1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales

Understand

Sagittarius A*, the ~4 x 10^6 solar mass black hole candidate at the Galactic Center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength Very Long Baseline Interferometry (VLBI).

• We report on 1.3 mm wavelength observations of Sgr A* using a VLBI array consisting of the JCMT on Mauna Kea, the ARO/SMT on Mt.
• Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California.
• Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines.