Constraining sub-grid physics with high-redshift spatially-resolved metallicity distributions

Gibson, B. K.; Pilkington, K.; Brook, C. B.; Stinson, G. S.; Bailin, J.

Abstract

Aims. We examine the role of energy feedback in shaping the distribution of metals within cosmological hydrodynamical simulations of L*disc galaxies. While negative abundance gradients today provide a boundary condition for galaxy evolution models, in support of inside-out disc growth, empirical evidence as to whether abundance gradients steepen or flatten with time remains highly contradictory. Methods. We made use of a suite of L*discs, realised with and without "enhanced" feedback. All the simulations were produced using the smoothed particle hydrodynamics code Gasoline, and their in situ gas-phase metallicity gradients traced from redshift z ∼ 2 to the present-day. Present-day age-metallicity relations and metallicity distribution functions were derived for each system. Results. The "enhanced" feedback models, which have been shown to be in agreement with a broad range of empirical scaling relations, distribute energy and re-cycled ISM material over large scales and predict the existence of relatively "flat" and temporally invariant abundance gradients. Enhanced feedback schemes reduce significantly the scatter in the local stellar age-metallicity relation and, especially, the [O/Fe]-[Fe/H] relation. The local [O/Fe] distribution functions for our L*discs show clear bimodality, with peaks at [O/Fe] = -0.05 and + 0.05 (for stars with [Fe/H] > -1), consistent with our earlier work on dwarf discs. Conclusions. Our results with "enhanced" feedback are inconsistent with our earlier generation of simulations realised with "conservative" feedback. We conclude that spatially-resolved metallicity distributions, particularly at high-redshift, offer a unique and under-utilised constraint on the uncertain nature of stellar feedback processes. © 2013 ESO.

Citation

Gibson, B. K., Pilkington, K., Brook, C. B., Stinson, G. S., & Bailin, J. (2013). Constraining sub-grid physics with high-redshift spatially-resolved metallicity distributions. Astronomy and Astrophysics, 554, A47. https://doi.org/10.1051/0004-6361/201321239

• Journal Article Type: Article
• Acceptance Date: Apr 5, 2013
• Online Publication Date: Jun 4, 2013
• Publication Date: Jun 11, 2013
• Deposit Date: Aug 6, 2018
• Journal: ASTRONOMY & ASTROPHYSICS
• Print ISSN: 0004-6361
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 554
• Article Number: ARTN A47
• Pages: A47
• DOI: https://doi.org/10.1051/0004-6361/201321239
• Keywords: Galaxies: abundances; Galaxies: evolution; Galaxies: formation; Galaxy: disk
• Public URL: https://hull-repository.worktribe.com/output/541705
• Publisher URL: https://www.aanda.org/articles/aa/abs/2013/06/aa21239-13/aa21239-13.html