Equations of state for supernovae and compact stars

Oertel, Micaela; Hempel, Matthias; Klähn, T.; Typel, S.

doi:10.1103/revmodphys.89.015007

Cited by 1,096 publications

(1,073 citation statements)

References 1,018 publications

(1,438 reference statements)

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“…Other experimental constraints on symmetry energy parameters are reviewed in Lattimer & Lim (2013) and Oertel et al (2017). They indicate that consistency with measurements of nuclear masses, giant dipole resonances and dipole polarizabilities, neutron-skin thicknesses, and flows in heavy-ion collisions is achieved for 30 MeV S 0  32 MeV and 40 MeV L 60 MeV (left panel of Figure 9).…”

Section: Comparison With Experimental Constraintsmentioning

confidence: 99%

“…The symmetry energy is also important in calculations of the r-process (Mumpower et al 2016), supernovae (Fischer et al 2014), and neutron-star mergers (Bauswein et al 2016). Terrestrial experiments measuring nuclear masses, dipole resonances, and neutronskin thicknesses can constrain the symmetry energy (Lattimer & Lim 2013), as can experiments using normal and radioactive nuclear beams (Oertel et al 2017).…”

Section: Introductionmentioning

confidence: 99%

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Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

Tews¹,

Lattimer²,

Ohnishi³

et al. 2017

ApJ

295

213

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We propose the existence of a lower bound on the energy of pure neutron matter (PNM) on the basis of unitary-gas considerations. We discuss its justification from experimental studies of cold atoms as well as from theoretical studies of neutron matter. We demonstrate that this bound results in limits to the density-dependent symmetry energy, which is the difference between the energies of symmetric nuclear matter and PNM. In particular, this bound leads to a lower limit to the volume symmetry energy parameter S 0 . In addition, for assumed values of S 0 above this minimum, this bound implies both upper and lower limits to the symmetry energy slope parameter L, which describes the lowest-order density dependence of the symmetry energy. A lower bound on neutron-matter incompressibility is also obtained. These bounds are found to be consistent with both recent calculations of the energies of PNM and constraints from nuclear experiments. Our results are significant because several equations of state that are currently used in astrophysical simulations of supernovae and neutron star mergers, as well as in nuclear physics simulations of heavy-ion collisions, have symmetry energy parameters that violate these bounds. Furthermore, below the nuclear saturation density, the bound on neutron-matter energies leads to a lower limit to the density-dependent symmetry energy, which leads to upper limits to the nuclear surface symmetry parameter and the neutron-star crust-core boundary. We also obtain a lower limit to the neutron-skin thicknesses of neutronrich nuclei. Above the nuclear saturation density, the bound on neutron-matter energies also leads to an upper limit to the symmetry energy, with implications for neutron-star cooling via the direct Urca process.

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Section: Comparison With Experimental Constraintsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

Tews¹,

Lattimer²,

Ohnishi³

et al. 2017

ApJ

295

213

View full text Add to dashboard Cite

show abstract

“…Note that this problem can hardly be resolved by enhancing the shear viscosity (e.g., to stabilize 4U 1608-522 one should enhance it by a factor of 1000, and we are unaware of any physically motivated mechanism predicting such a strong enhancement) or by fitting the mass-radius relation [for example, 4U 1608-522 should be stable according to equations (1)-(2) if radius R 5 km. However, these equations are written for a baryonic equation of state, and thus they are inapplicable for such a small radius, because such equations of state predict larger radii (see, e.g., Oertel, Hempel, Klähn, & Typel 2016;Zdunik, Fortin, & Haensel 2016); observations also favour larger NS radii (e.g.,Özel & Freire 2016)].…”

Section: X-ray Observations Of Transiently Accreting Neutron Stars Inmentioning

confidence: 99%

R modes and neutron star recycling scenario

Chugunov¹,

Gusakov²,

Kantor

2017

Monthly Notices of the Royal Astronomical Society

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To put new constraints on the r-mode instability window, we analyse the formation of millisecond pulsars (MSPs) within the recycling scenario, making use of three sets of observations: (a) X-ray observations of neutron stars (NSs) in low-mass X-ray binaries; (b) timing of millisecond pulsars; and (c) X-ray and UV observations of MSPs. As shown in previous works, r-mode dissipation by shear viscosity is not sufficient to explain observational set (a), and enhanced r-mode dissipation at the red-shifted internal temperatures T ∞ ∼ 10 8 K is required to stabilize the observed NSs. Here, we argue that models with enhanced bulk viscosity can hardly lead to a self-consistent explanation of observational set (a) due to strong neutrino emission, which is typical for these models (unrealistically powerful energy source is required to keep NSs at the observed temperatures). We also demonstrate that the observational set (b) , combined with the theory of internal heating and NS cooling, provides evidence of enhanced r-mode dissipation at low temperatures, T ∞ ∼ 2×10 7 K. Observational set (c) allows us to set an upper limit on the internal temperatures of MSPs, T ∞ < 2 × 10 7 K (assuming a canonical NS with the accreted crust). Recycling scenario can produce MSPs at these temperatures only if r-mode instability is suppressed in the whole MSP spin frequency range (ν 750 Hz) at temperatures 2 × 10 7 T ∞ 3 × 10 7 K, providing thus a new constraint on the r-mode instability window. These observational constraints are analysed in more details in application to the resonance uplift scenario of Gusakov et al. (2014b,a).

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“…The determination of the composition and properties of dilute nuclear matter is a long-standing problem which has gained renewed interest in recent years in various contexts, for a recent review see [6]. The topics of current interest are, for example, the improvements on the supernova and warm neutron star equations of state and thermodynamics [7,8] which include the multi-cluster composition of matter [9,10,11,12,13,14,15,16,17,18,19,20,21].…”

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confidence: 99%

Composition of Nuclear Matter with Light Clusters and Bose–Einstein Condensation of $$\alpha $$ α Particles

et al. 2017

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The Bose-Einstein condensation of α partciles in the multicomponent environment of dilute, warm nuclear matter is studied. We consider the cases of matter composed of light clusters with mass numbers A ≤ 4 and matter that in addition these clusters contains 56 Fe nuclei. We apply the quasiparticle gas model which treats clusters as bound states with infinite life-time and binding energies independent of temperature and density. We show that the α particles can form a condensate at low temperature T ≤ 2 MeV in such matter in the first case. When the 56 Fe nucleus is added to the composition the cluster abundances are strongly modified at low temperatures, with an important implication that the α condensation at these temperatures is suppressed.

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Equations of state for supernovae and compact stars

Cited by 1,096 publications

References 1,018 publications

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

R modes and neutron star recycling scenario

Composition of Nuclear Matter with Light Clusters and Bose–Einstein Condensation of $$\alpha $$ α Particles

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