2014MNRAS.440..353B

The recent detection of fast radio bursts has generated strong interest in identifying the origin of these bright, non-repeating, highly dispersed pulses. The principal limitation in understanding the origin of these bursts is the lack of reliable distance estimates; their high dispersion measures imply that they may be at cosmological distances (0.1 < z < 1.0). Here, we discuss new distance constraints to the FRB010621 (a.k.a J1852-08) first reported by Keane. We use velocity resolved Hα and Hβ observations of diffuse ionized gas towards the burst to calculate an extinction-corrected emission measure along the line of sight. We combine this emission measure with models of Galactic rotation and of electron distribution to derive a 90 percent probability of the pulse residing in the Galaxy. However, we cannot differentiate between the two Galactic interpretations of Keane: a neutron star with unusual pulse amplitude distribution or Galactic black hole annihilation.