标题： 中心区域通过获得反向旋转气体在形成恒星的星系中的增长 显示英文标题

标题： The growth of the central region by acquisition of counter-rotating gas in star-forming galaxies

摘要： 星系通过内部和外部过程增长。 在大约10%的附近红色星系中，这些星系的恒星形成很少，气体和恒星是反向旋转的，这表明外部气体获取在这些星系中的重要性。 然而，对蓝色、恒星形成星系中这种现象的系统研究很少，因此外部气体获取在驱动蓝色星系演化中的作用尚不明确。 基于对一个大型代表性星系样本的新测量，使用积分场光谱学，我们发现蓝色星系中有相当一部分是反向旋转的（489个星系中有9个）。 蓝色反向旋转星系的中心区域显示出更年轻的恒星种群和更强烈的持续恒星形成，与外围部分相比，表明中心区域正在持续增长。 这一结果提供了外部气体在蓝色星系中获取的观测证据；与现有的气体管道相互作用将气体输送到核区（< 1 kpc）以形成新的恒星。 显示英文摘要

摘要： Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic studies of such phenomena in blue, star-forming galaxies are rare, leaving uncertain the role of external gas acquisition in driving evolution of blue galaxies. Based on new measurements with integral field spectroscopy of a large representative galaxy sample, we find an appreciable fraction of counter-rotators among blue galaxies (9 out of 489 galaxies). The central regions of blue counter-rotators show younger stellar populations and more intense, ongoing star formation than their outer parts, indicating ongoing growth of the central regions. The result offers observational evidence that the acquisition of external gas in blue galaxies is possible; the interaction with pre-existing gas funnels the gas into nuclear regions (< 1 kpc) to form new stars.