THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. I. ASTROMETRY

Journal Article · Sat May 15 00:00:00 EDT 2010 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/139/5/1695; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301172

Lanyi, G E; Jacobs, C S; Naudet, C J; Sovers, O J; Zhang, L D ^[1]; Boboltz, D A; Fey, A L ^[2]; Charlot, P ^[3]; Fomalont, E B ^[4]; Geldzahler, B J ^[5]; Gordon, D ^[6]; Ma, C ^[7]; Romney, J D ^[8]

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1. Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)
2. U.S. Naval Observatory, 3450 Massachusetts Ave., NW, Washington, DC 20392-5420 (United States)
3. Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, BP 89, 33271 Floirac Cedex (France)
4. National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville, VA 22903 (United States)
5. National Aeronautics and Space Administration, 300 E. St., SW, Washington, DC 20546 (United States)
6. NVI Inc./NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
7. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
8. National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)

We present astrometric results for compact extragalactic objects observed with the Very Long Baseline Array at radio frequencies of 24 and 43 GHz. Data were obtained from ten 24 hr observing sessions made over a five-year period. These observations were motivated by the need to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies to enable improved deep space navigation after 2016 and to improve state-of-the-art astrometry. Source coordinates for 268 sources were estimated at 24 GHz and for 131 sources at 43 GHz. The median formal uncertainties of right ascension and declination at 24 GHz are 0.08 and 0.15 mas, respectively. Median formal uncertainties at 43 GHz are 0.20 and 0.35 mas, respectively. Weighted root-mean-square differences between the 24 and 43 GHz positions and astrometric positions based on simultaneous 2.3 and 8.4 GHz Very Long Baseline Interferometry observations, such as the ICRF, are less than about 0.3 mas in both coordinates. With observations over five years we have achieved a precision at 24 GHz approaching that of the ICRF but unaccounted systematic errors limit the overall accuracy of the catalogs.

• OSTI ID: 21301172
• Journal Information: Astronomical Journal (New York, N.Y. Online), Vol. 139, Issue 5; Other Information: DOI: 10.1088/0004-6256/139/5/1695; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
COORDINATES
GALAXIES
GHZ RANGE 01-100
INTERFEROMETRY
QUASARS
RADIOWAVE RADIATION