학술논문
Detection and Bulk Properties of the HR 8799 Planets with High-resolution Spectroscopy
Document Type
article
Author
Wang, Jason J; Ruffio, Jean-Baptiste; Morris, Evan; Delorme, Jacques-Robert; Jovanovic, Nemanja; Pezzato, Jacklyn; Echeverri, Daniel; Finnerty, Luke; Hood, Callie; Zanazzi, JJ; Bryan, Marta L; Bond, Charlotte Z; Cetre, Sylvain; Martin, Emily C; Mawet, Dimitri; Skemer, Andy; Baker, Ashley; Xuan, Jerry W; Wallace, J Kent; Wang, Ji; Bartos, Randall; Blake, Geoffrey A; Boden, Andy; Buzard, Cam; Calvin, Benjamin; Chun, Mark; Doppmann, Greg; Dupuy, Trent J; Duchêne, Gaspard; Feng, Y Katherina; Fitzgerald, Michael P; Fortney, Jonathan; Freedman, Richard S; Knutson, Heather; Konopacky, Quinn; Lilley, Scott; Liu, Michael C; Lopez, Ronald; Lupu, Roxana; Marley, Mark S; Meshkat, Tiffany; Miles, Brittany; Millar-Blanchaer, Maxwell; Ragland, Sam; Roy, Arpita; Ruane, Garreth; Sappey, Ben; Schofield, Tobias; Weiss, Lauren; Wetherell, Edward; Wizinowich, Peter; Ygouf, Marie
Source
The Astronomical Journal. 162(4)
Subject
Language
Abstract
Using the Keck Planet Imager and Characterizer, we obtained high-resolution (R ∼ 35,000) K-band spectra of the four planets orbiting HR 8799. We clearly detected H2O and CO in the atmospheres of HR 8799 c, d, and e, and tentatively detected a combination of CO and H2O in b. These are the most challenging directly imaged exoplanets that have been observed at high spectral resolution to date when considering both their angular separations and flux ratios. We developed a forward-modeling framework that allows us to jointly fit the spectra of the planets and the diffracted starlight simultaneously in a likelihood-based approach and obtained posterior probabilities on their effective temperatures, surface gravities, radial velocities, and spins. We measured v sin (i) values of 10.1-2.7+2.8km s-1 for HR 8799 d and 15.0-2.6+2.3 km s-1 for HR 8799 e, and placed an upper limit of