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The Spitzer Survey of Stellar Structure in Galaxies (S^4G): Multi-component Decomposition Strategies and Data Release

Salo, Heikki and Laurikainen, Eija and Laine, Jarkko and Comerón, Sébastien and Gadotti, Dimitri A. and Buta, Ron and Sheth, Kartik and Zaritsky, Dennis and Ho, Luis C. and Knapen, Johan and Athanassoula, E. and Bosma, Albert and Laine, Seppo and Cisternas, Mauricio and Kim, Taehyun and Muñoz-Mateos, Juan-Carlos and Regan, Michael and Hinz, Joannah L. and Gil de Paz, Armando and Menéndez-Delmestre, Karín and Mizusawa, Trisha and Erroz-Ferrer, Santiago and Meidt, Sharon E. and Querejeta, Miguel (2015) The Spitzer Survey of Stellar Structure in Galaxies (S^4G): Multi-component Decomposition Strategies and Data Release. Astrophysical Journal Supplement Series, 219 (1). Art. No. 4. ISSN 0067-0049.

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The Spitzer Survey of Stellar Structure in Galaxies (S^4G) is a deep 3.6 and 4.5 μm imaging survey of 2352 nearby (<40 Mpc) galaxies. We describe the S^4G data analysis pipeline 4, which is dedicated to two-dimensional structural surface brightness decompositions of 3.6 μm images, using GALFIT3.0. Besides automatic 1-component Sérsic fits, and 2-component Sérsic bulge + exponential disk fits, we present human-supervised multi-component decompositions, which include, when judged appropriate, a central point source, bulge, disk, and bar components. Comparison of the fitted parameters indicates that multi-component models are needed to obtain reliable estimates for the bulge Sérsic index and bulge-to-total light ratio (B/T), confirming earlier results. Here, we describe the preparations of input data done for decompositions, give examples of our decomposition strategy, and describe the data products released via IRSA and via our web page ( These products include all the input data and decomposition files in electronic form, making it easy to extend the decompositions to suit specific science purposes. We also provide our IDL-based visualization tools (GALFIDL) developed for displaying/running GALFIT-decompositions, as well as our mask editing procedure (MASK_EDIT) used in data preparation. A detailed analysis of the bulge, disk, and bar parameters derived from multi-component decompositions will be published separately.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Sheth, Kartik0000-0002-5496-4118
Zaritsky, Dennis0000-0002-5177-727X
Ho, Luis C.0000-0001-6947-5846
Laine, Seppo0000-0003-1250-8314
Mizusawa, Trisha0000-0001-7182-5307
Additional Information:© 2015 American Astronomical Society. Received 2014 October 3; accepted 2014 November 26; published 2015 July 1. H.S., E.L., and S.C. acknowledge the Academy of Finland for support. J.L. was supported by the Väisälä Foundation Grant. E.A. and A.B. acknowledge the CNES (Centre National d’Etudies Spatiales—France) for financial support. The authors also acknowledge support from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement number 289313. We thank J. Janz for discussions and for help with the initial preparation of the web-pages. We also thank the Spitzer IRAC Instrument Support Team for its help with the sigmaimages.
Funding AgencyGrant Number
Academy of FinlandUNSPECIFIED
Väisälä FoundationUNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Marie Curie Fellowship289313
Subject Keywords:galaxies: fundamental parameters; galaxies: kinematics and dynamics; galaxies: spiral; galaxies: structure
Issue or Number:1
Record Number:CaltechAUTHORS:20150831-152209133
Persistent URL:
Official Citation:The Spitzer Survey of Stellar Structure in Galaxies (S4G): Multi-component Decomposition Strategies and Data Release Heikki Salo et al. 2015 ApJS 219 4
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59996
Deposited By: Ruth Sustaita
Deposited On:01 Sep 2015 16:07
Last Modified:13 Nov 2019 23:21

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