标题： 盘星系与矮星系结构差异的研究 显示英文标题

标题： On the Structural Differences between Disk and Dwarf Galaxies

摘要： 富含气体的矮星系和盘状星系在许多物理量上重叠，使得它们的分类具有主观性。 我们报告了在质量（光度）与尺度长度平面中矮星系和盘状星系分离为两个独特序列的发现。 这为晚型星系提供了一种客观的分类方案，只需要星系的光学或近红外表面光电测量。 由于这些样本的有质量Tully-Fisher关系在有质量与旋转速度之间产生了一个连续的关系，我们得出结论，矮星系和盘状星系之间的差异一定是由于它们的恒星光分布，使得矮星系比盘状星系更弥散。 这种结构上的分离可能是低质量和高质量星系之间的先天差异造成的，也可能是由等级合并产生的，在这种合并中，盘状星系是从矮星系中构建起来的。 矮星系和盘状星系之间的结构差异也可能由基础动力学驱动，其中盘状星系中的强旋转产生一个轴对称物体，经历高效的恒星形成，而与矮星系中较低的旋转和更无序的运动相反，后者产生一个弥散的三轴物体，具有低效恒星形成的记录。 显示英文摘要

摘要： Gas-rich dwarf and disk galaxies overlap in numerous physical quantities that make their classification subjective. We report the discovery of a separation between dwarfs and disks into two unique sequences in the mass (luminosity) versus scale length plane. This provides an objective classification scheme for late-type galaxies that only requires optical or near-IR surface photometry of a galaxy. Since the baryonic Tully-Fisher relation for these samples produces a continuous relation between baryonic mass and rotational velocity, we conclude that the difference between dwarfs and disks must be because of their distribution of stellar light such that dwarfs are more diffuse than disk galaxies. This structural separation may be due to a primordial difference between low and high mass galaxies or produced by hierarchical mergers where disks are built up from dwarfs. Structural differences between dwarf and disk galaxies may also be driven by the underlying kinematics where the strong rotation in disks produces an axial symmetric object that undergoes highly efficient star formation in contrast to the lower rotation, more disordered motion of dwarfs that produces a diffuse, triaxial object with a history of inefficient star formation.