Inferring the Energy and Distance Distributions of Fast Radio Bursts Using the First CHIME/FRB Catalog

• Published in: The Astrophysical journal 2023-02, Vol.944 (1)
• Main Authors: Shin, Kaitlyn, Masui, Kiyoshi W., Bhardwaj, Mohit, Cassanelli, Tomas, Chawla, Pragya, Dobbs, Matt, Dong, Fengqiu Adam, Fonseca, Emmanuel, Gaensler, B. M., Herrera-Martín, Antonio, Kaczmarek, Jane, Kaspi, Victoria, Leung, Calvin, Merryfield, Marcus, Michilli, Daniele, Münchmeyer, Moritz, Pearlman, Aaron B., Rafiei-Ravandi, Masoud, Smith, Kendrick, Stairs, Ingrid, Tendulkar, Shriharsh P.
• Format: Article
• Language: English
• Subjects: Astronomy & Astrophysics
• ISSN: 0004-637X

Abstract Fast radio bursts (FRBs) are brief, energetic, typically extragalactic flashes of radio emission whose progenitors are largely unknown. Although studying the FRB population is essential for understanding how these astrophysical phenomena occur, such studies have been difficult to conduct without large numbers of FRBs and characterizable observational biases. Using the recently released catalog of 536 FRBs published by the Canadian Hydrogen Intensity Mapping Experiment/Fast Radio Burst (CHIME/FRB) collaboration, we present a study of the FRB population that also calibrates for selection effects. Assuming a Schechter function, we infer a characteristic energy cut-off of Echar=2.38−1.64+5.35×1041 erg and a differential power-law index ofγ= −1.3−0.4+0.7 . Simultaneously, we infer a volumetric rate of [ 7.3−3.8+8.8 (stat.) −1.8+2.0 ( sys. ) ] ×104 Gpc−3yr−1above a pivot energy of 1039erg and below a scattering timescale of 10 ms at 600 MHz, and find we cannot significantly constrain the cosmic evolution of the FRB population with star-formation rate. Modeling the host’s dispersion measure (DM) contribution as a log-normal distribution and assuming a total Galactic contribution of 80 pc cm−3, we find a median value of DMhost=84−49+69 pc cm−3, comparable with values typically used in the literature. Proposed models for FRB progenitors should be consistent with the energetics and abundances of the full FRB population predicted by our results. Finally, we infer the redshift distribution of FRBs detected with CHIME, which will be tested with the localizations and redshifts enabled by the upcoming CHIME/FRB Outriggers project.