Exoplanet characterization with long slit spectroscopy

Abstract

Extrasolar planets observation and characterization by high contrast imaging instruments is set to be a very important subject in observational astronomy. Dedicated instruments are being developed to achieve this goal with very high efficiency. In particular, full spectroscopic characterization of low temperature planetary companions is an extremely important milestone. We present a new data analysis method for long slit spectroscopy (LSS) with coronagraphy, which allows characterization of planetary companions of low effective temperature. In a speckle-limited regime, this method allows an accurate estimation and subtraction of the scattered starlight, to extract a clean spectrum of the planetary companion. We performed intensive LSS simulations with IDL/CAOS to obtain realistic spectra of low (R=35) and medium (R=400) resolution in the J, H, and K bands. The simulated spectra were used to test our method and estimate its performance in terms of contrast reduction and extracted spectra quality. Our simulations are based on a software package dedicated to the development of SPHERE, a second generation instrument for the ESO-VLT. Our method allows a contrast reduction of 0.5 to 2.0 magnitudes compared to the coronagraphic observations. For M0 and G0 stars located at 10 pc, we show that it would lead to the characterization of companions with Teff of 600 K and 900 K respectively, at angular separations of 1.0 as. We also show that errors in the wavelength calibration can produce significant errors in the characterization, and must therefore be minimized as much as possible.

10 pages, 12 figures, 3 tables, accepted for publication in A&A

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Cited by in corpus (34)

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• Imaging Extrasolar Giant Planets
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• Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor
• Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
• First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Tel and HD 1160 revisited
• Spatially resolved spectroscopy of the exoplanet HR 8799 c
• The near-infrared spectral energy distribution of β Pictoris b
• First light of the VLT planet finder SPHERE. I. Detection and characterization of the sub-stellar companion GJ 758 B
• Multiple rings in the transition disk and companion candidates around RXJ1615.3-3255. High contrast imaging with VLT/SPHERE
• Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory
• Application of a damped Locally Optimized Combination of Images method to the spectral characterization of faint companions using an Integral Field Spectrograph
• High-Cadence, High-Contrast Imaging for Exoplanet Mapping: Observations of the HR 8799 Planets with VLT/SPHERE Satellite Spot-Corrected Relative Photometry
• Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. II. Concept validation with ZELDA on VLT/SPHERE
• Apodized Pupil Lyot Coronagraphs for Arbitrary Apertures. IV. Reduced Inner Working Angle and Increased Robustness to Low-Order Aberrations
• Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+
• Using Data Imputation for Signal Separation in High Contrast Imaging
• Discovery of a brown dwarf companion to the star HIP 64892
• Characterizing HR3549B using SPHERE
• Early Results from VLT-SPHERE: Long-Slit Spectroscopy of 2MASS 0122-2439B, a Young Companion Near the Deuterium Burning Limit
• Improved achromatization of phase mask coronagraphs using colored apodization
• The ESO SupJup Survey II: The 12C/13C ratios of three young brown dwarfs with CRIRES${}^{+}$
• High-contrast spectroscopy of SCR J1845-6357 B
• The ESO SupJup Survey IV. Unveiling the carbon isotope ratio of GQ Lup B and its host star
• Characterising brown dwarf companions with IRDIS long-slit spectroscopy: HD 1160 B and HD 19467 B
• Orbiting a binary: SPHERE characterisation of the HD 284149 system
• Apodization in high-contrast long-slit spectroscopy. II. Concept validation and first on-sky results with VLT/SPHERE
• Apodization in high-contrast long-slit spectroscopy. Closer, deeper, fainter, cooler
• Exoplanet Atmosphere Measurements from Direct Imaging
• SAFARI I: A SPHERE discovery of a super metal-rich M dwarf companion to the star HD 86006
• Ionized regions in the central arcsecond of NGC 1068. YJHK spatially resolved spectroscopy
• New insights on the central stellar population and gas outflow in NGC 1068 from YJH spectroscopy with SPHERE/VLT
• The mid-infrared spectrum of $\beta$ Pictoris b. First VLTI/MATISSE interferometric observations of an exoplanet
• Characterization of stellar companion from high-contrast long-slit spectroscopy data: The EXtraction Of SPEctrum of COmpanion (EXOSPECO) algorithm