Arp 72系统中潮汐矮星系的动力学
Dynamics of tidal dwarf galaxies in the system Arp 72
浏览论文内容
中文总结 AI 辅助
本研究利用MEGARA、GMRT设备观测数据，分析Arp 72系统中两个潮汐矮星系的动力学，验证其符合潮汐矮星系特性，发现这类天体偏离重子-塔利-费希尔关系。
中文摘要 AI 辅助
星系间的一些相互作用会产生主要由星系盘物质构成的潮汐尾，在这些潮汐尾中，气体和恒星的聚集会形成类似矮星系的结构，这类潮汐天体通常会开始形成恒星，并在动力学上独立于它们的母星系，因此被归类为潮汐矮星系（Tidal Dwarf Galaxies，TDGs）。根据定义，TDG应仅由重子物质构成，暗物质占比可忽略不计。本研究利用GTC（Gran Telescopio Canarias，大加那利望远镜）搭载的MEGARA多光谱仪获取的高分辨率Hα观测数据，以及GMRT（Giant Metrewave Radio Telescope，巨米波射电望远镜）的中性氢（HI）数据，分析Arp 72系统中两个TDG的动力学；其中HI数据还用于确定气体质量。我们从运动学数据中推导了旋转曲线和速度弥散，以此估算系统的动力学质量，并通过3D拟合将TDG建模为带有额外压力支撑的旋转盘，假设质量分布遵循指数定律，再结合气体质量与恒星质量确定总重子质量。在特定动力学考量下，我们建立了动力学质量与重子质量的关系，此外还使用经压力支撑校正的圆周速度，将TDG的行为与文献中的重子-塔利-费希尔关系（BTFR）进行比较，结果显示独立的TDG会偏离该关系。研究的两个天体符合TDG的预期特性。
英文摘要
Some interactions between galaxies produce tidal tails primarily composed of material from their disks. Within these tails, concentrations of gas and stars can form, resembling dwarf galaxies. These tidal objects often begin to form stars and become dynamically independent of their parent galaxies, leading to their classification as Tidal Dwarf Galaxies (TDGs). By definition, TDGs should consist solely of baryonic material, with a negligible dark matter fraction. In this study, we analyze the dynamics of two TDGs in the Arp 72 system using high-resolution Hα observations obtained with the MEGARA multi-spectrograph at the GTC (Gran Telescopio Canarias) and neutral hydrogen (HI) data from the GMRT (Giant Metrewave Radio Telescope). The HI data were also used to determine the gas mass. We derived the rotation curves and velocity dispersion from the kinematic data, which allowed us to estimate the dynamical mass of the systems. The TDGs were modeled through 3D fitting as rotating disks with additional pressure support, assuming a mass distribution following an exponential law. The gas mass was combined with the stellar mass to determine the total baryonic mass. Under specific dynamical considerations, we established the relationship between the dynamical mass and the baryonic mass. Additionally, we used the pressure-support corrected circular velocity to compare the behavior of TDGs in the context of the baryonic Tully-Fisher relation (BTFR) with the literature, showing how detached TDGs fall off the relation. The two studied objects are consistent with the expected properties of a TDG.
