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Title: Unveiling the structure of barred galaxies at 3.6 μm with the Spitzer survey of stellar structure in galaxies (S{sup 4}G). I. Disk breaks

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, r {sub br}/R {sub bar}, 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, r {sub br}/R {sub bar} 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 withmore » 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.« less
Authors:
;  [1] ; ;  [2] ;  [3] ; ;  [4] ; ;  [5] ;  [6] ; ; ;  [7] ;  [8] ; ; ;  [9] ;  [10] ;  [11] ;  [12] more »; « less
  1. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
  2. European Southern Observatory, Casilla 19001, Santiago 19 (Chile)
  3. National Radio Astronomy Observatory/NAASC, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
  4. Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France)
  5. The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  6. IBM Research Division, T.J. Watson Research Center, Yorktown Heights, NY 10598 (United States)
  7. Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain)
  8. University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721 (United States)
  9. Division of Astronomy, Department of Physical Sciences, University of Oulu, Oulu, FIN-90014 (Finland)
  10. European Space Agency, ESTEC, Keplerlaan 1, 2200-AG, Noordwijk (Netherlands)
  11. MMTO, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  12. Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States)
Publication Date:
OSTI Identifier:
22351449
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 782; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ARMS; BENDING; DECOMPOSITION; EVOLUTION; GALAXIES; IMAGES; LUMINOSITY; PHOTOMETRY; POINT SOURCES; RESONANCE; SPIRAL CONFIGURATION; STARS; TWO-DIMENSIONAL CALCULATIONS