论文标题
使用Astrosat的球状簇NGC 1261的水平分支形态
The Horizontal Branch morphology of the globular cluster NGC 1261 using AstroSat
论文作者
论文摘要
我们介绍了使用Far-UV（FUV）和近紫外（NUV）图像在Astrosat Satellite上使用紫外线成像望远镜（UVIT）获得的Far-UV（FUV）和近紫外（NUV）图像获得的结果。我们利用了与HST，GAIA和基于地面的光学光度数据相结合的UVIT数据来构建不同的UV颜色磁性图（CMDS）。我们检测到FUV中的蓝色HB（BHB）和两个极端HB（EHB）星，而全HB，即红色HB（RHB），BHB以及NUV CMD中检测到EHB。在NUV和FUV中鉴定出的2个EHB恒星已被确认是集群的成员。 HB恒星在紫外线CMD中形成一个紧密的序列，该序列几乎与Padova的等音对齐。这项研究阐明了紫外成像对探测GC中HB形态的重要性。
We present the results obtained from the UV photometry of the globular cluster NGC 1261 using Far-UV (FUV) and Near-UV (NUV) images acquired with the Ultraviolet Imaging Telescope (UVIT) onboard the Astrosat satellite. We utilized the UVIT data combined with HST, GAIA, and ground-based optical photometric data to construct the different UV colour-magnitude diagrams (CMDs). We detected blue HB (BHB), and two extreme HB (EHB) stars in FUV, whereas full HB, i.e., red HB (RHB), BHB as well as EHB is detected in NUV CMDs. The 2 EHB stars, identified in both NUV and FUV, are confirmed members of the cluster. The HB stars form a tight sequence in UV-optical CMDs, which is almost aligned with Padova isochrones. This study sheds light on the significance of UV imaging to probe the HB morphology in GCs.
