Toward the ICRF3: Astrometric Comparison of the USNO 2016A VLBI Solution with ICRF2 and Gaia DR1

被引：12

作者：

Frouard, Julien ^{[1
]}

Johnson, Megan C. ^{[1
]}

Fey, Alan ^{[1
]}

Makarov, Valeri V. ^{[1
]}

Dorlan, Bryan N. ^{[1
]}

机构：

[1] USNO, 3450 Massachusets Ave NW, Washington, DC 20392 USA

来源：

ASTRONOMICAL JOURNAL | 2018年 / 155卷 / 06期

基金：

美国国家科学基金会; 美国国家航空航天局;

关键词：

astrometry; catalogs; reference systems; NONPARAMETRIC REGRESSION; WILD BOOTSTRAP; POSITIONS;

D O I：

10.3847/1538-3881/aabafa

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The VLBI USNO 2016A (U16A) solution is part of a work-in-progress effort by USNO toward the preparation of the ICRF3. Most of the astrometric improvement with respect to the ICRF2 is due to the re-observation of the VCS sources. Our objective in this paper is to assess U16A's astrometry. A comparison with ICRF2 shows statistically significant offsets of size 0.1 mas between the two solutions. While Gaia DR1 positions are not precise enough to resolve these offsets, they are found to be significantly closer to U16A than ICRF2. In particular, the trend for typically larger errors for southern sources in VLBI solutions is decreased in U16A. Overall, the VLBI-Gaia offsets are reduced by 21%. The U16A list includes 718 sources not previously included in ICRF2. Twenty of those new sources have statistically significant radio-optical offsets. In two-thirds of the cases, these offsets can be explained from PanSTARRS images.

引用

页数：11