AI 中文总结
研究利用SKA-VLBI天体测量来测量银河系核恒星盘相关OH脉泽的三维运动，通过分析脉泽源自行运动数据及精确距离信息，揭示其空间运动学结构，有望展现恒星环结构及相关特性。
AI 中文摘要
平方公里阵列-甚长基线干涉测量（SKA-VLBI）天体测量将使我们能够测量银河系中心（GC）核恒星盘（NSD）中与OH/IR恒星的星际包层（CSE）相关的OH脉泽以及中央分子区（CMZ）中高质量恒星形成区域的数千个三维运动。预计这些OH脉泽的空间运动学分布应表明NSD中存在一个环结构，它是由GC中恒星形成活动向外传播形成的。这可能通过一组OH/IR恒星清楚地显现出来，其中一些恒星的脉动周期应大于400天，相应年龄小于5亿年，还有一些正在进行恒星形成的区域。这些OH/IR恒星应拥有1612-MHz的OH脉泽，其中一些应成为SKA-MID波段2（约1.6 GHz）中中等精度的大样本VLBI天体测量的目标。脉泽源自行运动的数据将在恒星环结构中呈现出流运动。此外，为了直接找到距离约8千秒差距处可能的椭圆恒星环的长轴方向，需要脉泽源精确距离（误差<100秒差距）的信息。这些距离可以通过SKA-MID波段5a（5-7 GHz）中可测量的三角视差和/或从承载脉泽源的长周期变星的脉动周期-光度关系导出的光度视差来获得。
英文摘要
SKA-VLBI astrometry will enable us to measure up to thousands of three dimensional motions of OH masers associated with circumstellar envelopes (CSEs) of OH/IR stars in the Nuclear Stellar Disk (NSD) and sites of high mass star formation in the Central Molecular Zone (CMZ) of the Galactic Center (GC). It is expected that the spatio-kinematical distribution of those OH masers should indicate the existence of a ring structure in the NSD, which has formed as a result of outward propagation of star-formation activities in the GC. This is likely visualized clearly by a group of OH/IR stars, some of which should have stellar pulsation periods of >400 days and the corresponding ages of <500 Myr, and some sites of ongoing star formation. These OH/IR stars should host 1612-MHz OH masers, some of which should become targets of huge-sample VLBI astrometry, in moderate accuracy, in SKA-MID Band 2 (~1.6 GHz). The data of maser source proper motions will exhibit a stream motion in the stellar ring structure. Furthermore, the information of accurate distances (error <100 pc) of the maser sources are necessary to directly find the major-axis direction of a possible elliptical ring of stars at ~8 kpc. These distances may be yielded through trigonometric parallaxes measurable in SKA-MID Band 5a (5--7 GHz) and/or photometric parallaxes derived from the pulsation period--luminosity relation of long period variable stars hosting the maser sources.
Comments11 pages, 4 figures, Published in Advancing Astrophysics with SKA II (AASKAII), 2026 (arXiv:2606.20366). Report-no:AASKAII/Imai01
