J/A+A/489/49 Observations of candidate GPS sources (Vollmer+, 2008)
Quasi-simultaneous multi-frequency observations of inverted-spectrum radio
sources from the multi-epoch SPECFIND catalog.
Vollmer B., Krichbaum T.P., Angelakis E., Kovalev Y.Y.
<Astron. Astrophys. 489, 49 (2008)>
=2008A&A...489...49V 2008A&A...489...49V
ADC_Keywords: Radio sources ; Galaxies, radio
Keywords: radio continuum: galaxies - galaxies active
Abstract:
Gigahertz-Peaked Spectrum (GPS) sources are likely the precursors of
local radio galaxies. Existing GPS source samples are small (<200).
We aim to extend the available sample of the Gigahertz-Peaked Spectrum
(GPS) and High Frequency Peaker (HFP) sources in order to study their
nature with greater detail and higher statistical significance.
Description:
A sample of 214 radio sources, which were extracted from the SPECFIND
catalog (Cat. VIII/74) and show an inverted radio spectrum, were
observed quasi-simultaneously at 4.85, 10.45, and 32GHz with the
100-m Effelsberg radio telescope. Using the VLBA calibrator survey
(VCS) we have investigated the parsec-scale morphology of the sources.
Table 5: results of the observations.
Table 6: properties of the sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 92 214 Results of the observations
table6.dat 70 214 Properties of the sources
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See also:
VIII/74 : SPECFIND Catalog of radio continuum spectra (Vollmer+ 2005)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Source name (JHHMM+DDMM)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs Declination (J2000)
36- 40 I5 mJy S4.85 Flux density at 4.85GHz
42- 44 I3 mJy e_S4.85 Error on S4.85GHz
46- 49 I4 mJy S10.45 ?=- Flux density at 10.45GHz
51- 53 I3 mJy e_S10.45 ? Error on S10.45GHz
55- 58 I4 mJy S32 ?=- Flux density at 32.00GHz
60- 62 I3 mJy e_S32 ? Error on S32GHz
64- 68 F5.2 --- SI1 ? Spectral index between 4.85 and 10.45GHz
70- 73 F4.2 --- e_SI1 ? Error on SI1
75- 79 F5.2 --- SI2 ? Spectral index between 10.45 and 32.00GHz
81- 84 F4.2 --- e_SI2 ? Error on SI2
86- 92 A7 --- Res Frequencies at which the source is resolved
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Source name (JHHMM+DDMM)
12 A1 --- l_z Limit flag on z
13- 17 F5.3 --- z ? Redshift (1)
19 A1 --- VCS [y/n] VLBA calibrator survey source
21- 23 A3 --- Type Object type from SIMBAD
25- 27 A3 --- Rtype Radio type (GPS or HFP) (2)
29- 31 A3 --- Sample Sample membership (3)
33- 34 A2 --- Var [VE ] Variable or Extended (at 4.85GHz) source
36- 40 I5 MHz nup ? Peak frequency
42- 45 I4 mJy Sp ? Peak flux density
47- 51 A5 --- Note [low b] source at galactic latitude |b|<10°
53 A1 --- l_c8.6 Limit flag on c8.6GHz
54- 57 F4.2 --- c8.6 ? VLBI compactness ratio at 8.6 GHz
59 A1 --- l_c2.3 Limit flag on c2.3GHz
60- 63 F4.2 --- c2.3 ? VLBI compactness ratio at 2.3 GHz
65- 70 A6 --- Class VLBI morphological class (6)
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Note (1): Redshift from Veron-Cetty & Veron (2006, Cat. VII/248)
Note (2): Gigahertz-Peaked Spectrum (GPS) or High Frequency Peaker (HFP).
The classification criteria are described in Sect. 6 of the paper.
Note (3): Sample as follows:
B = Snellen et al. (1998A&AS..131..435S 1998A&AS..131..435S)
S = Stanghellini et al. (1998, Cat. J/A+AS/131/303)
F = Fanti et al. (2001, Cat. J/A+A/369/380)
D = Dallacasa et al. (2000, Cat. J/A+A/363/887)
M = Marecki et al. (1999, Cat. J/A+AS/135/273)
L = Labiano et al. (2007, Cat. J/A+A/463/97)
Note (6): Classification based on VLBI images as follows:
nc = naked core candidate
cj = core-jet candidate
cso = compact symmmetric object candidate
cj/cso = core-jet or compact symmetric object candidate, components
cross-identification between 2 and 8GHz is questionable
The VCS classification for the following sources was corrected
according to deeper multi-frequency VLBI studies:
J0003+2129 (Orienti et al., 2006, Cat. J/A+A/450/959),
J1407+2827 (e.g., Stanghellini et al., 1997A&A...318..376S 1997A&A...318..376S),
J1551+5806 (Snellen et al., 2000MNRAS.319..429S 2000MNRAS.319..429S);
our cso candidates J0111+3906, J0713+4349, J1823+7938, J2022+6136
are confirmed by Peck & Taylor (2000ApJ...534...90P 2000ApJ...534...90P).
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Acknowledgements:
Bernd Vollmer, vollmer(at)astro.u-strasbg.fr
References:
Vollmer et al., 2005A&A...436..757V 2005A&A...436..757V
(End) Patricia Vannier [CDS] 18-Sep-2008