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Title: Information Content Analysis for Selection of Optimal JWST  Observing Modes for Transiting Exoplanet Atmospheres

Abstract

The James Webb Space Telescope ( JWST ) is nearing its launch date of 2018, and is expected to revolutionize our knowledge of exoplanet atmospheres. In order to specifically identify which observing modes will be most useful for characterizing a diverse range of exoplanetary atmospheres, we use an information content (IC) based approach commonly used in the studies of solar system atmospheres. We develop a system based upon these IC methods to trace the instrumental and atmospheric model phase space in order to identify which observing modes are best suited for particular classes of planets, focusing on transmission spectra. Specifically, the atmospheric parameter space we cover is T  = 600–1800 K, C/O = 0.55–1, [M/H] = 1–100 × Solar for an R  = 1.39 R{sub J}, M  = 0.59 M{sub J} planet orbiting a WASP-62-like star. We also explore the influence of a simplified opaque gray cloud on the IC. We find that obtaining broader wavelength coverage over multiple modes is preferred over higher precision in a single mode given the same amount of observing time. Regardless of the planet temperature and composition, the best modes for constraining terminator temperatures, C/O ratios, and metallicity are NIRISS SOSS+NIRSpec G395. If the target’s host star is dim enough such that themore » NIRSpec prism is applicable, then it can be used instead of NIRISS SOSS+NIRSpec G395. Lastly, observations that use more than two modes should be carefully analyzed because sometimes the addition of a third mode results in no gain of information. In these cases, higher precision in the original two modes is favorable.« less

Authors:
 [1];  [2]
  1. Department of Astronomy and Astrophysics, Pennsylvania State University, State College, PA 16802 (United States)
  2. School of Earth and Space Exploration, Arizona State University, Phoenix, AZ 85282 (United States)
Publication Date:
OSTI Identifier:
22663733
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 4; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; CHEMICAL ANALYSIS; CLOUDS; GAIN; METALLICITY; PHASE SPACE; PLANETS; SATELLITE ATMOSPHERES; SATELLITES; SOLAR SYSTEM; STARS; TELESCOPES; WAVELENGTHS

Citation Formats

Batalha, Natasha E., and Line, M. R., E-mail: neb149@psu.edu. Information Content Analysis for Selection of Optimal JWST  Observing Modes for Transiting Exoplanet Atmospheres. United States: N. p., 2017. Web. doi:10.3847/1538-3881/AA5FAA.
Batalha, Natasha E., & Line, M. R., E-mail: neb149@psu.edu. Information Content Analysis for Selection of Optimal JWST  Observing Modes for Transiting Exoplanet Atmospheres. United States. doi:10.3847/1538-3881/AA5FAA.
Batalha, Natasha E., and Line, M. R., E-mail: neb149@psu.edu. Sat . "Information Content Analysis for Selection of Optimal JWST  Observing Modes for Transiting Exoplanet Atmospheres". United States. doi:10.3847/1538-3881/AA5FAA.
@article{osti_22663733,
title = {Information Content Analysis for Selection of Optimal JWST  Observing Modes for Transiting Exoplanet Atmospheres},
author = {Batalha, Natasha E. and Line, M. R., E-mail: neb149@psu.edu},
abstractNote = {The James Webb Space Telescope ( JWST ) is nearing its launch date of 2018, and is expected to revolutionize our knowledge of exoplanet atmospheres. In order to specifically identify which observing modes will be most useful for characterizing a diverse range of exoplanetary atmospheres, we use an information content (IC) based approach commonly used in the studies of solar system atmospheres. We develop a system based upon these IC methods to trace the instrumental and atmospheric model phase space in order to identify which observing modes are best suited for particular classes of planets, focusing on transmission spectra. Specifically, the atmospheric parameter space we cover is T  = 600–1800 K, C/O = 0.55–1, [M/H] = 1–100 × Solar for an R  = 1.39 R{sub J}, M  = 0.59 M{sub J} planet orbiting a WASP-62-like star. We also explore the influence of a simplified opaque gray cloud on the IC. We find that obtaining broader wavelength coverage over multiple modes is preferred over higher precision in a single mode given the same amount of observing time. Regardless of the planet temperature and composition, the best modes for constraining terminator temperatures, C/O ratios, and metallicity are NIRISS SOSS+NIRSpec G395. If the target’s host star is dim enough such that the NIRSpec prism is applicable, then it can be used instead of NIRISS SOSS+NIRSpec G395. Lastly, observations that use more than two modes should be carefully analyzed because sometimes the addition of a third mode results in no gain of information. In these cases, higher precision in the original two modes is favorable.},
doi = {10.3847/1538-3881/AA5FAA},
journal = {Astronomical Journal (Online)},
number = 4,
volume = 153,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}