A stellar dynamical mass measurement of an inactive black hole at redshift 2

Understand

Supermassive black holes and their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties.

• Determining the evolution of these correlations requires precise measurements of the masses of distant black holes.
• We observe the gravitationally lensed quiescent galaxy MRG-M0138, at redshift 1.95, using JWST integral field spectroscopy to spatially resolve the kinematics of stars within the black hole's sphere of influence.
• By using a foreground lens model and fitting stellar dynamical models, we determine the mass of its inactive black hole, $M_{\bullet}=6.0^{+2.1}_{-1.7}\times10^9$ solar masses.