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Near-infrared Emission Spectrum of WASP-103b Using Hubble Space Telescope/Wide Field Camera 3

Cartier, Kimberly M. S. and Beatty, Thomas G. and Zhao, Ming and Line, Michael and Ngo, Henry and Mawet, Dimitri and Stassun, Keivan G. and Wright, Jason T. and Kreidberg, Laura and Fortney, Jonathan and Knutson, Heather (2017) Near-infrared Emission Spectrum of WASP-103b Using Hubble Space Telescope/Wide Field Camera 3. Astronomical Journal, 153 (1). Art. No. 34. ISSN 1538-3881.

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We present here our observations and analysis of the dayside emission spectrum of the hot Jupiter WASP-103b. We observed WASP-103b during secondary eclipse using two visits of the Hubble Space Telescope with the G141 grism on Wide Field Camera 3 in spatial scan mode. We generated secondary eclipse light curves of the planet in both blended white-light and spectrally binned wavechannels from 1.1-1.7 µm and corrected the light curves for flux contamination from a nearby companion star. We modeled the detector systematics and secondary eclipse spectrum using Gaussian process regression and found that the near-IR emission spectrum of WASP-103b is featureless across the observed near-IR region to down to a sensitivity of 175 ppm, and shows a shallow slope toward the red. The atmosphere has a single brightness temperature of T_B = 2890 K across this wavelength range. This region of the spectrum is indistinguishable from isothermal, but may not manifest from a physically isothermal system, i.e., pseudo-isothermal. A solar-metallicity profile with a thermal inversion layer at 10^(−2) bar fits the spectrum of WASP-103b with high confidence, as do an isothermal profile with solar metallicity and a monotonically decreasing atmosphere with C/O > 1. The data rule out a monotonically decreasing atmospheric profile with solar composition, and we rule out a low-metallicity decreasing profile as unphysical for this system. The pseudo-isothermal profile could be explained by a thermal inversion layer just above the layer probed by our observations, or by clouds or haze in the upper atmosphere. Transmission spectra at optical wavelengths would allow us to better distinguish between potential atmospheric models.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cartier, Kimberly M. S.0000-0001-8213-1597
Beatty, Thomas G.0000-0002-9539-4203
Zhao, Ming0000-0002-4258-9517
Line, Michael0000-0002-2338-476X
Ngo, Henry0000-0001-5172-4859
Mawet, Dimitri0000-0002-8895-4735
Stassun, Keivan G.0000-0002-3481-9052
Wright, Jason T.0000-0001-6160-5888
Kreidberg, Laura0000-0003-0514-1147
Fortney, Jonathan0000-0002-9843-4354
Knutson, Heather0000-0002-0822-3095
Additional Information:© 2016. The American Astronomical Society. Received 2016 October 3; revised 2016 November 22; accepted 2016 November 25; published 2016 December 29. This work is partially funded by Hubble Space Telescope grants HST-GO-13660.005 (PI Wright) and HST-GO-13660.001-A (PI Zhao), and partially supported by funding from the Center for Exoplanets and Habitable Worlds. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX13AC07G and by other grants and contracts. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We gratefully acknowledge the use of SOA/NASA ADS, NASA, and STScI resources. Facilities: HST (WFC3), Keck (NIRC2). Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.
Group:Astronomy Department
Funding AgencyGrant Number
Center for Exoplanets and Habitable WorldsUNSPECIFIED
Eberly College of ScienceUNSPECIFIED
Pennsylvania Space Grant ConsortiumUNSPECIFIED
NASANAS 5-26555
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:eclipses; planetary systems; planets and satellites: atmospheres; techniques: photometric; techniques: spectroscopic
Issue or Number:1
Record Number:CaltechAUTHORS:20170104-141040048
Persistent URL:
Official Citation:Kimberly M. S. Cartier et al 2017 AJ 153 34
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:73219
Deposited By: George Porter
Deposited On:04 Jan 2017 22:30
Last Modified:06 Nov 2019 18:29

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