The Outer Disks of Early-Type Galaxies. I. Surface-Brightness Profiles of Barred Galaxies

dc.creatorErwin, Peter
dc.creatorPohlen, Michael
dc.creatorBeckman, John E.
dc.date2007-09-21
dc.date.accessioned2026-07-07T11:19:31Z
dc.date.available2026-07-07T11:19:31Z
dc.descriptionWe present a study of 66 barred, early-type (S0-Sb) disk galaxies, focused on the disk surface brightness profile outside the bar region and the nature of Freeman Type I and II profiles, their origins, and their possible relation to disk truncations. This paper discusses the data and their reduction, outlines our classification system, and presents $R$-band profiles and classifications for all galaxies in the sample. The profiles are derived from a variety of different sources, including the Sloan Digital Sky Survey (Data Release 5). For about half of the galaxies, we have profiles derived from more than one telescope; this allows us to check the stability and repeatability of our profile extraction and classification. The vast majority of the profiles are reliable down to levels of mu_R ~ 27 mag arcsec^-2; in exceptional cases, we can trace profiles down to mu_R > 28. We can typically follow disk profiles out to at least 1.5 times the traditional optical radius R_25; for some galaxies, we find light extending to ~ 3 R_25. We classify the profiles into three main groups: Type I (single-exponential), Type II (down-bending), and Type III (up-bending). The frequencies of these types are approximately 27%, 42%, and 24%, respectively, plus another 6% which are combinations of Types II and III. We further classify Type II profiles by where the break falls in relation to the bar length, and in terms of the postulated mechanisms for breaks at large radii ("classical trunction" of star formation versus the influence of the Outer Lindblad Resonance of the bar). We also classify the Type III profiles by the probable morphology of the outer light (disk or spheroid). Illustrations are given for all cases. (Abridged)
dc.description41 pages, 26 PDF figures. To appear in the Astronomical Journal. Version with full-resolution figures available at http://www.mpe.mpg.de/~erwin/research/
dc.identifierhttps://arxiv.org/abs/0709.3505
dc.identifierhttp://arxiv.org/abs/0709.3505
dc.identifierAstron.J.135:20-54,2008
dc.identifierdoi:10.1088/0004-6256/135/1/20
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/193707
dc.subjectAstrophysics
dc.titleThe Outer Disks of Early-Type Galaxies. I. Surface-Brightness Profiles of Barred Galaxies
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