Abstract

The Russian–Turkish 1.5-m telescope (hereafter RTT-150) takes an active part in the work on the ground optical support of observations by the Russian Spectrum–Röntgen–Gamma (SRG) observatory (with the participation of Germany) aimed at the identification and classification of new X-ray sources detected by the SRG telescopes. The instrumental capabilities of RTT-150 (occasionally, without any significant usage of telescope time and detriment for astrophysical programs) are used in astrometric observations to control the correction of the orbit of the SRG space observatory itself. In these cases, RTT-150 provides the Ballistic Center of the Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences with high-precision astrometric measurements of the SRG position, which have been used to successfully keep it in its operational orbit for more than three years of its exploitation. Beginning from the stage of flight to the zone of the Lagrange point \(L_{2}\) in July 2019 and at the main phase of the all-sky survey mission until March 2023, 96 sets (with a duration of about 30 min each) of high-precision positional observations with more than 5000 astrometric and photometric measurements were carried out at the RTT-150 observing facility. In most cases, the positional accuracy of the measurements dependent on seeing and apparent SRG brightness agrees with the accuracy of the provided ephemerides, \(0.10^{\prime\prime}\) and \(0.15^{\prime\prime}\) in declination and right ascension, respectively. In the summer months in projection onto the central region of the Galaxy in fields extremely rich in sources, the astrometric accuracy is \(1^{\prime\prime}\), sufficient for the SRG detection after the corrections and subsequent refinements of its trajectory. Geographically, RTT-150 is the southernmost instrument among the Russian telescopes for the ground astrophysical support of SRG. This fact is also extremely important in positional SRG observations at the lowest positions in declination \(DEC\sim{-}30^{\circ}\). We present the results of our astrometric and photometric observations with RTT-150 and our astrometric data reduction technique in various fields up to those extremely rich in sources.

中文翻译：

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使用 RTT-150 进行轨道修正控制的 SRG 空间天文台高精度天体测量观测

摘要

俄罗斯-土耳其 1.5 米望远镜（以下简称 RTT-150）积极参与俄罗斯频谱伦琴伽马（SRG）天文台（德国参与）观测的地面光学支持工作，旨在SRG 望远镜探测到的新 X 射线源的识别和分类。RTT-150 的仪器功能（偶尔，在不大量使用望远镜时间且不损害天体物理计划的情况下）用于天体测量观测，以控制 SRG 空间观测站本身轨道的校正。在这些情况下，RTT-150 为俄罗斯科学院凯尔迪什应用数学研究所弹道中心提供 SRG 位置的高精度天体测量，在三年多的开发过程中，这些技术已成功地将其保持在运行轨道上。从飞行阶段开始到拉格朗日点区域2019年7月\(L_{2}\)到2023年3月全天巡天任务的主要阶段，共进行了96组（每组持续时间约30分钟）超过5000个天体的高精度位置观测光度测量是在 RTT-150 观测设施进行的。在大多数情况下，测量的位置精度取决于视宁度和表观 SRG 亮度，与所提供的星历表的精度一致，\(0.10^{\prime\prime}\)和\(0.15^{\prime\prime}\ ）分别为赤纬和赤经。在夏季，投影到银河系中心区域的光源极其丰富的区域，天体测量精度为\(1^{\prime\prime}\)，足以用于对其轨迹进行修正和后续细化后的 SRG 检测。从地理上看，RTT-150是俄罗斯望远镜中最南端的为SRG提供地面天体物理支持的仪器。这一事实对于赤纬最低位置的位置 SRG 观测也极其重要\(DEC\sim{-}30^{\circ}\)。我们展示了使用 RTT-150 进行天体测量和光度观测的结果，以及我们在各个领域（直至来源极为丰富的领域）的天体测量数据缩减技术。