Kavli Affiliate: Erin Kara
| First 5 Authors: Emma T. Chickles, Kevin B. Burdge, Joheen Chakraborty, Vik S. Dhillon, Paul Draghis
| Summary:
Type Ia supernovae, critical for studying cosmic expansion, arise from
thermonuclear explosions of white dwarfs, but their precise progenitor pathways
remain unclear. Growing evidence supports the “double-degenerate” scenario,
where two white dwarfs interact. The absence of other companion types capable
of explaining the observed Ia rate, along with observations of hyper-velocity
white dwarfs interpreted as surviving companions of such systems provide
compelling evidence in favor of this scenario. Upcoming millihertz
gravitational wave observatories like the Laser Interferometer Space Antenna
(LISA) are expected to detect thousands of double-degenerate systems, though
the most compact known candidate Ia progenitors produce only marginally
detectable gravitational wave signals. Here, we report observations of ATLAS
J1138-5139, a binary white dwarf system with an orbital period of 28 minutes.
Our analysis reveals a 1 solar mass carbon-oxygen white dwarf accreting from a
helium-core white dwarf. Given its mass, the accreting carbon-oxygen white
dwarf is poised to trigger a typical-luminosity Type Ia supernova within a few
million years, or to evolve into a stably mass-transferring AM CVn system.
ATLAS J1138-5139 provides a rare opportunity to calibrate binary evolution
models by directly comparing observed orbital parameters and mass transfer
rates closer to merger than any previously identified candidate Type Ia
progenitor. Its compact orbit ensures detectability by LISA, demonstrating the
potential of millihertz gravitational wave observatories to reveal a population
of Type Ia progenitors on a Galactic scale, paving the way for multi-messenger
studies offering insights into the origins of these cosmologically significant
explosions.
| Search Query: ArXiv Query: search_query=au:”Erin Kara”&id_list=&start=0&max_results=3