Improved time-delay lens modelling and $H_0$ inference with transient sources

Understand

Strongly lensed explosive transients such as supernovae, gamma-ray bursts, fast radio bursts, and gravitational waves are very promising tools to determine the Hubble constant ($H_0$) in the near future in addition to strongly lensed quasars.

• In this work, we show that the transient nature of the point source provides an advantage over quasars: the lensed host galaxy can be observed before or after the transient's appearance.
• Therefore, the lens model can be derived from images free of contamination from bright point sources.
• We quantify this advantage by comparing the precision of a lens model obtained from the same lenses with and without point sources.