances of α and Fe-peak elements are similar to those of halo objects and moderate deficiency of s-process elements is seen. IRAS 07140-2321, despite being a short-period binary with a circumstellar shell, does not exhibit selective depletion of refractory elements.
We have compiled the stellar parameters and abundances for post-AGB stars with s-process enhancement, those showing significant depletion of condensable elements and those showing neither. The compilation shows that the s-process-enhanced group contains a very small number of binaries, and observed [α/Fe] are generally similar to thick-disc values. It is likely that they represent AGB evolution of single stars.
The compilation of the depleted group contains a larger fraction of binaries and generally supports the hypothesis of dusty discs surrounding binary post-AGB stars inferred via the shape of their spectral energy distribution and mid-infrared interferometry. IRAS 07140-2321 and BD+39°4926 are difficult to explain with this scenario and indicate the existence of an additional parameter/condition needed to explain the depletion phenomenon. However, the conditions for discernible depletion, minimum temperature of 5000 K and initial metallicity larger than -1.0 dex found from our earlier work still serve as useful criteria.
Abstract Copyright: 2011 The Authors Monthly Notices of the Royal Astronomical Society2011 RAS
Journal keyword(s): stars: abundances - stars: AGB and post-AGB - stars: atmospheres - circumstellar matter - stars: evolution
Simbad objects: 99
To bookmark this query, right click on this link: simbad:2012MNRAS.419.1254R and select 'bookmark this link' or equivalent in the popup menu