Subarcsecond imaging of 3C 123: 108 GHz continuum observations of the radio hot spots

We present the results of subarcsecond 108 GHz continuum interferometric observations toward the radio-luminous galaxy 3C 123. Using multiarray observations, we utilize the high-u, v dynamic range of the BIMA millimeter array to sample fully spatial scales ranging from 0″.5 to 50″. This allows us to make one-to-one comparisons of millimeter-wavelength emission in the radio lobes and hot spots to VLA centimeter observations at 1.4, 4.9, 8.4, and 15 GHz, At 108 GHz, the bright, eastern double hot spot in the southern lobe is resolved. This is only the second time that a multiple hot spot region has been resolved in the millimeter regime. We model the synchrotron spectra of the hot spots and radio lobes using simple broken power-law models with high-energy cutoffs and discuss the hot spot spectra and their implications for models of multiple hot spot formation.