Cocoon shock breakout emission from binary neutron star mergers
arXiv:2408.15973 · doi:10.1103/PhysRevD.111.063031
Abstract
Shock breakout emission is among the first observable signals in a wide variety of astrophysical phenomena, including neutron star (NS) mergers, and it can be the dominant component in low-luminosity short -ray bursts, as exemplified by GRB 170817A. In this work, we investigate the cocoon shock breakout emission in NS mergers and how its signal depends on the outermost layers of the ejecta profile, which we derive from general relativistic radiation hydrodynamic simulations. We study the formation of the cocoon as a consequence of a relativistic jet propagating through the ejecta. To explore the influence of the outermost layers of the ejecta on the breakout emission, we explore cases where the ejecta has a sharp cutoff or an extended smooth tail. We find that the shock breakout emission is strongly influenced by the shape of the ejecta outer layers, with extended tails yielding results consistent with the observed properties of GRB 170817A, whereas sharp cutoffs overestimate the radiated energy. Using a Bayesian analysis, we estimate the best fit parameters of the central engine, considering both accreting black hole and magnetized neutron star scenarios. Our findings indicate a slight preference for the scenarios where the engine is a black hole. Our work probes the nature of neutron star mergers and highlights the importance of the shape of the ejecta profile in modeling early electromagnetic counterparts to these mergers.
27 pages, 12 figures. Version published in Phys. Rev. D
References in corpus (27)
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- Multi-messenger Observations of a Binary Neutron Star Merger
- Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
- An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
- Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
- The X-ray counterpart to the gravitational wave event GW 170817
- Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis
- Illuminating Gravitational Waves: A Concordant Picture of Photons from a Neutron Star Merger
- Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers
- A Radio Counterpart to a Neutron Star Merger
- Neutrino-driven winds from neutron star merger remnants
- Kilonovae
- The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. V. Rising X-ray Emission from an Off-Axis Jet
- Neutrino signatures and the neutrino-driven wind in Binary Neutron Star Mergers
- The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-Time Emission from the Kilonova Ejecta
- The dynamical mass ejection from binary neutron star mergers: Radiation-hydrodynamics study in general relativity
- A Deep Chandra X-ray Study of Neutron Star Coalescence GW170817
- The Dynamics of Binary Neutron Star Mergers and of GW170817
- Jet collimation in the ejecta of double neutron star merger: new canonical picture of short gamma-ray bursts
- Properties of hypermassive neutron stars formed in mergers of spinning binaries
- Off-axis prompt X-ray transients from the cocoon of short gamma-ray bursts
- General-Relativistic Large-Eddy Simulations of Binary Neutron Star Mergers
- Outflows from accretion disks formed in neutron star mergers: effect of black hole spin
- A New Open-Source Nuclear Equation of State Framework based on the Liquid-Drop Model with Skyrme Interaction
- Relativistic Radiation Mediated Shocks
- Binary Neutron Star Merger Simulations with a Calibrated Turbulence Model
- Monte-Carlo simulations of relativistic radiation mediated shocks: II. photon starved regime