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Radio Variability of Sgr A* at Centimeter Wavelengths

Heino Falcke
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Abstract

Results of two years of continuous monitoring of flux density variations at 8.3 and 2.3 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 lambda^2 dependence of the timescale. At 2.3 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.

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Heino Falcke. 1999-09-27. Radio Variability of Sgr A* at Centimeter Wavelengths. https://arxiv.org/abs/astro-ph/9909441

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