Abstract
Focusing on the remnant black holes after merging binary black holes, we show that ringdown gravitational waves of Population III binary black holes mergers can be detected with the rate of $5.9-500~{\rm events~yr^{-1}}~({\rm SFR_p}/ (10^{-2.5}~M_\odot~{\rm yr^{-1}~Mpc^{-3}})) \cdot ({\rm [f_b/(1+f_b)]/0.33})$ for various parameters and functions. This rate is estimated for the events with SNR$>8$ for the second generation gravitational wave detectors such as KAGRA. Here, ${\rm SFR_p}$ and ${\rm f_b}$ are the peak value of the Population III star formation rate and the fraction of binaries, respectively. When we consider only the events with SNR$>35$, the event rate becomes $0.046-4.21~{\rm events~yr^{-1}}~({\rm SFR_p}/ (10^{-2.5}~M_\odot~{\rm yr^{-1}~Mpc^{-3}})) \cdot ({\rm [f_b/(1+f_b)]/0.33})$. This suggest that for remnant black hole's spin $q_f>0.95$ we have the event rate with SNR$>35$ less than $0.037~{\rm events~yr^{-1}}~({\rm SFR_p}/ (10^{-2.5}~M_\odot~{\rm yr^{-1}~Mpc^{-3}})) \cdot ({\rm [f_b/(1+f_b)]/0.33})$, while it is $3-30~{\rm events~yr^{-1}}~({\rm SFR_p}/ (10^{-2.5}~M_\odot~{\rm yr^{-1}~Mpc^{-3}})) \cdot ({\rm [f_b/(1+f_b)]/0.33})$ for the third generation detectors such as Einstein Telescope. If we detect many Population III binary black holes merger, it may be possible to constrain the Population III binary evolution paths not only by the mass distribution but also by the spin distribution.
Highlights
The final part of gravitational waves (GWs) from merging binary black holes (BBHs) is called the ringdown phase
Focusing on the remnant black holes after merging binary black holes, we show that ringdown gravitational waves of Population III binary black hole mergers can be detected at the rate of 5.9–500 events yr −1 (SFRp /(10−2.5 M yr −1 Mpc−3 )) · ([fb /(1 + fb )]/0.33) for various parameters and functions
When the remnant compact object is a black hole (BH), this phase is described by quasinormal modes (QNMs) of the BH
Summary
The final part of gravitational waves (GWs) from merging binary black holes (BBHs) is called the ringdown phase. Using the results presented in the above sections, we calculate the mass and spin distributions of the remnant BHs after merger, and show the event rates of QNMs for each model in KAGRA. We use the β function defined by Hurley et al [12] in our standard model, we treat the accretion rate of the receiver star described by the constant β parameter. To study the dependence of Pop III BBH properties on the initial distribution functions and binary parameters, we calculate ten models with the Pop III binary population synthesis method [5,6] in this paper. The columns show the model name, IMF, IEF, the CE parameter αλ, and the loss fraction β of transfered stellar matter at the RLOF in each model
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
