The Mid-Infrared RR Lyrae Period-Luminosity Relation

ORAL

Abstract

We present new period-luminosity (PL) relations for RR Lyrae variable stars in the globular cluster Omega Centauri in 3.6 and 4.5 microns, derived from time-resolved data from the Spitzer Warm Mission. We will discuss how these relations compare to previous work on RR Lyrae in other wavelengths and clusters, particularly with regards to the metallicity effect on the PL relation; as Omega Centauri contains over 100 RR Lyrae with literature values for metallicities spanning roughly 1.5 dex, it is the ideal cluster in which to study metallicity effects. Theoretical work has predicted no metallicity term in the mid-infrared PL relation, which this data corroborates.

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Authors

  • Meredith Durbin

    • Pomona College

  • Victoria Scowcroft

    • Carnegie Observatories

  • Wendy Freedman

    • Carnegie Observatories

  • Barry Madore

    • Carnegie Observatories

  • Andy Monson

    • Carnegie Observatories

  • Mark Seibert

    • Carnegie Observatories

  • Jeff Rich

    • Carnegie Observatories