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Orbits of 152 globular clusters of the Milky Way galaxy constructed from Gaia DR2

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Research in Astronomy and Astrophysics 2021年第7期21卷 177-191页

作者： Anisa Talgatovna Bajkova Vadim Vadimovich Bobylev Pulkovo Astronomical Observatory St.Petersburg 196140Russia

We present orbits and their properties for 152 globular clusters of the Milky Way galaxy obtained using average Gaia DR2 proper motions and other astrometric data from the list of Vasiliev. For orbital integration we have applied the axisymmetric model of the Galactic potential based on the Navarro-Frenk-White dark halo, and modified by Bajkova & Bobylev utilizing circular velocities of Galactic objects in a wide region of Galactocentric distances(up to 200 kpc) from the Bhattacharjee et al. catalog. Based on the analysis of the obtained orbits, we have modified the composition of the subsystems of globular clusters presented in Massari et al..

关键词： (Galaxy) globular clusters general

Galactic interstellar scintillation observed from four globular cluster pulsars by FAST

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中国科学:物理学、力学、天文学英文版 2023年第9期66卷 119-127页

作者： Dandan Zhang Zhenzhao Tao Mao Yuan Jumei Yao Pei Wang Qijun Zhi Weiwei Zhu Xun Shi Michael Kramer Di Li Lei Zhang Guangxing Li School of Mathematical Sciences School of Physics and Electronic SciencesGuizhou Normal UniversityGuiyang 550001China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550001China Department of Astronomy Beijing Normal UniversityBeijing 100875China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China South-Western Institute for Astronomy Research(SWIFAR) Yunnan UniversityKunming 650000China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Max-Planck Institut fr Radioastronomie Bonn D-53121Germany Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China Computational Astronomy Platform Zhejiang LabHangzhou 311121China

We report detections of scintillation arcs for pulsars in globular clusters M5,M13 and M15 for the first time using the Fivehundred-meter Aperture Spherical radio Telescope(FAST).From observations of these arcs at multiple epochs,we infer that screen-like scattering medium exists at distances 4.1_(-0.3)^(+0.2),6.7_(-0.2)^(+0.2)and 1.3_(-1.0)^(+0.7) kpc from Earth in the directions of M5,M13 and M15,*** means M5's and M13's scattering screens are located at 3.0_(-0.2)^(+0.1) and 4.4_(-0.1)^(+0.1) kpc above the galactic plane,whereas,M15's is at 0.6_(-0.5)^(+0.3) kpc below the *** estimate the scintillation timescale and decorrelation bandwidth for each pulsar at each epoch using the one-dimensional auto-correlation in frequency and time of the dynamic *** found that the boundary of the Local Bubble may have caused the scattering of M15,and detected the most distant off-plane scattering screens to date through pulsar scintillation,which provides evidence for understanding the medium circulation in the Milky Way.

关键词： pulsars scintillation globular clusters

An orbital motion study of globular cluster NGC6205

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Science China Mathematics 2002年第1期45卷 129-136页

作者：陈力赵君亮陈鼎王家骥 Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Chinese National Observatories Chinese Academy of Sciences Beijing 100012 China Jt. Laboratory for Optical Astronomy Chinese Academy of Sciences Shanghai 200030 China

The positions and absolute proper motions of 264 stars in the field of about 70′ x 70′ around the globular cluster NGC6205 were determined. In the astrometric reduction, three early and three late epoch plates taken with the 40-cm refractor at Shensan, Shanghai, China, were used, with the epoch span of 73 a. The reduction was done using the central overlapping method, with 5 Hipparcos stars and 38 Tycho-2 stars as reference stars. Based on the reduced data of proper motion, the membership probabilities of the sample stars were determined. An absolute proper motion of the cluster of(1.49±0.36)mas a-1 in R.A. and (3.06±0.35)mas a-1 in Decl. was obtained. From this proper motion, together with distance and radial velocity data, we derived the space motion of NGC6205 and the orbit of the cluster in the Galaxy via numerical integration.

关键词： globular clusters absolute proper motion space motion orbit