2 research outputs found
Distribution of fast radio burst dispersion measures in CHIME/FRB Catalog 1: implications on the origin of FRBs
Recently, CHIME/FRB project published its first fast radio burst (FRB)
catalog (hereafter, Catalog 1), which totally contains 536 unique bursts. With
the help of the latest set of FRBs in this large-size catalog, we aim to
investigate the dispersion measure (DM) or redshift () distribution of the
FRB population, and solution of this problem could be used to clarify the
question of FRB origin. In this study, we adopted the M\&E 2018 model, to fit
the observed distribution of FRBs in Catalog 1. In the M\&E 2018 model, we
are mostly interested in the function, i.e., number of bursts per
proper time per comoving volume, which is represented by the star formation
rate (SFR) with a power-law index . Our estimated value of is
() at the 68 (95) per cent confidence
level, implying that the FRB population evolves with redshift consistent with,
or faster than, the SFR. Specially, the consistency of the values estimated
by this study and the SFR provides a potential support for the hypothesis of
FRBs originating from young magnetars.Comment: 7 pages, 2 figures, accepted for publication in Astronomy Report
Do Multi-Structural One-Off FRBs Trace Similar Cosmology History with Repeaters?
Fast Radio Bursts (FRBs) are millisecond-duration transient events that are typically observed at radio wavelengths and cosmological distances but their origin remains unclear. Furthermore, most FRB origin models are related to the processes at stellar scales, involving neutron stars, blackholes, supernovae, etc. In this paper, our purpose is to determine whether multi-structural one-off FRBs and repeaters share similarities. To achieve this, we focus on analyzing the relationship between the FRB event rate and the star formation rate, complemented by statistical testing methods. Based on the CHIME/FRB Catalog 1, we calculate the energy functions for four subsamples, including apparent non-repeating FRBs (one-offs), repeaters, multi-structural one-offs, and the joint repeaters and multi-structural events, respectively. We then derive the FRB event rates at different redshifts for all four subsamples, all of which were found to share a similar cosmological evolution trend. However, we find that the multi-structural one-offs and repeaters are distinguishable from the KS and MWW tests