The researchers found that the evolution of the WX Centauri ultra-fine X-ray source is dominated by magnetic winds

Researchers led by a Ph.D. Candidate Zang Lei and Professor Qian Shengbang of the Yunnan Observatories of the Chinese Academy of Sciences discovered that the orbital evolution of the WX Centauri ultrafine X-ray source (WX Cen) is dominated by angular momentum loss (AML) driven by the magnetic wind from the secondary donor and from the accretion disk alone or together.

This work was published in Astrophysical Journal On the 15th of February.

WX Cen is likely one of the galactic counterparts to binary ultrasmooth X-ray sources (CBSS), in which mass is transferred from a secondary donor to a primary massive white dwarf via an accretion disk.

To further study mass exchange and orbital evolution, the researchers analyzed orbital The contrast of WX Cen was detailed using continuous light curves from the Exoplanet Survey Satellite (TESS) and photometric observations collected by the American Association of Variable Stargazers (AAVSO) database. The result means that the orbital period is constantly decreasing.

Moreover, based on the results of previous research, the researchers estimated the secondary donor mass to be around 0.6 solar masswhen the mass of the white dwarf is about 0.9 solar masses.

By looking at conservative mass transfer from Donors Secondary to the white dwarf, WX Cen’s orbital period should increase, which is the opposite of the observed continuous decrease. Therefore, the authors speculated that the decrease in period could be plausibly explained as a consequence of AML induced by the magnetic winds from the secondary stage and from accretion. tweak alone or together.

Based on the above physics scenario, the researchers calculated the relationship between Alfvne’s radius and the mass loss rate of the system. They found that if the Alvin secondary radius became smaller than 20 solar radii, the rate of mass loss required to reduce the orbital period would be too high to be supported by stellar wind losses alone. and a radius of two thousand accumulator disc More than 5.5 solar radii.