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10 results on '"Arthur Vigan"'

1. The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256–1257 b

Author

Simon Petrus, Niall Whiteford, Polychronis Patapis, Beth A. Biller, Andrew Skemer, Sasha Hinkley, Genaro Suárez, Paulina Palma-Bifani, Caroline V. Morley, Pascal Tremblin, Benjamin Charnay, Johanna M. Vos, Jason J. Wang, Jordan M. Stone, Mickaël Bonnefoy, Gaël Chauvin, Brittany E. Miles, Aarynn L. Carter, Anna Lueber, Christiane Helling, Ben J. Sutlieff, Markus Janson, Eileen C. Gonzales, Kielan K. W. Hoch, Olivier Absil, William O. Balmer, Anthony Boccaletti, Mariangela Bonavita, Mark Booth, Brendan P. Bowler, Zackery W. Briesemeister, Marta L. Bryan, Per Calissendorff, Faustine Cantalloube, Christine H. Chen, Elodie Choquet, Valentin Christiaens, Gabriele Cugno, Thayne Currie, Camilla Danielski, Matthew De Furio, Trent J. Dupuy, Samuel M. Factor, Jacqueline K. Faherty, Michael P. Fitzgerald, Jonathan J. Fortney, Kyle Franson, Julien H. Girard, Carol A. Grady, Thomas Henning, Dean C. Hines, Callie E. Hood, Alex R. Howe, Paul Kalas, Jens Kammerer, Grant M. Kennedy, Matthew A. Kenworthy, Pierre Kervella, Minjae Kim, Daniel Kitzmann, Adam L. Kraus, Masayuki Kuzuhara, Pierre-Olivier Lagage, Anne-Marie Lagrange, Kellen Lawson, Cecilia Lazzoni, Jarron M. Leisenring, Ben W. P. Lew, Michael C. Liu, Pengyu Liu, Jorge Llop-Sayson, James P. Lloyd, Bruce Macintosh, Mathilde Mâlin, Elena Manjavacas, Sebastián Marino, Mark S. Marley, Christian Marois, Raquel A. Martinez, Elisabeth C. Matthews, Brenda C. Matthews, Dimitri Mawet, Johan Mazoyer, Michael W. McElwain, Stanimir Metchev, Michael R. Meyer, Maxwell A. Millar-Blanchaer, Paul Mollière, Sarah E. Moran, Sagnick Mukherjee, Eric Pantin, Marshall D. Perrin, Laurent Pueyo, Sascha P. Quanz, Andreas Quirrenbach, Shrishmoy Ray, Isabel Rebollido, Jea Adams Redai, Bin B. Ren, Emily Rickman, Steph Sallum, Matthias Samland, Benjamin Sargent, Joshua E. Schlieder, Karl R. Stapelfeldt, Motohide Tamura, Xianyu Tan, Christopher A. Theissen, Taichi Uyama, Malavika Vasist, Arthur Vigan, Kevin Wagner, Kimberly Ward-Duong, Schuyler G. Wolff, Kadin Worthen, Mark C. Wyatt, Marie Ygouf, Alice Zurlo, Xi Zhang, Keming Zhang, Zhoujian Zhang, and Yifan Zhou

Subjects
Exoplanet atmospheres, Infrared spectroscopy, Direct imaging, L dwarfs, Nested sampling, James Webb Space Telescope, Astrophysics, QB460-466
Abstract

The unprecedented medium-resolution ( R _λ ∼ 1500–3500) near- and mid-infrared (1–18 μ m) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12–20 M _Jup ) L–T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this data set utilizing a forward-modeling approach applying our Bayesian framework, ForMoSA . We explore five distinct atmospheric models to assess their performance in estimating key atmospheric parameters: T _eff , log( g ), [M/H], C/O, γ , f _sed , and R . Our findings reveal that each parameter’s estimate is significantly influenced by factors such as the wavelength range considered and the model chosen for the fit. This is attributed to systematic errors in the models and their challenges in accurately replicating the complex atmospheric structure of VHS 1256 b, notably the complexity of its clouds and dust distribution. To propagate the impact of these systematic uncertainties on our atmospheric property estimates, we introduce innovative fitting methodologies based on independent fits performed on different spectral windows. We finally derived a T _eff consistent with the spectral type of the target, considering its young age, which is confirmed by our estimate of log( g ). Despite the exceptional data quality, attaining robust estimates for chemical abundances [M/H] and C/O, often employed as indicators of formation history, remains challenging. Nevertheless, the pioneering case of JWST’s data for VHS 1256 b has paved the way for future acquisitions of substellar spectra that will be systematically analyzed to directly compare the properties of these objects and correct the systematics in the models.

