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PHANGS-ALMA Data Processing and Pipeline

Leroy, Adam K. and Hughes, Annie and Liu, Daizhong and Pety, Jérôme and Rosolowsky, Erik and Saito, Toshiki and Schinnerer, Eva and Schruba, Andreas and Usero, Antonio and Faesi, Christopher M. and Herrera, Cinthya N. and Chevance, Mélanie and Hygate, Alexander P. S. and Kepley, Amanda A. and Koch, Eric W. and Querejeta, Miguel and Sliwa, Kazimierz and Will, David and Wilson, Christine D. and Anand, Gagandeep S. and Barnes, Ashley and Belfiore, Francesco and Bešlić, Ivana and Bigiel, Frank and Blanc, Guillermo A. and Bolatto, Alberto D. and Boquien, Médéric and Cao, Yixian and Chandar, Rupali and Chastenet, Jérémy and Chiang, I-Da and Congiu, Enrico and Dale, Daniel A. and Deger, Sinan and den Brok, Jakob S. and Eibensteiner, Cosima and Emsellem, Eric and García-Rodríguez, Axel and Glover, Simon C. O. and Grasha, Kathryn and Groves, Brent and Henshaw, Jonathan D. and Jiménez Donaire, María J. and Kim, Jaeyeon and Klessen, Ralf S. and Kreckel, Kathryn and Kruijssen, J. M. Diederik and Larson, Kirsten L. and Lee, Janice C. and Mayker, Ness and McElroy, Rebecca and Meidt, Sharon E. and Mok, Angus and Pan, Hsi-An and Puschnig, Johannes and Razza, Alessandro and Sánchez-Bl’azquez, Patricia and Sandstrom, Karin M. and Santoro, Francesco and Sardone, Amy and Scheuermann, Fabian and Sun, Jiayi and Thilker, David A. and Turner, Jordan A. and Ubeda, Leonardo and Utomo, Dyas and Watkins, Elizabeth J. and Williams, Thomas G. (2021) PHANGS-ALMA Data Processing and Pipeline. Astrophysical Journal Supplement Series, 255 (1). Art. No. 19. ISSN 0067-0049. doi:10.3847/1538-4365/abec80.

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We describe the processing of the PHANGS–ALMA survey and present the PHANGS–ALMA pipeline, a public software package that processes calibrated interferometric and total power data into science-ready data products. PHANGS–ALMA is a large, high-resolution survey of CO(2–1) emission from nearby galaxies. The observations combine ALMA's main 12 m array, the 7 m array, and total power observations, and use mosaics of dozens to hundreds of individual pointings. We describe the processing of the u − v data, imaging and deconvolution, linear mosaicking, combining interferometer and total power data, noise estimation, masking, data product creation, and quality assurance. Our pipeline has a general design and can also be applied to Very Large Array and ALMA observations of other spectral lines and continuum emission. We highlight our recipe for deconvolution of complex spectral line observations, which combines multiscale clean, single-scale clean, and automatic mask generation in a way that appears robust and effective. We also emphasize our two-track approach to masking and data product creation. We construct one set of "broadly masked" data products, which have high completeness but significant contamination by noise, and another set of "strictly masked" data products, which have high confidence but exclude faint, low signal-to-noise emission. Our quality assurance tests, supported by simulations, demonstrate that 12 m+7 m deconvolved data recover a total flux that is significantly closer to the total power flux than the 7 m deconvolved data alone. In the appendices, we measure the stability of the ALMA total power calibration in PHANGS–ALMA and test the performance of popular short-spacing correction algorithms.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Leroy, Adam K.0000-0002-2545-1700
Hughes, Annie0000-0002-9181-1161
Liu, Daizhong0000-0001-9773-7479
Pety, Jérôme0000-0003-3061-6546
Rosolowsky, Erik0000-0002-5204-2259
Saito, Toshiki0000-0002-2501-9328
Schinnerer, Eva0000-0002-3933-7677
Usero, Antonio0000-0003-1242-505X
Faesi, Christopher M.0000-0001-5310-467X
Herrera, Cinthya N.0000-0001-6405-0785
Chevance, Mélanie0000-0002-5635-5180
Hygate, Alexander P. S.0000-0002-6488-471X
Kepley, Amanda A.0000-0002-3227-4917
