GeminiFocus 2019 Year in Review | Page 9

filters, but also with long- slit optical spectroscopy. FRB 180916. J0158 + 65 was found to be at the apex of a prominent V-shaped star-forming region of a spiral galaxy located at a redshift of 0.0337, or about 149.0 Megaparsecs. Figure 2 shows both the optical image and the spectra at both the location of FRB 180916. J0158 + 65 and from the core of the galaxy. Figure 2. Gemini North image and optical spectra of the source. Panel A shows the r image of the host galaxy and a zoom-in of the star-forming region where FRB 180916. J0158 + 65 is located (highlighted by the white cross and red circle, respectively). The uncertainty in the position of FRB 180916.J0158 + 65 is smaller than the resolution of the optical image. Panel B shows the spectrum extracted from a 2-arcsecond aperture around the position of FRB 180916.J0158 + 65 (orange) and a 5-arcsecond aperture around the core of the host galaxy (blue). Significant emission lines are labeled. Towards the Understanding of FRBs The host and local envi- ronment of FRB 180916. J0158 + 65 is markedly dif- ferent and less extreme than that of the first re- peating FRB, which was located inside a low-metal- licity star-forming region of a dwarf galaxy, and associ- ated with a very compact (< 0.7 parsecs) per- sistent radio counterpart of unclear origin. This new host also contrasts with the mas- sive elliptical galaxies where two of the three localized non-repeating FRBs were located, where little or no star-formation is present. However, it may be consistent with the star- forming galaxy associated with the third lo- calized non-repeater. The observed diversity in hosts and local environments may point to multiple classes of FRBs with different progenitors. Many scenarios were proposed to explain FRB 121102, the first repeating FRB. Several of them proposed that the bursts originate from a young and rapidly rotating magne- tar, either interacting with a superluminous January 2020 / 2019 Year in Review supernova or a massive black hole. The for- mer models could still explain FRB 180916. J0158 + 65 by invoking an older source, of approximately 300 years, whereas the latter seems to be less likely in this case given the location in the host galaxy (see Marcote et al., 2020, for further details). The origin of FRBs remains unclear, and a large number of precise localizations will be required to establish the ultimate physical conditions required to produce these kinds of bursts. The proximity of FRB 180916. J0158 + 65, the closest FRB so-far localized, allows dedicated observations across the full electromagnetic spectrum, from radio to very high energy gamma rays, to search for prompt or persistent multiwavelength GeminiFocus 7