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Unveiling the structure of barred galaxies at 3.6 μm with the Spitzer Survey of Stellar Structure in Galaxies (S4G). I. Disk breaks.
Faculty Scholarship
  • Taehyun Kim, National Radio Astronomy Observatory
  • Dimitri A. Gadotti, European Southern Observatory
  • Kartik Sheth, National Radio Astronomy Observatory
  • E. Athanassoula, Aix Marseille Universite
  • Albert Bosma, Aix Marseille Universite
  • Myung Gyoon Lee, Seoul National University
  • Barry F. Madore, Observatories of the Carnegie Institute for Science
  • Bruce G. Elmegreen, T. J. Watson Research Center
  • Johan H. Knapen, Universidad de La Laguna
  • Dennis Zaritsky, University of Arizona
  • Luis C. Ho, The Observatories of the Carnegie Institution for Science
  • Sebastien Comeron, University of Oulu
  • Benne W. Holwerda, University of Louisville
  • Joannah L. Hinz, University of Arizona
  • Juan Carlos Munoz-Mateos, European Southern Observatory
  • Mauricio Cisternas, Instituto de Astrofísica de Canarias, Spain
  • Santiago Erroz-Ferrer, Instituto de Astrofísica de Canarias
  • Ron Buta, University of Alabama - Tuscaloosa
  • Eija Laurikainen, University of Oulu
  • Heikki Salo, University of Oulu
  • Jarkko Laine, University of Oulu
  • Karin Menendez-Delmestre, Universidade Federal de Rio de Janeiro
  • Michael W. Regan, Space Telescope Science Institute
  • Bonita de Swardt, South African Astronomical Observatory
  • Armando Gil de Paz, Universidad Complutense de Madrid
  • Mark Seibert, Observatories of the Carnegie Institution of Washington
  • Trisha Mizusawa, Florida Institute of Technology
Document Type
Article
Publication Date
2-1-2014
Department
Physics and Astronomy
Abstract

We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the disk break and using a single disk scale length in the model fit for Type II (down-bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We find that for galaxies with B/T 0.1, the break radius to bar radius, rbr/Rbar, varies between 1 and 3, but as a function of B/T the ratio remains roughly constant. This suggests that in bulge-dominated galaxies the disk break is likely related to the outer Lindblad resonance of the bar and thus moves outward as the bar grows. For galaxies with small bulges, B/T < 0.1, rbr/Rbar spans a wide range from 1 to 6. This suggests that the mechanism that produces the break in these galaxies may be different from that in galaxies with more massive bulges. Consistent with previous studies, we conclude that disk breaks in galaxies with small bulges may originate from bar resonances that may be also coupled with the spiral arms, or be related to star formation thresholds.

Comments

Copyright 2014. The American Astronomical Society. All rights reserved.

https://doi.org/10.1088/0004-637X/782/2/64

DOI
10.1088/0004-637X/782/2/64
Citation Information

Kim, Taehyun, et al. "Unveiling the Structure of Barred Galaxies at 3.6 μm with the Spitzer Survey of Stellar Structure in Galaxies (S4G). I. Disk Breaks." 2014. The Astrophysical Journal 782(2): 19 pp.