1S0 Pairing Gaps, Chemical Potentials and Entrainment Matrix in Superfluid Neutron-Star Cores for the Brussels–Montreal Functionals

Allard, Valentin; Chamel, Nicolas

doi:10.3390/universe7120470

Cited by 11 publications

(18 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Full numerical results can be found in [45]. Together with the results for the equation of state and superfluid properties published in [15][16][17][18]43], they provide consistent microscopic inputs for modelling the magneto-thermal evolution of neutron stars.…”

Section: Discussionsupporting

confidence: 52%

“…To estimate the heat in Equation (53), we implicitly assumed µ(A, Z − 2, P β , B ) < µ(A, Z, P β , B ), which generally holds for even A nuclei, but not necessarily for odd A nuclei. In the latter case, we typically have (43), this implies that γ β e (A, Z) < γ β e (A, Z − 1). In other words, as the pressure reaches P β (A, Z, B ), the nucleus (A, Z) decays, but the daughter nucleus (A, Z − 1) is actually stable against electron capture, and therefore, no heat is released Q(A, Z, B ) = 0.…”

Section: Heat Releasedmentioning

confidence: 99%

“…The functional BSk24 underlying the model HFB-24 was also adopted to calculate the equation of state of the inner crust of a magnetar [18]. This same functional was also applied to construct a unified equation of state for unmagnetized neutron stars [15][16][17], and to calculate superfluid properties [43]. Results are publicly available on CompOSE 2 .…”

Section: Initial Composition Of the Outer Crustmentioning

confidence: 99%

See 2 more Smart Citations

Onset of Electron Captures and Shallow Heating in Magnetars

Chamel

Fantina

2022

Universe

Self Cite

View full text Add to dashboard Cite

The loss of magnetic pressure accompanying the decay of the magnetic field in a magnetar may trigger exothermic electron captures by nuclei in the shallow layers of the stellar crust. Very accurate analytical formulas are obtained for the threshold density and pressure, as well as for the maximum amount of heat that can be possibly released, taking into account the Landau–Rabi quantization of electron motion. These formulas are valid for arbitrary magnetic field strengths, from the weakly quantizing regime to the most extreme situation in which electrons are all confined to the lowest level. Numerical results are also presented based on experimental nuclear data supplemented with predictions from the Brussels-Montreal model HFB-24. This same nuclear model has been already employed to calculate the equation of state in all regions of magnetars.

show abstract

Section: Discussionsupporting

confidence: 52%

Section: Heat Releasedmentioning

confidence: 99%

Section: Initial Composition Of the Outer Crustmentioning

confidence: 99%

See 1 more Smart Citation

Onset of Electron Captures and Shallow Heating in Magnetars

Chamel

Fantina

2022

Universe

Self Cite

View full text Add to dashboard Cite

show abstract

“…We need to be mindful of the fact that the use of a realistic equation of state (within a fully relativistic calculation, following, for example, Lin, Andersson and Comer 2008) may shift the results. We also need to pay attention to the fact that aspects of the entrainment are still being discussed (Noel and Urban 2016;Delsate et al 2016;Watanabe and Pethick 2017;Sauls, Chamel and Alpar 2020;Allard and Chamel 2021). At the end of the day, the superfluid imprint on the tide is likely to remain small.…”

Section: Discussionmentioning

confidence: 99%

Dynamical tides in superfluid neutron stars

Passamonti,

Andersson,

Pnigouras

2022

Preprint

View full text Add to dashboard Cite

We study the tidal response of a superfluid neutron star in a binary system, focussing on Newtonian models with superfluid neutrons present throughout the star's core and the inner crust. Within the two-fluid formalism, we consider the main aspects that arise from the presence of different regions inside the star, with particular focus on the various interfaces. Having established the relevant theory, we determine the tidal excitation of the most relevant oscillation modes during binary inspiral. Our results suggest that superfluid physics has a negligible impact on the static tidal deformation. The overwhelming contribution to the Love number is given by, as for normal matter stars, the ordinary fundamental mode (f-mode). Strong entrainment, here described by a phenomenological expression which mimics the large effective neutron mass expected at the bottom of the crust, is shown to have significant impact on the superfluid modes, but our results for the dynamical tide are nevertheless similar to the static limit: the fundamental modes are the ones most significantly excited by the tidal interaction, with the ordinary f-mode dominating the superfluid one. We also discuss the strain built up in the star's crust during binary inspiral, showing that the superfluid f-mode may (depending on entrainment) reach the limit where the crust breaks, although it does so after the ordinary f-mode. Overall, our results suggest that the presence of superfluidity may be difficult to establish from binary neutron star gravitational-wave signals.

show abstract

“…We have recently studied the dynamics of hot neutron-proton superfluid mixtures with the self-consistent time-dependent nuclear energy density functional theory [15]. By applying it to neutron stars, we have computed 1 S 0 neutron and proton pairing gaps in the homogeneous core in the presence of arbitrary currents and we have determined the mutual neutron-proton entrainment coupling coefficients [16]. We have also shown within the same framework that there exists a dynamical "gapless" state in which nuclear superfluidity is not destroyed, even though the energy spectrum of quasiparticle excitations exhibits no gap [17].…”

Section: Introductionmentioning

confidence: 99%