Multi-wavelength observations of the lensed quasar PKS 1830$-$211 during the 2019 $\gamma$-ray flare

S. Vercellone, I. Donnarumma, C. Pittori +32

PKS 1830$-$211 is a $\gamma$-ray emitting, high-redshift (z $=2.507\pm 0.002$), lensed flat-spectrum radio quasar. During the period mid-February to mid-April 2019, this source underw…