Query : 2011A&A...530A..78T

2011A&A...530A..78T - Astronomy and Astrophysics, volume 530A, 78-78 (2011/6-1)

Implications of a non-universal IMF from C, N, and O abundances in very metal-poor galactic stars and damped Lyα absorbers.


Abstract (from CDS):

Recently revealed C, N, and O abundances in the most metal-poor damped Lyα (DLA) absorbers are compared with those of extremely metal-poor stars in the Galactic halo, as well as extragalactic H II regions, to decipher nucleosynthesis and chemical enrichment in the early Universe. These comparisons surprisingly identify a relatively high C/O ratio and a low N/O ratio in DLA systems, which is hard to explain theoretically. We propose that if these features are confirmed by future studies, this effect occurs because the initial mass function in metal-poor DLA systems has a cut-off at the upper mass end at around 20-25M, thus lacks the massive stars that provide the nucleosynthesis products leading to the low C/O and high N/O ratios. This finding is a reasonable explanation of the nature of DLA systems in which a sufficient amount of cold HI gas remains intact because of the suppression of ionization by massive stars. In addition, our claim strongly supports a high production rate of N in very massive stars, which might be acceptable in light of the recent nucleosynthesis calculations with fast rotation models. The updates of both abundance data and nucleosynthesis results will strengthen our novel proposition that the C/O and N/O abundances are a powerful tool for inferring the form of the initial mass function.

Abstract Copyright:

Journal keyword(s): stars: abundances - galaxies: abundances - galaxies: evolution - galaxies: ISM

Simbad objects: 5

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Number of rows : 5
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 12169 1
2 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 6630 1
3 M 99 H2G 12 18 49.625 +14 24 59.36 10.45 10.44 9.87     ~ 872 2
4 M 51 GiP 13 29 52.698 +47 11 42.93   9.26 8.36 8.40   ~ 4191 4
5 M 83 SBG 13 37 00.91920 -29 51 56.7400 8.85 8.11 7.52 7.21   ~ 2471 2

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