TY - JOUR
T1 - exoALMA. VI. Rotating under pressure
T2 - rotation curves, azimuthal velocity substructures, and pressure variations
AU - Stadler, Jochen
AU - Benisty, Myriam
AU - Winter, Andrew J.
AU - Izquierdo, Andrés F.
AU - Longarini, Cristiano
AU - Galloway-Sprietsma, Maria
AU - Curone, Pietro
AU - Andrews, Sean M.
AU - Bae, Jaehan
AU - Facchini, Stefano
AU - Rosotti, Giovanni
AU - Teague, Richard
AU - Barraza-Alfaro, Marcelo
AU - Cataldi, Gianni
AU - Cuello, Nicolas
AU - Czekala, Ian
AU - Fasano, Daniele
AU - Flock, Mario
AU - Fukagawa, Misato
AU - Garg, Himanshi
AU - Hall, Cassandra
AU - Hammond, Iain
AU - Hilder, Thomas
AU - Huang, Jane
AU - Ilee, John D.
AU - Kanagawa, Kazuhiro
AU - Lesur, Geoffroy
AU - Lodato, Giuseppe
AU - Loomis, Ryan A.
AU - Menard, Francois
AU - Orihara, Ryuta
AU - Pinte, Christophe
AU - Price, Daniel J.
AU - Yen, Hsi-Wei
AU - Wafflard-Fernandez, Gaylor
AU - Wilner, David J.
AU - Wölfer, Lisa
AU - Yoshida, Tomohiro C.
AU - Zawadzki, Brianna
N1 - Funding: J.S., M.B., and D.F. have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (PROTOPLANETS, grant agreement No. 101002188). J.S. has performed computations on the “Mesocentre SIGAMM” machine, hosted by Observatoire de la Cote d’Azur. A.J.W. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101104656. Support for A.F.I. was provided by NASA through a NASA Hubble Fellowship, grant No. HST-HF2-51532.001-A, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. C.L. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 823823 (DUSTBUSTERS) and by the UK Science and Technology research Council (STFC) via the consolidated grant No. ST/W000997/1. P.C. acknowledges support by the Italian Ministero dell’Istruzione, Università e Ricerca, through the grant Progetti Premiali 2012—iALMA (CUP C52I13000140001) and by the ANID BASAL project FB210003. J.B. acknowledges support from NASA XRP grant No. 80NSSC23K1312. N.C. has received funding from the European Research Council (ERC) under the European Union Horizon Europe research and innovation program (grant agreement No. 101042275, project Stellar-MADE). S.F. is funded by the European Union (ERC, UNVEIL, 101076613), and acknowledges the financial contribution from PRIN-MUR 2022YP5ACE. M.F. is supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (KAKENHI, grant No. JP22H01274). C.H. acknowledges support from NSF AAG grant No. 2407679. I.H. acknowledges a Research Training Program scholarship from the Australian Government. T.H. is supported by an Australian Government Research Training Program (RTP) Scholarship. J.D.I. acknowledges support from an STFC Ernest Rutherford Fellowship (grant No. ST/W004119/1) and a University Academic Fellowship from the University of Leeds. G.L. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 823823 (DUSTBUSTERS). F.M. has received funding from the European Research Council (ERC) under the European Union’s Horizon Europe research and innovation program (grant agreement No. 101053020, project Dust2Planets). C.P. acknowledges Australian Research Council funding via grant Nos. FT170100040, DP18010423, DP220103767, and DP240103290. D.P. acknowledges Australian Research Council funding via grant Nos. DP18010423, DP220103767, and DP240103290. G.R. acknowledges funding from the Fondazione Cariplo, grant No. 2022-1217, and the European Research Council (ERC) under the European Union’s Horizon Europe Research & Innovation Programme under grant agreement No. 101039651 (DiscEvol). H.-W.Y. acknowledges support from the National Science and Technology Council (NSTC) in Taiwan through grant No. NSTC 113-2112-M-001-035- and from an Academia Sinica Career Development Award (grant No. AS-CDA-111-M03). G.W.F. acknowledges support from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (grant agreement No. 815559, MHDiscs). G.W.F. was granted access to the HPC resources of IDRIS under the allocation A0120402231 made by GENCI. T.C.Y. acknowledges support by a Grant-in-Aid for JSPS Fellows (grant No. JP23KJ1008). Support for B.Z. was provided by The Brinson Foundation.
PY - 2025/5/1
Y1 - 2025/5/1
N2 - The bulk motion of the gas in protoplanetary disks around newborn stars is nearly Keplerian. By leveraging the high angular and spectral resolution of the Atacama Large Millimeter/submillimeter Array (ALMA), we can detect small-scale velocity perturbations in molecular line observations caused by local gas pressure variations in the disk, possibly induced by embedded protoplanets. This Letter presents the azimuthally averaged rotational velocity and its deviations from Keplerian rotation (δυϕ) for the exoALMA sample, as measured in the 12CO J = 3–2 and 13CO J = 3–2 emission lines. The rotation signatures show evidence for vertically stratified disks, in which 13CO rotates faster than 12CO due to a distinct thermal gas pressure gradient at their emitting heights. We find δυϕ substructures in the sample on both small (∼10 au) and large (∼100 au) radial scales, reaching deviations up to 15% from background Keplerian velocity in the most extreme cases. More than 75% of the rings and 80% of the gaps in the dust continuum emission resolved in δυϕ are colocated with gas pressure maxima and minima, respectively. Additionally, gas pressure substructures are observed far beyond the dust continuum emission. For the first time, we determined the gas pressure derivative at the midplane from observations, and found it to align well with the dust substructures within the given uncertainties. Based on our findings, we conclude that gas pressure variations are likely the dominant mechanism for ring and gap formation in the dust continuum.
AB - The bulk motion of the gas in protoplanetary disks around newborn stars is nearly Keplerian. By leveraging the high angular and spectral resolution of the Atacama Large Millimeter/submillimeter Array (ALMA), we can detect small-scale velocity perturbations in molecular line observations caused by local gas pressure variations in the disk, possibly induced by embedded protoplanets. This Letter presents the azimuthally averaged rotational velocity and its deviations from Keplerian rotation (δυϕ) for the exoALMA sample, as measured in the 12CO J = 3–2 and 13CO J = 3–2 emission lines. The rotation signatures show evidence for vertically stratified disks, in which 13CO rotates faster than 12CO due to a distinct thermal gas pressure gradient at their emitting heights. We find δυϕ substructures in the sample on both small (∼10 au) and large (∼100 au) radial scales, reaching deviations up to 15% from background Keplerian velocity in the most extreme cases. More than 75% of the rings and 80% of the gaps in the dust continuum emission resolved in δυϕ are colocated with gas pressure maxima and minima, respectively. Additionally, gas pressure substructures are observed far beyond the dust continuum emission. For the first time, we determined the gas pressure derivative at the midplane from observations, and found it to align well with the dust substructures within the given uncertainties. Based on our findings, we conclude that gas pressure variations are likely the dominant mechanism for ring and gap formation in the dust continuum.
KW - Protoplanetary disks
KW - Planet formation
KW - Planetary system formation
KW - Planetary-disk interactions
U2 - 10.3847/2041-8213/adb152
DO - 10.3847/2041-8213/adb152
M3 - Article
SN - 2041-8205
VL - 984
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L11
ER -