Published
2024
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2. The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. IV. NIRISS Aperture Masking Interferometry Performance and Lessons Learned

Author

Steph Sallum, Shrishmoy Ray, Jens Kammerer, Anand Sivaramakrishnan, Rachel Cooper, Alexandra Z. Greebaum, Deepashri Thatte, Matthew De Furio, Samuel M. Factor, Michael R. Meyer, Jordan M. Stone, Aarynn Carter, Beth Biller, Sasha Hinkley, Andrew Skemer, Genaro Suárez, Jarron M. Leisenring, Marshall D. Perrin, Adam L. Kraus, Olivier Absil, William O. Balmer, Sarah K. Betti, Anthony Boccaletti, Mariangela Bonavita, Mickael Bonnefoy, Mark Booth, Brendan P. Bowler, Zackery W. Briesemeister, Marta L. Bryan, Per Calissendorff, Faustine Cantalloube, Gael Chauvin, Christine H. Chen, Elodie Choquet, Valentin Christiaens, Gabriele Cugno, Thayne Currie, Camilla Danielski, Trent J. Dupuy, Jacqueline K. Faherty, Michael P. Fitzgerald, Jonathan J. Fortney, Kyle Franson, Julien H. Girard, Carol A. Grady, Eileen C. Gonzales, Thomas Henning, Dean C. Hines, Kielan K. W. Hoch, Callie E. Hood, Alex R. Howe, Markus Janson, Paul Kalas, Grant M. Kennedy, Matthew A. Kenworthy, Pierre Kervella, Daniel Kitzmann, Masayuki Kuzuhara, Anne-Marie Lagrange, Pierre-Olivier Lagage, Kellen Lawson, Cecilia Lazzoni, Ben W. P. Lew, Michael C. Liu, Pengyu Liu, Jorge Llop-Sayson, James P. Lloyd, Anna Lueber, Bruce Macintosh, Elena Manjavacas, Sebastian Marino, Mark S. Marley, Christian Marois, Raquel A. Martinez, Brenda C. Matthews, Elisabeth C. Matthews, Dimitri Mawet, Johan Mazoyer, Michael W. McElwain, Stanimir Metchev, Brittany E. Miles, Maxwell A. Millar-Blanchaer, Paul Molliere, Sarah E. Moran, Caroline V. Morley, Sagnick Mukherjee, Paulina Palma-Bifani, Eric Pantin, Polychronis Patapis, Simon Petrus, Laurent Pueyo, Sascha P. Quanz, Andreas Quirrenbach, Isabel Rebollido, Jea Adams Redai, Bin B. Ren, Emily Rickman, Matthias Samland, B. A. Sargent, Joshua E. Schlieder, Glenn Schneider, Karl R. Stapelfeldt, Ben J. Sutlieff, Motohide Tamura, Xianyu Tan, Christopher A. Theissen, Taichi Uyama, Arthur Vigan, Malavika Vasist, Johanna M. Vos, Kevin Wagner, Jason J. Wang, Kimberly Ward-Duong, Niall Whiteford, Schuyler G. Wolff, Kadin Worthen, Mark C. Wyatt, Marie Ygouf, Xi Zhang, Keming Zhang, Zhoujian Zhang, Yifan Zhou, and Alice Zurlo

Subjects
James Webb Space Telescope, Interferometry, Direct imaging, High contrast techniques, Observational astronomy, Astrophysics, QB460-466
Abstract

We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same data set to explore the random, static, and calibration errors of NIRISS AMI observables. We compare the observed noise properties and achievable contrast to theoretical predictions. We explore possible sources of calibration errors and show that differences in charge migration between the observations of HIP 65426 and point-spread function calibration stars can account for the achieved contrast curves. Lastly, we use self-calibration tests to demonstrate that with adequate calibration NIRISS F380M AMI can reach contrast levels of ∼9–10 mag at ≳ λ / D . These tests lead us to observation planning recommendations and strongly motivate future studies aimed at producing sophisticated calibration strategies taking these systematic effects into account. This will unlock the unprecedented capabilities of JWST/NIRISS AMI, with sensitivity to significantly colder, lower-mass exoplanets than lower-contrast ground-based AMI setups, at orbital separations inaccessible to JWST coronagraphy.

