Dynamical Mass Ejection from Binary Neutron Star Mergers
By David Radice, F. Galeazzi, Jonas Lippuner, Luke F. Roberts, Christian D. Ott, Luciano Rezzolla. 2016
279 citations recorded by the source corpus.
We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad ∼60∘ angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. We find neutrino cooling and heating to affect, quantitatively and qualitatively, composition, morphology, and total mass of the outflows. This is also reflected in the infrared and radio signatures of the binary. The final nucleosynthetic yields of the ejecta are robust and insensitive to input physics or merger type in the regions of the second and third r-process peaks. The yields for elements on the first peak vary between our simulations, but none of our models is able to explain the Solar abundances of first-peak elements without invoking additional first-peak contributions from either neutrino and viscously-driven winds operating on longer timescales after the mergers, or from core-collapse supernovae.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/4ba8517c8e1f37a54136e4790376fc2d09c2736d
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In Astronomy and Astrophysics
Citations in the corpus
- Impact of ejecta morphology and composition on the electromagnetic signatures of neutron star mergers (2017, background): “The first component is cold and extremely neutron-rich (with electron fractions Ye < 0.04), while the second component can potentially have higher Ye resulting from the copious production of e−e+-pairs, which rapidly drives matter to a more symmetric state (Wanajo et al. 2014; Radice et al. 2016).”
- Off-axis emission of short γ-ray bursts and the detectability of electromagnetic counterparts of gravitational-wave-detected binary mergers (2016, methodology): “An energetic cocoon is expected to form as the SGRB relativistic jet propagates through the immediate surroundings of the NS binary merger, polluted with ∼0.01 M of material tidally ejected from the merging compact objects (Kiuchi et al. 2014, 2015; Radice et al. 2016).”
- The Emergence of a Lanthanide-rich Kilonova Following the Merger of Two Neutron Stars (2017, background): “…extremely neutronrich, low electron fraction (Ye), “tidal” ejecta component, recent studies (Perego et al. 2014; Wanajo et al. 2014; Just et al. 2015; Radice et al. 2016) have highlighted that this material is likely complemented by higher Ye material that still undergoes r-process…”
- Neutron Star Mergers Might Not Be the Only Source of r-process Elements in the Milky Way (2018, background): “However, other hydrodynamical codes lead to broader ranges in electron fraction and entropy (Bauswein et al. 2013; Sekiguchi et al. 2015; Foucart et al. 2016; Radice et al. 2016; Bovard et al. 2017).”
- Binary Neutron Star Mergers: Mass Ejection, Electromagnetic Counterparts, and Nucleosynthesis (2018, methodology): “…this symmetry is typically broken at the time of the merger, when turbulence operating in the shear layer between the two NSs can exponentially amplify small initial asymmetries, such as those due to floating-point truncation in the simulations (Paschalidis et al. 2015; Radice et al. 2016a).”
- Signatures of hypermassive neutron star lifetimes on r-process nucleosynthesis in the disc ejecta from neutron star mergers (2017, background): “When neutrino absorption is included in the calculations, a larger fraction of lighter elements (A < 130) can be obtained (e.g., Wanajo et al. 2014; Goriely et al. 2015; Sekiguchi et al. 2015; Radice et al. 2016; Foucart et al. 2016a,b; Roberts et al. 2017).”
- Long-term GRMHD simulations of neutron star merger accretion discs: implications for electromagnetic counterparts (2018, background): “…to be sufficiently neutron-rich to produce mainly A > 130 elements, with varying amounts of lighter material depending on the equation of state (EOS) of dense matter and the treatment of neutrino physics (e.g., Wanajo et al. 2014; Roberts et al. 2017; Radice et al. 2016; Foucart et al. 2016,?).”
- The Origin of r-process Elements in the Milky Way (2017, background): “…& Schramm (1974), recently gained popularity because the high neutron fraction allows robust production of the 2nd and 3rd r-process peaks (e.g., Freiburghaus et al. 1999; Korobkin et al. 2012; Bauswein et al. 2013; Radice et al. 2016; Thielemann et al. 2017, but see Nishimura et al. 2015).”
- Production of the entire range of r-process nuclides by black hole accretion disc outflows from neutron star mergers (2016, background): “…include the effects of e± captures and neutrino irradiation in full general-relativity have shown that the dynamical ejecta can have a wider electron fraction distribution(Ye ∼ 0.1−0.4) than models without weak interaction effects (Sekiguchi et al. 2015; Foucart et al. 2015; Radice et al. 2016).”