J/AJ/127/3587 VLBI ICRF. II (Fey+, 2004)
The second extension of the International Celestial Reference Frame: ICRF-EXT.1.
Fey A.L., Ma C., Arias E.F., Charlot P., Feissel-Vernier M., Gontier A.-M.,
Jacobs C.S., Li J., Macmillan D.S.
<Astron. J., 127, 3587-3608 (2004)>
=2004AJ....127.3587F 2004AJ....127.3587F
ADC_Keywords: Fundamental catalog ; Positional data ; VLBI
Keywords: astrometry - catalogs - quasars: general - radio continuum: galaxies -
reference systems - techniques: interferometric
Abstract:
We use very long baseline interferometry data obtained between
mid-1995 and the end of 2002 May together with older data to extend
and revise the International Celestial Reference Frame (ICRF). Revised
positions of ICRF candidate and "other" sources, based on inclusion of
the additional data, are presented. Positions, in the frame of the
ICRF, for an additional 109 new sources are also presented. All but
four of the new sources are located north of δ=-30°.
Positions of the ICRF defining sources remain unchanged. We present a
summary of current astrometric and geodetic observing programs and
discuss the evolution and future of the ICRF.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 123 109 ICRF coordinates of 109 new sources
table2.dat 123 294 Revised coordinates of the 294 ICRF candidate sources
table3.dat 123 102 Revised coordinates of the 102 ICRF other sources
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See also:
I/251 : VLBI International Celestial Reference Frame (ICRF) (Ma+, 1997)
I/218 : New Reference Frame defined by Extragalactic Radio Source
(IAU WG, 1995)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
http://hpiers.obspm.fr/webiers/results/icrf/README.html : ICRF Home Page
http://aa.usno.navy.mil/AA/data/docs/ICRS_links.html : ICRS at USNO
http://hpiers.obspm.fr/webiers/results/icrf/Updating.html : Updating
Byte-by-byte Description of file: table1.dat table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [ICRF]
6- 21 A16 --- ICRF ICRF designation (1)
23- 30 A8 --- IERS IERS identification (2)
32- 33 I2 h RAh Hour of Right Ascension (J2000)
35- 36 I2 min RAm Minute of Right Ascension (J2000)
38- 46 F9.6 s RAs Second of Right Ascension (J2000)
48 A1 --- DE- Sign of the Declination (J2000)
49- 50 I2 deg DEd Degree of Declination (J2000)
52- 53 I2 arcmin DEm Arcminute of Declination (J2000)
55- 62 F8.5 arcsec DEs Arcsecond of Declination (J2000)
64- 71 F8.6 s e_RAs Error in RAs
73- 79 F7.5 arcsec e_DEs Error in DEs
81- 86 F6.3 --- CRA-DE Correlation between right ascension and
declination
88- 94 F7.1 d MEpoch MJD of mean epoch of observation (3)
96-102 F7.1 d FEpoch MJD of first epoch of observation (3)
104-110 F7.1 d LEpoch MJD of last epoch of observation (3)
112-115 I4 --- Nexp Number of 24 hour observing sessions
117-122 I6 --- Nobs Number of observations
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Note (1): ICRF designations, constructed from J2000.0 coordinates with the
format: ICRF JHHMMSS.s+DDMMSS or ICRF JHHMMSS.s-DDMMSS.
Note (2): IERS designations, previously constructed from B1950 coordinates:
IERS BHHMM+DDd or IERS BHHMM-DDd
Note (3): MJD=JD-2400000.5.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 11-May-2005