scholarly journals Collimated outflows from long-lived binary neutron star merger remnants

2020 ◽  
Vol 495 (1) ◽  
pp. L66-L70 ◽  
Author(s):  
Riccardo Ciolfi

ABSTRACT The connection between short gamma-ray bursts (SGRBs) and binary neutron star (BNS) mergers was recently confirmed by the association of GRB 170817A with the merger event GW170817. However, no conclusive indications were obtained on whether the merger remnant that powered the SGRB jet was an accreting black hole (BH) or a long-lived massive neutron star (NS). Here, we explore the latter case via BNS merger simulations covering up to 250 ms after merger. We report, for the first time in a full merger simulation, the formation of a magnetically driven collimated outflow along the spin axis of the NS remnant. For the system at hand, the properties of such an outflow are found largely incompatible with an SGRB jet. With due consideration of the limitations and caveats of our present investigation, our results favour a BH origin for GRB 170817A and SGRBs in general. Even though this conclusion needs to be confirmed by exploring a larger variety of physical conditions, we briefly discuss possible consequences of all SGRB jets being powered by accreting BHs.

1996 ◽  
Vol 165 ◽  
pp. 489-502
Author(s):  
Tsvi Piran

Neutron star binaries, such as the one observed in the famous binary pulsar PSR 1913+16, end their life in a catastrophic merger event (denoted here NS2M). The merger releases ∼5 1053 ergs, mostly as neutrinos and gravitational radiation. A small fraction of this energy suffices to power γ-ray bursts (GRBs) at cosmological distances. Cosmological GRBs must pass, however, an optically thick fireball phase and the observed γ rays emerge only at the end of this phase. Hence, it is difficult to determine the nature of the source from present observations (the agreement between the rates of GRBs and NS2Ms providing only indirect evidence for this model). In the future a coinciding detection of a GRB and a gravitational-radiation signal could confirm this model.


2013 ◽  
Vol 87 (8) ◽  
Author(s):  
Nicholas Stone ◽  
Abraham Loeb ◽  
Edo Berger

1999 ◽  
Vol 527 (1) ◽  
pp. L39-L42 ◽  
Author(s):  
H.-Thomas Janka ◽  
Thomas Eberl ◽  
Maximilian Ruffert ◽  
Chris L. Fryer

2010 ◽  
Vol 104 (14) ◽  
Author(s):  
Kenta Kiuchi ◽  
Yuichiro Sekiguchi ◽  
Masaru Shibata ◽  
Keisuke Taniguchi

Author(s):  
A. R. Chasovnikov ◽  
V. M. Lipunov ◽  
E. S. Gorbovskoy

We consider the neutron stars mergers from the point of view of the spinar model. We present calculations of the maximum luminosity of merging neutron stars, both total and in optical ranges. The possibility of observing such gamma-ray bursts using the MASTER system of robotic telescopes is also discussed.


Author(s):  
Nils Andersson

This chapter discusses the different stages of an inspiralling neutron star binary system, through the formation of a black hole and the possible emergence of a gamma-ray burst. Tidal effects and the information encoded in the so-called Love numbers are explored. The violent dynamics of the merger is considered and models of gamma-ray bursts and the late time kilonova emission are also explored.


2017 ◽  
Vol 32 (39) ◽  
pp. 1730035 ◽  
Author(s):  
Keith Riles

Gravitational wave astronomy opened dramatically in September 2015 with the LIGO discovery of a distant and massive binary black hole coalescence. The more recent discovery of a binary neutron star merger, followed by a gamma ray burst (GRB) and a kilonova, reinforces the excitement of this new era, in which we may soon see other sources of gravitational waves, including continuous, nearly monochromatic signals. Potential continuous wave (CW) sources include rapidly spinning galactic neutron stars and more exotic possibilities, such as emission from axion Bose Einstein “clouds” surrounding black holes. Recent searches in Advanced LIGO data are presented, and prospects for more sensitive future searches are discussed.


2019 ◽  
Vol 489 (1) ◽  
pp. L91-L96 ◽  
Author(s):  
Michael W Coughlin ◽  
Tim Dietrich ◽  
Ben Margalit ◽  
Brian D Metzger

ABSTRACT The combined detection of a binary neutron star merger in both gravitational waves (GWs) and electromagnetic (EM) radiation spanning the entire spectrum – GW170817/AT2017gfo/GRB170817A – marks a breakthrough in the field of multimessenger astronomy. Between the plethora of modelling and observations, the rich synergy that exists among the available data sets creates a unique opportunity to constrain the binary parameters, the equation of state of supranuclear density matter, and the physical processes at work during the kilonova and gamma-ray burst. We report, for the first time, Bayesian parameter estimation combining information from GW170817, AT2017gfo, and GRB170817 to obtain truly multimessenger constraints on the tidal deformability $\tilde{\Lambda } \in [302,860]$, total binary mass M ∈ [2.722, 2.751] M⊙, the radius of a 1.4 solar mass neutron star $R \in [11.3,13.5] \,\,\rm km$ (with additional $0.2\ \rm km$ systematic uncertainty), and an upper bound on the mass ratio of q ≤ 1.27, all at 90 per cent confidence. Our joint novel analysis uses new phenomenological descriptions of the dynamical ejecta, debris disc mass, and remnant black hole properties, all derived from a large suite of numerical relativity simulations.


Sign in / Sign up

Export Citation Format

Share Document