Comparison of Gravitational Waves from Central Engines of Gamma-Ray Bursts: Neutrino-dominated Accretion Flows, Blandford–Znajek Mechanisms, and Millisecond Magnetars

Abstract

Neutrino-dominated accretion flow (NDAF) around a rotating stellar-mass black hole (BH) is one of the plausible candidates for the central engines of gamma-ray bursts (GRBs). Because the timevariant and anisotropic emission of neutrinos from NDAFs leads to GRB variability, NDAFs can be regarded as the sources of the strong gravitational waves (GWs). We calculate the dependences of the GW strains on both the BH spin and the accretion rate. We demonstrate that for typical GRBs with either single pulse or multiple pulses, the GWs from NDAFs might be detected at a distance of ∼ 100 kpc/∼ 1 Mpc by advanced LIGO/Einstein Telescope with a typical frequency of ∼ 10 − 100 Hz. Besides NDAFs, the other two competitive candidates for GRB central engine are Blandford-Znajek (BZ) mechanism and millisecond magnetars. We explore the GW signals from these two as well, and compare the corresponding results with NDAFs'. We find that for a certain GRB, the possible detected distance from NDAFs is about two orders of magnitude higher than that from BZ mechanism, but at least two orders of magnitude lower than that from magnetars. The typical GW frequency for BZ mechanism is the same with that of NDAFs, ∼ 10 − 100 Hz, while the typical frequency for magnetars is ∼ 2000 Hz. Therefore, the GWs released by the central engines of adjacent GRBs might be used to determine whether there is an NDAF, a BZ jet or a magnetar in GRB center.

Anisotropic multimessenger signals from black hole neutrino-dominated accretion flows with outflows in binary compact object mergers

“…One can note that GWs from NDAFs with and without outflows can be detected by ET, CE, DECIGO/BBO, and ultimate-DECIGO in the detectable frequency of ∼ 1 − 200 Hz and ∼ 10 − 200 Hz at 10 kpc for SGRBs with a single pulse or the multiple pulses, respectively. The properties of this GWs are similar to those of GWs originated from a precessing jet launched by a warped NDAF (e.g., Sun et al 2012;Liu et al 2017b).…”

“…We can notice that the typical GW frequencies are in the ranges of ∼ 1 − 1000 and ∼ 10 − 1000 Hz for the cases of NDAFs with and without outflows, respectively, which is determined by the GRB variabilities (f ∼ 1/2δt, see e.g., Liu et al 2017b). The GW waveforms induced by a single pulse and the multiple pulses are very different also caused by the distinction on the variabilities of the neutrino emission.…”

“…(1978) first proposed GW radiation resulting from anisotropic neutrinos, and the methods have been applied to CCSNe (e.g., Burrows & Hayes 1996;Kotake et al 2006Kotake et al , 2007. GWs arising from anisotropic neutrino emission in NDAFs have been investigated (e.g., Suwa & Murase 2009;Kotake et al 2012;Liu et al 2017b;Song et al 2020;. Liu et al (2017b) examined the BH spin and accretion rate impacts on the strains of GWs in NDAFs; compared their strains, frequencies, and detection possi- bility to those from magnetars; and presented no GW emission from the BZ mechanism (Blandford & Znajek 1977).…”

“…GWs arising from anisotropic neutrino emission in NDAFs have been investigated (e.g., Suwa & Murase 2009;Kotake et al 2012;Liu et al 2017b;Song et al 2020;. Liu et al (2017b) examined the BH spin and accretion rate impacts on the strains of GWs in NDAFs; compared their strains, frequencies, and detection possi- bility to those from magnetars; and presented no GW emission from the BZ mechanism (Blandford & Znajek 1977). The above works mainly focus on the collapsar scenario, here we adopt the similar method to calculate the GWs from NDAFs in BNS/BH-NS merger scenarios.…”

“…This type of accretion disk is named a neutrino-dominated accretion flow (NDAF, e.g., Popham et al 1999;Narayan et al 2001;Di Matteo et al 2002;Kohri & Mineshige 2002;Kohri et al 2005;Lee et al 2005;Gu et al 2006;Chen & Beloborodov 2007;Kawanaka & Mineshige 2007;Liu et al 2007;Kawanaka et al 2013;Xue et al 2013); for reviews, see Liu et al (2017a) and Zhang (2018). Neutrino emission and GWs induced by the jet precession or anisotropic neutrinos in the NDAF model have been investigated (e.g., Suwa & Murase 2009;Romero et al 2010;Sun et al 2012;Liu et al 2016Liu et al , 2017bSong et al 2018Song et al , 2020Wei et al 2019;. Besides that, the Blandford-Znajek (BZ) mechanism (Blandford & Znajek 1977) is another way to release energy in BH hyperaccretion scenario.…”