Calibrating the RR Lyrae Population in WLM with HST and JWST ERS
Abstract
RR Lyrae are a common, dependable Population II distance indicator, and provide an independent tracer of early star formation. Here, we utilize deep archival HST/ACS and JWST/NIRCam early release science (ERS) observations of nearby dwarf star-forming galaxy WLM to undertake a first study of RR Lyrae in JWST filters. We independently identify RR Lyrae in HST and JWST imaging in order to evaluate JWST's efficiency at finding RR Lyrae in the near-IR. We use an MCMC template-fitting technique to obtain the periods, amplitudes, and mean magnitudes from the RR Lyrae time-series data in both HST and JWST filters. The spatially overlapping HST and JWST observations allow us to directly compare properties of the same RR Lyrae observed with the two different instruments, as well as tie the JWST RR Lyrae properties to the Gaia distance scale, which has been calibrated using HST. With the improved angular resolution of JWST over previous generations of space telescope, our calibrations lay the groundwork to find and characterize RR Lyrae in increasingly distant galaxies.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- June 2024
- Bibcode:
- 2024AAS...24410109S