Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Type Ia supernovae and the formation history of early-type galaxies   Using the standard prescription for the rates of supernovae type II and type
Ia, we compare the predictions of a simple model of star formation in galaxies
with the observed radial gradients of abundance ratios in a sample of
early-type galaxies to infer the relative contribution of each type of
supernova. The data suggests a correlation between the fractional contribution
of Type Ia to the chemical enrichment of the stellar populations (1-xi) and
central velocity dispersion of order 1-xi ~ -0.16log sigma_0+0.40, so that the
type Ia contribution in stars ranges from a negligible amount in massive
galaxies up to 10% in low-mass systems. Our model is parametrized by a star
formation timescale (t_SF) which controls the duration of the starburst. A
correlation with galaxy radius as a power law (t_SF ~ r^beta) translates into a
radial gradient of the abundance ratios. The data implies a wide range of
formation scenarios for a simple model that fixes the luminosity profile,
ranging from inside-out (beta=2), to outside-in formation (beta=-1), as is
consistent with numerical simulations of elliptical galaxy formation. An
alternative scenario that links t_SF to the dynamical timescale favours
inside-out formation over a smaller range. In both cases, massive galaxies are
predicted to have undergone a more extended period of star formation in the
outer regions with respect to their low-mass counterparts.

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The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
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The categories of this paper are: math
17
The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio