English

Resolving the Super-Earth/Gas Giant Connection in Stellar Mass and Metallicity

Earth and Planetary Astrophysics 2025-02-05 v1 Astrophysics of Galaxies Solar and Stellar Astrophysics

Abstract

The observed correlation between inner super-Earths and outer gas giants places strong constraints on formation theories. Building on previous work, Bryan &\& Lee 2024 showed that there is a statistically significant positive correlation between super-Earths and outer gas giants around metal-rich FGK stars, and that this correlation disappears for metal-poor hosts. Here we consider how this connection evolves across stellar mass. Starting with our sample of 85 M-dwarfs (<<0.6 M_{\odot}) hosting inner super-Earths, we calculate P(GG|SE, [Fe/H]>>0) = 9.4 (+10.2 -3.1)%\% and P(GG|SE, [Fe/H]\leq0)<<3.1%\%. Compared to the field gas giant frequency calculated from the Rosenthal et al 2021 sample, we find P(GG|[Fe/H]>>0) = 10.3 (+6.9 -3.1)%\%, and P(GG|[Fe/H]\leq0)<<2.6%\% for M-dwarfs. While we see a higher gas giant frequency around metal-rich M-dwarfs for both samples, we find no significant correlations between super-Earths and gas giants. Combining our 85 M-dwarf sample with our FGK sample from Bryan &\& Lee 2024, we resolve the SE/GG correlation in stellar mass (0.3--1.5 M_{\odot}) and metallicity. We show the positive correlation emerges in metal-rich K-dwarfs and strengthens with increasing stellar mass. Gas giant properties also impact the correlation -- for metal rich stars, the positive correlation is strengthened by: 1) dynamically hot gas giants for all stellar masses; 2) distant gas giants only for higher mass stars; and 3) single gas giants for K-dwarfs and multiple gas giants around more massive stars. We discuss how the stellar mass dependence of the inner-outer planet correlation can be understood from the increasing disk mass budget for higher mass stars.

Keywords

Cite

@article{arxiv.2502.01748,
  title  = {Resolving the Super-Earth/Gas Giant Connection in Stellar Mass and Metallicity},
  author = {Marta L. Bryan and Eve J. Lee},
  journal= {arXiv preprint arXiv:2502.01748},
  year   = {2025}
}

Comments

accepted to ApJL