J/A+A/426/463 B3-VLA CSS sample (Orienti+, 2004)
The B3-VLA CSS sample. V. VLBA images at 6 and 3.6 cm.
Orienti M., Dallacasa D., Fanti C., Fanti R., Tinti S., Stanghellini C.
<Astron. Astrophys. 426, 463 (2004)>
=2004A&A...426..463O 2004A&A...426..463O
ADC_Keywords: Radio sources ; Galaxies, radio ; QSOs ; Redshifts
Keywords: galaxies: active - galaxies: nuclei - radio continuum: galaxies -
galaxies: quasar: general - polarization
Abstract:
We present the results of VLBA observations at 6 and 3.6cm for
eighteen Compact Steep Spectrum radio sources (CSS) from the B3-VLA
CSS sample. In most cases these VLBA images display a "Double/Triple"
morphology, and the core is unambiguously detected in seven sources.
Multifrequency images allow us to study the spectral properties of the
individual source components and to constrain the spectral age. In
lobe-dominated sources the radiative ages deduced from the synchrotron
theory are in the range of up 5x103 years, if equipartition magnetic
field is assumed. Polarized emission is detected at a few percent
level for two sources only. They were the only two sources displaying
polarized emission in VLA A configuration data, and this implies that
beam depolarization is not effective in reducing the integrated
fractional polarization for these sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 59 18 The VLBA sample
table2.dat 53 54 Observational parameters of source components
tables.tex 104 173 LaTeX version of the tables
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See also:
J/A+A/369/380 : CSS/GPS radio sources VLA observations (Fanti+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Source name, HHMM+DDdA (B1950);
11 A1 --- Type [GgQE] Optical identification from Paper I,
Fanti et al., 2001, Cat. J/A+A/369/380 (1)
14- 17 F4.1 mag Rmag ? R magnitude
20- 24 F5.3 --- z ? Redshift
25 A1 --- n_z [R] R indicates a photometric redshift from R
(from POSS prints) magnitude (see Paper I
for details)
27- 31 F5.1 mJy S4.9GHzvla VLA 4.9GHz (6cm) flux density, from Paper I
33- 37 F5.1 mJy S5GHzvlba Total VLBA 5.0GHz flux density, measured on
the images presented here
39- 43 F5.1 mJy S8.4GHzvla VLA 8.4GHz (3.6cm) flux density, from Paper I
45- 49 F5.1 mJy S8.4GHzvlba ? Total VLBA 8.4GHz flux density, measured on
the images presented here
51- 53 I3 mas LAS VLBA Largest Angular Size, measured on the
most suitable images at the different
resolution and frequency, presented here
55 A1 --- l_LLS [~] Limit flag on LLS (2)
56- 59 F4.2 kpc LLS Largest Linear Size from VLBA data (in kpc/h)
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Note (1): Optical identification :
G = galaxy on the POSS prints
g = galaxy fainter than the POSS limit
Q = quasar
E = unknown optical counterpart (Vigotti et al., 1989, Cat. J/AJ/98/419)
Note (2): For E sources z=1.00 was assumed and LLS is given with a leading "~".
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Source name (B1950)
9- 10 A2 --- Comp Sub-component label of the source
11 A1 --- n_Comp [~] ~: the component is extended (1)
12 A1 --- n_Name [*] Note on Name (2)
14- 18 F5.1 mJy S5.0GHz VLBA flux density at 5.0GHz
21- 25 F5.1 mJy S4.8GHz ? VLBA flux density at 5.0GHz
27 A1 --- l_Sp+Index1 Limit flag on Sp+Index(1.67-5.0)
28- 31 F4.2 --- Sp+Index1 ? Spectral index α1.675.0 (3)
33- 37 F5.2 --- Sp+Index2 ? Spectral index α5.08.4 (3)
40- 43 F4.1 mas thetamaj ? Deconvolved angular size of major axis (4)
45- 48 F4.1 mas thetamin ? Deconvolved angular size of minor axis (4)
51- 53 I3 deg PA ? Position angle of the major axis (4)
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Note (1): Extended component: its flux density is measured using TVSTAT
and the angular sizes of major and minor axis are measured on the
image contour plot (see text)
Note (2): *: measurements on diffuse components, for which no other
parameter (major/minor axis and position angle) except the flux
density could be given.
Note (3): Spectral indices α1.675.0 and α5.08.4
obtained from the data of Paper II (Dallacasa et al.,
2002A&A...389..115D 2002A&A...389..115D) and those presented here
Note (4): Deconvolved angular sizes of major and minor axis of the
best-fitting Gaussian component and position angle of the major axis
as estimated on the most suitable images at the different resolution
and frequency, using JMFIT.
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Acknowledgements: D. Dallacasa
References:
Fanti et al., Paper I 2001A&A...369..380F 2001A&A...369..380F, Cat. J/A+A/369/380
Dallacasa et al., Paper II 2002A&A...389..115D 2002A&A...389..115D
Dallacasa et al., Paper III 2002A&A...389..126D 2002A&A...389..126D
(End) Patricia Vannier [CDS] 28-Jul-2004