0.3 < z < 1.5不同红星系类型的演化路径和大质量E-S0通过主要合并的晚期积累
Evolutionary paths among different red galaxy types at 0.3 < z < 1.5 and the late buildup of massive E-S0's through major mergers
摘要：
最近的一些观察似乎不同意星系形成的等级理论，即大合并在大质量E-S 0的后期积累中所起的作用。我们通过分析位于红色序列及其周围0.3 < z < 1.5处的大质量星系（M_* > 5 * 10^10 Msun）样本的形态、结构扭曲水平和恒星形成增强来重新解决这个问题。我们使用了格罗斯带上约155弧分^[2]区域内约1800个K_s < 20.5等的源作为初始样本，并结合了彩虹河外数据库和戈雅巡天的数据。可以直接与主要合并的中间阶段及其最终产物相关联的红色星系类别已经被定义。我们报告的观测证据存在一个占主导地位的演化路径在大质量的红星系在0.6<z<1.5，包括在不规则的磁盘转换成不规则的球状体，这些到规则的球状体。这一结果意味着：1）低红移的大质量红色规则星系起源于z~1.5的早期红序列及其邻域中的不规则星系; 2）大部分现代大质量红色规则星系的祖先是蓝盘，它们主要通过0.6 < z < 1.2的大合并迁移到红序列（这些合并因此开始于z~1.5）; 3）E-S 0的形成，通过富含气体的主要合并，在z=0时以M_*> 10^11 Msun结束，自z~0.6起已经冻结。所有这些事实都支持，主要的并合在今天的E-S 0的最终形成中起了主导作用，在0.6<z<1.2时，M_*> 10^11 Msun，这与星系形成的分级情景非常一致。
英文摘要：
Some recent observations seem to disagree with hierarchical theories of galaxy formation about the role played by major mergers in the late buildup of massive E-S0's. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M_* > 5 * 10^10 Msun) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with K_s < 20.5 mag over an area ~155 arcmin^2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. We report observational evidence of the existence of a dominant evolutionary path among massive red galaxies at 0.6<z<1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result implies that: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z~1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence mostly through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z~1.5); and 3) the formation of E-S0's that end up with M_*> 10^11 Msun at z=0 through gas-rich major mergers has frozen since z~0.6. All these facts support that major mergers have played the dominant role in the definitive buildup of present-day E-S0's with M_*> 10^11 Msun at 0.6<z<1.2, in good agreement with hierarchical scenarios of galaxy formation.
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。
