THE THREE-DIMENSIONAL SHAPE OF IRREGULAR GALAXIES
THE THREE-DIMENSIONAL SHAPE OF IRREGULAR GALAXIES
复制标题
不规则星系的三维形状
DOI：
--
复制
发表时间：
1966
期刊：
影响因子：
--
通讯作者：
J. Hitchcock
中科院分区：
文献类型：
--
作者：
P. Hodge;J. Hitchcock
为了检验经常提出的不规则星系总是扁平系统的假设，我们测量了131个不规则星系的投影轴比。我们的列表是根据Humason、Mayall、Sandage目录（1956年）和货车登伯格（1959年）的矮星系目录编制的。由于太空中绝大多数不规则星系都是小系统，因此大多数被检查的星系都具有矮星系的特征。我们首先在帕洛玛巡天照片上测量了所有131个星系的轴比，然后在我们的底片上用120英寸的利克和100英寸的威尔逊山反射器进行了一些测量。除了少数例外，两个来源之间的一致性非常好。所有的图像都至少测量了两次，由我们中的两个人独立测量，许多图像由第三个人测量了第三次。虽然星系的实际尺寸在不同的测量者之间有系统的差异，但轴比没有系统的差异。平均轴比的平均或然误差为±0.1。
In order to check the frequently made assumption that irregular galaxies are always flat systems, we have measured projected axial ratios for 131 irregular galaxies. Our list was compiled from the Humason, Mayall, Sandage catalog (1956) and van den Bergh’s (1959) catalog of dwarf galaxies. Since the vast majority of irregular galaxies in space are small systems, most of those examined have dwarf characteristics. We measured axial ratios for all 131 galaxies first on the Palomar Sky Survey Prints and then supplemented the material with a few measures on our plates taken with the 120-inch Lick and 100-inch Mount Wilson reflectors. With a few exceptions, agreement between the two sources was very good. All images were measured at least twice, independently by two of us, and many were measured a third time by a third person. Although the actual dimensions for the galaxies differed systematically from one measurer to the next, there was no systematic difference in the axial ratios. The mean probable error of the mean axial ratios is ±0.1.