The explosion energy of early stellar populations: The Fe-peak element ratios in low metallicity damped Lyman-alpha systems

Abstract

The relative abundances of the Fe-peak elements (Ti-Zn) at the lowest metallicities are intimately linked to the physics of core-collapse supernova explosions. With a sample of 25 very metal-poor damped Lyman-alpha systems, we investigate the trends of the Fe-peak element ratios with metallicity. For nine of the 25 DLAs, a direct measurement (or useful upper limit) of one or more of the Ti,Cr,Co,Ni,Zn/Fe abundance ratios could be determined from detected absorption lines. For the remaining systems (without detections), we devised a new form of spectral stacking to estimate the typical Fe-peak element ratios of the DLA population in this metallicity regime. We compare these data to analogous measurements in metal-poor stars of the Galactic halo and to detailed calculations of explosive nucleosynthesis in metal-free stars. We conclude that most of the DLAs in our sample were enriched by stars that released an energy of < 1.2 x 10^51 erg when they exploded as core-collapse supernovae. Finally, we discuss the exciting prospect of measuring Fe-peak element ratios in damped Lyman-alpha systems with Fe/H < 1/1000 of solar when 30-m class telescopes become available. Only then will we be able to pin down the energy that was released by the supernovae of the first stars.

13 pages, 6 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society

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Cited by in corpus (13)

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• The most metal-poor damped Lyman alpha systems: An insight into dwarf galaxies at high redshift
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• Discovery of the most metal-poor damped Lyman-alpha system
• Chemical abundances of damped Lyman alpha systems in the XQ-100 survey
• A Community Science Case for E-ELT HIRES
• The Mean Metal-line Absorption Spectrum of DLAs in BOSS
• Oxygen and zinc abundances in 417 Galactic bulge red giants
• Towards ultra metal-poor DLAs: linking the chemistry of the most metal-poor DLA to the first stars
• Empirical Constraints on Core Collapse Supernova Yields using Very Metal Poor Damped Lyman Alpha Absorbers
• The Chemical Evolution of Very Metal-Poor Damped Lyman-$\alpha$ Systems
• The Physical Nature of the Most Metal-Poor Damped Lyman Alpha Systems