THE OUTER DISKS OF EARLY-TYPE GALAXIES. I. SURFACE-BRIGHTNESS PROFILES OF BARRED GALAXIES
THE OUTER DISKS OF EARLY-TYPE GALAXIES. I. SURFACE-BRIGHTNESS PROFILES OF BARRED GALAXIES
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DOI：
10.1088/0004-6256/135/1/20
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发表时间：
2007-09
期刊：
影响因子：
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通讯作者：
P. Erwin;M. Pohlen;J. Beckman
中科院分区：
文献类型：
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作者：
P. Erwin;M. Pohlen;J. Beckman
我们提出了一个研究66酒吧，早期型（S 0-Sb）盘星系，集中在酒吧区域外的磁盘表面亮度轮廓，其目的是投掷光的性质弗里曼I型和II型配置文件，其起源，以及它们可能的关系盘截断。本文讨论了数据和他们的减少，概述了我们的分类系统，并提出了R-波段配置文件的所有星系的样本，沿着与他们的分类。在随后的论文中，我们将探索这些剖面所揭示的外盘结构，并调查它们可能的起源。这些轮廓来自各种不同的来源，包括斯隆数字巡天（数据发布5）。对于大约一半的星系，我们有来自一个以上的望远镜的配置文件，这使我们能够检查我们的配置文件提取和分类的稳定性和可重复性。绝大多数的剖面在μR ≤ 27 mag arcsec−2的水平下都是可靠的;在特殊情况下，我们可以追踪到μR > 28的剖面。我们通常可以追踪到至少1.5倍于传统光学半径R25的圆盘轮廓;对于某些星系，我们发现光延伸到1.3 × R25。对于I型（单指数）分布，这意味着我们可以追踪指数盘到6-7个标度长度。我们将配置文件分为三个主要组：I型（单指数），II型（向下弯曲），III型（向上弯曲）。这些类型的频率分别约为27%、42%和24%，另外还有6%是II型和III型的组合。我们进一步分类II型配置文件的断裂福尔斯的酒吧长度的关系，并在假设的机制，在大半径（“经典截断”的星星形成与外Lindblad共振的酒吧的影响）。我们还分类III型配置文件的外部光（磁盘或球体）的可能形态。所有情况下都有插图。
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.