Speaker
Description
Fast Radio Bursts (FRBs) are luminous, coherent radio pulses primarily of extragalactic origin. While a Galactic magnetar has been linked to a few FRB-like events, the progenitors for the vast majority of FRBs remain elusive, largely due to the poor localization capabilities of current FRB instruments. To circumvent this limitation, we employ a statistical approach by investigating the redshift evolution of the FRB volumetric rate density. If FRB progenitors are associated with short-lived star-formation remnants, such as magnetars, their volumetric rate density should track the cosmic star-formation history, increasing toward higher redshifts (z ~ 1-2). In contrast, a nearly constant or decreasing density would suggest an origin in old stellar populations, such as white dwarfs and old neutron stars. While previous studies were limited by small sample sizes (e.g., 164 non-repeaters by Hashimoto et al. 2020), leading to divergent conclusions, this work utilizes 1,077 non-repeaters from the CHIME/FRB Catalog 2. Containing approximately an order of magnitude more non-repeater samples than Catalog 1, this dataset allows for a more robust statistical analysis. We present preliminary results on the volumetric rate density as a function of redshift. The preliminary result suggests a decreasing trend of the volumetric rate density of non-repeaters towards higher redshifts up to z~2, being consistent with the old stellar population scenario. We will also discuss the potential impact of frequency-dependent selection effects on our inference. Significant populations of FRBs at z<0.2 are detected at <600 MHz at the source frame, while such low-frequency events are not detectable at higher redshifts due to the limited bandwidth of CHIME.
| Participate the oral/poster presentation award competition | No |
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