March 28, 2023


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What happens after the merger of massive binary white dwarfs? | Urania

Double white dwarfs are an important source of gravitational waves in our galaxy, and their mass is associated with Type Ia supernovae, electron-capture supernovae, and millisecond pulsars.

white dwarfs They can combine into binary systems due to radiation gravitational waves. However, the evolution of the fusion residue remains unclear.

Now, a research group led by Associate Professor WU Chengyuan of the Yunnan Observatories of the Chinese Academy of Sciences has investigated the evolutionary implications of the white dwarf’s oxygen, carbon-neon, and oxygen fusion processes.

I dropped out published In Astrophysical Journal Letters on February 22, 2023.

Scientists have built suitable models to study the evolution of the fusion remnants. They found that these fusion leftovers can evolve into carbon-oxygen giants, and their evolutionary performance is related to their total mass.

Assuming a constant loss of wind mass, remnants less than 1.9 solar masses could evolve into oxygen and neon white dwarfs, while remnants greater than 1.95 solar masses could experience explosions. supernovae With electron capture, they become oxygen-neon-iron white dwarfs.

The team used the models to explain the oxygen-rich body IRAS 00500 + 6713 (J005311) located in the infrared nebula in Cassiopeia. The spectrum of this body is similar to that of oxygen-rich Wolf-Rayet Stars It has a relatively high weight loss rate and a very high wind speed.

Currently, the origin of this object is still unclear. WU explained the features of observing the object with its models and found that the object formed from the fusion of a 1.08 solar mass oxygen-neon white dwarf with a 0.52 solar mass carbon-oxygen white dwarf.

See also  NASA: Huge amount of oxygen on the moon. Enough for all the people of the earth

Agnes Nowak

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Source: CAS

Pictured: merging white dwarfs. Credit: NASA/Todd Stromayer (GSFC)/Dana Berry (Chandra X-ray Observatory)