A Radio-Optical Reference Frame.VIII.CCD Observations from KPNO and CTIO: Internal Calibration and First Results

Abstract

view Abstract Citations (16) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Radio-Optical Reference Frame.VIII.CCD Observations from KPNO and CTIO: Internal Calibration and First Results Zacharias, N. ; de Vegt, C. ; Winter, L. ; Johnston, K. J. Abstract In this pilot investigation, precise optical positions in the FK5 system are presented for a set of 16 compact extragalactic radio sources, which will be part of the future radio-optical reference frame. The 0.9 m KPNO and CTIO telescopes equipped with 2 K CCDs have been used for this project. The astrometric properties of these instruments are investigated in detail. New techniques of using wide field CCD observations for astrometry in general are developed. An internal precision of 5-31 mas in position per single exposure is found, depending on the brightness of the object. The tie to the primary optical reference system is established by photographic astrometry using dedicated astrographs on both hemispheres. An accuracy of ~30 mas per source is estimated for the multistep reduction procedure when based on the future Hipparcos catalog, while the FK5-based positions suffer from system errors of 100-200 mas as compared to the radio positions. This work provides a contribution to the international effort to link the Hipparcos instrumental coordinate system to the quasi-inertial VLBI radio reference frame. Precise radio and optical astrometry of a large sample of compact extragalactic sources will also contribute to the astrophysics of these objects by comparing the respective centers of emission at the optical and radio wavelengths. Publication: The Astronomical Journal Pub Date: December 1995 DOI: 10.1086/117750 arXiv: arXiv:astro-ph/9508096 Bibcode: 1995AJ....110.3093Z Keywords: REFERENCE SYSTEMS; Astrophysics E-Print: AAS v.4 LaTeX, 2 parts on 1 file (main text + deluxetable), accepted by AJ, Dec.95, fig. with reprints full text sources arXiv | ADS | data products SIMBAD (16) NED (16) Related Materials (6) Part 1: 1990AJ.....99.1284M Part 2: 1991AJ....101.2266R Part 3: 1992AJ....103.2090R Part 4: 1992AJ....104..891F Part 5: 1994AJ....107..379R Part 6: 1994AJ....108..725R