English

Dynamical masses across the Hertzsprung-Russell diagram

Solar and Stellar Astrophysics 2024-10-07 v1 Astrophysics of Galaxies

Abstract

We infer the dynamical masses of stars across the Hertzsprung-Russell (H-R) diagram using wide binaries from the Gaia survey. Gaia's high-precision astrometry measures the wide binaries' orbital motion, which contains the mass information. Using wide binaries as the training sample, we measure the mass of stars across the two-dimensional H-R diagram using the combination of statistical inference and neural networks. Our results provide the dynamical mass measurements for main-sequence stars from 0.1 to 2 M_\odot, unresolved binaries and unresolved triples on the main sequence, and the mean masses of giants and white dwarfs. Two regions in the H-R diagram show interesting behaviors in mass, where one of them is pre-main-sequence stars, and the other one may be related to close compact object companions like M dwarf-white dwarf binaries. These mass measurements depend solely on Newtonian dynamics, providing independent constraints on stellar evolutionary models and the occurrence rate of compact objects.

Keywords

Cite

@article{arxiv.2308.08584,
  title  = {Dynamical masses across the Hertzsprung-Russell diagram},
  author = {Hsiang-Chih Hwang and Yuan-Sen Ting and Sihao Cheng and Joshua S. Speagle},
  journal= {arXiv preprint arXiv:2308.08584},
  year   = {2024}
}

Comments

Fig. 5 and Fig. 12 are the key results. Submitted to MNRAS. Comments are welcome!