Bower, Geoffrey C.Markoff, SeraDexter, JasonGurwell, MarkMoran, JamesBrunthaler, AndreasFalcke, HeinoFragile, P. ChrisMaitra, DipankarMarrone, DanPeck, AlisonRushton, AnthonyWright, Melvyn C. H.2017-05-182015Bower, Geoffrey C., Sera Markoff, Jason Dexter, Mark A. Gurwell, James M. Moran, Andreas Brunthaler, Heino Falcke, et al. 2015. “Radio and Millimeter Monitoring of Sgr A*: Spectrum, Variability, and Constraints on the G2 Encounter.” The Astrophysical Journal 802 (1) (March 24): 69. doi:10.1088/0004-637x/802/1/69.1538-4357http://nrs.harvard.edu/urn-3:HUL.InstRepos:32715177We report new observations with the Very Large Array, Atacama Large Millimeter Array, and Submillimeter Array at frequencies from 1.0 to 355 GHz of the Galactic Center black hole, Sagittarius A*. These observations were conducted between 2012 October and 2014 November. While we see variability over the whole spectrum with an amplitude as large as a factor of 2 at millimeter wavelengths, we find no evidence for a change in the mean flux density or spectrum of Sgr A* that can be attributed to interaction with the G2 source. The absence of a bow shock at low frequencies is consistent with a cross-sectional area for G2 that is less than 2 10 ´ 29 cm2. This result fits with several model predictions including a magnetically arrested cloud, a pressure-confined stellar wind, and a stellar photosphere of a binary merger. There is no evidence for enhanced accretion onto the black hole driving greater jet and/or accretion flow emission. Finally, we measure the millimeter wavelength spectral index of Sgr A* to be flat; combined with previous measurements, this suggests that there is no spectral break between 230 and 690 GHz. The emission region is thus likely in a transition between optically thick and thin at these frequencies and requires a mix of lepton distributions with varying temperatures consistent with stratification.en-USblack hole physicsaccretiongalaxies: jetsgalaxies: activeGalaxy: centerJournal Article2017-02-2820152017-05-1810.1088/0004-637x/802/1/69