The impact of bars on disk breaks as probed by S4G imaging
| Autor: | Muñoz-Mateos, J. C., Sheth, K., de Paz, A. Gil, Meidt, S. E., Athanassoula, E., Bosma, A., Comerón, S., Elmegreen, D. M., Elmegreen, B. G., Erroz-Ferrer, S., Gadotti, D. A., Hinz, J. L., Ho, L. C., Holwerda, B., Jarrett, T. H., Kim, T., Knapen, J. H., Laine, J., Laurikainen, E., Madore, B. F., Menendez-Delmestre, K., Mizusawa, T., Regan, M., Salo, H., Schinnerer, E., Seibert, M., Skibba, R., Zaritsky, D. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/771/1/59 |
| Popis: | We have analyzed the radial distribution of old stars in a sample of 218 nearby face-on disks, using deep 3.6um images from the Spitzer Survey of Stellar Structure in Galaxies (S4G). In particular, we have studied the structural properties of those disks with a broken or down-bending profile. We find that, on average, disks with a genuine single exponential profile have a scale-length and a central surface brightness which are intermediate to those of the inner and outer components of a down-bending disk with the same total stellar mass. In the case of barred galaxies, the ratio between the break and the bar radii (Rbr/Rbar) depends strongly on the total stellar mass of the galaxy. For galaxies more massive than 10^10 Msun, the distribution is bimodal, peaking at Rbr/Rbar~2 and ~3.5. The first peak, which is the most populated one, is linked to the Outer Lindblad Resonance of the bar, whereas the second one is consistent with a dynamical coupling between the bar and the spiral pattern. For galaxies below 10^10 Msun, breaks are found up to ~10 Rbar, but we show that they could still be caused by resonances given the rising nature of rotation curves in these low-mass disks. While not ruling out star formation thresholds, our results imply that radial stellar migration induced by non-axysymmetric features can be responsible not only for those breaks at 2 Rbar, but also for many of those found at larger radii. Comment: Accepted for publication in ApJ. 32 pages, 14 figures. The whole figureset of Fig. 14 can be downloaded from http://www.cv.nrao.edu/~jmunoz/f14_large.pdf |
| Databáze: | arXiv |
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