Title: Galaxy Zoo: Bars in Disk Galaxies Show Chinese title

Title: 银河动物园：盘状星系中的条纹结构

Abstract: We present first results from Galaxy Zoo 2, the second phase of the highly successful Galaxy Zoo project (www.galaxyzoo.org). Using a volume-limited sample of 13665 disk galaxies (0.01< z < 0.06 and M_r<-19.38), we study the fraction of galaxies with bars as a function of global galaxy properties like colour, luminosity and bulge prominence. Overall, 29.4+/-0.5% of galaxies in our sample have a bar, in excellent agreement with previous visually-classified samples of galaxies (although this overall fraction is lower than measured by automated bar-finding methods). We see a clear increase in the bar fraction with redder (g-r) colours, decreased luminosity and in galaxies with more prominent bulges, to the extent that over half of the red, bulge-dominated, disk galaxies in our sample possess a bar. We see evidence for a colour bi-modality for our sample of disk galaxies, with a "red sequence" that is both bulge and bar-dominated, and a "blue cloud" which has little, or no, evidence for a (classical) bulge or bar. These results are consistent with similar trends for barred galaxies at higher redshift in the COSMOS survey, and with early studies using the RC3. We discuss these results in the context of internal (secular) galaxy evolution scenarios and the possible links to the formation of classical bulges (which have a de Vaucouleurs profile) and pseudo-bulges (with exponential profiles) in disk galaxies. Show Chinese abstract

Abstract: 我们首先介绍了银河动物园2项目的结果，这是高度成功的银河动物园项目（www.galaxyzoo.org）的第二阶段。 使用一个体积受限的13665个盘状星系样本（0.01< z < 0.06 和 M_r<-19.38），我们研究了具有棒状结构的星系比例随整体星系特性（如颜色、光度和核球显著性）的变化。 总体而言，我们的样本中有29.4+/-0.5%的星系具有棒状结构，与之前通过人工分类的星系样本结果非常一致（尽管这一总体比例低于自动棒状结构识别方法测得的值）。 我们观察到随着颜色更红（g-r）、光度降低以及核球更显著的星系，棒状结构的比例明显增加，以至于在我们的样本中，超过一半的红色、核球主导的盘状星系具有棒状结构。 我们发现我们的盘状星系样本存在颜色双峰性，其中“红色序列”既具有核球又具有棒状结构，而“蓝色云团”则几乎没有或没有（经典）核球或棒状结构的证据。 这些结果与COSMOS调查中更高红移的棒状星系的类似趋势一致，并与早期使用RC3的研究结果一致。 我们在内部（演化）星系演化情景的背景下讨论这些结果，并探讨其与盘状星系中经典核球（具有de Vaucouleurs轮廓）和伪核球（具有指数轮廓）形成的可能联系。