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dc.contributor.author
Hayoz, Jean
dc.contributor.author
Cugno, G.
dc.contributor.author
Quanz, Sascha P.
dc.contributor.author
Patapis, Polychronis
dc.contributor.author
Alei, Eleonora
dc.contributor.author
Bonse, Markus Johannes
dc.contributor.author
Dannert, Felix A.
dc.contributor.author
Garvin, E. O.
dc.contributor.author
Gebhard, T. D.
dc.contributor.author
Konrad, Björn Sten
dc.contributor.author
Sartori, L. F.
dc.date.accessioned
2023-11-16T15:03:03Z
dc.date.available
2023-11-16T04:51:32Z
dc.date.available
2023-11-16T15:03:03Z
dc.date.issued
2023-10
dc.identifier.issn
0004-6361
dc.identifier.issn
1432-0746
dc.identifier.other
10.1051/0004-6361/202245752
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/642279
dc.identifier.doi
10.3929/ethz-b-000642279
dc.description.abstract
Context. The investigation of the atmospheres of closely separated, directly imaged gas giant exoplanets is challenging due to the presence of stellar speckles that pollute their spectrum. To remedy this, the analysis of medium- to high-resolution spectroscopic data via cross-correlation with spectral templates (cross-correlation spectroscopy) is emerging as a leading technique. Aims. We aim to define a robust Bayesian framework combining, for the first time, three widespread direct-imaging techniques, namely photometry, low-resolution spectroscopy, and medium-resolution cross-correlation spectroscopy in order to derive the atmospheric properties of close-in directly imaged exoplanets. Current atmospheric characterisation frameworks are indeed either not compatible with all three observing techniques or they lack the commitment to efficient sampling strategies that allow high-dimensional forward models. Methods. Our framework CROCODILE (cross-correlation retrievals of directly imaged self-luminous exoplanets) naturally combines the three techniques by adopting adequate likelihood functions. To validate our routine, we simulated observations of gas giants similar to the well-studied β Pictoris b planet and we explored the parameter space of their atmospheres to search for potential biases. Results. We obtain more accurate measurements of atmospheric properties when combining photometry, low- and medium-resolution spectroscopy into atmospheric retrievals than when using the techniques separately as is usually done in the literature. Indeed, the combined fit is, on average, 20% more accurate than fitting only medium-resolution cross-correlation spectroscopy. We find that medium-resolution (R ≈ 4000) K-band cross-correlation spectroscopy alone is not suitable to constrain the atmospheric properties of our synthetic datasets; however, this problem disappears when simultaneously fitting photometry throughout the Y and M bands and low-resolution (R ≈ 60) spectroscopy between the Y and H bands. Our thorough testing demonstrates that free chemistry is a suitable forward model to retrieve the atmospheric thermal and chemical properties of cloudless gas giants at chemical equilibrium. Conclusions. CROCODILE provides a robust statistical framework to interpret medium-resolution spectroscopic data of close-in directly imaged exoplanets, where speckles originating from stellar stray light render the extraction of the continuum difficult. Our framework allows the atmospheric characterisation of directly imaged exoplanets using the high-quality spectral data that will be provided by the new generation of instruments such as the Enhanced Resolution Imager and Spectrograph (ERIS) at the Very Large Telescope, the Mid-Infrared Instrument (MIRI) aboard the James Webb Space Telescope, and in the future the Mid-infrared ELT Imager and Spectrograph (METIS) at the Extremely Large Telescope.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
EDP Sciences
en_US
dc.rights.uri
http://creativecommons.org/licenses/by/4.0/
dc.subject
planets and satellites: atmospheres
en_US
dc.subject
methods: data analysis
en_US
dc.subject
techniques: imaging spectroscopy
en_US
dc.subject
techniques: high angular resolution
en_US
dc.title
CROCODILE: Incorporating medium-resolution spectroscopy of close-in directly imaged exoplanets into atmospheric retrievals via cross-correlation
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution 4.0 International
dc.date.published
2023-10-20
ethz.journal.title
Astronomy & Astrophysics
ethz.journal.volume
678
en_US
ethz.journal.abbreviated
Astron. Astrophys.
ethz.pages.start
A178
en_US
ethz.size
22 p.
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.grant
Constraining gas giant planet formation via high-contrast exoplanet imaging
en_US
ethz.grant
NCCR PlanetS P1.1 Extension
en_US
ethz.grant
NCCR PlanetS: 3rd funding phase
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02010 - Dep. Physik / Dep. of Physics::02532 - Institut für Teilchen- und Astrophysik / Inst. Particle Physics and Astrophysics::09680 - Quanz, Sascha Patrick / Quanz, Sascha Patrick
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02010 - Dep. Physik / Dep. of Physics::02532 - Institut für Teilchen- und Astrophysik / Inst. Particle Physics and Astrophysics::09680 - Quanz, Sascha Patrick / Quanz, Sascha Patrick
ethz.grant.agreementno
200399
ethz.grant.agreementno
182901
ethz.grant.agreementno
205606
ethz.grant.fundername
SNF
ethz.grant.fundername
SNF
ethz.grant.fundername
SNF
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.program
Projekte MINT
ethz.grant.program
NCCR (NFS)
ethz.grant.program
NCCR (NFS)
ethz.date.deposited
2023-11-16T04:51:34Z
ethz.source
SCOPUS
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2023-11-16T15:03:05Z
ethz.rosetta.lastUpdated
2024-02-03T06:38:51Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
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