THE OUTER DISKS OF EARLY-TYPE GALAXIES. I. SURFACE-BRIGHTNESS PROFILES OF BARRED GALAXIES

By P. Erwin, M. Pohlen, J. Beckman. 2007

178 citations recorded by the source corpus.

We present a study of 66 barred, early-type (S0–Sb) disk galaxies, focused on the disk surface brightness profile outside the bar region, with the aim of throwing light on 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 for all galaxies in the sample, along with their classifications. In subsequent papers, we will explore the structure of outer disks as revealed by these profiles, and investigate their possible origins. 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 μR ≈ 27 mag arcsec−2; in exceptional cases, we can trace profiles down to μR > 28. We can typically follow disk profiles out to at least 1.5 times the traditional optical radius R25; for some galaxies, we find light extending to ∼3 × R25. For type I (single-exponential) profiles, this means that we can trace the exponential disk out to 6–7 scale lengths. 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 truncation” 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.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/95746f98c2133a6330aa685de619e31942969f81

How researchers see this paper

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In Astronomy and Astrophysics

1. I. Minchev
2. B. Famaey
3. F. Lelli
4. J. Schombert
5. S. McGaugh
6. P. Hopkins
7. Joss Bland-Hawthorn
8. Jens Thomas

In Instrumentation

1. I. Minchev
2. B. Famaey
3. F. Lelli
4. S. McGaugh
5. J. Schombert
6. Jens Thomas
7. Joss Bland-Hawthorn
8. R. Bender

Citations in the corpus

• THE SINFONI BLACK HOLE SURVEY: THE BLACK HOLE FUNDAMENTAL PLANE REVISITED AND THE PATHS OF (CO)EVOLUTION OF SUPERMASSIVE BLACK HOLES AND BULGES (2016, methodology): “NGC 4697: The profile is measured on R−band images taken during the observations described in Erwin et al. (2008).”
• Evolution of galactic discs: multiple patterns, radial migration, and disc outskirts (2012, background): “…simple continuation of the inner exponential profiles (Type I), steeper (Type II) or even shallower (Type III) than the extrapolations of the inner profiles to large radii (see Bland-Hawthorn et al. 2005; Ellis and Bland-Hawthorn 2007 and Erwin et al. 2008, hereafter EPB08, and references therein).”
• SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES (2016, background): “We stress that the results depend on the fitted radial range, which may be ambiguous for galaxies with outer downbending (type II) or up-bending (type III) profiles (cf. Erwin et al. 2008).”