Extragalactic Optical-Radio Link Research at USNO
Abstract
Over 500 counterparts of International Celestial Reference Frame (ICRF) sources were observed during 24 deep CCD observing runs as part of the USNO CCD Astrograph Catalog (UCAC) project, providing a direct link to Tycho-2 stars. For some sources a positional accuracy of 10 mas is achieved. A sample of 12 extragalactic ICRF sources are being observed at the Naval Observatory Flagstaff Station's (NOFS) 1.55-meter telescope over several years to monitor optical position stability. First, high resolution imaging of selected sources is obtained at the Lick 3-meter Adaptive Optics system to correlate source structure with optical-radio centroid offsets. As part of the Space Interferometry Mission (SIM), preparatory science about 240 bright QSO's are monitored for photometric variability in B,V,R and I. The USNO Robotic Astrometric Telescope (URAT) will be able to combine deep CCD imaging of all ICRF2 target areas and millions of compact galaxies with a stellar, astrometric, all-sky survey of multiple epochs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA475018
Entities
People
- A. Fey
- D. Boboltz
- G. S. Hennessy
- K. J. Johnston
- M. I. Zacharias
- Norbert Zacharias
- R. Gaume
- R. Ojha
Organizations
- United States Naval Observatory