exoALMA. XVIII. Interpreting large scale kinematic structures as moderate warping

Andrew J. Winter; Myriam Benisty; Andrés F. Izquierdo; Giuseppe Lodato; Richard Teague; Carolin N. Kimmig; Sean M. Andrews; Jaehan Bae; Marcelo Barraza-Alfaro; Nicolás Cuello; Pietro Curone; Ian Czekala; Stefano Facchini; Daniele Fasano; Cassandra Hall; Caitlyn Hardiman; Thomas Hilder; John D. Ilee; Misato Fukagawa; Cristiano Longarini; François Ménard; Ryuta Orihara; Christophe Pinte; Daniel J. Price; Giovanni Rosotti; Jochen Stadler; David J. Wilner; Lisa Wölfer; Hsi-Wei Yen; Tomohiro C. Yoshida; Brianna Zawadzki

arXiv · 2507.11669

exoALMA. XVIII. Interpreting large scale kinematic structures as moderate warping

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Abstract

The exoALMA program gave an unprecedented view of the complex kinematics of protoplanetary disks, revealing diverse structures that remain poorly understood. We show that moderate disk warps ($\sim 0.5-2^\circ$) can naturally explain many of the observed large-scale velocity features with azimuthal wavenumber $m = 1$. Using a simple model, we interpret line-of-sight velocity variations as changes in the projected Keplerian rotation caused by warping of the disk. While not a unique explanation, this interpretation aligns with growing observational evidence that warps are common. We demonstrate that such warps can also produce spiral structures in scattered light and CO brightness temperature, with $\sim 10$ K variations in MWC 758. Within the exoALMA sample, warp properties correlate with stellar accretion rates, suggesting a link between the inner disc and outer disc kinematics. If warps cause large-scale kinematic structure, this has far reaching implications for turbulence, angular momentum transport, and planet formation.

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Andrew J. Winter, Myriam Benisty, Andrés F. Izquierdo, Giuseppe Lodato, Richard Teague, Carolin N. Kimmig, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Nicolás Cuello, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Cassandra Hall, Caitlyn Hardiman, Thomas Hilder, John D. Ilee, Misato Fukagawa, Cristiano Longarini, François Ménard, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, David J. Wilner, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida, Brianna Zawadzki. 2025-07-15. exoALMA. XVIII. Interpreting large scale kinematic structures as moderate warping. https://arxiv.org/abs/2507.11669

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