Accurate evolutions of inspiralling neutron-star binaries: Prompt and delayed collapse to a black hole

By Luca Baiotti, B. Giacomazzo, Luciano Rezzolla. 2008

220 citations recorded by the source corpus.

Binary neutron-star systems represent primary sources for the gravitational-wave detectors that are presently operating or are close to being operating at the target sensitivities. We present a systematic investigation in full general relativity of the dynamics and gravitational-wave emission from binary neutron stars which inspiral and merge, producing a black hole surrounded by a torus. Our results represent the state of the art from several points of view: (i) We use high-resolution shock-capturing methods for the solution of the hydrodynamics equations and high-order finite-differencing techniques for the solution of the Einstein equations; (ii) We employ adaptive mesh-refinement techniques with 'moving boxes' that provide high-resolution around the orbiting stars; (iii) We use as initial data accurate solutions of the Einstein equations for a system of binary neutron stars in irrotational quasicircular orbits; (iv) We exploit the isolated-horizon formalism to measure the properties of the black holes produced in the merger; (v) Finally, we use two approaches, based either on gauge-invariant perturbations or on Weyl scalars, to calculate the gravitational waves emitted by the system. Within our idealized treatment of the matter, these techniques allow us to perform accurate evolutions on time scales never reported before (i.e. {approx}30 ms) and to providemore » the first complete description of the inspiral and merger of a neutron-star binary leading to the prompt or delayed formation of a black hole and to its ringdown. We consider either a polytropic equation of state or that of an ideal fluid and show that already with this idealized treatment a very interesting phenomenology can be described. In particular, we show that while higher-mass polytropic binaries lead to the prompt formation of a rapidly rotating black hole surrounded by a dense torus, lower-mass binaries give rise to a differentially rotating star, which undergoes large oscillations and emits large amounts of gravitational radiation. Eventually, also the hyper-massive neutron star collapses to a rotating black hole surrounded by a torus. Finally, we also show that the use of a nonisentropic equation of state leads to significantly different evolutions, giving rise to a delayed collapse also with high-mass binaries, as well as to a more intense emission of gravitational waves and to a geometrically thicker torus.« less

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/801598a9b9af83710082585b1d746580441fd99e

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Citations in the corpus

Using Gravitational-wave Observations and Quasi-universal Relations to Constrain the Maximum Mass of Neutron Stars (2017, background): “…to determine the mass of the binary that would lead to a prompt collapse, i.e., to a black hole within few milliseconds after merger, (see, e.g., Baiotti et al. (2008); Bauswein et al. (2013)), or to determine the lifetime of the merged object (see, e.g., Lasky et al. (2014); Ravi & Lasky…”
Beyond second-order convergence in simulations of binary neutron stars in full general-relativity (2013, background): “The dynamics of the inspiral and merger of BNS has been described many times and in great detail in the literature,e.g.,(Baiotti et al. 2008); for this reason we do not give a very in-depth discussion of it here.”
Constraining the Maximum Mass of Neutron Stars from Multi-messenger Observations of GW170817 (2017, background): “…Mth ≈ kMmax, then the merger product undergoes “prompt” dynamical-timescale collapse to a black hole (BH) (e.g. Shibata 2005; Shibata & Taniguchi 2006; Baiotti et al. 2008; Hotokezaka et al. 2011), where the proportionality factor k ≈ 1.3 − 1.6 is greater for smaller values of the NS…”
NEUTRINO SIGNATURES AND THE NEUTRINO-DRIVEN WIND IN BINARY NEUTRON STAR MERGERS (2008, methodology): “…by Baumgarte et al. (2000), Morrison et al. (2004), Duez et al. (2004, 2006), and Shibata et al. (2006), while full 3D GR simulations of the merger were carried out by Shibata & Uryū (2002); Shibata et al. (2003, 2005); Shibata & Uryu (2007), Anderson et al. (2008a), and Baiotti et al. (2008).”
Neutron Star Extreme Matter Observatory: A kilohertz-band gravitational-wave detector in the global network (2020, background): “However, if a neutron star survives the merger, gravitational waves can be emitted at frequencies of ∼1− 4 kHz for up to hundreds of milliseconds (Baiotti et al. 2008; Shibata & Taniguchi 2006).”
THC: a new high-order finite-difference high-resolution shock-capturing code for special-relativistic hydrodynamics (2012, background): “…Perucho et al. 2007; Perucho et al. 2010), and because of its potential role in the amplification of magnetic fields in gamma-ray bursts (see, e.g. Zhang et al. 2009), and binary neutron-star mergers (Baiotti et al. 2008; Giacomazzo et al. 2009; Obergaulinger et al. 2010; Rezzolla et al. 2011).”
The physics of gamma-ray bursts & relativistic jets (2014, background): “[815,817,818,686]), while a supra-massive neutron star would give extended gravitational wave signals due to a secular bar-mode instability (e.”
THE MISSING LINK: MERGING NEUTRON STARS NATURALLY PRODUCE JET-LIKE STRUCTURES AND CAN POWER SHORT GAMMA-RAY BURSTS (2011, background): “…a HMNS can exist as long as it is able to resist against collapse via a suitable redistribution of angular momentum (e.g. deforming into a “bar” shape, Shibata & Taniguchi 2006; Baiotti et al. 2008), or through the pressure support coming from the large temperature-increase produced by the merger.”
Dynamical Mass Ejection from Binary Neutron Star Mergers (2016, background): “5, and quasi-circular binaries (QC) result in the formation of hypermassive neutron stars (HMNSs) (Baumgarte et al. 2000), meta-stable massive remnants temporarily supported against gravitational collapse by a large degree of differential rotation (Baiotti et al. 2008; Kaplan et al. 2014).”
Neutron-star Radius Constraints from GW170817 and Future Detections (2017, background): “The threshold binary mass Mthres depends sensitively on the EoS (Shibata 2005; Baiotti et al. 2008; Hotokezaka et al. 2011; Bauswein et al. 2013a).”
The Einstein Toolkit: a community computational infrastructure for relativistic astrophysics (2011, methodology): “Many of the successful techniques used to evolve BH–BH binaries have proven to be equally applicable to merging NS–NS [54, 56–74] and BH–NS [44, 74–90] binaries (for reviews, see also [91, 92]), allowing for further investigations into the former and the first full GR simulations of the latter.”
Gravitational waves and non-axisymmetric oscillation modes in mergers of compact object binaries (2011, methodology): “…distinguishable in the GW signal and could be used for characterizing the hypermassive compact object (Zhuge et al. 1994; Oechslin et al. 2002; Shibata & Uryū2002; Shibata et al. 2005; Shibata & Taniguchi 2006; Oechslin & Janka 2007; Baiotti et al. 2008; Kiuchi et al. 2009; Bauswein et al.2010).”