NGC 3115 is the nearest galaxy hosting a billion solar mass black hole and is also a low-luminosity active galactic nucleus ( LLAGN ) .
X-ray observations of this LLAGN are able to spatially resolve the hot gas within the sphere of gravitational influence of the supermassive black hole .
These observations make NGC 3115 an important testbed for black hole accretion theory in galactic nuclei since they constrain the outer boundary conditions of the hot accretion flow .
We present a compilation of the multiwavelength spectral energy distribution ( SED ) of the nucleus of NGC 3115 from radio to X-rays .
We report the results from modeling the observed SED with radiatively inefficient accretion flow ( RIAF ) models .
The radio emission can be well-explained by synchrotron emission from the RIAF without the need for contribution from a relativistic jet .
We obtain a tight constraint on the RIAF density profile , \rho ( r ) \propto r ^ { -0.73 _ { -0.02 } ^ { +0.01 } } , implying that mass-loss through subrelativistic outflows from the RIAF is significant .
The lower frequency radio observation requires the synchrotron emission from a nonthermal electron population in the RIAF , similarly to Sgr A* .