J/PASJ/55/351 ATCA observations of 202 compact radio sources (Tingay+, 2003)
ATCA monitoring observations of 202 compact radio sources in support of the
VSOP AGN survey.
Tingay S.J., Jauncey D.L., King E.A., Tzioumis A.K., Lovell J.E.J.,
Edwards P.G.
<Publ. Astron. Soc. Jap., 55, 351-384 (2003)>
=2003PASJ...55..351T 2003PASJ...55..351T
ADC_Keywords: Active gal. nuclei ; Radio sources ; Polarization ; Interferometry
Keywords: galaxies: active - radio continuum: galaxies - surveys -
technique: interferometric
Abstract:
The Australia Telescope Compact Array (ATCA) has been used in support
of the VLBI Space Observatory Programme (VSOP) space VLBI mission, to
monitor the total and polarised flux densities of 202 objects that
make up 83% of the VSOP all-sky Survey of compact extragalactic radio
sources south of DE=+10°. The primary goal of the ATCA
observations is to provide information on the total and polarised
emission from the compact components in these sources, for correlation
with parameters obtained from VSOP imaging observations. These data
represent the first high resolution, long timescale flux density
monitoring observations of a large number of southern compact radio
sources. In the future, comparison of the ATCA and VSOP data will be
used to investigate relativistic beaming models and identify
similarities or differences between the major classes of extragalactic
radio sources. As an illustration of the scientific value of the ATCA
data we undertake a comparison of the properties of the gamma-ray loud
and gamma-ray quiet AGN in the southern component of the VSOP Survey
sample, finding that in a flat-spectrum sub-sample the gamma-ray loud
AGN are more variable than the gamma-ray quiet AGN.
Description:
Observations of 202 radio sources from the VSOP Survey sample
(Hirabayashi et al., 2000, Cat. J/PASJ/52/997) were made over
a 3.5 year period with the ATCA (table 1) in the 8.6, 4.8, 2.5, and
1.4GHz bands.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 38 17 Approximate flux densities and spectral indices
for the 17 sources dropped from the ATCA monitoring.
table3.dat 91 185 Mean flux densities, variability indices, mean
percentage linear polarisations, mean spectral
indices, and structure flags for the 185 (=202-17)
VSOP Survey sources monitored with the ATCA.
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See also:
J/PASJ/52/997 : VSOP 5 GHz AGN Survey (Hirabayashi+, 2000)
J/ApJS/131/95 : VSOP 5 GHz continuum survey (Fomalont+, 2000)
J/ApJS/155/33 : VSOP 5 GHz AGN Survey. III (Scott+, 2004)
J/ApJ/616/110 : VSOP 5 GHz AGN Survey. IV (Horiuchi+, 2004)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- VSOP Source name (JHHMM+DDMM)
12- 15 F4.2 Jy <I8.6> Mean flux density at 8.6GHz
17- 20 F4.2 Jy <I4.8> Mean flux density at 4.8GHz
22- 25 F4.2 Jy <I2.5> Mean flux density at 2.5GHz
27- 30 F4.2 Jy <I1.4> Mean flux density at 1.4GHz
32- 36 F5.2 --- Mean spectral index between 4.8 and 8.6GHz
38 A1 --- Flag [ce] Flag about radio structure (G1)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- VSOP Source name (JHHMM+DDMM)
12- 16 F5.2 Jy <I8.6> Mean flux density at 8.6GHz
18- 22 F5.2 Jy <I4.8> Mean flux density at 4.8GHz
24- 28 F5.2 Jy <I2.5> Mean flux density at 2.5GHz
30- 34 F5.2 Jy <I1.4> Mean flux density at 1.4GHz
37- 40 F4.2 --- M8.6 Total flux density variability index
at 8.6GHz (1)
42- 45 F4.2 --- M4.8 Total flux density variability index
at 4.8GHz (1)
47- 50 F4.2 --- M2.5 Total flux density variability index
at 2.5GHz (1)
52- 55 F4.2 --- M1.4 Total flux density variability index
at 1.4GHz (1)
57 A1 --- l_<m8.6> Limit flag on <m8.6>
58- 62 F5.2 % <m8.6> Mean percentage linear polarisation at 8.6GHz
64 A1 --- l_<m4.8> Limit flag on <m4.8>
65- 68 F4.2 % <m4.8> Mean percentage linear polarisation at 4.8GHz
70 A1 --- l_<m2.5> Limit flag on <m2.5>
71- 75 F5.2 % <m2.5> Mean percentage linear polarisation at 2.5GHz
77 A1 --- l_<m1.4> Limit flag on <m1.4>
78- 81 F4.2 % <m1.4> Mean percentage linear polarisation at 1.4GHz
83- 87 F5.2 --- Mean spectral index between 4.8 and 8.6GHz
91 A1 --- Flag [cel] Flag about radio structure (G1)
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Note (1):
The variability index is defined as the RMS variation from the mean
flux density, divided by the mean flux density. It should be noted
that over the period of these observations, significant radio
frequency interference (RFI) was present in the 2.5GHz band at the
ATCA, and to a lesser extent in the 1.4GHz band. The RFI in the 2.5GHz
data has been removed as much as possible by careful editing but some
of the scatter in the visibility amplitudes for some sources at some
times at this frequency may be due to residual RFI in the data.
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Global notes:
Note (G1): Flags have the following meaning:
c = highly compact structure, little evidence for structure on
baselines less than 6km in length
e = significantly extended structure at a majority of frequencies
and on baselines less than 6km in length
l = evidence for extended structure mainly at 1.4GHz or 2.5GHz, with
the source appearing to be more compact at the higher frequencies
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History:
* 13-Feb-2004: From electronic version of the journal
* 18-Aug-2005: table3, the following names were corrected (to be
coherent with the VSOP catalog by Hirabayashi et al.,
2000PASJ...52..997H 2000PASJ...52..997H, Cat. J/PASJ/52/997)
- J1647-6438 replaced by J1647-6437
- J1932-4536 replaced by J1932-4546
(End) James Marcout, Patricia Bauer [CDS] 13-Feb-2004