exoALMA. IX. Regularized Maximum Likelihood Imaging of Non-Keplerian Features

The planet-hunting Atacama Large Millimeter/submillimeter Array (ALMA) large program exoALMA observed 15 protoplanetary disks at ∼ 0 . ″ 15 angular resolution and ∼100 m s −1 spectral resolution, characterizing disk structures and kinematics in enough detail to detect non-Keplerian features (NKFs) i...

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Bibliographic Details
Published in:Astrophysical journal. Letters Vol. 984; no. 1; p. L14
Main Authors: Zawadzki, Brianna, Czekala, Ian, Galloway-Sprietsma, Maria, Bae, Jaehan, Barraza-Alfaro, Marcelo, Benisty, Myriam, Cataldi, Gianni, Curone, Pietro, Facchini, Stefano, Fasano, Daniele, Flock, Mario, Fukagawa, Misato, Garg, Himanshi, Hall, Cassandra, Hilder, Thomas, Huang, Jane, Ilee, John D., Isella, Andrea, Izquierdo, Andrés F., Kanagawa, Kazuhiro, Lesur, Geoffroy, Longarini, Cristiano, Loomis, Ryan A., Orihara, Ryuta, Pinte, Christophe, Price, Daniel J., Rosotti, Giovanni, Stadler, Jochen, Teague, Richard, Yen, Hsi-Wei, Wafflard-Fernandez, Gaylor, Wilner, David J., Winter, Andrew J., Wölfer, Lisa, Yoshida, Tomohiro C.
Format: Journal Article
Language:English
Published: Austin The American Astronomical Society 01.05.2025
IOP Publishing
Bristol : IOP Publishing
Subjects:
Angular resolution
Best practice
Computational methods
Deconvolution
Emissions
Imaging
Kinematics
Planet formation
Protoplanetary disks
Radio telescopes
Robustness
Sciences of the Universe
Spectral resolution
Submillimeter astronomy
Synthesis
Visibility
Deconvolution
Computational methods
Instrumentation and Methods for Astrophysics
Submillimeter astronomy
Protoplanetary disks
Planet formation
Earth and Planetary Astrophysics
ISSN:2041-8205, 2041-8213
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Summary:The planet-hunting Atacama Large Millimeter/submillimeter Array (ALMA) large program exoALMA observed 15 protoplanetary disks at ∼ 0 . ″ 15 angular resolution and ∼100 m s −1 spectral resolution, characterizing disk structures and kinematics in enough detail to detect non-Keplerian features (NKFs) in the gas emission. As these features are often small and low-contrast, robust imaging procedures are critical for identifying and characterizing NKFs, including determining which features may be signatures of young planets. The exoALMA collaboration employed two different imaging procedures to ensure the consistent detection of NKFs: CLEAN, the standard iterative deconvolution algorithm, and regularized maximum likelihood (RML) imaging. This Letter presents the exoALMA RML images, obtained by maximizing the likelihood of the visibility data given a model image and subject to regularizer penalties. Crucially, in the context of exoALMA, RML images serve as an independent verification of marginal features seen in the fiducial CLEAN images. However, best practices for synthesizing RML images of multichanneled (i.e., velocity-resolved) data remain undefined, as prior work on RML imaging for protoplanetary disk data has primarily addressed single-image cases. We used the open-source Python package MPoL to explore RML image validation methods for multichanneled data and synthesize RML images from the exoALMA observations of seven protoplanetary disks with apparent NKFs in the 12 CO J = 3–2 CLEAN images. We find that RML imaging methods independently reproduce the NKFs seen in the CLEAN images of these sources, suggesting that the NKFs are robust features rather than artifacts from a specific imaging procedure.
Bibliography:AAS60287
Interstellar Matter and the Local Universe
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content type line 14
ISSN:2041-8205
2041-8213
DOI:10.3847/2041-8213/adc434