Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The oxygen abundance in the IFU era   Spatially-resolved information of gas-phase emission provided by integral
field units (IFUs) are allowing us to perform a new generation of emission-line
surveys, based on large samples of HII regions and full two-dimensional
coverage. Here we present two highlights of our current studies employing this
technique: 1) A statistical approach to the abundance gradients of spiral
galaxies, which indicates an -universal- radial gradient for oxygen abundance;
and 2) The discovery of a new scaling relation of HII regions in spiral
galaxies, the "local" mass-metallicity relation of star-forming galaxies.

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The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
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The categories of this paper are: eess
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat