Estimating up-limits of eccentricities for the binary black holes in the LIGO-Virgo catalog GWTC-1

In the first Gravitational-Wave Transient Catalogue of LIGO and Virgo,all events are announced having zero eccentricity.In the present paper,we investigate the performance of SEOBNRE,which is a spin-aligned eccentric waveform model in time-domain.By comparing with all the eccentric waveforms in SXS library,we find that the SEOBNRE coincides perfectly with numerical relativity data.Employing the SEOBNRE,we re-estimate the eccentricities of all black hole merger events.We find that most of these events allow a possibility for existence of initial eccentricities at 10 Hz band,but are totally circularized at the observed frequency(≥20 Hz).The upcoming update of LIGO and the next generation detector like Einstein Telescope will observe the gravitational waves starting at 10 Hz or even lower.If the eccentricity exists at the lower frequency,then it may significantly support the dynamical formation mechanism taking place in globular clusters.