利用Gaia与高斯过程减小地基天体测量误差
天体物理仪器与方法
2021-08-25 v1
摘要
大气湍流引起的随机视场畸变是地基成像天体测量精度的根本限制。该畸变场可在具有Gaia DR2星表提供的精确位置的恒星处测得；我们发展了高斯过程回归(GPR)以将畸变场插值到每次曝光中任意位置。我们引入了对标准GPR技术的扩展，利用了二维畸变场无旋这一知识。以暗能量巡天(Dark Energy Survey)的数百张90秒曝光作为试验平台，我们发现GPR修正将湍流畸变的方差平均减小约12倍，且在Gaia星表较密区域表现更佳。在riz波段，未经修正前每坐标畸变的RMS通常为约7毫角秒(mas)，应用GPR模型后约为2 mas。GPR天体测量修正的验证在于：使用修正后，对r=18.5的跨海王星天体阋神星(Eris)历时5年的riz波段观测进行轨道拟合的残差从10 mas RMS降至5 mas RMS。我们还提出了一种尚未实现的GPR方法，用于在一组重叠曝光中同时估计湍流场与五维恒星解，这应在未来深场巡天中带来进一步的湍流减小。
引用
@article{arxiv.2010.13742,
title = {Reducing ground-based astrometric errors with Gaia and Gaussian processes},
author = {W. F. Fortino and G. M. Bernstein and P. H. Bernardinelli and M. Aguena and S. Allam and J. Annis and D. Bacon and K. Bechtol and S. Bhargava and D. Brooks and D. L. Burke and J. Carretero and A. Choi and M. Costanzi and L. N. da Costa and M. E. S. Pereira and J. De Vicente and S. Desai and P. Doel and A. Drlica-Wagner and K. Eckert and T. F. Eifler and A. E. Evrard and I. Ferrero and J. Frieman and J. García-Bellido and E. Gaztanaga and D. W. Gerdes and R. A. Gruendl and J. Gschwend and G. Gutierrez and W. G. Hartley and S. R. Hinton and D. L. Hollowood and K. Honscheid and D. J. James and M. Jarvis and S. Kent and K. Kuehn and N. Kuropatkin and M. A. G. Maia and J. L. Marshall and F. Menanteau and R. Miquel and R. Morgan and J. Myles and R. L. C. Ogando and A. Palmese and F. Paz-Chinchón and A. A. Plazas and A. Roodman and E. S. Rykoff and E. Sanchez and B. Santiago and V. Scarpine and M. Schubnell and S. Serrano and I. Sevilla-Noarbe and M. Smith and E. Suchyta and G. Tarle and C. To and D. L. Tucker and T. N. Varga and A. R. Walker and J. Weller and W. Wester},
journal= {arXiv preprint arXiv:2010.13742},
year = {2021}
}
备注
18 pages, 6 figures