English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Understanding the physical processes sculpting the appearance of younggas-giant planets is complicated by degeneracies confounding effectivetemperature, surface gravity, cloudiness, and chemistry. To enable moredetailed studies, spectroscopic observations covering a wide range ofwavelengths is required. Here we present the first L-band spectroscopicobservations of HR 8799 d and e and the first low-resolution wide bandwidthL-band spectroscopic measurements of HR 8799 c. These measurements werefacilitated by an upgraded LMIRCam/ALES instrument at the LBT, together with anew apodizing phase plate coronagraph. Our data are generally consistent withprevious photometric observations covering similar wavelengths, yet thereexists some tension with narrowband photometry for HR 8799 c. With the additionof our spectra, each of the three innermost observed planets in the HR 8799system have had their spectral energy distributions measured with integralfield spectroscopy covering $\sim0.9$ to $4.1~\mu\mathrm{m}$. We combine thesespectra with measurements from the literature and fit synthetic modelatmospheres. We demonstrate that the bolometric luminosity of the planets isnot sensitive to the choice of model atmosphere used to interpolate betweenmeasurements and extrapolate beyond them. Combining luminosity with age andmass constraints, we show that the predictions of evolutionary models arenarrowly peaked for effective temperature, surface gravity, and planetaryradius. By holding these parameters at their predicted values, we show thatmore flexible cloud models can provide good fits to the data while beingconsistent with the expectations of evolutionary models.

L-band Integral Field Spectroscopy of the HR 8799 Planetary System