Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutronization During Carbon Simmering In Type Ia Supernova Progenitors   When a Type Ia supernova (SN Ia) progenitor first ignites carbon in its core,
it undergoes ${\sim} \,10^{3}-10^{4} \,$yr of convective burning prior to the
onset of thermonuclear runaway. This carbon simmering phase is important for
setting the thermal profile and composition of the white dwarf. Using the
\texttt{MESA} stellar evolution code, we follow this convective burning and
examine the production of neutron-rich isotopes. The neutron content of the SN
fuel has important consequences for the ensuing nucleosynthesis, and, in
particular, for the production of secondary Fe-peak nuclei like Mn and stable
Ni. These elements have been observed in the X-ray spectra of SN remnants like
Tycho, Kepler, and 3C 397, and their yields can provide valuable insights into
the physics of SNe Ia and the properties of their progenitors. We find that
weak reactions during simmering can at most generate a neutron excess of
${\approx} \, 3 \times 10^{-4}$. This is ${\approx} \, 8 \times 10^{-4}$ lower
than that found in previous studies that do not take the full density and
temperature profile of the simmering region into account. Our results imply
that the progenitor metallicity is the main contributor to the neutron excess
in SN Ia fuel for $Z \gtrsim 1/3 \, Z_{\odot}$. Alternatively, at lower
metallicities, this neutron excess provides a floor that should be present in
any centrally-ignited SN~Ia scenario.

3
The categories of this paper are: physics
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol