Abstract
The ringdown of the gravitational-wave signal from a merger of two black holes has been suggested as a probe of the structure of the remnant compact object, which may be more exotic than a black hole. It has been pointed out that there will be a train of echoes in the late-time ringdown stage for different types of exotic compact objects. In this paper, we present a template-based search methodology using Bayesian statistics to search for echoes of gravitational waves. Evidence for the presence or absence of echoes in gravitational-wave events can be established by performing Bayesian model selection. The Occam factor in Bayesian model selection will automatically penalize the more complicated model that echoes are present in gravitational-wave strain data because of its higher degree of freedom to fit the data. We find that the search methodology was able to identify gravitational-wave echoes with Abedi et al.'s echoes waveform model about 82.3% of the time in simulated Gaussian noise in the Advanced LIGO and Virgo network and about 61.1% of the time in real noise in the first observing run of Advanced LIGO with $\geq 5\sigma$ significance. Analyses using this method are performed on the data of Advanced LIGO's first observing run, and we find no statistical significant evidence for the detection of gravitational-wave echoes. In particular, we find $<1\sigma$ combined evidence of the three events in Advanced LIGO's first observing run. The analysis technique developed in this paper is independent of the waveform model used, and can be used with different parametrized echoes waveform models to provide more realistic evidence of the existence of echoes from exotic compact objects.
Highlights
As of this writing, the Laser Interferometer Gravitationalwave Observatory (LIGO) [1] and the Advanced Virgo [2] have successfully detected ten compact binary coalescence events from binary black hole systems [3,4,5,6,7,8] and one binary neutron star collision [9]
We found that the search methodology was able to identify gravitational-wave echoes with Abedi et al.’s echoes waveform model about 82.3% of the time in simulated Gaussian noise in Advanced LIGO and Virgo network and about 61.1% of the time in real noise in the first observing run of Advanced LIGO with ≥ 5σ significance
WORK In this paper, we have demonstrated that our proposed search methodology using Bayesian model selection between the presence of echoes and their absence can identify and estimate the parameters of an inspiral-merger-ringdown-echo (IMRE) signal buried in both Gaussian noise and real noise in the first observing run (O1) of Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)
Summary
The Laser Interferometer Gravitationalwave Observatory (LIGO) [1] and the Advanced Virgo [2] have successfully detected ten compact binary coalescence events from binary black hole systems [3,4,5,6,7,8] and one binary neutron star collision [9]. These discoveries mark the beginning of a new era of gravitational-wave (GW) astronomy and astrophysics, where we can infer and probe the properties and structure of astronomical objects using gravitational waves. Cardoso et al showed that the time delay between each echo ∆techo can be used to infer the nature of an ECO [11], namely
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
