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Giant molecular cloud catalogues for PHANGS-ALMA: methods and initial results

Rosolowsky, Erik and Hughes, Annie and Leroy, Adam K. and Sun, Jiayi and Querejeta, Miguel and Schruba, Andreas and Usero, Antonio and Herrera, Cinthya N. and Liu, Daizhong and Pety, Jérôme and Saito, Toshiki and Bešlić, Ivana and Bigiel, Frank and Blanc, Guillermo and Chevance, Mélanie and Dale, Daniel A. and Deger, Sinan and Faesi, Christopher M. and Glover, Simon C. O. and Henshaw, Jonathan D. and Klessen, Ralf S. and Kruijssen, J. M. Diederik and Larson, Kirsten and Lee, Janice and Meidt, Sharon and Mok, Angus and Schinnerer, Eva and Thilker, David A. and Williams, Thomas G. (2021) Giant molecular cloud catalogues for PHANGS-ALMA: methods and initial results. Monthly Notices of the Royal Astronomical Society, 502 (1). pp. 1218-1245. ISSN 0035-8711.

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We present improved methods for segmenting CO emission from galaxies into individual molecular clouds, providing an update to the CPROPS algorithms presented by Rosolowsky & Leroy. The new code enables both homogenization of the noise and spatial resolution among data, which allows for rigorous comparative analysis. The code also models the completeness of the data via false source injection and includes an updated segmentation approach to better deal with blended emission. These improved algorithms are implemented in a publicly available PYTHON package, PYCPROPS. We apply these methods to 10 of the nearest galaxies in the PHANGS-ALMA survey, cataloguing CO emission at a common 90 pc resolution and a matched noise level. We measure the properties of 4986 individual clouds identified in these targets. We investigate the scaling relations among cloud properties and the cloud mass distributions in each galaxy. The physical properties of clouds vary among galaxies, both as a function of galactocentric radius and as a function of dynamical environment. Overall, the clouds in our target galaxies are well-described by approximate energy equipartition, although clouds in stellar bars and galaxy centres show elevated line widths and virial parameters. The mass distribution of clouds in spiral arms has a typical mass scale that is 2.5× larger than interarm clouds and spiral arms clouds show slightly lower median virial parameters compared to interarm clouds (1.2 versus 1.4).

