Euclid: High-precision imaging astrometry and photometry from Early Release Observations. I. Internal kinematics of NGC 6397 by combining Euclid and Gaia data
M. Libralato, L. R. Bedin, M. Griggio, D. Massari, J. Anderson, J. -C. Cuillandre, A. M. N. Ferguson, A. Lançon, S. S. Larsen, M. Schirmer, F. Annibali, E. Balb… 展开作者
M. Libralato, L. R. Bedin, M. Griggio, D. Massari, J. Anderson, J. -C. Cuillandre, A. M. N. Ferguson, A. Lançon, S. S. Larsen, M. Schirmer, F. Annibali, E. Balbinot, E. Dalessandro, D. Erkal, P. B. Kuzma, T. Saifollahi, G. Verdoes Kleijn, M. Kümmel, R. Nakajima, M. Correnti, G. Battaglia, B. Altieri, A. Amara, S. Andreon, C. Baccigalupi, M. Baldi, A. Balestra, S. Bardelli, A. Basset, P. Battaglia, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, A. Caillat, S. Camera, V. Capobianco, C. Carbone, J. Carretero, S. Casas, M. Castellano, G. Castignani, S. Cavuoti, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, F. Courbin, H. M. Courtois, M. Cropper, A. Da Silva, H. Degaudenzi, G. De Lucia, J. Dinis, F. Dubath, X. Dupac, S. Dusini, M. Fabricius, M. Farina, S. Farrens, F. Faustini, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, M. Fumana, S. Galeotta, B. Garilli, K. George, W. Gillard, B. Gillis, C. Giocoli, P. Gómez-Alvarez, A. Grazian, F. Grupp, L. Guzzo, S. V. H. Haugan, J. Hoar, H. Hoekstra, W. Holmes, F. Hormuth, A. Hornstrup, P. Hudelot, K. Jahnke, M. Jhabvala, E. Keihänen, S. Kermiche, A. Kiessling, M. Kilbinger, B. Kubik, M. Kunz, H. Kurki-Suonio, R. Laureijs, D. Le Mignant, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, M. Martinelli, N. Martinet, F. Marulli, R. Massey, E. Medinaceli, S. Mei, M. Melchior, Y. Mellier, M. Meneghetti, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, C. Neissner, R. C. Nichol, S. -M. Niemi, J. W. Nightingale, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. A. Popa, L. Pozzetti, F. Raison, R. Rebolo, A. Refregier, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, M. Roncarelli, E. Rossetti, R. Saglia, Z. Sakr, A. G. Sánchez, D. Sapone, B. Sartoris, M. Sauvage, P. Schneider, T. Schrabback, A. Secroun, E. Sefusatti, G. Seidel, M. Seiffert, S. Serrano, C. Sirignano, G. Sirri, J. Skottfelt, L. Stanco, J. Steinwagner, P. Tallada-Crespí, A. N. Taylor, H. I. Teplitz, I. Tereno, R. Toledo-Moreo, F. Torradeflot, A. Tsyganov, I. Tutusaus, L. Valenziano, T. Vassallo, A. Veropalumbo, Y. Wang, J. Weller, G. Zamorani, E. Zucca, C. Burigana, V. Scottez, D. Scott, R. L. Smart
备注：
23 pages, 21 figures. Accepted for publication in A&A on October 24, 2024. Astro-photometric catalogs and stacked images will be available at the CDS after the paper will be published
The instruments at the focus of the Euclid space observatory offer superb, diffraction-limited imaging over an unprecedented (from space) wide field of view of 0.57 deg$^2$. This exquisite image quality has the potential to produce high-precision astrometry for point sources once the undersampling of Euclid's cameras is taken into account by means of accurate, effective point spread function (ePSF) modelling. We present a complex, detailed workflow to simultaneously solve for the geometric distortion (GD) and model the undersampled ePSFs of the Euclid detectors. Our procedure was successfully developed and tested with data from the Early Release Observations (ERO) programme focused on the nearby globular cluster NGC 6397. Our final one-dimensional astrometric precision for a well-measured star just below saturation is 0.7 mas (0.007 pixel) for the Visible Instrument (VIS) and 3 mas (0.01 pixel) for the Near-Infrared Spectrometer and Photometer (NISP). Finally, we present a specific scientific application of this high-precision astrometry: the combination of Euclid and Gaia data to compute proper motions and study the internal kinematics of NGC 6397. Future work, when more data become available, will allow for a better characterisation of the ePSFs and GD corrections that are derived here, along with assessment of their temporal stability, and their dependencies on the spectral energy distribution of the sources as seen through the wide-band filters of Euclid.
