The infrared L′-band view of the Galactic Center with NAOS-CONICA at VLT

Abstract

We report on Galactic Center L′-band observations made during NAOS/CONICA Science Verification. Colors of the inner 2″ stars reveal an infrared excess of S2, the closest star to the black hole, that could sign the first thermal infrared detection of Sgr A*. A multi-wavelength maximum likelihood analysis has allowed us to eliminate all but two of the candidates for gravitational lensing proposed by Alexander (2001). Our observations of the thin and intersecting structures of the Northern Arm could trace several shocks heating the neighbouring dust rather than a stream of matter in orbit around the central mass as previously thought.