Second Repeating FRB 180814.J0422+73: Ten-year Fermi-LAT Upper limits and Implications

Understand

The second repeating fast radio burst source, FRB 180814.J0422+73, was detected recently by the CHIME collaboration.

• We use the ten-year Fermi Large Area Telescope (LAT) archival data to place a flux upper limit in the energy range of 100 MeV$-$10 GeV at the position of the source, which is $\sim 10^{-11}$ erg cm$^{-2}$ s$^{-1}$ for a six-month time bin on average, and $2.35\times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$ for the entire ten-year time span.
• For the maximum redshift of $z=0.11$, the ten-year upper limit of luminosity is $7.32\times 10^{43}$ erg s$^{-1}$.
• We utilize these upper limits to constrain the FRB progenitor and central engine.