On the relationship between the duration and energy of non-repeating fast radio bursts: census with the CHIME data. Issue 4 (20th June 2022)

• Record Type: Journal Article
• Authors: Kim, Seong Jin; Hashimoto, Tetsuya; Chen, Bo Han; Goto, Tomotsugu; Ho, Simon C-C; Hsiao, Tiger Yu-Yang; Wong, Yi Hang Valerie; Yamasaki, Shotaro
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 4(2022)
• Page Start: 5987
• Page End: 5995
• Publication Date: 2022-06-20
• Subjects: (transients:) fast radio bursts -- cosmology: observation; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1689
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: A correlation between the intrinsic energy and the burst duration of non-repeating fast radio bursts (FRBs) has been reported. If it exists, the correlation could be used to estimate the intrinsic energy from the duration, and thus could provide a new distance measure for cosmology. However, the correlation arose from small-number statistics (68 FRBs) and was not free from contamination by latent repeating populations, which might not have such a correlation. Finding a way to separate/exclude the repeating bursts from the mixture of all different types of FRBs is essential for investigating this property. Using a much larger sample from the new FRB catalogue (containing 536 FRBs) recently released by the CHIME (Canadian Hydrogen Intensity Mapping Experiment)/FRB Project, combined with a new classification method developed based on unsupervised machine learning, we carried out further scrutiny of the relationship. We found that there is a weak correlation between the intrinsic energy and duration for non-repeating FRBs at z < 0.3, with a Kendall τ correlation coefficient of 0.239 and a significance of 0.001 (statistically significant), whose slope looks similar to that of gamma-ray bursts. This correlation becomes weaker and insignificant at higher redshifts ( z > 0.3), possibly owing to the lack of faint FRBs at high z and/or the redshift evolution of the correlation. The 'scattering time' in the CHIME/FRB catalogue shows an intriguing trend: it varies along the line obtained from a linear fit on the energy versus duration plane between these two parameters. A possible cosmological application of the relationship must wait for more observations of faint FRBs at high z .