Published
2024
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3. The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 μm

Author

Aarynn L. Carter, Sasha Hinkley, Jens Kammerer, Andrew Skemer, Beth A. Biller, Jarron M. Leisenring, Maxwell A. Millar-Blanchaer, Simon Petrus, Jordan M. Stone, Kimberly Ward-Duong, Jason J. Wang, Julien H. Girard, Dean C. Hines, Marshall D. Perrin, Laurent Pueyo, William O. Balmer, Mariangela Bonavita, Mickael Bonnefoy, Gael Chauvin, Elodie Choquet, Valentin Christiaens, Camilla Danielski, Grant M. Kennedy, Elisabeth C. Matthews, Brittany E. Miles, Polychronis Patapis, Shrishmoy Ray, Emily Rickman, Steph Sallum, Karl R. Stapelfeldt, Niall Whiteford, Yifan Zhou, Olivier Absil, Anthony Boccaletti, Mark Booth, Brendan P. Bowler, Christine H. Chen, Thayne Currie, Jonathan J. Fortney, Carol A. Grady, Alexandra Z. Greebaum, Thomas Henning, Kielan K. W. Hoch, Markus Janson, Paul Kalas, Matthew A. Kenworthy, Pierre Kervella, Adam L. Kraus, Pierre-Olivier Lagage, Michael C. Liu, Bruce Macintosh, Sebastian Marino, Mark S. Marley, Christian Marois, Brenda C. Matthews, Dimitri Mawet, Michael W. McElwain, Stanimir Metchev, Michael R. Meyer, Paul Molliere, Sarah E. Moran, Caroline V. Morley, Sagnick Mukherjee, Eric Pantin, Andreas Quirrenbach, Isabel Rebollido, Bin B. Ren, Glenn Schneider, Malavika Vasist, Kadin Worthen, Mark C. Wyatt, Zackery W. Briesemeister, Marta L. Bryan, Per Calissendorff, Faustine Cantalloube, Gabriele Cugno, Matthew De Furio, Trent J. Dupuy, Samuel M. Factor, Jacqueline K. Faherty, Michael P. Fitzgerald, Kyle Franson, Eileen C. Gonzales, Callie E. Hood, Alex R. Howe, Masayuki Kuzuhara, Anne-Marie Lagrange, Kellen Lawson, Cecilia Lazzoni, Ben W. P. Lew, Pengyu Liu, Jorge Llop-Sayson, James P. Lloyd, Raquel A. Martinez, Johan Mazoyer, Paulina Palma-Bifani, Sascha P. Quanz, Jea Adams Redai, Matthias Samland, Joshua E. Schlieder, Motohide Tamura, Xianyu Tan, Taichi Uyama, Arthur Vigan, Johanna M. Vos, Kevin Wagner, Schuyler G. Wolff, Marie Ygouf, Xi Zhang, Keming Zhang, and Zhoujian Zhang

Subjects
Exoplanets, Exoplanet astronomy, Extrasolar gaseous planets, Astrophysics, QB460-466
Abstract

We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 μ m, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 μ m. At a separation of ∼0.″82 (87 ${}_{-31}^{+108}$ au), HIP 65426b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first-ever direct detection of an exoplanet beyond 5 μ m. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5 σ contrast limits of ∼1 × 10 ^−5 and ∼2 × 10 ^−4 at 1″ for NIRCam at 4.4 μ m and MIRI at 11.3 μ m, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3 M _Jup beyond separations of ∼100 au. Together with existing ground-based near-infrared data, the JWST photometry are fit well by a BT-SETTL atmospheric model from 1 to 16 μ m, and they span ∼97% of HIP 65426b's luminous range. Independent of the choice of model atmosphere, we measure an empirical bolometric luminosity that is tightly constrained between $\mathrm{log}\left({L}_{\mathrm{bol}}/{L}_{\odot }\right)$ = −4.31 and −4.14, which in turn provides a robust mass constraint of 7.1 ± 1.2 M _Jup . In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterize the population of exoplanets amenable to high-contrast imaging in greater detail.

Published
2023
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4. The JWST Early-release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 μm Spectrum of the Planetary-mass Companion VHS 1256–1257 b

