No Microwave Flare of Sagittarius A* around the G2 Periastron Passing

Abstract

In order to explore any change caused by the G2 cloud approaching, we have monitored the flux density of Sgr A* at 22 GHz from Feb. 2013 to Aug. 2014 with a sub-array of Japanese VLBI Network . The observation period included the expected periastron dates. The number of observation epochs was 283 days. We have observed no significant microwave enhancement of Sgr A* in the whole observation period. The average flux density in the period is $S=1.23+/-0.33$ Jy. The average is consistent with the usually observed flux density range of Sgr A* at 22 GHz.

Accepted for publication in Astrophysical Journal Letters, 14 pages, 1 figure

References in corpus (4)

• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Flaring Activity of Sgr A* at 43 and 22 GHz: Evidence for Expanding Hot Plasma
• Detection of Galactic Center source G2 at 3.8 $\mu$m during periapse passage
• Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei

Cited by in corpus (4)

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• Close stellar encounters at the Galactic Centre I: The effect on the observed stellar populations
• Closing the gap: Follow-up observations of peculiar dusty objects close to Sgr A* using ERIS