First constraints on the strength of the extragalactic magnetic field from γ-ray observations of GRB 221009A
arXiv (Cornell University)(2023)
摘要
The extragalactic magnetic field (EGMF) could be probed with γ-ray
observations of distant sources. Primary very high energy (VHE) γ-rays
from these sources absorb on extragalactic background light photons, and
secondary electrons/positrons from the pair production acts create cascade
γ-rays. These cascade γ-rays could be detected with space
γ-ray telescopes such as Fermi-LAT. The γ-ray burst GRB 221009A
was an exceptionally bright transient well suited for intergalactic
γ-ray propagation studies. Using publicly-available Fermi-LAT data, we
obtain upper limits on the spectrum of delayed emission from GRB 221009A during
the time windows of 10, 30, and 90 days after the burst, and compare these with
model spectra calculated for various EGMF strengths B, obtaining constraints
on B. We show that the values of B between 10^-20 G and 10^-18 G are
excluded.
更多查看译文
关键词
extragalactic magnetic field,grb 221009a,magnetic field
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要