Author

Brittany E. Miles, Beth A. Biller, Polychronis Patapis, Kadin Worthen, Emily Rickman, Kielan K. W. Hoch, Andrew Skemer, Marshall D. Perrin, Niall Whiteford, Christine H. Chen, B. Sargent, Sagnick Mukherjee, Caroline V. Morley, Sarah E. Moran, Mickael Bonnefoy, Simon Petrus, Aarynn L. Carter, Elodie Choquet, Sasha Hinkley, Kimberly Ward-Duong, Jarron M. Leisenring, Maxwell A. Millar-Blanchaer, Laurent Pueyo, Shrishmoy Ray, Steph Sallum, Karl R. Stapelfeldt, Jordan M. Stone, Jason J. Wang, Olivier Absil, William O. Balmer, Anthony Boccaletti, Mariangela Bonavita, Mark Booth, Brendan P. Bowler, Gael Chauvin, Valentin Christiaens, Thayne Currie, Camilla Danielski, Jonathan J. Fortney, Julien H. Girard, Carol A. Grady, Alexandra Z. Greenbaum, Thomas Henning, Dean C. Hines, Markus Janson, Paul Kalas, Jens Kammerer, Grant M. Kennedy, Matthew A. Kenworthy, Pierre Kervella, Pierre-Olivier Lagage, Ben W. P. Lew, Michael C. Liu, Bruce Macintosh, Sebastian Marino, Mark S. Marley, Christian Marois, Elisabeth C. Matthews, Brenda C. Matthews, Dimitri Mawet, Michael W. McElwain, Stanimir Metchev, Michael R. Meyer, Paul Molliere, Eric Pantin, Andreas Quirrenbach, Isabel Rebollido, Bin B. Ren, Glenn Schneider, Malavika Vasist, Mark C. Wyatt, Yifan Zhou, Zackery W. Briesemeister, Marta L. Bryan, Per Calissendorff, Faustine Cantalloube, Gabriele Cugno, Matthew De Furio, Trent J. Dupuy, Samuel M. Factor, Jacqueline K. Faherty, Michael P. Fitzgerald, Kyle Franson, Eileen C. Gonzales, Callie E. Hood, Alex R. Howe, Adam L. Kraus, Masayuki Kuzuhara, Anne-Marie Lagrange, Kellen Lawson, Cecilia Lazzoni, Pengyu Liu, Jorge Llop-Sayson, James P. Lloyd, Raquel A. Martinez, Johan Mazoyer, Sascha P. Quanz, Jea Adams Redai, Matthias Samland, Joshua E. Schlieder, Motohide Tamura, Xianyu Tan, Taichi Uyama, Arthur Vigan, Johanna M. Vos, Kevin Wagner, Schuyler G. Wolff, Marie Ygouf, Xi Zhang, Keming Zhang, and Zhoujian Zhang

Subjects
Brown dwarfs, Exoplanet atmospheres, Extrasolar gaseous giant planets, Astrophysics, QB460-466
Abstract

We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a

Published
2023
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7. Evidence That the Directly Imaged Planet HD 131399 Ab Is a Background Star.

Author

Eric L. Nielsen, Robert J. De Rosa, Julien Rameau, Jason J. Wang, Thomas M. Esposito, Maxwell A. Millar-Blanchaer, Christian Marois, Arthur Vigan, S. Mark Ammons, Etienne Artigau, Vanessa P. Bailey, Sarah Blunt, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, René Doyon, Gaspard Duchêne, Daniel Fabrycky, Michael P. Fitzgerald, and Katherine B. Follette

Published
2017
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9. HIGH-CADENCE, HIGH-CONTRAST IMAGING FOR EXOPLANET MAPPING: OBSERVATIONS OF THE HR 8799 PLANETS WITH VLT/SPHERE SATELLITE-SPOT-CORRECTED RELATIVE PHOTOMETRY.

Author

Dániel Apai, Markus Kasper, Andrew Skemer, Jake R. Hanson, Anne-Marie Lagrange, Beth A. Biller, Mickaël Bonnefoy, Esther Buenzli, and Arthur Vigan

Subjects
BROWN dwarf stars, EXTRASOLAR planets, ASTRONOMICAL photometry, DATA analysis, PHOTOMETRY
Abstract

Time-resolved photometry is an important new probe of the physics of condensate clouds in extrasolar planets and brown dwarfs. Extreme adaptive optics systems can directly image planets, but precise brightness measurements are challenging. We present VLT/SPHERE high-contrast, time-resolved broad H-band near-infrared photometry for four exoplanets in the HR 8799 system, sampling changes from night to night over five nights with relatively short integrations. The photospheres of these four planets are often modeled by patchy clouds and may show large-amplitude rotational brightness modulations. Our observations provide high-quality images of the system. We present a detailed performance analysis of different data analysis approaches to accurately measure the relative brightnesses of the four exoplanets. We explore the information in satellite spots and demonstrate their use as a proxy for image quality. While the brightness variations of the satellite spots are strongly correlated, we also identify a second-order anti-correlation pattern between the different spots. Our study finds that KLIP reduction based on principal components analysis with satellite-spot-modulated artificial-planet-injection-based photometry leads to a significant (∼3×) gain in photometric accuracy over standard aperture-based photometry and reaches 0.1 mag per point accuracy for our data set, the signal-to-noise ratio of which is limited by small field rotation. Relative planet-to-planet photometry can be compared between nights, enabling observations spanning multiple nights to probe variability. Recent high-quality relative H-band photometry of the b–c planet pair agrees to about 1%. [ABSTRACT FROM AUTHOR]

Published
2016
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