Unveiling the structure of barred galaxies at 3.6 μm with the spitzer survey of stellar structure in galaxies (S^4G). I. Disk breaks



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Gil de Paz, Armando and ..., otros (2014) Unveiling the structure of barred galaxies at 3.6 μm with the spitzer survey of stellar structure in galaxies (S^4G). I. Disk breaks. Astrophysical journal, 782 (2). ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1088/0004-637X/782/2/64


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_br/R_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_br/R_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 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.

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© 2014. The American Astronomical Society. Artículo firmado por 27 autores. The authors are grateful to the entire S<SUP>4</SUP>G team for their effort in this project. We thank the anonymous referee for a thorough reading of the manuscript and helpful comments. T. K., K. S., J.-C.M.-M., and T. M. acknowledge support from the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We also gratefully acknowledge support from NASA JPL/Spitzer grant RSA 1374189 provided for the S4G project. T. K. and M. G. L. were supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MEST) (No. 2012R1A4A1028713). D. A. G. thanks funding under the Marie Curie Actions of the European Commission (FP7-COFUND). E. A. and A. B. thank the Centre National d'Etudes Spatiales for financial support. They also acknowledge financial support from the People Programme (Marie Curie Actions) of the European Union's FP7/2007-2013/ to the DAGAL network under REA grant agreement No. PITN-GA-2011-289313. This research is based on observations and archival data made with the Spitzer Space Telescope and made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with National Aeronautics and Space Administration (NASA). We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr).

Uncontrolled Keywords:Surface-brightness profiles; On spiral galaxies; Star-formation; Secular evolution; Galactic disks; Light-distribution; Elliptic galaxies; Scaling relations; Radial migration; Space-telescope
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:34851
Deposited On:16 Dec 2015 15:56
Last Modified:10 Dec 2018 15:05

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