Evidence for a Delayed Progenitor Population for CHIME non-repeating Fast Radio Bursts from a Self-Consistent Forward and Backward Inference Framework
Abstract
Fast radio bursts (FRBs) are luminous extragalactic radio transients whose physical origins remain uncertain. Using over one thousand non-repeating events from CHIME/FRB Catalog 2, we infer the intrinsic FRB demographics with a self-consistent framework that combines backward non-parametric inference and forward population synthesis while accounting for probabilistic dispersion measure--redshift estimates, baseband-to-catalog fluence corrections, and the latest fuzzy multidimensional selection function. We first apply a backward non-parametric method, the weighted Lynden--Bell C− estimator, to recover the intrinsic redshift and energy distributions without assuming any population model. Independently, we perform forward Monte Carlo population synthesis in observable dispersion measure--fluence space, treating candidate intrinsic redshift and energy distributions as population hypotheses and comparing the resulting selected synthetic catalogs with observations. We find that the intrinsic redshift distribution peaks at z∼1, significantly lower than the cosmic star formation history (SFH) peak at z∼1.7, indicating clear tension with a pure SFH-tracking scenario, suggesting that at least some FRBs are delayed with respect to SFH. The intrinsic energy distribution is consistent with a power law of index α≈1.9 and steepens at higher energies. We find no significant evidence for a redshift-energy distribution correlation.
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BibTeX
@misc{zhang2026evidence,
title = {{Evidence for a Delayed Progenitor Population for CHIME non-repeating Fast Radio Bursts from a Self-Consistent Forward and Backward Inference Framework}},
author = {Zi-Liang Zhang and Bing Zhang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2607.04792},
eprint = {2607.04792},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.04792},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Evidence for a Delayed Progenitor Population for CHIME non-repeating Fast Radio Bursts from a Self-Consistent Forward and Backward Inference Framework
AU - Zi-Liang Zhang
AU - Bing Zhang
PY - 2026
DA - 2026/09/27
PB - arXiv
DO - 10.48550/arxiv.2607.04792
UR - https://arxiv.org/abs/2607.04792
AB - Fast radio bursts (FRBs) are luminous extragalactic radio transients whose physical origins remain uncertain. Using over one thousand non-repeating events from CHIME/FRB Catalog 2, we infer the intrinsic FRB demographics with a self-consistent framework that combines backward non-parametric inference and forward population synthesis while accounting for probabilistic dispersion measure--redshift estimates, baseband-to-catalog fluence corrections, and the latest fuzzy multidimensional selection function. We first apply a backward non-parametric method, the weighted Lynden--Bell C^− estimator, to recover the intrinsic redshift and energy distributions without assuming any population model. Independently, we perform forward Monte Carlo population synthesis in observable dispersion measure--fluence space, treating candidate intrinsic redshift and energy distributions as population hypotheses and comparing the resulting selected synthetic catalogs with observations. We find that the intrinsic redshift distribution peaks at z∼1, significantly lower than the cosmic star formation history (SFH) peak at z∼1.7, indicating clear tension with a pure SFH-tracking scenario, suggesting that at least some FRBs are delayed with respect to SFH. The intrinsic energy distribution is consistent with a power law of index α≈1.9 and steepens at higher energies. We find no significant evidence for a redshift-energy distribution correlation.
ER -