SIMBAD references

We have imaged the Sgr B2 Main region with the Very Large Array in the BnA configuration (θ_beam= 0".13) in both the H52α (45.453 GHz) radio recombination line and 7 mm continuum emission. At a distance of 8500 pc, this spatial resolution corresponds to a physical scale of 0.005 pc (∼1100 AU). The current observations detect H52α emission in 12 individual ultracompact and hypercompact H II regions. Two of the sources with detected H52α emission have broad (ΔV_FWHM∼ 50 km/s) recombination lines, and two of the sources show lines with peaks at more than one velocity. We use line parameters from the H52α lines and our previous H66α line observations to determine the relative contribution of thermal, pressure, and kinematic broadening, and electron density. These new observations suggest that pressure broadening can account for the broad lines in some of the sources, but that gas motions (e.g., turbulence, accretion, or outflow) contribute significantly to the broad lines in at least one of the sources (Sgr B2 F3).