English

Flat tails in FRB and pulsar energy distributions: implications for optimizing nearby FRB surveys

High Energy Astrophysical Phenomena 2025-08-26 v2

Abstract

Fast radio bursts (FRBs) are energetic, short-duration radio pulses of unclear origin. To explore effective survey strategies for detecting FRBs from nearby globular clusters (GCs), we investigate the burst energy distribution, which has a strong influence on the detection rate. We re-analyze FRBs and pulsars exhibiting broad energy distributions by fitting their high-energy tails with power-law models. Two cosmological repeating FRBs (FRB 20201124A and FRB 20220912A), one nearby FRB (FRB 20200120E), and two pulsars (RRATs J1846-0257 and J1854+0306), exhibit power-law indices of α1\alpha \gtrsim -1, suggesting that their bright pulses contribute significantly to the total radio pulse energy. The brightest bursts from these sources can be fitted with a power-law model (αBri=0.26±0.05\alpha_{\rm Bri} = -0.26 \pm 0.05), suggesting that an extremely flat index is required to naturally derive high-luminosity FRBs from low-luminosity sources. We present detailed survey strategies for FAST, MeerKAT and Parkes cryoPAF in the search for FRBs in nearby GCs using different power-law indices, recommending targets for observation. We suggest that combining observations with FAST (3\sim3 hours) and Parkes cryoPAF (10-20 hours) is practicable for discovering new FRBs in nearby GCs.

Keywords

Cite

@article{arxiv.2503.13210,
  title  = {Flat tails in FRB and pulsar energy distributions: implications for optimizing nearby FRB surveys},
  author = {S. B. Zhang and G. Hobbs and S. Johnston and S. Dai and Y. Li and J. S. Wang and X. Yang and X. F. Wu and L. Staveley-Smith},
  journal= {arXiv preprint arXiv:2503.13210},
  year   = {2025}
}

Comments

ApJ accepted version, significantly revised. Happy hunting for nearby FRBs!