Using Keck Planet Imager and Characterizer (KPIC) high-resolution (R~35000) spectroscopy from 2.29-2.49 μm, we present uniform atmospheric retrievals for eight young substellar companions with masses of ~10-30 MJup, orbital separations […]
![Left: C/O as a function of projected separation or semi-major axis for the eight companions in this study. The points are sized by companion mass, using the mass legend in the right panel. The blue line and region show the solar C/O value from Asplund et al. (2021). Right: In color: 1σ contours of C/O and [C/H] for the eight companions, which are all consistent with solar composition (intersection of dashed gray lines) to the 2σ level. In § 6.4.1, we justify that their host stars likely have solar composition as well. We overplot hot Jupiters which have abundance measurements for at least one oxygen-bearing and one carbon-bearing species from JWST or high-resolution spectroscopy as black points (Alderson et al. 2023; August et al. 2023; Bean et al. 2023; Bell et al. 2023; Brogi et al. 2023; Finnerty et al. 2024; Xue et al. 2024), which are also sized by mass. The hot Jupiters show considerable scatter and super-solar (and super-stellar) metallicities except for one planet, unlike our companions which cluster around solar (and stellar) composition. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/Are-These-Planets.png?resize=1200%2C719&ssl=1)
Using Keck Planet Imager and Characterizer (KPIC) high-resolution (R~35000) spectroscopy from 2.29-2.49 μm, we present uniform atmospheric retrievals for eight young substellar companions with masses of ~10-30 MJup, orbital separations […]