Confining Burst Energy Function and Spectral Fringe Pattern of FRB 20121102A with Multifrequency Observations

Abstract The observed spectral shapes variation and tentative bimodal burst energy distribution (E-distribution) of fast radio (FRB) 20121102A with the FAST telescope are great puzzles. Adopting published multifrequency data Arecibo telescopes at L band Green Bank Telescope (GBT) C band, we investigate these puzzles through Monte Carlo simulations. intrinsic function (E-function) is modeled as dp / mathvariant="italic">dE ? E ? ? mathvariant="normal">E , profile described a Gaussian function. A fringe pattern its peak frequency ( ? p ) in 0.5–8 GHz inferred from GBT sample. We estimate likelihood ? E standard deviation ? s by utilizing Kolmogorov–Smirnov test probability for simulated specific E-distributions. Our simulations yield ${\alpha }_{{\rm{E}}}={1.82}_{-0.30}^{+0.10}$?> = 1.82 0.30 + 0.10 ${\sigma }_{{\rm{s}}}={0.18}_{-0.06}^{+0.28}$?> ? mathvariant="normal">s 0.18 0.06 0.28 (3 confidence level) These results suggest that single power-law adequate to model E-function FRB 20121102A. variations indices E-distributions different ranges due both physical observational reasons, i.e., narrow width discrete broad range among bursts, selection effects bandpass sensitivity. putative cannot be explained current radiation physics models FRBs. Some caveats possible artificial may introduce such feature discussed.