Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Galaxy Mergers and the Mass-Metallicity Relation: Evidence for Nuclear
  Metal Dilution and Flattened Gradients from Numerical Simulations   Recent results comparing interacting galaxies to the mass-metallicity
relation show that their nuclear oxygen abundances are unexpectedly low. We
present analysis of N-body/SPH numerical simulations of equal-mass mergers that
confirm the hypothesis that these underabundances are accounted for by radial
inflow of low-metallicity gas from the outskirts of the two merging galaxies.
The underabundances arise between first and second pericenter, and the
simulated abundance dilution is in good agreement with observations. The
simulations further predict that the radial metallicity gradients of the disk
galaxies flatten shortly after first passage, due to radial mixing of gas.
These predictions will be tested by future observations of the radial
metallicity distributions in interacting galaxies.

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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin