@article{a2150538bcde4885a760a1ce70bdbcce,
title = "Molecules with ALMA at planet-forming scales (MAPS). V. CO gas distributions",
abstract = "Here we present high-resolution (15-24 au) observations of CO isotopologue lines from the Molecules with ALMA on Planet-forming Scales (MAPS) ALMA Large Program. Our analysis employs observations of the (J = 2-1) and (1-0) lines of 13CO and C18O and the (J = 1-0) line of C17O for five protoplanetary disks. We retrieve CO gas density distributions, using three independent methods: (1) a thermochemical modeling framework based on the CO data, the broadband spectral energy distribution, and the millimeter continuum emission; (2) an empirical temperature distribution based on optically thick CO lines; and (3) a direct fit to the C17O hyperfine lines. Results from these methods generally show excellent agreement. The CO gas column density profiles of the five disks show significant variations in the absolute value and the radial shape. Assuming a gas-to-dust mass ratio of 100, all five disks have a global CO-to-H2 abundance 10-100 times lower than the interstellar medium ratio. The CO gas distributions between 150 and 400 au match well with models of viscous disks, supporting the longstanding theory. CO gas gaps appear to be correlated with continuum gap locations, but some deep continuum gaps do not have corresponding CO gaps. The relative depths of CO and dust gaps are generally consistent with predictions of planet-disk interactions, but some CO gaps are 5-10 times shallower than predictions based on dust gaps. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.",
author = "Ke Zhang and Booth, {Alice S.} and Law, {Charles J.} and Bosman, {Arthur D.} and Schwarz, {Kamber R.} and Bergin, {Edwin A.} and {\"O}berg, {Karin I.} and Andrews, {Sean M.} and Guzm{\'a}n, {Viviana V.} and Catherine Walsh and Chunhua Qi and {Van'T Hoff}, {Merel L.R.} and Feng Long and Wilner, {David J.} and Jane Huang and Ian Czekala and Ilee, {John D.} and Gianni Cataldi and Bergner, {Jennifer B.} and Yuri Aikawa and Richard Teague and Jaehan Bae and Loomis, {Ryan A.} and Calahan, {Jenny K.} and Felipe Alarc{\'o}n and Fran{\c c}ois M{\'e}nard and {Le Gal}, Romane and Anibal Sierra and Yoshihide Yamato and Hideko Nomura and Takashi Tsukagoshi and P{\'e}rez, {Laura M.} and Leon Trapman and Yao Liu and Kenji Furuya",
note = "Funding Information: This paper makes use of the following ALMA data: ADS/ JAO.ALMA#2018.1.01055.L. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. K.Z. acknowledges the support of the Office of the Vice Chancellor for Research and Graduate Education at the University of Wisconsin-Madison with funding from the Wisconsin Alumni Research Foundation. K.Z., K.R.S., J.H., J.B., J.B.B., and I.C. acknowledge the support of NASA through Hubble Fellowship grants HST-HF2-51401.001, HST-HF2-51419.001, HST-HF2- 51460.001-A, HST-HF2-51427.001-A, HST-HF2-51429.001-A, and HST-HF2-51405.001-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.J.L. acknowledges funding from the National Science Foundation Graduate Research Fellowship under grant DGE1745303. A.D.B, E.A.B., and A.F. acknowledge support from NSF AAG grant No. 1907653. V.V.G. acknowledges support from FONDECYT Iniciaci{\'o}n 11180904 and ANID project Basal AFB-170002. Y.L. acknowledges the financial support by the Natural Science Foundation of China (grant No. 11973090). K.I.{\"O} acknowledges support from the Simons Foundation (SCOL No. 321183) and an NSF AAG grant (No. 1907653). S.M.A. and J.H. acknowledge funding support from the National Aeronautics and Space Administration under grant No. 17-XRP17 2-0012 issued through the Exoplanets Research Program. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds and from the Science and Technology Facilities Council (grant Nos. ST/R000549/1, ST/ T000287/1, and MR/T040726/1). R.T. and F.L. acknowledges support from the Smithsonian Institution as a Submillimeter Array (SMA) Fellow. M.L.R.H. acknowledges support from the Michigan Society of Fellows. Y. A. and G. C. acknowledge support by NAOJ ALMA Scientific Research grant code 2019- 13B. Y.A. acknowledges support by Grant-in-Aid for Scientific Research (S) 18H05222, and Grant-in-Aid for Transformative Research Areas (A) 20H05844 and 20H05847. J.K.C. acknowledges support from the National Science Foundation Graduate Research Fellowship under grant No. DGE 1256260 and the National Aeronautics and Space Administration FINESST grant, under grant No. 80NSSC19K1534. A.S. acknowledges support from ANID/CONICYT Programa de Astronom{\'i}a Fondo ALMA-CONICYT 2018 31180052. F.M. acknowledges support from ANR of France under contract ANR-16- CE31-0013 (Planet-Forming-Disks) and ANR-15-IDEX-02 (through CDP {"}Origins of Life{"}). R.L.G. acknowledges support from a CNES fellowship grant. H.N. acknowledges support by NAOJ ALMA Scientific Research grant code 2018-10B and Grant-in-Aid for Scientific Research No. 18H05441. Y.Y. is supported by IGPEES, WINGS Program, the University of Tokyo. L.M.P. acknowledges support from ANID project Basal AFB-170002 and from ANID FONDECYT Iniciaci{\'o}n project No. 11181068. T.T. is supported by JSPS KAKENHI grant Nos. JP17K14244 and JP20K04017. Publisher Copyright: {\textcopyright} 2021. The American Astronomical Society. All rights reserved.",
year = "2021",
month = nov,
doi = "10.3847/1538-4365/ac1580",
language = "English (US)",
volume = "257",
journal = "Astrophysical Journal, Supplement Series",
issn = "0067-0049",
publisher = "IOP Publishing Ltd.",
number = "1",
}