PEARLS: A Potentially Isolated Quiescent Dwarf Galaxy with a TRGB Distance of 31 Mpc
Abstract
We have serendipitously identified a nearby quiescent isolated galaxy, known as PEARLSDG, in JWST imaging as part of the PEARLS GTO program. While a wealth of observations suggest that the vast majority of isolated classical dwarf galaxies are currently star-forming, recent observations of the large abundance of diverse low surface brightness galaxies beyond the reach of previous large spectroscopic surveys suggest that our understanding of the dwarf galaxy population may be incomplete. In PEARLS imaging, individual red-giant branch stars are visible in this near-IR imaging, suggesting a distance of 31 Mpc. Spectra obtained with the Lowell Discovery Telescope find a recessional velocity consistent with the Hubble Flow and >1500 km/s separated from the nearest massive galaxy in SDSS. The lack of emission lines in this spectrum, as well as a wealth of archival photometry point to an sSFR of 2x10-12 yr-1. These observations suggest that this galaxy was either quenched from internal mechanisms or had a very high-velocity interaction with a nearby massive galaxy in the past. This analysis highlights the possibility that many nearby quiescent dwarf galaxies are waiting to be discovered and that JWST has the potential to identify them.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- February 2024
- Bibcode:
- 2024AAS...24333803C