Koch, Eric W.0000-0001-9605-780X
Querejeta, Miguel0000-0002-0472-1011
Wilson, Christine D.0000-0001-5817-0991
Anand, Gagandeep S.0000-0002-5259-2314
Barnes, Ashley0000-0003-0410-4504
Belfiore, Francesco0000-0002-2545-5752
Bešlić, Ivana0000-0003-0583-7363
Bigiel, Frank0000-0003-0166-9745
Blanc, Guillermo A.0000-0003-4218-3944
Bolatto, Alberto D.0000-0002-5480-5686
Boquien, Médéric0000-0003-0946-6176
Cao, Yixian0000-0001-5301-1326
Chandar, Rupali0000-0003-0085-4623
Chastenet, Jérémy0000-0002-5235-5589
Chiang, I-Da0000-0003-2551-7148
Congiu, Enrico0000-0002-8549-4083
Dale, Daniel A.0000-0002-5782-9093
Deger, Sinan0000-0003-1943-723X
den Brok, Jakob S.0000-0002-8760-6157
Eibensteiner, Cosima0000-0002-1185-2810
Emsellem, Eric0000-0002-6155-7166
García-Rodríguez, Axel0000-0002-0697-0177
Glover, Simon C. O.0000-0001-6708-1317
Grasha, Kathryn0000-0002-3247-5321
Groves, Brent0000-0002-9768-0246
Henshaw, Jonathan D.0000-0001-9656-7682
Jiménez Donaire, María J.0000-0002-9165-8080
Kim, Jaeyeon0000-0002-0432-6847
Klessen, Ralf S.0000-0002-0560-3172
Kreckel, Kathryn0000-0001-6551-3091
Kruijssen, J. M. Diederik0000-0002-8804-0212
Larson, Kirsten L.0000-0003-3917-6460
Lee, Janice C.0000-0002-2278-9407
Mayker, Ness0000-0002-5993-6685
McElroy, Rebecca0000-0003-2290-7060
Meidt, Sharon E.0000-0002-6118-4048
Mok, Angus0000-0001-7413-7534
Pan, Hsi-An0000-0002-1370-6964
Puschnig, Johannes0000-0003-1111-3951
Razza, Alessandro0000-0001-7876-1713
Sánchez-Bl’azquez, Patricia0000-0003-0651-0098
Sandstrom, Karin M.0000-0002-4378-8534
Santoro, Francesco0000-0002-6363-9851
Sardone, Amy0000-0002-5783-145X
Sun, Jiayi0000-0003-0378-4667
Thilker, David A.0000-0002-8528-7340
Turner, Jordan A.0000-0003-2261-5746
Utomo, Dyas0000-0003-4161-2639
Watkins, Elizabeth J.0000-0002-7365-5791
Williams, Thomas G.0000-0002-0012-2142
Additional Information:© 2021. The American Astronomical Society. Received 2020 September 26; revised 2021 February 2; accepted 2021 February 14; published 2021 July 19. We gratefully acknowledge a prompt and constructive review by the anonymous referee during a difficult time. This work also benefited immensely from helpful discussions with Crystal Brogan, Jeffrey Mangum, and the North American ALMA Science Center and European Southern Observatory staff, including Dirk Petry. The computing and software infrastructure used to process PHANGS–ALMA and develop this pipeline at OSU was built and supported by David Will, who for years was the most supportive and welcoming person in a supportive and welcoming department. He will be sorely missed. This work was carried out as part of the PHANGS collaboration. The work of A.K.L., J.S., and D.U. is partially supported by the National Science Foundation (NSF) under grants No. 1615105, 1615109, and 1653300, as well as by the National Aeronautics and Space Administration (NASA) under ADAP grants NNX16AF48G and NNX17AF39G. E.R. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), funding reference number RGPIN-2017-03987, and computational support from Compute Canada. D.L., T.S., E.S., C.M.F., K.S., and T.G.W. acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 694343). C.H., A.H., and J.P. acknowledge support by the Programme National "Physique et Chimie du Milieu Interstellaire" (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES. A.H. acknowledges support by the Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU with INP and IN2P3, co-funded by CEA and CNES. A.U. and A.G.