J/A+A/342/378 6 and 20cm flux densities of radio galaxies (Gurvits+ 1999)
The "angular size - redshift" relation for compact radio structures
in quasars and radio galaxies
Gurvits L.I., Kellermann K.I., Frey S.
<Astron. Astrophys. 342, 378 (1999)>
=1999A&A...342..378G 1999A&A...342..378G (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Galaxies, radio ; Redshifts ;
Radio sources ; VLBI
Keywords: galaxies: active - galaxies: quasars: general -
cosmology: observations - radio continuum: galaxies
Abstract:
We discuss the "angular size-redshift" relation for compact radio
sources distributed over a wide range of redshifts 0.011≤z≤4.72. Our
study is based on a sample of 330 5 GHz VLBI contour maps taken from
the literature. Unlike extended source samples, the "angular size -
redshift" relation for compact radio sources appears consistent with
the predictions of standard Friedmann world models with q0≃0.5
without the need to consider evolutionary or selection effects due to
a "linear size-luminosity" dependence. By confining our analysis to
sources having a spectral index, -0.38≤α≤0.18, and a total
radio luminosity, Lh2≥ 1026W/Hz (H0=100hkm/s/Mpc, q0=0.5 used
as a numerical example), we are able to restrict the dispersion in the
"angular size-redshift" relation. The best fitting regression
analysis in the framework of the Friedmann-Robertson-Walker model
gives the value of the deceleration parameter q0=0.21±0.30 if
there are no evolutionary or selection effects due to a "linear
size-luminosity", "linear size-redshift" or "linear size-spectral
index" dependence.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 330 "VLBI angular size - z" for 330 sources
refs.dat 153 86 References
table1.tex 113 780 LaTeX version of table1
table1.ps 72 1342 PostScript version of table1
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- IAU IAU name (based on 1950 position)
10- 17 A8 --- Name Alternative name
19- 23 F5.3 --- z Redshift
25 A1 --- Type [BGQ] Type of the optical counterpart (1)
27- 31 F5.2 Jy S6cm Flux density at 6 cm from Gregory et al.
(1996) unless otherwise stated.
32 A1 --- n_S6cm [q] Note on S6cm (2)
34- 38 F5.2 Jy S20cm ? Flux density at 20 cm (or alternative) from
White and Becker (1992) unless otherwise
stated
39 A1 --- n_S20cm [f-y] Note on S20cm (2)
41- 45 F5.2 --- SI Spectral index
47 A1 --- l_theta Symbol of an upper limit
48- 51 F4.1 mas theta Angular size
53 A1 --- Struc [CJLS] Structure code (3)
55- 58 A4 --- r_z Redshift reference in refs.dat file
60- 63 A4 --- r_S6cm 6cm flux density reference in refs.dat file
65- 68 A4 --- r_S20cm 20cm flux density reference in refs.dat file
70- 73 A4 --- r_VLBI VLBI reference in refs.dat file
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Note (1): Q: quasar
B: BL Lac object
G: radio galaxy (including Seyfert galaxies of all types)
Note (2): f: Spectral index calculated using S11=0.61Jy
g: Spectral index calculated using S11=3.56Jy
h: Spectral index calculated using S75=5.05Jy
i: Spectral index calculated using S11=1.10Jy
j: Spectral index calculated using S11=1.33Jy
k: Spectral index calculated using S11=0.40Jy
l: Spectral index calculated using S11=0.56Jy
m: Spectral index calculated using S11=0.45Jy
n: Spectral index calculated using S75=0.14Jy
o: Spectral index calculated using S11=2.74Jy
p: Spectral index calculated using S11=1.08Jy
q: S6 and S20 values for the compact core component
x: Spectral index calculated using S11=1.76Jy
y: Spectral index calculated using S11=1.34Jy
Note (3): Characteristic angular size (case C) or
its upper limit (cases J, L, and S).
Radio structure code:
C: size between the core and the most distant 2%-component
J: upper limit of θ along jet direction
L: upper limit of θ along major axis of the beam
S: upper limit of θ along minor axis of the beam
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ref Reference code
6- 24 A19 --- BibCode BibCode
26- 47 A22 --- Aut Author's name
49-153 A105 ---- Comm Comments
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Acknowledgements: Leonid Gurvits
(End) Patricia Bauer [CDS] 04-Dec-1998