Detecting Water In the atmosphere of HR 8799 c with L-band High Dispersion Spectroscopy Aided By Adaptive Optics

Abstract

High dispersion spectroscopy of brown dwarfs and exoplanets enables exciting science cases, e.g., mapping surface inhomogeneity and measuring spin rate. Here, we present $L$ band observations of HR 8799 c using Keck NIRSPEC (R=15,000) in adaptive optics (AO) mode (NIRSPAO). We search for molecular species (H${}_2$O and CH${}_4$) in the atmosphere of HR 8799 c with a template matching method, which involves cross correlation between reduced spectrum and a template spectrum. We detect H${}_2$O but not CH${}_4$, which suggests disequilibrium chemistry in the atmosphere of HR 8799 c, and this is consistent with previous findings. We conduct planet signal injection simulations to estimate the sensitivity of our AO-aided high dispersion spectroscopy observations. We conclude that $10^{-4}$ contrast can be reached in $L$ band. The sensitivity is mainly limited by the accuracy of line list used in modeling spectra and detector noise. The latter will be alleviated by the NIRSPEC upgrade.

arXiv comment14 pages, 5 figures, 5 tables, accepted for publication on AJ, references updated

References in corpus (35)

• Validation of the new Hipparcos reduction
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Images of a fourth planet orbiting HR 8799
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• A high accuracy computed water line list
• Line and Mean Opacities for Ultracool Dwarfs and Extrasolar Planets
• ExoMol line lists IV: The rotation-vibration spectrum of methane up to 1500 K
• The fast spin-rotation of a young extrasolar planet
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• Gaseous Mean Opacities for Giant Planet and Ultracool Dwarf Atmospheres over a Range of Metallicities and Temperatures
• Clouds and Chemistry: Ultracool Dwarf Atmospheric Properties from Optical and Infrared Colors
• Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b
• Imaging Spectroscopy for Extrasolar Planet Detection
• Masses, Radii, and Cloud Properties of the HR 8799 Planets
• Thermal Emission and Albedo Spectra of Super Earths with Flat Transmission Spectra
• Synthetic Spectra and Colors of Young Giant Planet Atmospheres: Effects of Initial Conditions and Atmospheric Metallicity
• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
• A global cloud map of the nearest known brown dwarf
• Simultaneous Detection of Water, Methane and Carbon Monoxide in the Atmosphere of Exoplanet HR8799b
• First light of the VLT planet finder SPHERE. III. New spectrophotometry and astrometry of the HR8799 exoplanetary system
• Atmospheric characterization of Proxima b by coupling the Sphere high-contrast imager to the Espresso spectrograph
• First light of the VLT planet finder SPHERE. IV. Physical and chemical properties of the planets around HR8799
• Directly Imaged L-T Transition Exoplanets in the Mid-Infrared
• Observing Exoplanets with High Dispersion Coronagraphy. I. The scientific potential of current and next-generation large ground and space telescopes
• Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection Unit
• Medium-resolution integral-field spectroscopy for high-contrast exoplanet imaging: Molecule maps of the $\beta$ Pictoris system with SINFONI
• The Orbit and Transit Prospects for $\beta$ Pictoris b constrained with One Milliarcsecond Astrometry
• The CHARA Array Angular Diameter of HR 8799 Favors Planetary Masses for Its Imaged Companions
• High Resolution 4.7 um Keck/NIRSPEC Spectra of Protostars. II: Detection of the 13CO Isotope in Icy Grain Mantles
• Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-Consistent Measurements
• VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit
• Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet
• Evidence for the Direct Detection of the Thermal Spectrum of the Non-Transiting Hot Gas Giant HD 88133 b

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• On the Chemical Abundance of HR 8799 and the Planet c
• Retrieving C and O Abundance of HR 8799 c by Combining High- and Low-Resolution Data
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• Dynamical Mass of the Exoplanet Host Star HR 8799
• Behind the Mask: can HARMONI@ELT detect biosignatures in the reflected light of Proxima b?
• High Resolution Spectroscopy and High Contrast Imaging with the ELT : looking for O${}_2$ in Proxima b
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• The mid-infrared spectrum of $\beta$ Pictoris b. First VLTI/MATISSE interferometric observations of an exoplanet
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