FRB 121102 Is Coincident with a Star-forming Region in Its Host Galaxy

Abstract

We present optical, near-infrared, and mid-infrared imaging of the host galaxy of FRB 121102 with the Gemini North telescope, the Hubble Space Telescope , and the Spitzer Space Telescope . The FRB 121102 host galaxy is resolved, revealing a bright star-forming region located in the outskirts of the irregular, low-metallicity dwarf galaxy. The star-forming region has a half-light radius of 0.68 kpc ( ), encompassing the projected location of the compact ( pc), persistent radio source that is associated with FRB 121102. The half-light diameter of the dwarf galaxy is 5–7 kpc, and broadband spectral energy distribution fitting indicates that it has a total stellar mass of . The properties of the host galaxy of FRB 121102 are comparable to those of extreme emission line galaxies, also known as hosts to some hydrogen-poor superluminous supernovae and long-duration γ -ray bursts. The projected location of FRB 121102 within the star-forming region supports the proposed connection of FRBs with newly born neutron stars or magnetars.