A systematic retrieval analysis of secondary eclipse spectra. II. A uniform analysis of nine planets and their C to O ratios

Michael Line, Heather Knutson, Aaron S. Wolf, Yuk L. Yung

Research output: Contribution to journalArticle

90 Citations (Scopus)

Abstract

Secondary eclipse spectroscopy provides invaluable insights into the temperatures and compositions of exoplanetary atmospheres. We carry out a systematic temperature and abundance retrieval analysis of nine exoplanets (HD 189733b, HD 209458b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, and TrES-3b) observed in secondary eclipse using a combination of space- and ground-based facilities. Our goal with this analysis is to provide a consistent set of temperatures and compositions from which self-consistent models can be compared and to probe the underlying processes that shape these atmospheres. This paper is the second in a three part series of papers exploring the retrievability of temperatures and abundances from secondary eclipse spectra and the implications of these results for the chemistry of exoplanet atmospheres. In this investigation we present a catalogue of temperatures and abundances for H2O, CH4, CO, and CO2. We find that our temperatures and abundances are generally consistent with those of previous studies, although we do not find any statistically convincing evidence for super-solar C to O ratios (e.g., solar C/O falls in the 1σ confidence intervals in eight of the nine planets in our sample). Furthermore, within our sample we find little evidence for thermal inversions over a wide range of effective temperatures (with the exception of HD 209458b), consistent with previous investigations. The lack of evidence for inversions for most planets in our sample over such a wide range of effective temperatures provides additional support for the hypothesis that TiO is unlikely to be the absorber responsible for the formation of these inversions.

Original languageEnglish (US)
Article number70
JournalAstrophysical Journal
Volume783
Issue number2
DOIs
StatePublished - Mar 10 2014
Externally publishedYes

Fingerprint

eclipses
retrieval
planets
planet
temperature
extrasolar planets
inversions
atmospheres
atmosphere
analysis
confidence interval
catalogs
confidence
absorbers
spectroscopy
probe
chemistry
intervals
probes
inversion

Keywords

  • methods: statistical
  • planets and satellites: atmospheres
  • planets and satellites: composition
  • planets and satellites: gaseous planets
  • planets and satellites: individual (HD 189733b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, TrES-3b)

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

A systematic retrieval analysis of secondary eclipse spectra. II. A uniform analysis of nine planets and their C to O ratios. / Line, Michael; Knutson, Heather; Wolf, Aaron S.; Yung, Yuk L.

In: Astrophysical Journal, Vol. 783, No. 2, 70, 10.03.2014.

Research output: Contribution to journalArticle

@article{3026d95e49d840db8c494ccafba3e167,
title = "A systematic retrieval analysis of secondary eclipse spectra. II. A uniform analysis of nine planets and their C to O ratios",
abstract = "Secondary eclipse spectroscopy provides invaluable insights into the temperatures and compositions of exoplanetary atmospheres. We carry out a systematic temperature and abundance retrieval analysis of nine exoplanets (HD 189733b, HD 209458b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, and TrES-3b) observed in secondary eclipse using a combination of space- and ground-based facilities. Our goal with this analysis is to provide a consistent set of temperatures and compositions from which self-consistent models can be compared and to probe the underlying processes that shape these atmospheres. This paper is the second in a three part series of papers exploring the retrievability of temperatures and abundances from secondary eclipse spectra and the implications of these results for the chemistry of exoplanet atmospheres. In this investigation we present a catalogue of temperatures and abundances for H2O, CH4, CO, and CO2. We find that our temperatures and abundances are generally consistent with those of previous studies, although we do not find any statistically convincing evidence for super-solar C to O ratios (e.g., solar C/O falls in the 1σ confidence intervals in eight of the nine planets in our sample). Furthermore, within our sample we find little evidence for thermal inversions over a wide range of effective temperatures (with the exception of HD 209458b), consistent with previous investigations. The lack of evidence for inversions for most planets in our sample over such a wide range of effective temperatures provides additional support for the hypothesis that TiO is unlikely to be the absorber responsible for the formation of these inversions.",
keywords = "methods: statistical, planets and satellites: atmospheres, planets and satellites: composition, planets and satellites: gaseous planets, planets and satellites: individual (HD 189733b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, TrES-3b)",
author = "Michael Line and Heather Knutson and Wolf, {Aaron S.} and Yung, {Yuk L.}",
year = "2014",
month = "3",
day = "10",
doi = "10.1088/0004-637X/783/2/70",
language = "English (US)",
volume = "783",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - A systematic retrieval analysis of secondary eclipse spectra. II. A uniform analysis of nine planets and their C to O ratios