-R. acknowledge support from the Spanish funding grants AYA2016-79006-P (MINECO/FEDER) and PID2019-108765GB-I00 (MICINN). A.U. acknowledges support from the Spanish funding grant PGC2018-094671-B-I00 (MCIU/AEI/FEDER). C.M.F. acknowledges support from the NSF under Award No. 1903946. M.C. and J.M.D.K. gratefully acknowledge funding from the German Research Foundation (DFG) through an Emmy Noether Research Group (grant No. KR4801/1-1). M.C., J.M.D.K., and J.J.K. gratefully acknowledge funding from the DFG Sachbeihilfe (grant No. KR4801/2-1). J.M.D.K. gratefully acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program via the ERC Starting Grant MUSTANG (grant agreement No. 714907). F.B., A.T.B., I.B., J.d.B., and J.P. acknowledge funding from the European Union's Horizon 2020 research and innovation program (grant agreement No. 726384/EMPIRE). R.S.K. and S.C.O.G. acknowledge financial support from the DFG via the collaborative research center (SFB 881, Project-ID 138713538) "The Milky Way System" (subprojects A1, B1, B2, and B8). They also acknowledge subsidies from the Heidelberg Cluster of Excellence STRUCTURES in the framework of Germany's Excellence Strategy (grant EXC-2181/1-390900948) and funding from the ERC via the ERC Synergy Grant ECOGAL (grant 855130). K.K. and F.S. gratefully acknowledge funding from the DFG in the form of an Emmy Noether Research Group (grant No. KR4598/2-1). E.W. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project-ID 138713538–SFB 881 ("The Milky Way System," subproject P2). C.E. acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG) Sachbeihilfe, grant No. BI1546/3-1. A.S. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1903834. This paper makes use of the following ALMA data, which have been processed as part of the PHANGS–ALMA CO(2–1) survey: ADS/JAO.ALMA#2012.1.00650.S, ADS/JAO.ALMA#2013.1.00803.S, ADS/JAO.ALMA#2013.1.01161.S, ADS/JAO.ALMA#2015.1.00121.S, ADS/JAO.ALMA#2015.1.00782.S, ADS/JAO.ALMA#2015.1.00925.S, ADS/JAO.ALMA#2015.1.00956.S, ADS/JAO.ALMA#2016.1.00386.S, ADS/JAO.ALMA#2017.1.00392.S, ADS/JAO.ALMA#2017.1.00766.S, ADS/JAO.ALMA#2017.1.00886.L, ADS/JAO.ALMA#2018.1.01321.S, ADS/JAO.ALMA#2018.1.01651.S. ADS/JAO.ALMA#2018.A.00062.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. Software: ALMA Calibration Pipeline (L. Davis et al. 2021, in preparation), CASA (McMullin et al. 2007), numpy (Oliphant 2006), scipy (Virtanen et al. 2020), astropy (Astropy Collaboration et al. 2013, 2018) IDL Astronomy User's Library (Landsman et al. 1993), cprops (Rosolowsky & Leroy 2006), GILDAS Pety et al. (2005), R R Core Team (2015), PHANGS–ALMA Total Power Pipeline (Herrera et al. 2020), spectral-cube, radio-beam.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)RGPIN-2017-03987
European Research Council (ERC)694343
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut national des sciences de l'Univers (INSU)UNSPECIFIED
Commissariat a l'Energie Atomique (CEA)UNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)UNSPECIFIED
Ministerio de Economía, Industria y Competitividad (MINECO)AYA2016-79006-P
Ministerio de Ciencia e Innovación (MCINN)PID2019-108765GB-I00
Fondo Europeo de Desarrollo Regional (FEDER)UNSPECIFIED
Ministerio de Ciencia, Innovación y Universidades (MCIU)PGC2018-094671-B-I00
Deutsche Forschungsgemeinschaft (DFG)KR4801/1-1
Deutsche Forschungsgemeinschaft (DFG)KR4801/2-1
European Research Council (ERC)714907
European Research Council (ERC)726384
Deutsche Forschungsgemeinschaft (DFG)SFB 881
Deutsche Forschungsgemeinschaft (DFG)138713538
Deutsche Forschungsgemeinschaft (DFG)EXC-2181/1-390900948
European Research Council (ERC)855130
Deutsche Forschungsgemeinschaft (DFG)KR4598/2-1
Deutsche Forschungsgemeinschaft (DFG)BI1546/3-1
NSF Astronomy and Astrophysics FellowshipAST-1903834
Subject Keywords:Radio interferometry; Interstellar medium; CO line emission; Millimeter astronomy; Astronomy data reduction; Galaxies; Star formation
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Radio interferometry (1346); Interstellar medium (847); CO line emission (262); Millimeter astronomy (1061); Astronomy data reduction (1861); Galaxies (573); Star formation (1569)
Record Number:CaltechAUTHORS:20210729-202324882
Persistent URL:
Official Citation:Adam K. Leroy et al 2021 ApJS 255 19
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:110076
Deposited By: Tony Diaz
Deposited On:02 Aug 2021 18:41
Last Modified:02 Aug 2021 18:41

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