High-Frequency Measurements of the Spectrum of Sagittarius A*

E. Serabyn, J. Carlstrom, O. Lay, D. C. Lis, T. R. Hunter,, J. H. Lacy, R. E. Hills
1997 Astrophysical Journal  
We report near-simultaneous interferometric measurements of the spectrum of Sagittarius A* over the 5-354 GHz range and single-dish observations that have yielded the first detection of Sgr A* at 850 GHz. We confirm that Sgr A*'s spectrum rises more steeply at short millimeter wavelengths than at centimeter wavelengths, leading to a near-millimeter/submillimeter excess that dominates its luminosity. Below 900 GHz, Sgr A*'s observed luminosity is 70 ‫ע‬ 30 L . A new upper limit to Sgr A*'s 24.3
more » ... m flux, together with a compilation of other , extant IR data, imply a far-infrared spectral turnover, which can result from either an intrinsic synchrotron cutoff or excess extinction near Sgr A*. If the former applies, Sgr A*'s total synchrotron luminosity is !10 3 L , while , in the latter case it is !3 # 10 4 L if spherical symmetry also applies.
doi:10.1086/311010 fatcat:xhr5zszrcnd4hmatabtabf7juu