AU - Line, Michael

AU - Knutson, Heather

AU - Wolf, Aaron S.

AU - Yung, Yuk L.

PY - 2014/3/10

Y1 - 2014/3/10

N2 - Secondary eclipse spectroscopy provides invaluable insights into the temperatures and compositions of exoplanetary atmospheres. We carry out a systematic temperature and abundance retrieval analysis of nine exoplanets (HD 189733b, HD 209458b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, and TrES-3b) observed in secondary eclipse using a combination of space- and ground-based facilities. Our goal with this analysis is to provide a consistent set of temperatures and compositions from which self-consistent models can be compared and to probe the underlying processes that shape these atmospheres. This paper is the second in a three part series of papers exploring the retrievability of temperatures and abundances from secondary eclipse spectra and the implications of these results for the chemistry of exoplanet atmospheres. In this investigation we present a catalogue of temperatures and abundances for H2O, CH4, CO, and CO2. We find that our temperatures and abundances are generally consistent with those of previous studies, although we do not find any statistically convincing evidence for super-solar C to O ratios (e.g., solar C/O falls in the 1σ confidence intervals in eight of the nine planets in our sample). Furthermore, within our sample we find little evidence for thermal inversions over a wide range of effective temperatures (with the exception of HD 209458b), consistent with previous investigations. The lack of evidence for inversions for most planets in our sample over such a wide range of effective temperatures provides additional support for the hypothesis that TiO is unlikely to be the absorber responsible for the formation of these inversions.

AB - Secondary eclipse spectroscopy provides invaluable insights into the temperatures and compositions of exoplanetary atmospheres. We carry out a systematic temperature and abundance retrieval analysis of nine exoplanets (HD 189733b, HD 209458b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, and TrES-3b) observed in secondary eclipse using a combination of space- and ground-based facilities. Our goal with this analysis is to provide a consistent set of temperatures and compositions from which self-consistent models can be compared and to probe the underlying processes that shape these atmospheres. This paper is the second in a three part series of papers exploring the retrievability of temperatures and abundances from secondary eclipse spectra and the implications of these results for the chemistry of exoplanet atmospheres. In this investigation we present a catalogue of temperatures and abundances for H2O, CH4, CO, and CO2. We find that our temperatures and abundances are generally consistent with those of previous studies, although we do not find any statistically convincing evidence for super-solar C to O ratios (e.g., solar C/O falls in the 1σ confidence intervals in eight of the nine planets in our sample). Furthermore, within our sample we find little evidence for thermal inversions over a wide range of effective temperatures (with the exception of HD 209458b), consistent with previous investigations. The lack of evidence for inversions for most planets in our sample over such a wide range of effective temperatures provides additional support for the hypothesis that TiO is unlikely to be the absorber responsible for the formation of these inversions.

KW - methods: statistical

KW - planets and satellites: atmospheres

KW - planets and satellites: composition

KW - planets and satellites: gaseous planets

KW - planets and satellites: individual (HD 189733b, HD 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, TrES-3b)

UR - http://www.scopus.com/inward/record.url?scp=84896768194&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84896768194&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/783/2/70

DO - 10.1088/0004-637X/783/2/70

M3 - Article

AN - SCOPUS:84896768194

VL - 783

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 70

ER -