VLBI astrometry of radio stars to link radio and optical celestial reference frames - II. 11 radio stars
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Department of Geodesy and Geodynamics, Finnish Geospatial Research Institute (FGI), National Land Survey of Finland（芬兰国家土地测量局芬兰地理研究所大地测量与地球动力学系）；Korea Astronomy and Space Science Institute（韩国天体物理与空间科学研究所）；University of Helsinki（赫尔辛基大学）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森尼天体物理中心）
Predicting Gaia astrometry's ability to constrain the populations of circumbinary planets
School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学学院）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所）；European Space Agency (ESA), European Space Astronomy Centre (ESAC)（欧洲空间局（ESA），欧洲空间天文中心（ESAC））
Mass-dependent multiplicity fraction in low mass stars revealed by Gaia astrometry
Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Fakultät für Physik und Astronomie, Universität Heidelberg（海德堡大学物理与天文学院）；Department of Astronomy, California Institute of Technology（加州理工学院天文学系）
Bayesian analysis of Gaia epoch astrometry and radial velocities with kima
Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所）；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学院）；Observatoire Astronomique de l’Université de Genève（日内瓦大学天文台）
A VLBA Survey of radio stars in the Orion Nebula Cluster: II. Astrometry
从甚长基线阵列（VLBA）的观测，我们以前确定了一个人口的123个年轻的恒星系统的非热无线电发射朝向猎户座星云团（ONC）的核心。我们在Gaia DR2星表中找到了34个在0.2”射电位置内的光源。大多数射电源都可能是盖亚探测到的同伴。然而，有11颗恒星的VLBA位置与盖亚相差$<1.6$ mas，其中一些射电源可能是光学星的直接对应物。我们能够获得23颗恒星的射电自行。结合VLBA和Gaia的恒星自行数据，我们得到ONC的整体运动和速度色散为（$μ_α*,μ_δ$）=（$1.20\pm0.09,0.18\pm0.09$）mas yr $^{-1}$和（$σ_{μ_α*},σ_{μ_δ}$）=（$0.84\pm0.09,1.30\pm0.09$）mas yr $^{-1}$ .最后，我们通过估计标量和矢量积的平均值来寻找有序运动，这导致$\mathbf{\overline{v\cdot\hat{r}}}=-0.61\pm1.00$ km s $^{-1}$和$\mathbf{\overline{v\times\hat{r}}}=0.57\pm0.95$ km s $^{-1}$。这些数据并没有显示年轻的星团处于膨胀、收缩或旋转状态。
New members of the Lupus I cloud based on Gaia astrometry Physical and accretion properties from X-Shooter spectra
我们表征12个年轻的恒星物体（YSO）位于狼疮I区域，空间上重叠的上半人马座狼疮（UCL）的亚恒星协会。本研究的目的是了解是否狼疮I云有更多的成员比已经声称到目前为止在文献中，并获得更深入的了解该地区的全球属性。我们使用盖亚DR 2目录选择了我们的目标，基于它们与狼疮I真正成员一致的运动学特性。在X射手观察到的12个YSO样本中，我们确定了10个狼疮I成员。由于技术问题，我们无法确定两个目标的成员状态，即Gaia DR 2 6014269268967059840和2 MASS J15361110-3444473。我们发现我们的四个目标是吸积体，其中2 MASS J15551027-3455045，质量约为0.03 M_Sun，是迄今为止狼疮复合体中质量最小的吸积体之一。我们的几个目标（包括吸积体）是相对于狼疮I的主灯丝在原位和离云形成的，因此，我们的研究可能暗示在狼疮I主灯丝周围有扩散的M-矮星种群。在这种情况下，我们想强调的是，我们与盖亚目录的运动学分析在识别狼疮I云的新成员方面发挥了关键作用。
A pilot study on the CSST astrometric capability: Detecting astrometric binaries with Gaia synergy via simulated data
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；School of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
BE Lyncis is not a Black Hole Binary: Lessons From Gaia and Hipparcos Astrometry
California Institute of Technology（加州理工学院）；Texas Tech University（德克萨斯理工大学）；Universitat de Barcelona（巴塞罗那大学）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）
通过 Gaia 和 Hipparcos 恒星测量数据，研究者发现 BE Lyn 不可能是黑洞双星，其观测到的自行异常与预期不符，且黑洞双星模型与观测数据矛盾。
Precise dynamical masses of new directly imaged companions from combining relative astrometry, radial velocities, and Hipparcos-Gaia eDR3 accelerations
Astrometric modeling of unresolved variable binary systems. II. Application to Gaia epoch astrometry of nearby pulsating and convective red giants
KU Leuven（荷语鲁汶大学）；Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CY Cergy Paris Université, CNRS（巴黎天文台，巴黎文理研究大学，索邦大学，巴黎西岱大学，塞吉-蓬图瓦兹大学，法国国家科学研究中心）；French-Chilean Laboratory for Astronomy, IRL 3386, CNRS and U. de Chile（法智利天文学联合实验室，法国国家科学研究中心和智利大学）
