Heikki Salo, Eija Laurikainen, Jarkko Laine, Sebastien Comerón, Dimitri A. Gadotti, Ron Buta, Kartik Sheth, Dennis Zaritsky, Luis Ho, Johan Knapen, E. Athanassoula, Albert Bosma, Seppo Laine, Mauricio Cisternas, Taehyun Kim, Juan Carlos Muñoz-Mateos, Michael Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-DelmestreTrisha Mizusawa, Santiago Erroz-Ferrer, Sharon E. Meidt, Miguel Querejeta

Research output: Contribution to journalReview articlepeer-review

205 Scopus citations


The Spitzer Survey of Stellar Structure in Galaxies (S4G) is a deep 3.6 and 4.5 μm imaging survey of 2352 nearby (<40 Mpc) galaxies. We describe the S4G 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.

Original languageEnglish (US)
Article number4
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Jul 20 2015


  • fundamental parameters
  • galaxies: kinematics and dynamics
  • galaxies: spiral
  • galaxies: structure

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'THE SPITZER SURVEY of STELLAR STRUCTURE in GALAXIES (S4G): MULTI-COMPONENT DECOMPOSITION STRATEGIES and DATA RELEASE'. Together they form a unique fingerprint.
  • S4G pipeline 4: multi-component decompositions

    Salo, H. (Creator), Laurikainen, E. (Creator), Laine, J. (Creator), Comerón, S. (Contributor), Gadotti, D. A. (Creator), Buta, R. (Creator), Sheth, K. (Creator), Zaritsky, D. F. (Creator), Ho, L. (Creator), Knapen, J. (Creator), Athanassoula, E. (Creator), Bosma, A. (Creator), Laine, S. (Creator), Cisternas, M. (Creator), Kim, T. (Creator), Muñoz-Mateos, J. C. (Contributor), Regan, M. (Creator), Hinz, J. L. (Creator), De Paz, A. G. (Contributor), Menendez-Delmestre, K. (Creator), Mizusawa, T. (Creator), Erroz-Ferrer, S. (Creator), Meidt, S. E. (Creator), Querejeta, M. (Creator) & Ho, L. (Creator), Centre de Donnees Strasbourg (CDS), 2015


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