Measuring the effects of General Relativity at the Galactic Center with Future Extremely Large Telescopes

TL;DR

Future extremely large telescopes will enable precise tests of General Relativity near the Galactic Center by observing stellar orbits, detecting relativistic effects, and constraining dark mass with advanced simulations and adaptive optics.

Contribution

This paper presents realistic simulations of how next-generation telescopes can test GR effects and dark matter near the Galactic Center, including observational challenges and instrument constraints.

Findings

Simulations show improved detection of GR precession effects.

Enhanced sensitivity and astrometric precision improve constraints on dark mass.

The joint fit of over 100 stars can effectively test gravitational models.

Abstract

The Galactic center offers us a unique opportunity to test General Relativity (GR) with the orbits of stars around a supermassive black hole. Observations of these stars have been one of the great successes of adaptive optics on 8-10 m telescopes, driving the need for the highest angular resolution and astrometric precision. New tests of gravitational physics in the strong gravity regime with stellar orbits will be made possible through the leap in angular resolution and sensitivity from the next generation of extremely large ground-based telescopes. We present new simulations of specific science cases such as the detection of the GR precession of stars, the measurement of extended dark mass, and the distance to the Galactic center. We use realistic models of the adaptive optics system for TMT and the IRIS instrument to simulate these science cases. In additions, the simulations include observational issues such as the impact of source confusion on astrometry and radial velocities in the dense environment of the Galactic center. We qualitatively show how improvements in sensitivity, astrometric and spectroscopic precision, and increasing the number of stars affect the science with orbits at the Galactic center. We developed a tool to determine the constraints on physical models using a joint fit of over 100 stars that are expected to be observable with TMT. These science cases require very high astrometric precision and stability, thus they provide some of the most stringent constraints on the planned instruments and adaptive optics systems.