Short Time Scale Variation in the Sub-millimeter Flux of Sgr A*
Abstract
We report a reliable detection of short time scale variations of less than one hour in the 340 GHz flux of SgrA* . Using the ALMA Cycle 3 data, we obtain 1630 snapshot images with 10 seconds exposure of the 25"× 25" field centered on SgrA*. We measure the intensity of SgrA* relative to those of non-variable sources in the field. The relative flux densities of SgrA* show rapid and large variations (26-67%) over a period of 1-3 hours. The intensity variation includes two characteristic time scales less than an hour: the longer one is more than a thousand seconds but less than three thousand seconds, and the shorter one is around one minute, or even shorter. Both are found commonly in all the four observing epochs.
- Publication:
-
New Horizons in Galactic Center Astronomy and Beyond
- Pub Date:
- July 2021
- Bibcode:
- 2021ASPC..528..259M