J/other/AstBu/68.262 Sample of 467 GPS candidates (Mingaliev+, 2013)
Gigahertz-Peaked Spectrum (GPS) galaxies and quasars.
Mingaliev M.G., Sotnikova Yu.V., Mufakharov T.V., Erkenov A.K.,
Udovitskiy R.Yu.
<Astrophys. Bull., 68, 262 (2013)>
=2013AstBu..68..262M 2013AstBu..68..262M
ADC_Keywords: Active gal. nuclei ; Galaxies, radio ; Radio continuum
Keywords: galaxies: general - galaxies: active - radio continuum: galaxies
Abstract:
The results of a comprehensive analysis of continuous radio spectra of
a sample of Gigahertz-Peaked Spectrum (GPS) sources are reported. The
sources are selected from a flux-density-complete sample (S more or
equal 200mJy at 4.8 or 5GHz) using multifrequency measurements of
the RATAN-600 radio telescope and data from the CATS astrophysical
catalogs support system. The analysis revealed a very small number
(1-2%) of "classical" GPS objects, which is significantly less than
the expected fraction of 10%. GPS galaxies are found to have narrower
and steeper radio spectra than quasars. The low-frequency part of the
spectrum is seen to become steeper with increasing redshift. Galaxies
and quasars at the same z have comparable angular sizes, whereas their
luminosities may differ by one order of magnitude. At large redshifts
there is a deficit of objects with low (several GHz) peak frequencies.
The number of GPS galaxies decreases sharply with redshift, and most
of them are found at z between 0.01 and 1.81. GPS quasars are found at
large redshifts, from 0.11 to 3.99. A quarter of the sample consists
of blazars whose spectra may temporarily have a convex shape when the
object is in active state.
Description:
We selected objects with convex radio spectra from a flux-density
complete sample: S≥200mJy at 4.8 or 5GHz (we define the spectral
index alpha such that S∝nualpha) using multifrequency
measurements of the RATAN-600 radio telescope (2012A&A...544A..25M 2012A&A...544A..25M)
and data from the CATS astrophysical catalogs support system
(1997BaltA...6..275V 1997BaltA...6..275V). As a result, we selected 467 GPS candidates by
spectral type, with redshift data available for 249 of these objects.
The sample contains 118 galaxies, 187 quasars, and 162 sources without
optical counterparts. For each source name in J2000 equatorial
coordinates, the optical counterpart, redshift, peak frequency, radio
flux density, spectral indexes, FWHM, blazar type, morphological type
and variability are presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 93 467 Data for 467 GHz-Peaked Spectrum (GPS) candidates
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See also:
J/A+A/450/959 : VLBA images of High Frequency Peakers (Orienti+, 2006)
J/MNRAS/368/1411 : Flat-spectrum symmetric radio sources (Augusto+, 2006)
J/A+A/495/691 : Multifrequency cat. of blazars, Roma-BZCAT (Massaro+, 2009)
J/A+A/544/A25 : GPS radio sources multifrequency study (Mingaliev+, 2012)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name GPS source name (HHMMSS+DDMMSS, J2000)
15 A1 --- Type [QG-] Source type (1)
17- 20 F4.2 --- z ?=- Redshift (1)
22- 26 F5.2 GHz Fpeak [0.01/41.2] Observed peak frequency
28- 33 F6.2 Jy S5GHz Radio flux density at 5GHz
35- 37 F3.1 --- FWHM Full width at half maximum of radio spectrum
39- 42 F4.2 --- Sp- ?=- Spectral index below peak frequency
44- 48 F5.3 --- e_Sp- ?=- Spectral index below peak frequency error
50- 54 F5.2 --- Sp+ Spectral index above peak frequency
56- 60 F5.3 --- e_Sp+ Spectral index above peak frequency error
62- 67 F6.2 mas theta ?=- Angular size θ of emitting region
69- 79 A11 --- BlT Blazar type (2)
81- 85 A5 --- MType Morphological type (3)
87- 90 A4 % VI Variability index (4)
92- 93 A2 --- n_Name [g*- ] Comments on GPS (5)
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Note (1): From NED (NASA/IPAC Extragalactic Database)
Note (2): Blazar type according to BZCAT catalog (2009, Cat. J/A+A/495/691):
BLLac (BZB), BLLac cand. (BZ?), Blz.un.t (BZU, blazar of uncertain type),
or FSRQ (BZQ, flat-spectrum radio quasar)
Note (3): We adopt the morphological type from references [1-11], as follows:
cd = compact double structure
cso = compact symmetric structure
ct = compact triple structure
cx = complex structure
cj = core-jet structure
c = core dominated structure
unres = unresolved
Note (4): the variability is indicated as "<25" or ">25", or "lack" if
there is not enough data for variability estimation
Note (5): Comments as follows:
g = objects with classical GPS properties
* = objects identified as GPS in Mingaliev et al. 2012, Cat. J/A+A/544/A25
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Acknowledgements:
Yu. Sotnikova, sjv(at)sao.ru
References:
1 = O'Dea et al., 1991ApJ...380...66O 1991ApJ...380...66O
2 = Stanghellini, et al., 1997A&A...325..943S 1997A&A...325..943S
3 = Orienti et al., 2006, Cat. J/A+A/450/959
4 = Augusto et al., 2006, Cat. J/MNRAS/368/1411
5 = Jeyakumar et al., 2000A&A...362...27J 2000A&A...362...27J
6 = Xiang et al., 2005A&A...434..123X 2005A&A...434..123X
7 = Fey & Charlot, 1997ApJS..111...95F 1997ApJS..111...95F
8 = Xiang et al., 2006A&A...454..729X 2006A&A...454..729X
9 = Dallacasa et al., 1998A&AS..129..219D 1998A&AS..129..219D
10 = Gugliucci et al., 2005ApJ...622..136G 2005ApJ...622..136G
11 = Lister et al., in Proc. 6th EVN Symp., Ed. by E. Ros, R.W. Porcas,
A.P. Lobanov, and J.A. Zensus (2000), p. 135
(End) Yu. Sotnikova [SAO, Russia], Patricia Vannier [CDS] 12-Sep-2013