Time–Frequency Correlation of Repeating Fast Radio Bursts: Correlated Aftershocks Tend to Exhibit Downward Frequency Drifts

Shotaro Yamasaki and Tomonori Totani
{"title":"Time–Frequency Correlation of Repeating Fast Radio Bursts: Correlated Aftershocks Tend to Exhibit Downward Frequency Drifts","authors":"Shotaro Yamasaki and Tomonori Totani","doi":"10.3847/2041-8213/adc10b","DOIUrl":null,"url":null,"abstract":"The production mechanism of fast radio bursts (FRBs)—mysterious, bright, millisecond-duration radio flashes from cosmological distances—remains unknown. Understanding potential correlations between burst occurrence times and various burst properties may offer important clues about their origins. Among these properties, the spectral peak frequency of an individual burst (the frequency at which its emission is strongest) is particularly important because it may encode direct information about the physical conditions and environment at the emission site. Analyzing over 4000 bursts from the three most active sources—FRB 20121102A, FRB 20201124A, and FRB 20220912A—we measure the two-point correlation function ξ(Δt, Δνpeak) in the two-dimensional space of time separation Δt and peak frequency shift Δνpeak between burst pairs. We find a universal trend of asymmetry about Δνpeak at high statistical significance; ξ(Δνpeak) decreases as Δνpeak increases from negative to positive values in the region of short time separation (Δt ≲ 0.3 s), where physically correlated aftershock events produce a strong time correlation signal. This indicates that aftershocks tend to exhibit systematically lower peak frequencies than mainshocks, with this tendency becoming stronger at shorter Δt. We argue that the “sad trombone effect”—the downward frequency drift observed among subpulses within a single event—is not confined within a single event but manifests as a statistical nature that extends continuously to independent yet physically correlated aftershocks with time separations up to Δt ∼ 0.3 s. This discovery provides new insights into underlying physical processes of repeater FRBs.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"61 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Astrophysical Journal Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3847/2041-8213/adc10b","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

The production mechanism of fast radio bursts (FRBs)—mysterious, bright, millisecond-duration radio flashes from cosmological distances—remains unknown. Understanding potential correlations between burst occurrence times and various burst properties may offer important clues about their origins. Among these properties, the spectral peak frequency of an individual burst (the frequency at which its emission is strongest) is particularly important because it may encode direct information about the physical conditions and environment at the emission site. Analyzing over 4000 bursts from the three most active sources—FRB 20121102A, FRB 20201124A, and FRB 20220912A—we measure the two-point correlation function ξ(Δt, Δνpeak) in the two-dimensional space of time separation Δt and peak frequency shift Δνpeak between burst pairs. We find a universal trend of asymmetry about Δνpeak at high statistical significance; ξ(Δνpeak) decreases as Δνpeak increases from negative to positive values in the region of short time separation (Δt ≲ 0.3 s), where physically correlated aftershock events produce a strong time correlation signal. This indicates that aftershocks tend to exhibit systematically lower peak frequencies than mainshocks, with this tendency becoming stronger at shorter Δt. We argue that the “sad trombone effect”—the downward frequency drift observed among subpulses within a single event—is not confined within a single event but manifests as a statistical nature that extends continuously to independent yet physically correlated aftershocks with time separations up to Δt ∼ 0.3 s. This discovery provides new insights into underlying physical processes of repeater FRBs.
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信