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Rosolowsky, Erik0000-0002-5204-2259
Hughes, Annie0000-0002-9181-1161
Leroy, Adam K.0000-0002-2545-1700
Sun, Jiayi0000-0003-0378-4667
Querejeta, Miguel0000-0002-0472-1011
Usero, Antonio0000-0003-1242-505X
Herrera, Cinthya N.0000-0001-6405-0785
Liu, Daizhong0000-0001-9773-7479
Pety, Jérôme0000-0003-3061-6546
Saito, Toshiki0000-0002-2501-9328
Bešlić, Ivana0000-0003-0583-7363
Bigiel, Frank0000-0003-0166-9745
Blanc, Guillermo0000-0003-4218-3944
Chevance, Mélanie0000-0002-5635-5180
Dale, Daniel A.0000-0002-5782-9093
Deger, Sinan0000-0003-1943-723X
Glover, Simon C. O.0000-0001-6708-1317
Henshaw, Jonathan D.0000-0001-9656-7682
Klessen, Ralf S.0000-0002-0560-3172
Kruijssen, J. M. Diederik0000-0002-8804-0212
Larson, Kirsten0000-0003-3917-6460
Lee, Janice0000-0002-2278-9407
Meidt, Sharon0000-0002-6118-4048
Mok, Angus0000-0001-7413-7534
Schinnerer, Eva0000-0002-3933-7677
Thilker, David A.0000-0002-8528-7340
Williams, Thomas G.0000-0002-0012-2142
Additional Information:© 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2021 January 8. Received 2020 December 14; in original form 2020 October 5. This work was carried out as part of the PHANGS collaboration. We are grateful for the comments of an anonymous referee whose review improved this work. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.00956.S and ADS/JAO.ALMA#2017.1.00886.S. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada) , NSC 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. This work made use of the ASTROPY (Astropy Collaboration 2013), SPECTRAL-CUBE, RADIO-BEAM and ASTRODENDRO packages for PYTHON and we gratefully acknowledge the ongoing efforts of our community’s developers. This work also made use of the NASA Astrophysics Data System and the NASA Extragalactic Database. ER acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), funding reference number RGPIN-2017-03987, and a resource allocation from Compute Canada. AH was supported by the Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU with INP and IN2P3 co-funded by CEA and CNES, and by the Programme National ‘Physique et Chimie du Milieu Interstellaire’ (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES. The work of AKL and JS is partially supported by the National Science Foundation (NSF) under grant numbers 1615105, 1615109, and 1653300, as well as by the National Aeronautics and Space Administration (NASA) under ADAP grant numbers NNX16AF48G and NNX17AF39G. AU acknowledges support from the Spanish funding grants AYA2016-79006-P (MINECO/FEDER), PGC2018-094671-B-I00 (MCIU/AEI/FEDER), and PID2019-108765GB-I00 (MICINN). DL, TW, TS, and ES acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme (grant agreement number 694343). FB and IB acknowledge funding from the European Union’s Horizon 2020 Framework Programme (grant agreement number 726384/EMPIRE). MC and JMDK gratefully acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG) in the form of an Emmy Noether Research Group (grant number KR4801/1-1) and the DFG Sachbeihilfe (grant number KR4801/2-1). JMDK is also supported by the European Research Council (ERC) under the European Union’s Horizon 2020 Framework Programme via the ERC Starting Grant MUSTANG (grant agreement number 714907). RSK and SCOG acknowledge financial support from the German Research Foundation (DFG) via the Collaborative Research Center (SFB 881, Project-ID 138713538) ‘The Milky Way System’ (subprojects A1, B1, B2, and B8). They also acknowledge funding from the Heidelberg Cluster of Excellence STRUCTURES in the framework of Germany’s Excellence Strategy (grant EXC-2181/1 - 390900948) and from the European Research Council via the ERC Synergy Grant ECOGAL (grant number 855130) and the ERC Advanced Grant STARLIGHT (grant number 339177). Data Availability. The data underlying this article are available in the article and in its online supplementary material. Supporting data sets from `in preparation’ articles will be publicly released on acceptance of those manuscripts.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)RGPIN-2017-03987
Programme National Cosmology et Galaxies (PNCG)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut national des sciences de l'Univers (INSU)UNSPECIFIED
Institut de physique du CNRSUNSPECIFIED
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)UNSPECIFIED
Commissariat à l’Energie Atomique (CEA)UNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Ministerio de Economía, Industria y Competitividad (MINECO)AYA2016-79006-P
Fondo Europeo de Desarrollo Regional (FEDER)UNSPECIFIED
Ministerio de Ciencia, Innovación y Universidades (MCIU)PGC2018-094671-B-I00
Ministerio de Ciencia e Innovación (MCINN)PID2019-108765GB-I00
European Research Council (ERC)694343
European Research Council (ERC)726384
Deutsche Forschungsgemeinschaft (DFG)KR4801/1-1
Deutsche Forschungsgemeinschaft (DFG)KR4801/2-1
European Research Council (ERC)714907
Deutsche Forschungsgemeinschaft (DFG)SFB 881
Deutsche Forschungsgemeinschaft (DFG)138713538
Bundesministerium für Bildung und Forschung (BMBF)EXC-2181/1 - 390900948
European Research Council (ERC)855130
European Research Council (ERC)339177
Subject Keywords:stars: formation, ISM: clouds, galaxies: individual (NGC 0628, NGC 1637, NGC 2903, NGC 3521, NGC 3621, NGC 3627, NGC 4826, NGC 5068, NGC 5643, NGC 6300)
Issue or Number:1
Record Number:CaltechAUTHORS:20210621-223906667
Persistent URL:
Official Citation:Erik Rosolowsky, Annie Hughes, Adam K Leroy, Jiayi Sun, Miguel Querejeta, Andreas Schruba, Antonio Usero, Cinthya N Herrera, Daizhong Liu, Jérôme Pety, Toshiki Saito, Ivana Bešlić, Frank Bigiel, Guillermo Blanc, Mélanie Chevance, Daniel A Dale, Sinan Deger, Christopher M Faesi, Simon C O Glover, Jonathan D Henshaw, Ralf S Klessen, J M Diederik Kruijssen, Kirsten Larson, Janice Lee, Sharon Meidt, Angus Mok, Eva Schinnerer, David A Thilker, Thomas G Williams, Giant molecular cloud catalogues for PHANGS-ALMA: methods and initial results, Monthly Notices of the Royal Astronomical Society, Volume 502, Issue 1, March 2021, Pages 1218–1245,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109521
Deposited By: George Porter
Deposited On:22 Jun 2021 15:23
Last Modified:22 Jun 2021 15:23

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