J/A+A/677/A174 Proto-neutron star inner crust (Dinh Thi+, 2023)
The proto-neutron star inner crust in a multi-component plasma approach.
Dinh Thi H., Fantina A.F., Gulminelli F.
<Astron. Astrophys. 677, A174 (2023)>
=2023A&A...677A.174D 2023A&A...677A.174D (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: stars: neutron - dense matter - plasmas - equation of states
Abstract:
Proto-neutron stars are born hot, with temperatures exceeding a few
times 1010K. In these conditions, the crust of the proto-neutron
star is expected to be made of a Coulomb liquid and composed of an
ensemble of different nuclear species.
In this work, we perform a study of the beta-equilibrated
proto-neutron-star crust in the liquid phase in a self-consistent
multicomponent approach. This also allows us to perform a consistent
calculation of the impurity parameter, which is often taken as a free
parameter in cooling simulations.
To this aim, we developed a self-consistent multi-component approach
at finite temperature using a compressible liquid-drop description of
the ions, with surface parameters adjusted to reproduce experimental
masses. The treatment of the ion centre-of mass motion was included
through a translational free-energy term accounting for in-medium
effects. The results of the self-consistent calculations of the
multi-component plasma are systematically compared with those
performed in a perturbative treatment as well as in the one-component
plasma approximation.
We show that the inclusion of non-linear mixing terms arising from the
ion centre-of-mass motion leads to a breakdown of the ensemble
equivalence between the one-component and multi-component approach.
Our findings also illustrate that the abundance of light nuclei
becomes important and eventually dominates the whole distribution at
higher density and temperature in the crust. This is reflected in the
impurity parameter, which, in turn, may have a potential impact on
neutron-star cooling. For practical application to astrophysical
simulations, we also provide a fitting formula for the impurity
parameter in the proto-neutron-star inner crust. Our results obtained
within a self-consistent multi-component approach show important
differences in the prediction of the proto-neutron-star composition
with respect to those obtained with a one-component approximation or a
perturbative multicomponent approximation, particularly in the deeper
region of the crust. This highlights the importance of a full,
self-consistent multi-component plasma calculation for reliable
predictions of the proto- neutron-star crust composition.
Description:
The impurity parameter obtained in a self-consistent multi-component
plasma approach at equilibrium is presented.
For each value of baryon density in the range relevant for the inner
crust of a non-accreting neutron star, the pressure, the temperature
and the impurity parameter at the corresponding temperature are given.
The crystallisation temperature has been evaluated using Eq.(49) in
the paper. The calculations have been performed using the BSk24
empirical parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
q0p5mev.dat 49 21 Baryon number density, pressure, temperature,
and impurity parameter at kB*T=0.5MeV
q1mev.dat 49 24 Baryon number density, pressure, temperature,
and impurity parameter at kB*T=1MeV
q1p5mev.dat 49 38 Baryon number density, pressure, temperature,
and impurity parameter at kB*T=1.5MeV
q2mev.dat 49 33 Baryon number density, pressure, temperature,
and impurity parameter at kB*T=2MeV
qtm.dat 49 21 Baryon number density, pressure, temperature,
and impurity parameter at the crystallisation
temperature
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Byte-by-byte Description of file: q0p5mev.dat q1mev.dat q1p5mev.dat q2mev.dat
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Bytes Format Units Label Explanations
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1- 10 E10.4 1/fm3 nb Baryon density (G1)
14- 23 E10.4 dPa P Pressure (G1)
27- 36 E10.4 K T Temperature (G1)
40- 49 E10.4 --- Qimp Impurity parameter at T (G1)
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Byte-by-byte Description of file: qtm.dat
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Bytes Format Units Label Explanations
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1- 10 E10.4 1/fm3 nb Baryon density (G1)
14- 23 E10.4 dPa P Pressure (G1)
27- 36 E10.4 K Tm Crystallisation temperature (G1)
40- 49 E10.4 --- Qimp Impurity parameter at Tm (G1)
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Global notes:
Note (G1): The SI unit dPa is equivalent to the CGS unit erg/cm3 or
equivalent to dyn/cm2.
The conversion factor between the nuclear units for the pressure (MeV/fm3)
and the SI unit dPa is 1.6021766e33.
The conversion factor between the nuclear units for the temperature
(kB*T in MeV) and K is 11604525006.
The impurity parameter is dimensionless.
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Acknowledgements:
Anthea Fantina, anthea.fantina(at)ganil.fr
References:
Dinh Thi, Fantina & Gulminelli, 2023A&A...672A.160D 2023A&A...672A.160D
Gulminelli & Raduta, 2015PhRvC..92e5803G 2015PhRvC..92e5803G
Fantina, de Ridder, Chamel & Gulminelli, 2020A&A...633A.149F 2020A&A...633A.149F
Carreau, Gulminelli, Chamel, Fantina & Pearson, 2020A&A...635A..84C 2020A&A...635A..84C
Haensel, Potekhin & Yakovlev, 2007ASSL..326.....H 2007ASSL..326.....H
Goriely, Chamel & Pearson, 2013PhRvC..88b4308G 2013PhRvC..88b4308G
(End) H. Dinh Thi [LPC Caen], A.F. Fantina [GANIL], P. Vannier [CDS] 29-Jul-2023