The physical properties of $\gamma$-ray quiet flat-spectrum radio quasars: why are they undetected by $Fermi$-LAT?

Xue-Jiao Deng, Rui Xue, Ze-Rui Wang +4

During a decade of the $Fermi$-Large Area Telescope (LAT) operation, thousands of blazars have been detected in the $\gamma$-ray band. However, there are still numbers of blazars that h…