Poster abstract details

We used a sample of NIR flares of Sgr A* observed in the polarimetry mode to study the nature of the observed quasi-periodic oscillations. Using the z-transformed discrete correlation function algorithm, we found a significant correlation between changes in the measured polarimetric data and total flux densities. This provides evidence that the variations probably do not originate from random changes in the accretion parameters. In order to constrain the physical properties of the emitting region we employed a relativistic disk model with an azimuthal over-density of relativistic electrons. A combination of a synchrotron mechanism and relativistic amplifications allows us to fit the real observed data, and make predictions about astrometric parameters of the accretion disk around Sgr A*. The modeled light curves show the same close to zero time-lag correlation between the flux and polarimetric data as has been deduced from observations.

The model enables us to constrain the expected direction of the collimated outflow from Sgr A*. The effects of gravitational shearing, fast synchrotron cooling of the components and confusion from a variable torus have been taken into account. Simulated centroids of NIR images lead us to the conclusion that any clear observation of position wander of the center of NIR images with future infrared interferometers will strongly prove the existence of orbiting hot spots in the vicinity of our Galactic super-massive black hole.