Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-02-06
Astronomy and Astrophysics
Astrophysics
9 pages, 4 figures, accepted for publication in Astronomy and Astrophysics
Scientific paper
10.1051/0004-6361:20054328
To constrain the conditions for very early nucleosynthesis in the Universe we compare the chemical enrichment pattern of an extremely metal-poor damped Lyman alpha (DLA) absorber with predictions from recent explosive nucleosynthesis model calculations. For this, we have analyzed chemical abundances in the DLA system at z_abs=2.6183 toward the quasar Q0913+072 (z_em=2.785) using public UVES/VLT high spectral resolution data. The total neutral hydrogen column density in this absorber is logN(HI)=20.36. Accurate column densities are derived for CII, NI, OI, AlII, SiII, and FeII. Upper limits are given for FeIII and NiII. With [C/H]=-2.83, [N/H]=-3.84, and [O/H]=-2.47, this system represents one of the most metal-poor DLA systems investigated so far. It offers the unique opportunity to measure accurate CNO abundances in a protogalactic structure at high redshift. Given the very low overall abundance level and the observed abundance pattern, the data suggest that the chemical evolution of this DLA system is dominated by one or at most a few stellar generations. With reference to numerical model calculations, the chemical abundances in the DLA system are consistent with an enrichment from a single starburst of a zero-metallicity population of massive stars (10-50 M_sun) exploding as core-collapse Supernovae (SNe), i.e., the classical Type II Supernovae (SNeII), and possibly as hyper-energetic (E>10^51erg) core-collapse Supernovae, so-called Hypernovae (HNe), as well. In contrast, models using non-zero metallicity progenitors or other explosion mechanisms, such as pair-instability Supernovae (PISNe) or Type Ia Supernovae (SNeIa), do not match the observed abundance pattern.
Erni Peter
Ledoux Cedric
Petitjean Patrick
Richter Philipp
No associations
LandOfFree
The most metal-poor damped Ly alpha system at z<3: constraints on early nucleosynthesis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The most metal-poor damped Ly alpha system at z<3: constraints on early nucleosynthesis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The most metal-poor damped Ly alpha system at z<3: constraints on early nucleosynthesis will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-730446