星系动物园：比较螺旋臂数的人口统计学和校正红移偏差的新方法
Galaxy Zoo: comparing the demographics of spiral arm number and a new method for correcting redshift bias
摘要：
本机宇宙中的大多数星系都呈现出各种形式的螺旋结构。许多星系拥有两个突出的旋臂，有些有更多，而另一些则显示出多臂絮状外观。螺旋臂与低红移星系盘中气体含量的增加和恒星的形成有关，因此对理解本星系盘中恒星的形成具有重要意义。由于螺旋结构的视觉外观和负责它的机制因星系而异，因此需要一种可靠的方法来定义具有不同视觉形态的螺旋样品。在本文中，我们开发了一种新的去偏置方法，以可靠地校正Galaxy Zoo 2中的红移依赖偏差，并发布了一组新的去偏置分类。使用这些，一个亮度有限的样本约18,000斯隆数字巡天螺旋星系的定义，然后进一步细分的旋臂数。为了探索不同的旋涡星系是如何形成的，比较了不同旋臂数的旋涡星系的人口统计学。研究发现，虽然所有的螺旋星系占据类似的恒星质量和环境范围，多臂星系显示出比双臂星系更蓝的颜色。我们的结论是，双臂结构是无处不在的恒星形成磁盘，而多臂螺旋结构似乎是一个短暂的阶段，与最近，随机恒星形成活动。
英文摘要：
The majority of galaxies in the local Universe exhibit spiral structure with a variety of forms. Many galaxies possess two prominent spiral arms, some have more, while others display a many-armed flocculent appearance. Spiral arms are associated with enhanced gas content and star-formation in the disks of low-redshift galaxies, so are important in the understanding of star-formation in the local universe. As both the visual appearance of spiral structure, and the mechanisms responsible for it vary from galaxy to galaxy, a reliable method for defining spiral samples with different visual morphologies is required. In this paper, we develop a new debiasing method to reliably correct for redshift-dependent bias in Galaxy Zoo 2, and release the new set of debiased classifications. Using these, a luminosity-limited sample of ~18,000 Sloan Digital Sky Survey spiral galaxies is defined, which are then further sub-categorised by spiral arm number. In order to explore how different spiral galaxies form, the demographics of spiral galaxies with different spiral arm numbers are compared. It is found that whilst all spiral galaxies occupy similar ranges of stellar mass and environment, many-armed galaxies display much bluer colours than their two-armed counterparts. We conclude that two-armed structure is ubiquitous in star-forming disks, whereas many-armed spiral structure appears to be a short-lived phase, associated with more recent, stochastic star-formation activity.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
