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4 results on '"Mathias Nowak"'

1. Interpreting the Atmospheric Composition of Exoplanets: Sensitivity to Planet Formation Assumptions

Author

Paul Mollière, Tamara Molyarova, Bertram Bitsch, Thomas Henning, Aaron Schneider, Laura Kreidberg, Christian Eistrup, Remo Burn, Evert Nasedkin, Dmitry Semenov, Christoph Mordasini, Martin Schlecker, Kamber R. Schwarz, Sylvestre Lacour, Mathias Nowak, Matthäus Schulik, Mollière, Paul [0000-0003-4096-7067], Molyarova, Tamara [0000-0003-0448-6354], Bitsch, Bertram [0000-0002-8868-7649], Henning, Thomas [0000-0002-1493-300X], Schneider, Aaron [0000-0002-1448-0303], Kreidberg, Laura [0000-0003-0514-1147], Eistrup, Christian [0000-0002-8743-1318], Burn, Remo [0000-0002-9020-7309], Nasedkin, Evert [0000-0002-9792-3121], Semenov, Dmitry [0000-0002-3913-7114], Mordasini, Christoph [0000-0002-1013-2811], Schlecker, Martin [0000-0001-8355-2107], Schwarz, Kamber R. [0000-0002-6429-9457], Lacour, Sylvestre [0000-0002-6948-0263], and Apollo - University of Cambridge Repository

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, ORBITAL MIGRATION, 530 Physics, BROWN DWARFS, 520 Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astronomy & Astrophysics, MASS, 620 Engineering, GAS ACCRETION, HR 8799, GIANT PLANETS, RETRIEVAL ANALYSIS, Space and Planetary Science, Physical Sciences, astro-ph.EP, THERMAL INVERSIONS, Astrophysics::Solar and Stellar Astrophysics, TRANSMISSION SPECTRUM, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics, IRRADIATED GASEOUS EXOPLANETS
Abstract

Constraining planet formation based on the atmospheric composition of exoplanets is a fundamental goal of the exoplanet community. Existing studies commonly try to constrain atmospheric abundances, or to analyze what abundance patterns a given description of planet formation predicts. However, there is also a pressing need to develop methodologies that investigate how to transform atmospheric compositions into planetary formation inferences. In this study we summarize the complexities and uncertainties of state-of-the-art planet formation models and how they influence planetary atmospheric compositions. We introduce a methodology that explores the effect of different formation model assumptions when interpreting atmospheric compositions. We apply this framework to the directly imaged planet HR 8799e. Based on its atmospheric composition, this planet may have migrated significantly during its formation. We show that including the chemical evolution of the protoplanetary disk leads to a reduced need for migration. Moreover, we find that pebble accretion can reproduce the planet's composition, but some of our tested setups lead to too low atmospheric metallicities, even when considering that evaporating pebbles may enrich the disk gas. We conclude that the definitive inversion from atmospheric abundances to planet formation for a given planet may be challenging, but a qualitative understanding of the effects of different formation models is possible, opening up pathways for new investigations., Accepted for publication in ApJ, base formation inversion code is available at: https://gitlab.com/mauricemolli/formation-inversion

Published
2022
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2. From atmospheric to exoplanet formation retrievals

Author

Paul Mollière, Tamara Molyarova, Bertram Bitsch, Christian Eistrup, Remo Burn, Evert Nasedkin, Thomas Henning, Dmitry Semenov, Christoph Mordasini, Laura Kreidberg, Martin Schlecker, Sylvestre Lacour, and Mathias Nowak

Subjects
Astrophysics::Earth and Planetary Astrophysics
Abstract

With new and upcoming observing facilities (JWST and the ELTs), the exoplanet community is poised to precisely measure the chemical inventory of exoplanet atmospheres. This will allow, for the first time, to start investigating whether one of the greatest promises of atmospheric characterization studies holds up: inverting the atmospheric composition to infer the planet formation history encoded in it. In my talk, I will show how such measurements allow to run so-called formation retrievals, which constrain a planet’s formation history using its atmospheric abundances in a Bayesian retrieval framework. I will demonstrate how simple and popular models for the composition of the protoplanetary disk and planet formation could lead to interesting insights when applied in formation retrievals. At the same time, I will discuss how such assumptions are too strongly simplified for making the exoplanet atmosphere — formation connection in practice, and what the most pressing theoretical challenges are. Achieving this connection will be a formidable and interdisciplinary challenge, but the exciting exoplanet observations that lie ahead will allow the community to tackle it in earnest.

Published
2021
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3. K-Stacker: an algorithm to hack the orbital parameters of planets hidden in high-contrast imaging: First applications to VLT/SPHERE multi-epoch observations

Author

Jean-Luc Beuzit, Arthur Vigan, Markus Feldt, Kjetil Dohlen, H. Le Coroller, E. Sissa, A. L. Maire, Pierre Vernazza, A. Schneeberger, Anthony Cheetham, S. Rochat, Michael R. Meyer, Thierry Fusco, Mariangela Bonavita, D. Estevez, D. Le Mignant, François Ménard, Joany Andreina Manjarres Ramos, Matthias Samland, Mathias Nowak, Mickael Bonnefoy, J. C. Lambert, Alice Zurlo, Valentina D'Orazi, Dino Mesa, Philippe Delorme, A. Boccaletti, Hervé Beust, R. Galicher, Roxanne Ligi, Gael Chauvin, A-M. Lagrange, Markus Janson, T. Fenouillet, Raffaele Gratton, David Mouillet, L. Arnold, M. Devinat, Silvano Desidera, Maud Langlois, J. Bec-Canet, C. Desgrange, Jean-François Sauvage, Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), European Southern Observatory (ESO), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Department of Astronomy, Stockholm University, Department of Biochemistry and Molecular Biology, Mayo Clinic, DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, University of Copenhagen = Københavns Universitet (KU), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), and University of Copenhagen = Københavns Universitet (UCPH)

