_version_ 1866910922389323776
author Trapman, Leon
Longarini, Cristiano
Rosotti, Giovanni P.
Andrews, Sean M.
Bae, Jaehan
Barraza-Alfaro, Marcelo
Benisty, Myriam
Cataldi, Gianni
Curone, Pietro
Czekala, Ian
Facchini, Stefano
Fasano, Daniele
Flock, Mario
Fukagawa, Misato
Galloway-Sprietsma, Maria
Garg, Himanshi
Hall, Cassandra
Huang, Jane
Ilee, John D.
Izquierdo, Andres F.
Kanagawa, Kazuhiro
Lesur, Geoffroy
Lodato, Giuseppe
Loomis, Ryan A.
Orihara, Ryuta
Paneque-Carreno, Teresa
Pinte, Christophe
Price, Daniel
Stadler, Jochen
Teague, Richard
van Terwisga, Sierk
Testi, Leonardo
Yen, Hsi-Wei
Wafflard-Fernandez, Gaylor
Wilner, David J.
Winter, Andrew J.
Wölfer, Lisa
Yoshida, Tomohiro C.
Zawadzki, Brianna
Zhang, Ke
author_facet Trapman, Leon
Longarini, Cristiano
Rosotti, Giovanni P.
Andrews, Sean M.
Bae, Jaehan
Barraza-Alfaro, Marcelo
Benisty, Myriam
Cataldi, Gianni
Curone, Pietro
Czekala, Ian
Facchini, Stefano
Fasano, Daniele
Flock, Mario
Fukagawa, Misato
Galloway-Sprietsma, Maria
Garg, Himanshi
Hall, Cassandra
Huang, Jane
Ilee, John D.
Izquierdo, Andres F.
Kanagawa, Kazuhiro
Lesur, Geoffroy
Lodato, Giuseppe
Loomis, Ryan A.
Orihara, Ryuta
Paneque-Carreno, Teresa
Pinte, Christophe
Price, Daniel
Stadler, Jochen
Teague, Richard
van Terwisga, Sierk
Testi, Leonardo
Yen, Hsi-Wei
Wafflard-Fernandez, Gaylor
Wilner, David J.
Winter, Andrew J.
Wölfer, Lisa
Yoshida, Tomohiro C.
Zawadzki, Brianna
Zhang, Ke
contents The gas masses of protoplanetary disks are important but elusive quantities. In this work we present new ALMA observations of N2H+ (3-2) for 11 exoALMA disks. N2H+ is a molecule sensitive to CO freeze-out and has recently been shown to significantly improve the accuracy of gas masses estimated from CO line emission. We combine these new observations with archival N2H+ and CO isotopologue observations to measure gas masses for 19 disks, predominantly from the exoALMA Large program. For 15 of these disks the gas mass has also been measured using gas rotation curves. We show that the CO + N2H+ line emission-based gas masses typically agree with the kinematically measured ones within a factor 3 (1-2σ). Gas disk masses from CO + N2H+ are on average a factor 2.3(+0.7,-1.0) x lower than the kinematic disk masses, which could suggest slightly lower N2 abundances and/or lower midplane ionization rates than typically assumed. Herbig disks are found to have ISM level CO gas abundances based on their CO and N2H+ fluxes, which sets them apart from T-Tauri disks where abundances are typically 3-30x lower. The agreement between CO + N2H+ -based and kinematically measured gas masses is promising and shows that multi-molecule line fluxes are a robust tool to accurately measure disk masses at least for extended disks.
format Preprint
id arxiv_https___arxiv_org_abs_2504_19371
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ExoALMA XIII. gas masses from N2H+ and C18O: a comparison of protoplanetary gas disk mass measurement techniques
Trapman, Leon
Longarini, Cristiano
Rosotti, Giovanni P.
Andrews, Sean M.
Bae, Jaehan
Barraza-Alfaro, Marcelo
Benisty, Myriam
Cataldi, Gianni
Curone, Pietro
Czekala, Ian
Facchini, Stefano
Fasano, Daniele
Flock, Mario
Fukagawa, Misato
Galloway-Sprietsma, Maria
Garg, Himanshi
Hall, Cassandra
Huang, Jane
Ilee, John D.
Izquierdo, Andres F.
Kanagawa, Kazuhiro
Lesur, Geoffroy
Lodato, Giuseppe
Loomis, Ryan A.
Orihara, Ryuta
Paneque-Carreno, Teresa
Pinte, Christophe
Price, Daniel
Stadler, Jochen
Teague, Richard
van Terwisga, Sierk
Testi, Leonardo
Yen, Hsi-Wei
Wafflard-Fernandez, Gaylor
Wilner, David J.
Winter, Andrew J.
Wölfer, Lisa
Yoshida, Tomohiro C.
Zawadzki, Brianna
Zhang, Ke
Earth and Planetary Astrophysics
Astrophysics of Galaxies
The gas masses of protoplanetary disks are important but elusive quantities. In this work we present new ALMA observations of N2H+ (3-2) for 11 exoALMA disks. N2H+ is a molecule sensitive to CO freeze-out and has recently been shown to significantly improve the accuracy of gas masses estimated from CO line emission. We combine these new observations with archival N2H+ and CO isotopologue observations to measure gas masses for 19 disks, predominantly from the exoALMA Large program. For 15 of these disks the gas mass has also been measured using gas rotation curves. We show that the CO + N2H+ line emission-based gas masses typically agree with the kinematically measured ones within a factor 3 (1-2σ). Gas disk masses from CO + N2H+ are on average a factor 2.3(+0.7,-1.0) x lower than the kinematic disk masses, which could suggest slightly lower N2 abundances and/or lower midplane ionization rates than typically assumed. Herbig disks are found to have ISM level CO gas abundances based on their CO and N2H+ fluxes, which sets them apart from T-Tauri disks where abundances are typically 3-30x lower. The agreement between CO + N2H+ -based and kinematically measured gas masses is promising and shows that multi-molecule line fluxes are a robust tool to accurately measure disk masses at least for extended disks.
title ExoALMA XIII. gas masses from N2H+ and C18O: a comparison of protoplanetary gas disk mass measurement techniques
topic Earth and Planetary Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2504.19371