High-precision astrometry towards ELTs
arXiv:1607.04412 · doi:10.1117/12.2232478
Abstract
With the aim of paving the road for future accurate astrometry with MICADO at the European-ELT, we performed an astrometric study using two different but complementary approaches to investigate two critical components that contribute to the total astrometric accuracy. First, we tested the predicted improvement in the astrometric measurements with the use of an atmospheric dispersion corrector (ADC) by simulating realistic images of a crowded Galactic globular cluster. We found that the positional measurement accuracy should be improved by up to ~2 mas with the ADC, making this component fundamental for high-precision astrometry. Second, we analysed observations of a globular cluster taken with the only currently available Multi-Conjugate Adaptive Optics assisted camera, GeMS/GSAOI at Gemini South. Making use of previously measured proper motions of stars in the field of view, we were able to model the distortions affecting the stellar positions. We found that they can be as large as ~200 mas, and that our best model corrects them to an accuracy of ~1 mas. We conclude that future astrometric studies with MICADO requires both an ADC and an accurate modelling of distortions to the field of view, either through an a-priori calibration or an a-posteriori correction.
13 pages, 7 figure. To appear in Adaptive Optics Systems V, eds. Marchetti E., Close L.M., Véran, J.-P., Proc. SPIE vol. 9909 id 54; 2016
References in corpus (15)
- The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations
- An ACS Survey of Globular Clusters V: Star Catalog for Each Cluster
- Analysis of isoplanatic high resolution stellar fields by Starfinder code
- Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. I. Sample Selection, Data Reduction and NGC 7078 Results
- Hubble Space Telescope proper motion (HSTPROMO) catalogs of Galactic globular clusters. II. Kinematic profiles and maps
- Star count density profiles and structural parameters of 26 Galactic globular clusters
- Gemini multi-conjugate adaptive optics system review II: Commissioning, operation and overall performance
- HST absolute Proper Motions of NGC 6681 (M70) and the Sagittarius Dwarf Spheroidal Galaxy
- Astrometric performance of the Gemini multi-conjugate adaptive optics system in crowded fields
- GeMS MCAO observations of the Galactic globular cluster NGC 2808: the absolute age
- Multiple stellar populations in the globular cluster M3 (NGC 5272): a Strömgren perspective
- An E-ELT Case Study: Colour-Magnitude Diagrams of an Old Galaxy in the Virgo Cluster
- Towards Precision Photometry with Extremely Large Telescopes: the Double Subgiant Branch of NGC 1851
- Resolved stellar population of distant galaxies in the ELT era
- On the use of asymmetric PSF on NIR images of crowded stellar fields
Cited by in corpus (5)
- The Proper Motion of Pyxis: the first use of Adaptive Optics in tandem with HST on a faint halo object
- Quantification of the expected residual dispersion of the MICADO Near-IR imaging instrument
- Optimal stellar photometry for multi-conjugate adaptive optics systems using science-based metrics
- Constraining VLBI-optical offsets in high redshift galaxies using strong gravitational lensing
- Optimal Differential Astrometry for Multiconjugate Adaptive Optics. I. Astrometric Distortion Mapping using On-sky GeMS Observations of NGC 6723