Surveying Flux Density in Galaxies with Apparent Large Black Holes at Millimeter/Submillimeter Wavelengths

Abstract We present millimeter and submillimeter continuum observations for 36 sources with potentially large black hole shadows at 230 345 GHz using the Submillimeter Array. The are selected based on criterion of diameter shadows. Our motivation is to explore nature accretion flow potential candidates low-luminosity active galactic nuclei (LLAGNs) through photometry millimeter/submillimeter wavelengths. detected result serves as pathfinder future high-angular resolution such Event Horizon Telescope. As a result, we successfully 17 eight GHz, respectively. reveal that three (IC 310, NGC 1277, 5846) show significant excess wavelengths in comparison extrapolation both from low-frequency radio infrared, which considered be attributed extended jet dust component, One possible explanation these excesses associated hot onto supermassive holes LLAGNs. By adopting advection-dominated model's semi-analytic model, obtained upper bound mass rate. Those less than 10 −2 M ̇ EDD , where Eddington rate computed via luminosity. This good agreement expected range ∼200 mJy flux densities negative spectral index IC 1459 within make it promising candidate experiments imaging shadow.