TY - JOUR

T1 - The Fate of the Merger Remnant in GW170817 and Its Imprint on the Jet Structure

AU - Murguia-Berthier, Ariadna

AU - Ramirez-Ruiz, Enrico

AU - Colle, Fabio De

AU - Janiuk, Agnieszka

AU - Rosswog, Stephan

AU - Lee, William H.

PY - 2021/2/20

Y1 - 2021/2/20

N2 - The first neutron star binary merger detected in gravitational waves, GW170817, and the subsequent detection of its emission across the electromagnetic spectrum showed that these systems are viable progenitors of short gamma-ray bursts (sGRB). The afterglow signal of GW170817 has been found to be consistent with a structured GRB jet seen off-axis, requiring significant amounts of relativistic material at large angles. This trait can be attributed to the interaction of the relativistic jet with the external wind medium. Here we perform numerical simulations of relativistic jets interacting with realistic wind environments in order to explore how the properties of the wind and central engine affect the structure of successful jets. We find that the angular energy distribution of the jet depends primarily on the ratio between the lifetime of the jet and the time it takes the merger remnant to collapse. We make use of these simulations to constrain the time it took for the merger remnant in GW170817 to collapse into a black hole based on the angular structure of the jet as inferred from afterglow observations. We conclude that the lifetime of the merger remnant in GW170817 was 1-1.7 s, which, after collapse, triggered the formation of the jet.

AB - The first neutron star binary merger detected in gravitational waves, GW170817, and the subsequent detection of its emission across the electromagnetic spectrum showed that these systems are viable progenitors of short gamma-ray bursts (sGRB). The afterglow signal of GW170817 has been found to be consistent with a structured GRB jet seen off-axis, requiring significant amounts of relativistic material at large angles. This trait can be attributed to the interaction of the relativistic jet with the external wind medium. Here we perform numerical simulations of relativistic jets interacting with realistic wind environments in order to explore how the properties of the wind and central engine affect the structure of successful jets. We find that the angular energy distribution of the jet depends primarily on the ratio between the lifetime of the jet and the time it takes the merger remnant to collapse. We make use of these simulations to constrain the time it took for the merger remnant in GW170817 to collapse into a black hole based on the angular structure of the jet as inferred from afterglow observations. We conclude that the lifetime of the merger remnant in GW170817 was 1-1.7 s, which, after collapse, triggered the formation of the jet.

KW - Gamma-ray bursts

KW - Jets

U2 - 10.3847/1538-4357/abd08e

DO - 10.3847/1538-4357/abd08e

M3 - Journal article

VL - 908

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 152

ER -