CaltechAUTHORS
Published March 2021 | Version Published + Accepted Version + Supplemental Material
Journal Article Open

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

Creators

  • 1. ROR icon University of Alberta
  • 2. ROR icon Research Institute in Astrophysics and Planetology
  • 3. ROR icon The Ohio State University
  • 4. ROR icon Spanish National Observatory
  • 5. ROR icon Max Planck Institute for Extraterrestrial Physics
  • 6. ROR icon International Research Institute for Radio Astronomy
  • 7. ROR icon Max Planck Institute for Astronomy
  • 8. ROR icon University of Bonn
  • 9. ROR icon Carnegie Observatories
  • 10. ROR icon Heidelberg University
  • 11. ROR icon University of Wyoming
  • 12. ROR icon Infrared Processing and Analysis Center
  • 13. ROR icon University of Massachusetts Amherst
  • 14. ROR icon Ghent University
  • 15. ROR icon University of Toledo
  • 16. ROR icon Johns Hopkins University

Abstract

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).

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 (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_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.

Attached Files

Published - stab085.pdf

Accepted Version - 2101.04697.pdf

Supplemental Material - stab085_supplemental_file.zip

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Additional details

Identifiers

Eprint ID
109521
Resolver ID
CaltechAUTHORS:20210621-223906667

Related works

Describes
https://arxiv.org/abs/2101.04697 (URL)

Funding

Natural Sciences and Engineering Research Council of Canada (NSERC)
RGPIN-2017-03987
Compute Canada
Programme National Cosmology et Galaxies (PNCG)
Centre National de la Recherche Scientifique (CNRS)
Institut national des sciences de l'Univers (INSU)
Institut de physique du CNRS
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)
Commissariat à l'Energie Atomique (CEA)
Centre National d'Études Spatiales (CNES)
NSF
AST-1615105
NSF
AST-1615109
NSF
AST-1653300
NASA
NNX16AF48G
NASA
NNX17AF39G
Ministerio de Economía, Industria y Competitividad (MINECO)
AYA2016-79006-P
Fondo Europeo de Desarrollo Regional (FEDER)
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

Dates

Created
2021-06-22
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)