Gibson, Bradley Kenneth, Pilkington, K., Brook, C. B., Stinson, G. S. and Bailin, J. (2013) Constraining sub-grid physics with high-redshift spatially-resolved metallicity distributions. Astronomy & Astrophysics, 554 . A47. ISSN 0004-6361
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Official URL: http://dx.doi.org/10.1051/0004-6361/201321239
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 similar to 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.
|Uncontrolled Keywords (separate with ;):||galaxies: abundances; galaxies: evolution; galaxies: formation; Galaxy: disk|
|Subjects:||Physical sciences > Astronomy|
|Schools:||Faculty of Science and Technology > School of Physical Sciences and Computing > Jeremiah Horrocks Institute|
|Deposited By:||Paul Harrison|
|Deposited On:||04 Aug 2014 13:22|
|Last Modified:||24 Oct 2016 07:13|
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