Falcke, H.: Radio Variability of Sgr A*

Radio Variability of Sgr A* at Centimeter Wavelengths

Falcke H.1,2

1Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany (hfalcke@mpifr-bonn.mpg.de)
2Steward Observatory, The University of Arizona, Tucson, AZ 85721

to appear in: "The Central Parsecs of the Galaxy", eds. H. Falcke, A. Cotera, W. Duschl, F. Melia, M. Rieke, ASP Conf. Series


Results of two years of continuous monitoring of flux density variations at 8.3 and 2.25 GHz of the Galactic Center super-massive black hole candidate Sgr A* are reported. The average RMS modulation indices are 6% and 2.5% at 8.3 & 2.3 GHz respectively. There is a certain degree of correlation between both frequencies. The timescale of variability at 8.3 & 2.3 GHz is between 50 and 200 days. We cannot confirm a lambda2 dependence of the timescale. At 2.25 GHz a quasi-periodic behaviour with a period of 57 days was discovered which is reminiscent to, though longer than those found in some compact extragalactic radio sources.

Paper: Available in full length as PostScript and LaTex Format.

Other publications can be found here.

Questions: Heino Falcke, hfalcke@mpifr-bonn.mpg.de