Subjects
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], planets and satellites: dynamical evolution and stability, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), Astrophysics, instrumentation: adaptive optics, 01 natural sciences, stars: individual: HD 95086, 03 medical and health sciences, Planet, instrumentation: high angular resolution, 0103 physical sciences, Gemini Planet Imager, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), 030304 developmental biology, Orbital elements, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 0303 health sciences, stars: individual: β Pictoris, Astronomy and Astrophysics, Astrometry, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], methods: data analysis, Exoplanet, Radial velocity, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Orbital motion, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Algorithm, Astrophysics - Earth and Planetary Astrophysics
Abstract

Recent high-contrast imaging surveys, looking for planets in young, nearby systems showed evidence of a small number of giant planets at relatively large separation beyond typically 20 au where those surveys are the most sensitive. Access to smaller physical separations between 5 and 20 au is the next step for future planet imagers on 10 m telescopes and ELTs in order to bridge the gap with indirect techniques (radial velocity, transit, astrometry with Gaia). In that context, we recently proposed a new algorithm, Keplerian-Stacker, combining multiple observations acquired at different epochs and taking into account the orbital motion of a potential planet present in the images to boost the ultimate detection limit. We showed that this algorithm is able to find planets in time series of simulated images of SPHERE even when a planet remains undetected at one epoch. Here, we validate the K-Stacker algorithm performances on real SPHERE datasets, to demonstrate its resilience to instrumental speckles and the gain offered in terms of true detection. This will motivate future dedicated multi-epoch observation campaigns in high-contrast imaging to search for planets in emitted and reflected light. Results. We show that K-Stacker achieves high success rate when the SNR of the planet in the stacked image reaches 7. The improvement of the SNR ratio goes as the square root of the total exposure time. During the blind test and the redetection of HD 95086 b, and betaPic b, we highlight the ability of K-Stacker to find orbital solutions consistent with the ones derived by the state of the art MCMC orbital fitting techniques, confirming that in addition to the detection gain, K-Stacker offers the opportunity to characterize the most probable orbital solutions of the exoplanets recovered at low signal to noise., Comment: Astronomy & Astrophysics accepted, 13 Pages, 11 Figures

Published
2020
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4. Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e

Author

Frank Eisenhauer, Th. Henning, P. Mollière, Jingxiu Wang, E. F. van Dishoeck, T. Molyarova, Jinyi Shangguan, Pierre Kervella, Tomas Stolker, Alexandra Z. Greenbaum, Mathias Nowak, Sylvestre Lacour, Alice Zurlo, E. Nasedkin, Gabriel-Dominique Marleau, Gilles Otten, D. Semenov, Anne-Lise Maire, Ignas Snellen, Laurent Pueyo, Sasha Hinkley, Arthur Vigan, Laura Kreidberg, Benjamin Charnay, Paulo J. V. Garcia, Julien Girard, P. T. de Zeeuw, R. Garcia Lopez, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, European Southern Observatory (ESO), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
010504 meteorology & atmospheric sciences, Opacity, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Spectral line, methods: numerical, Atmosphere, Planet, 0103 physical sciences, Radiative transfer, 010303 astronomy & astrophysics, instrumentation: spectrographs, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), planets and satellites: atmospheres, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Scattering, Astronomy and Astrophysics, Exoplanet, radiative transfer, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Clouds are ubiquitous in exoplanet atmospheres and represent a challenge for the model interpretation of their spectra. Complex cloud models are too numerically costly for generating a large number of spectra, while more efficient models may be too strongly simplified. We aim to constrain the atmospheric properties of the directly imaged planet HR 8799e with a free retrieval approach. We use our radiative transfer code petitRADTRANS for generating spectra, which we couple to the PyMultiNest tool. We added the effect of multiple scattering which is important for treating clouds. Two cloud model parameterizations are tested: the first incorporates the mixing and settling of condensates, the second simply parameterizes the functional form of the opacity. In mock retrievals, using an inadequate cloud model may result in atmospheres that are more isothermal and less cloudy than the input. Applying our framework on observations of HR 8799e made with the GPI, SPHERE and GRAVITY, we find a cloudy atmosphere governed by disequilibrium chemistry, confirming previous analyses. We retrieve that ${\rm C/O}=0.60_{-0.08}^{+0.07}$. Other models have not yet produced a well constrained C/O value for this planet. The retrieved C/O values of both cloud models are consistent, while leading to different atmospheric structures: cloudy, or more isothermal and less cloudy. Fitting the observations with the self-consistent Exo-REM model leads to comparable results, while not constraining C/O. With data from the most sensitive instruments, retrieval analyses of directly imaged planets are possible. The inferred C/O ratio of HR 8799e is independent of the cloud model and thus appears to be a robust. This C/O is consistent with stellar, which could indicate that the HR 8799e formed outside the CO$_2$ or CO iceline. As it is the innermost planet of the system, this constraint could apply to all HR 8799 planets., Comment: Accepted for publication in A&A, 28 pages, 13 figures, updated author list

Published
2020
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