High-precision astrometry with MICADO at the European Extremely Large Telescope
Abstract
In this article, we identify and discuss various statistical and systematic effects influencing the astrometric accuracy achievable with Multi-adaptive optics Imaging CAmera for Deep Observations, the near-infrared (NIR) imaging camera proposed for the 42-m European Extremely Large Telescope. These effects are instrumental (e.g. geometric distortion), atmospheric (e.g. chromatic differential refraction) and astronomical (reference source selection). We find that there are several phenomena having impact on ~100μas scales, meaning they can be substantially larger than the theoretical statistical astrometric accuracy of an optical/NIR 42-m telescope. Depending on type, these effects need to be controlled via dedicated instrumental design properties or via dedicated calibration procedures. We conclude that if this is done properly, astrometric accuracies of 40μas or better - with 40μasyr-1 in proper motions corresponding to ~20 km s-1 at 100 kpc distance - can be achieved in one epoch of actual observations.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2010
- DOI:
- 10.1111/j.1365-2966.2009.15940.x
- arXiv:
- arXiv:0910.5114
- Bibcode:
- 2010MNRAS.402.1126T
- Keywords:
-
- instrumentation: high angular resolution;
- techniques: high angular resolution;
- telescopes;
- astrometry;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 15 pages, 9 figures, 3 tables. Accepted by MNRAS