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J/AJ/133/1236       Fifth VLBA calibrator survey: VCS5       (Kovalev+, 2007)

The fifth VLBA calibrator survey: VCS5. Kovalev Y.Y., Petrov L., Fomalont E.B., Gordon D. <Astron. J., 133, 1236-1242 (2007)> =2007AJ....133.1236K
ADC_Keywords: Surveys; Radio sources; Positional data Keywords: astrometry - catalogs - surveys Abstract: This paper presents the fifth part of the Very Long Baseline Array (VLBA) Calibrator Survey (VCS), containing 569 sources not observed previously with very long baseline interferometry in geodetic or absolute astrometry programs. This campaign has two goals: (1) to observe additional sources that, together with previous survey results, form a complete sample, and (2) to find new strong sources suitable as phase calibrators. This VCS extension was based on three 24-hr VLBA observing sessions in 2005. It detected almost all extragalactic flat-spectrum sources with correlated flux density greater than 200mJy at 8.6GHz above declination -30° that were not observed previously. Source positions with milliarcsecond accuracy were derived from astrometric analysis of ionosphere-free combinations of group delays determined from the 2.3 and 8.6GHz frequency bands. The VCS5 catalog of source positions, plots of correlated flux density versus projected baseline length, contour plots, and FITS files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available on the World Wide Web at http://vlbi.gsfc.nasa.gov/vcs5 Description: The VCS5 observations were carried out in three 24hr observing sessions with the VLBA on 2005 July 8, 9, and 20. Each of the 675 target sources was observed in two scans of 120s each. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 106 590 The VCS5 catalog table2.dat 43 85 Sources not detected in VCS5 VLBA observations
See also: VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998) J/ApJS/141/13 : VLBA calibrator Survey - VCS1 catalog (Beasley+, 2002) J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003) J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005) J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006) http://vlbi.gsfc.nasa.gov/vcs5 : VCS5 Home Page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1 A1 --- Cat [CNU] Category (1) 3- 10 A8 --- IVS The IVS name (B1950), HHMM-DDd 12- 21 A10 --- VCS5 The IAU name (J2000), JHHMM-DDMM 23- 24 I2 h RAh Hour of Right ascension (J2000) 26- 27 I2 min RAm Minute of Right ascension (J2000) 29- 37 F9.6 s RAs Second of Right ascension (J2000) 39 A1 --- DE- Sign of the Declination (J2000) 40- 41 I2 deg DEd Degree of Declination (J2000) 43- 44 I2 arcmin DEm Arcminute of Declination (J2000) 46- 53 F8.5 arcsec DEs Arcsecond of Declination (J2000) 55- 60 F6.2 mas e_RAs Inflated error in Right Ascension 62- 67 F6.2 mas e_DEs Inflated error in Declination 69- 74 F6.3 --- Corr [-1,1] Correlation between RA & Dec errors 76- 78 I3 --- Nobs Number of group delays used for position determination 80 A1 --- l_Xtot Upper limit flag on Xtot 81- 84 F4.2 Jy Xtot ? The X-band (8.6GHz) total flux density integrated over entire map (2) 86 A1 --- l_XUnres Upper limit flag on XUnres 87- 90 F4.2 Jy XUnres ? The X-band (8.6GHz) unresolved flux density at longest VLBA baselines (2) 92 A1 --- l_Stot Upper limit flag on Stot 93- 96 F4.2 Jy Stot ? The S-band (2.3GHz) total flux density integrated over entire map (2) 98 A1 --- l_SUnres Upper limit flag on SUnres 99-102 F4.2 Jy SUnres ? The S-band (2.3GHz) unresolved flux density at longest VLBA baselines (2) 104-106 A3 --- Band Used Band for position estimation (3)
Note (1): Catagories as follows: C = calibrator N = non-calibrator, reliable coordinates U = non-calibrator, unreliable coordinates Note (2): NULL = no data are available. All bytes of the columns are blank. Note (3): Bands as follows: X = central frequency 8.6GHz S = central frequency 2.3GHz X/S = Both bands with central frequency 8.6 and 2.3GHz
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 8 A8 --- IVS The IVS name (B1950), HHMM-DDd (1) 10- 19 A10 --- IAU The IAU name (J2000), JHHMM-DDMM (1) 21- 22 I2 h RAh Hour of Right ascension (J2000) (2) 24- 25 I2 min RAm Minute of Right ascension (J2000) (2) 27- 31 F5.2 s RAs Second of Right ascension (J2000) (2) 33 A1 --- DE- Sign of the Declination (J2000) (2) 34- 35 I2 deg DEd Degree of Declination (J2000) (2) 37- 38 I2 arcmin DEm Arcminute of Declination (J2000) (2) 40- 43 F4.1 arcsec DEs Arcsecond of Declination (J2000) (2)
Note (1): The 85 sources presented in this table include the gravitation lens 1422+231 which was detected, but not processed in VCS5. Note (2): The J2000 source positions are taken from the NVSS survey (Condon et al., 1998, Cat. VIII/65), they were used for VCS5 VLBA observing and correlation.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 25-Jan-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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