Precision Astrometry with Adaptive Optics

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

32 pages, 12 figures; submitted to AJ

Scientific paper

10.1088/0004-6256/137/1/83

We investigate the limits of ground-based astrometry with adaptive optics using the core of the Galactic globular cluster M5. Adaptive optics systems provide near diffraction-limit imaging with the world's largest telescopes. The substantial improvement in both resolution and signal-to-noise ratio enables high-precision astrometry from the ground. We describe the dominant systematic errors that typically limit ground-based differential astrometry, and enumerate observational considerations for mitigating their effects. After implementing these measures, we find that the dominant limitation on astrometric performance in this experiment is caused by tilt anisoplanatism. We then present an optimal estimation technique for measuring the position of one star relative to a grid of reference stars in the face of this correlated random noise source. Our methodology has the advantage of reducing the astrometric errors as the square root of time and faster than the square root of the number of reference stars -- effectively eliminating noise caused by atmospheric tilt to the point that astrometric performance is limited by centering accuracy. Using 50 reference stars we demonstrate single-epoch astrometric precision of ~ 1 mas in 1 second, decreasing to < 100 microarcseconds in 2 minutes of integration time at the Hale 200-inch telescope. We also show that our astrometry is accurate to <~ 100 microarcseconds for observations separated by 2 months. Finally, we discuss the limits and potential of differential astrometry with current and next generation large aperture telescopes. At this level of accuracy, numerous astrometric applications become accessible, including planet detection, astrometric microlensing signatures, and kinematics of distant Galactic stellar populations.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Precision Astrometry with Adaptive Optics does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Precision Astrometry with Adaptive Optics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Precision Astrometry with Adaptive Optics will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-508455

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.