J/A+A/544/A25 GPS radio sources multifrequency study (Mingaliev+, 2012)
Multifrequency study of GHz-peaked spectrum sources and candidates with the
RATAN-600 radio telescope.
Mingaliev M.G., Sotnikova Yu.V., Torniainen I., Tornikoski M.,
Udovitskiy R.Yu.
<Astron. Astrophys., 544, A25 (2012)>
=2012A&A...544A..25M 2012A&A...544A..25M
ADC_Keywords: QSOs ; Active gal. nuclei ; Radio sources
Keywords: galaxies: active - galaxies: general - radio continuum: galaxies
Abstract:
Gigahertz peaked spectrum (GPS) radio sources are a class of
extragalactic radio sources characterized by a spectral peak in the
gigahertz domain. They are a mixed class of quasars and galaxies. A
large proportion of the sources studied in the literature have only
few data points in the radio domain, and the determination of
variability and shape of the simultaneous spectra is inadequate.
Sources currently included in the GPS source lists are very
heterogeneous.
We present the observational results from 12 observing campaigns
(carried out between 2006 and 2010) at the RATAN-600 radio telescope
to obtain the simultaneous radio spectra, which is valuable and
necessary to derive genuine GPS sources from flat-spectrum radio
sources caught in a flaring state when their spectra are temporarily
inverted. The sample contains both quasar- and galaxy-type GPS (122
sources) identified in the literature.
Description:
The observations were carried out at six frequencies (1.1, 2.3, 4.8,
7.7, 11.2 and 21.7GHz), during 12 observing campaigns: July and
October 2006, March and April 2007, September 2007, April and June
2008, November and October 2008, April, October and November 2009,
January, April, May, and July 2010. The flux densities were measured
at several epochs. A six-frequency broadband radio spectrum was
obtained by observing simultaneously with an accuracy of up to a
minute at 1.4, 2.7, 3.9, 6.25, 13, and 30cm.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
sources.dat 27 122 List of studied sources
table2.dat 93 597 The flux densities of GPS sources and candidates for
several epochs (RATAN-600 observations 2006-10)
table3.dat 85 69 Parameters of radio spectra for the sources with
spectral maximum (RATAN-600 observations 2006-10)
--------------------------------------------------------------------------------
See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/A+AS/132/341 : ROSAT GPS optical identification (Motch+ 1998)
J/A+AS/135/273 : 408MHz obs. of GPS sources from JVAS survey (Marecki+ 1999)
J/A+A/369/380 : CSS/GPS radio sources VLA observations (Fanti+, 2001)
J/MNRAS/373/1203 : The outer Galaxy at 1420 and 408MHz (Kerton, 2006)
J/A+A/469/451 : Radio continuum spectra of GPS galaxies (Torniainen+, 2007)
J/A+A/463/97 : Optical observations of GPS radio sources (Labiano+, 2007)
J/A+A/482/483 : GHz-peaked spectrum (GPS) sources (Torniainen+, 2008)
J/A+A/489/49 : Observations of candidate GPS sources (Vollmer+, 2008)
J/MNRAS/416/1135 : Unbiased sample of CSS and GPS (Randall+, 2011)
Byte-by-byte Description of file: sources.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- NVSS NVSS name (HHMMSS+DDMMSS)
15- 17 A3 --- Type [G QSO -] Optical class
19- 22 A4 --- sp Type if RATAN-600 spectra (1)
24- 27 F4.2 --- z ?=- Redshift
--------------------------------------------------------------------------------
Note (1): Type of RATAN-600 spectra as follows:
max = spectrum with maximum in the RATAN-600 frequency range
max1 = possible spectrum with a maximum in low frequencies not accessible
to RATAN-600
max2 = variable spectrum with maximum of Var{DELTA}S>2.5 at 21-4.8GHz
f = flat spectrum (0≥α≥-0.5)
ris = rising spectrum (α>0)
s = steep spectrum (spectral index α≤-0.5)
c = complex spectrum (one or more minima)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- NVSS NVSS name (HHMMSS+DDMMSS)
15- 21 F7.2 "YYYY/MM" Date Observation epoch at RATAN-600
23- 27 F5.3 Jy S21.7 ?=- Flux density at 21.7GHz
29- 33 F5.3 Jy e_S21.7 ? rms uncertainty on S21.7 (1)
34- 39 F6.3 Jy S11.2 ?=- Flux density at 11.2GHz
40 A1 --- f_S11.2 [*] Corrected at CDS (2)
41- 45 F5.3 Jy e_S11.2 ? rms uncertainty on S11.2 (1)
46- 51 F6.3 Jy S7.7 ?=- Flix density at 7.7GHz
52 A1 --- f_S7.7 [*] Corrected at CDS (2)
53- 57 F5.3 Jy e_S7.7 ? rms uncertainty on S7.7 (1)
58- 63 F6.3 Jy S4.8 ?=- Flux density at 4.8GHz
64 A1 --- f_S4.8 [*] Corrected at CDS (2)
65- 69 F5.3 Jy e_S4.8 ? rms uncertainty on S4.8 (1)
71- 75 F5.3 Jy S2.3 ?=- Flux density at 2.3GHz
77- 81 F5.3 Jy e_S2.3 ? rms uncertainty on S2.3 (1)
82- 87 F6.3 Jy S1 ? Flux density at 1GHz
88 A1 --- f_S1 [*] Corrected at CDS (2)
89- 93 F5.3 Jy e_S1 ? rms uncertainty on S1
--------------------------------------------------------------------------------
Note (1): Uncertainties for the corresponding frequencies, including the
uncertainty in the source's antenna temperature and the calibration curve.
Note (2): a few fluxes above 10Jy apparently miss the '1' leftmost digit
in the original table, fixed at CDS. See also the "History" section below.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- NVSS NVSS name (HHMMSS+DDMMSS)
15- 17 A3 --- Type [G QSO -] Optical class
19- 21 A3 --- gps Indication of GPS and candidates
23- 26 F4.2 --- z ?=- Redshift
28- 34 F7.1 MHz Fpeak Frequency in the observer frame
36- 40 F5.3 --- SIb ?=- Spectral index of optically thick part of
the spectra (αbelow)
42- 46 F5.3 --- e_SIb ? Estimated rms uncertainty on SIb
48- 53 F6.3 --- SIa Spectral index of optically thin part of
the spectra (αabove)
55- 59 F5.3 --- e_SIa Estimated rms uncertainty on SIba
61- 63 F3.1 --- FHWM Value of FWHM in decades of frequency
65- 68 F4.1 % V4.8 Variability index at 4.8GHz (1)
70- 74 F5.1 % V7.7 Variability index at 7.7GHz (1)
76- 79 F4.1 % V11.2 Variability index at 11.2GHz (1)
81- 85 F5.1 % V21.7 Variability index at 21.7GHz (1)
--------------------------------------------------------------------------------
Note (1): A negative value of index may exist when the estimated error
is greater than the observed scatter of the data.
--------------------------------------------------------------------------------
History:
* 15-Oct-2012: From electronic version of the journal
* 20-Dec-2012: in table2, fluxes should be above 10Jy missed their
leftmost '1' (communicated by H. Andernach). Such fluxes are
marked with as '*' in the table.
(End) Patricia Vannier [CDS] 15-Oct-2012