1,371 research outputs found

    Event Rate of Fast Radio Burst from Binary Neutron-star Mergers

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    It is proposed that one-off fast radio burst (FRB) with periodic structures may be produced during the inspiral phase of a binary neutron-star (BNS) merger. In this paper, we study the event rate of such kind of FRB. We first investigate the properties of two one-off FRBs with periodic structures (i.e., FRB~20191221A and FRB~20210213A) in this scenario, by assuming the fast magnetosonic wave is responsible for their radio emission. For the luminosities and periods of these bursts, it is found that the pre-merger BNS with magnetic field strength B1012GsB\gtrsim 10^{12}\,{\rm Gs} is required. This is relatively high compared with that of the most of the BNSs observed in our Galaxy, of which the magnetic field is around 109Gs10^{9}\,{\rm Gs}. Since the observed BNSs in our Galaxy are the binaries without suffering merger, a credited event rate of BNS-merger originated FRBs should be estimated by considering the evolution of both the BNS systems and their magnetic fields. Based on the population synthesis and adopting a decaying magnetic field of NSs, we estimate the event rate of BNS-mergers relative to their final magnetic fields. We find that the rapid merged BNSs tend to merge with high magnetization, and the event rate of BNS-merger originated FRBs, i.e., the BNS-mergers with both NSs' magnetic field being higher than 1012Gs10^{12}\,{\rm Gs} is 8×104yr1\sim8\times10^{4}\,\rm{yr}^{-1} (19%19 \% of the total BNS-mergers) in redshift z<1z<1.Comment: 11 pages, 2 figures, accepted for publication in Astrophysical Journa

    Impact of combinations of time-delay interferometry channels on stochastic gravitational wave background detection

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    The method of time delay interferometry (TDI) is proposed to cancel the laser noise in space-borne gravitational-wave detectors. Among all different TDI combinations, the most commonly used ones are the orthogonal channels A, E and T, where A and E are signal-sensitive and T is signal-insensitive. Meanwhile, for the detection of stochastic gravitational-wave background, one needs to introduce the overlap reduction function to characterize the correlation between channels. For the calculation of overlap reduction function, it is often convenient to work in the low-frequency approximation, and assuming the equal-arm Michelson channels. However, if one wishes to work on the overlap reduction function of A/E\rm A/E channels, then the low-frequency approximation fails. We derive the exact form of overlap reduction function for A/E\rm A/E channels. Based on the overlap reduction function, we calculate the sensitivity curves of TianQin, TianQin I+II and TianQin + LISA. We conclude that the detection sensitivity calculated with A/E\rm A/E channels is mostly consistent with that obtained from the equal-arm Michelson channels.Comment: 18 pages,10 figure
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