Searching for Ultracompact White Dwarf Binaries in Globular Clusters

ORAL

Abstract

Ultracompact white dwarf binaries or AM CVns are interacting hydrogen-poor binary star systems in short orbital periods consisting of either (i) two white dwarfs or (ii) a white dwarf and a helium-rich star. These systems are important for the studies of low-frequency gravitational waves and are expected to be progenitors of Type Ia Supernova. Moreover, AM CVns play a crucial role for the calibration of models employed in the study of binary star evolution. Due to stellar interactions, models suggest that the formation of AM CVns should be enhanced in globular clusters (GCs). However, no AM CVn has been confirmed to exist in a GC so far. We are doing the first dedicated search of outbursting AM CVns systems in the massive and low extinction GC 47 Tucanae using UV Hubble Space Telescope observations. We seek to identify them via their variable behavior and thus confirm that AM CVns can survive stellar interactions in GCs as models predict

*This research was funded by HST-GO-16217. We would also like to acknowledge NASA for their support and STScI for scheduling our observations. These observations are associated with Hubble Space Telescope observing program 16217.

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Presenters

  • Miriam Ramos Arevalo

    • University of Texas Rio Grande Valley

Authors

  • Miriam Ramos Arevalo

    • University of Texas Rio Grande Valley

  • Liliana E Rivera Sandoval

    • University of Texas Rio Grande Valley

  • Thomas J Maccarone

    • Texas Tech University

  • Craig Heinke

    • University of Alberta

  • Andrea Dieball

    • Helmholtz-Institut fur Strahlen- und Kernphysik, Uni Bonn

  • Christian Knigge

    • University of Southampton

  • David R Zurek

    • American Museum of Natural History