Designing a template bank to observe compact binary coalescences in Advanced LIGO's second observing run

TL;DR

This paper presents a new method for constructing a comprehensive template bank for detecting various compact binary coalescences in Advanced LIGO's second observing run, enhancing detection capabilities across a wide mass range.

Contribution

The paper introduces a novel template bank construction technique that includes high-mass black hole systems and varies starting frequencies to improve detection sensitivity.

Findings

Inclusion of binary-black-hole systems with masses up to hundreds of solar masses.

Implementation of variable starting frequency for waveform filters.

Exclusion of very short-duration, high-mass templates to optimize sensitivity.

Abstract

We describe the methodology and novel techniques used to construct a set of waveforms, or template bank, applicable to searches for compact binary coalescences in Advanced LIGO's second observing run. This template bank is suitable for observing systems composed of two neutron stars, two black holes, or a neutron star and a black hole. The Post-Newtonian formulation is used to model waveforms with total mass less than 4 $M_{\odot}$ and the most recent effective-one-body model, calibrated to numerical relativity to include the merger and ringdown, is used for total masses greater than 4 $M_{\odot}$. The effects of spin precession, matter, orbital eccentricity and radiation modes beyond the quadrupole are neglected. In contrast to the template bank used to search for compact binary mergers in Advanced LIGO's first observing run, here we are including binary-black-hole systems with total mass up to several hundreds of solar masses, thereby improving the ability to observe such systems. We introduce a technique to vary the starting frequency of waveform filters so that our bank can simultaneously contain binary-neutron-star and high-mass binary-black hole waveforms. We also introduce a lower-bound on the filter waveform length, to exclude very short-duration, high-mass templates whose sensitivity is strongly reduced by the characteristics and performance of the interferometers.