NEUTRINO SIGNATURES AND THE NEUTRINO-DRIVEN WIND IN BINARY NEUTRON STAR MERGERS

By L. Dessart, Christian D. Ott, Adam Burrows, Stephan Rosswog, E. Livne. 2008

249 citations recorded by the source corpus.

We present VULCAN/2D multigroup flux-limited-diffusion radiation-hydrodynamics simulations of binary neutron star mergers, using the Shen equation of state, covering ≳ 100 ms, and starting from azimuthal-averaged two-dimensional slices obtained from three-dimensional smooth-particle-hydrodynamics simulations of Rosswog & Price for 1.4 M☉(baryonic) neutron stars with no initial spins, co-rotating spins, or counter-rotating spins. Snapshots are post-processed at 10 ms intervals with a multiangle neutrino-transport solver. We find polar-enhanced neutrino luminosities, dominated by and “νμ” neutrinos at the peak, although νe emission may be stronger at late times. We obtain typical peak neutrino energies for νe, , and “νμ” of ∼ 12, ∼ 16, and ∼ 22 MeV, respectively. The supermassive neutron star (SMNS) formed from the merger has a cooling timescale of ≲ 1 s. Charge-current neutrino reactions lead to the formation of a thermally driven bipolar wind with 10−3 M☉ s−1 and baryon-loading in the polar regions, preventing any production of a γ-ray burst prior to black hole formation. The large budget of rotational free energy suggests that magneto-rotational effects could produce a much-greater polar mass loss. We estimate that ≲ 10−4 M☉ of material with an electron fraction in the range 0.1–0.2 becomes unbound during this SMNS phase as a result of neutrino heating. We present a new formalism to compute the annihilation rate based on moments of the neutrino-specific intensity computed with our multiangle solver. Cumulative annihilation rates, which decay as ∼t−1.8, decrease over our 100 ms window from a few ×1050 to ∼ 1049 erg s−1, equivalent to a few ×1054 to ∼ 1053 e−e+ pairs per second.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7778a9b3adf74340d1651f3b71b2dfa0e851ba29

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Citations in the corpus

On the astrophysical robustness of the neutron star merger r-process (2012, unknown): “9 in Dessart et al. (2009).”
Neutrino-driven winds from neutron star merger remnants (2014, background): “However, since this component was not included in the study of the merger process that provided our initial conditions, we neglect it here. see Dessart et al. (2009) and references therein.”
Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r‐process nuclei (2010, background): “Neutrino-heated winds are driven from the disk for a variety of accretion rates and disk radii during its early evolution (e.g. Metzger, Piro & Quataert 2008; Surman et al. 2008; Dessart et al. 2009).”
Production of the entire range of r-process nuclides by black hole accretion disc outflows from neutron star mergers (2016, background): “In addition to ejecting material dynamically, NS–NS/NS–BH mergers result in the formation of an accretion disc around the central remnant (e.g., Oechslin & Janka 2006); with the latter being a promptly formed BH or a longer-lived hypermassive NS (HMNS) (e.g., Shibata & Uryū 2000).”
Red or blue? A potential kilonova imprint of the delay until black hole formation following a neutron star merger (2014, methodology): “In addition, strong neutrino heating at polar latitudes in HMNS discs causes a genuine neutrino-driven wind at early times in this direction (see, e.g. Dessart et al. 2009).”
NEUTRINO-DRIVEN WINDS IN THE AFTERMATH OF A NEUTRON STAR MERGER: NUCLEOSYNTHESIS AND ELECTROMAGNETIC TRANSIENTS (2015, methodology): “These are neutrinodriven winds (Ruffert et al. 1997; Rosswog & RamirezRuiz 2002; Dessart et al. 2009; Perego et al. 2014; Just et al. 2015a) and late-time accretion disk disintegration (Metzger et al. 2008; Beloborodov 2008; Lee et al. 2009; Fernández & Metzger 2013; Just et al. 2015a).”
Delayed outflows from black hole accretion tori following neutron star binary coalescence (2013, background): “Such neutrino-driven outflows necessarily occur via thermal evaporation (e.g. McLaughlin & Surman 2005; Metzger et al. 2008; Surman et al. 2008; Dessart et al. 2009), as in the case of proto-neutron star winds, since momentum transfer from neutrinos is negligible.5 Even if neutrino irradiation from ”
GW170817: Joint Constraint on the Neutron Star Equation of State from Multimessenger Observations (2017, background): “…weeks timescale are more easily explained by neutrino, viscous, or magnetically driven outflows from the merger remnant (Metzger et al. 2008, 2009; Dessart et al. 2009; Fernández & Metzger 2013; Metzger & Fernández 2014; Perego et al. 2014; Siegel et al. 2014; Just et al. 2015; Wu et al. 2016;…”
PRODUCTION OF ALL THE r-PROCESS NUCLIDES IN THE DYNAMICAL EJECTA OF NEUTRON STAR MERGERS (2014, background): “Moreover, neutrino transport that can affect the ejecta Ye is neglected in all previous studies (except for the twodimensional Newtonian simulation by Dessart et al. 2009, without nucleosynthesis calculations).”
SYSTEMATICS OF DYNAMICAL MASS EJECTION, NUCLEOSYNTHESIS, AND RADIOACTIVELY POWERED ELECTROMAGNETIC SIGNALS FROM NEUTRON-STAR MERGERS (2013, background): “…merger remnant will experience mass loss due to neutrino energy deposition in the nearsurface regions (Ruffert & Janka 1999; Setiawan et al. 2004; Dessart et al. 2009; Wanajo & Janka 2012; Shibata & Sekiguchi 2012) (similar to the neutrinodriven wind of proto-neutron stars emerging from stellar…”
Signatures of hypermassive neutron star lifetimes on r-process nucleosynthesis in the disc ejecta from neutron star mergers (2017, methodology): “The neutron-to-seed ratio of this material is lower than that in the dynamical ejecta, because the longer evolutionary timescales allow weak interactions to modify the composition more significantly (e.g., Dessart et al. 2009; Fernández & Metzger 2013; Perego et al. 2014).”
Gamma-Ray Bursts in the Swift Era (2009, background): “One solution is to reconvert some of this energy via collisions outside the disk into electron-positron pairs or photons (Mochkovitch et al. 1993, Goodman et al. 1987, Rosswog and Ramirez-Ruiz 2002, Rosswog et al. 2003, Aloy et al. 2005, Dessart et al. 2009).”
Constraints on the neutron star equation of state from AT2017gfo using radiative transfer simulations (2018, background): “…source of blue ejecta, such as the magnetized neutrino-irradiated wind from a longlived hypermassive NS remnant prior to its collapse to a black hole (Metzger, Thompson & Quataert 2018; a purely neutrino-driven outflow is insufficient to explain the observed properties; Dessart et al. 2009).”
The long-term evolution of neutron star merger remnants { II. Radioactively powered transients (2013, background): “…2013), b) neutrino-driven winds from the remnant (Ruffert et al. 1997; Rosswog & Ramirez-Ruiz 2002, 2003; Rosswog et al. 2003; Surman et al. 2008; Dessart et al. 2009; Caballero et al. 2012; Wanajo & Janka 2012) and c) the final disintegration of accretion discs that occurs when viscous…”
Optical and X-ray emission from stable millisecond magnetars formed from the merger of binary neutron stars (2013, background): “The ejecta includes both matter which is unbound dynamically during the merger itself (‘tidal tails’) and that produced subsequently by outflows from the accretion disk or remnant NS (Dessart et al. 2009; Metzger et al. 2012).”