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Reliably identifying active galactic nuclei (AGNs) in dwarf galaxies is keyto understanding black hole demographics at low masses and constraining modelsfor black hole seed formation. Here we present Chandra X-ray Observatoryobservations of eleven dwarf galaxies that were chosen as AGN candidates usingWide-field Infrared Survey Explorer (WISE) mid-infrared (mid-IR) color-colorselection. Hubble Space Telescope images are also presented for ten of thegalaxies. Based on Sloan Digital Sky Survey spectroscopy, six galaxies in oursample have optical evidence for hosting AGNs and five are classified asstar-forming. We detect X-ray point sources with luminosities above thatexpected from X-ray binaries in the nuclei of five of the six galaxies withoptical evidence of AGNs. However, the X-ray emission from these AGNs isgenerally much lower than expected based on AGN scaling relations with infraredand optical tracers. We do not find compelling evidence for AGNs in the fiveoptically-selected star-forming galaxies despite having red mid-IR colors. Onlytwo are detected in X-rays and their properties are consistent withstellar-mass X-ray binaries. Based on this multiwavelength study, we concludethat two-color mid-IR AGN diagnostics at the resolution of WISE cannot be usedto reliably select AGNs in optically-star-forming dwarf galaxies. Futureobservations in the infrared with the James Webb Space Telescope offer apromising path forward.

A Chandra and HST View of WISE-Selected AGN Candidates in Dwarf Galaxies