The structure of galactic disks - Studying late-type spiral galaxies using SDSS
The structure of galactic disks - Studying late-type spiral galaxies using SDSS
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DOI：
10.1051/0004-6361:20064883
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发表时间：
2006-03
影响因子：
6.5
通讯作者：
M. Pohlen;I. Institute;U. D. O. Physics;Astronomy;U. Nottingham
中科院分区：
文献类型：
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作者：
M. Pohlen;I. Institute;U. D. O. Physics;Astronomy;U. Nottingham
利用SDSS巡天的成像数据，我们给出了一个完整样本的g'和r'径向恒星光分布，该样本包含了90个从正面到中间倾斜的临近晚型（Sb-Sdm）螺旋星系。表面亮度轮廓是可靠的（1 s的不确定性小于0.2 mag），低至mu，类似于27 mag/square”。只有大约10%的星系有一个正常/标准的纯指数盘，直到我们的噪音极限。其余星系的表面亮度分布更好地描述为一个破碎的指数。大约60%的星系在指数分布中有一个近似1.5-4.5倍尺度长度的断裂，然后是一个向下弯曲的，更陡峭的外部区域。另一个类似于30%的区域也显示出类似于4.0-6.0倍尺度长度之间的明显断裂，但随后是上弯的较浅的外部区域。少数星系有更复杂的表面亮度分布。轮廓的形状与哈勃类型相关。在后期哈勃类型中，下弯断裂更为频繁，而上弯断裂的比例则向早期类型上升。没有明确的关系被发现之间的环境，其特点是邻居的数量，和形状的轮廓的星系。
Using imaging data from the SDSS survey, we present the g' and r' radial stellar light distribution of a complete sample of similar to 90 face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness profiles are reliable (1s uncertainty less than 0.2 mag) down to mu similar to 27 mag/square". Only similar to 10% of all galaxies have a normal/standard purely exponential disk down to our noise limit. The surface brightness distribution of the rest of the galaxies is better described as a broken exponential. About 60% of the galaxies have a break in the exponential profile between similar to 1.5-4.5 times the scalelength followed by a downbending, steeper outer region. Another similar to 30% shows also a clear break between similar to 4.0-6.0 times the scalelength but followed by an upbending, shallower outer region. A few galaxies have even a more complex surface brightness distribution. The shape of the profiles correlates with Hubble type. Downbending breaks are more frequent in later Hubble types while the fraction of upbending breaks rises towards earlier types. No clear relation is found between the environment, as characterised by the number of neighbours, and the shape of the profiles of the galaxies.