Detection of a compact nuclear radio source in the Local Group elliptical galaxy M32

The Local Group compact elliptical galaxy M32 hosts one of the nearest candidate supermassive black holes (SMBHs), which has a previously suggested X-ray counterpart. Based on sensitive observations taken with the Karl G. Jansky Very Large Array (VLA), we detect for the first time a compact radio source coincident with the nucleus of M32, which exhibits an integrated flux density of $\sim 47.3\pm 6.1\mu Jy$ at 6.6 GHz. We discuss several possibilities for the nature of this source, favoring an origin of the long-sought radio emission from the central SMBH, for which we also revisit the X-ray properties based on recently acquired Chandra and XMM-Newton data. Our VLA observations also discover radio emission from three previously known optical planetary nebulae in the inner region of M32.