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J/A+A/482/483     GHz-peaked spectrum (GPS) sources    (Torniainen+, 2008)

Cluster analyses of gigahertz-peaked spectrum sources with self-organising maps. Torniainen I., Tornikoski M., Turunen M., Lainela M., Lahteenmaki A., Hovatta T., Mingaliev M.G., Aller M.F., Aller H.D. <Astron. Astrophys. 482, 483 (2008)> =2008A&A...482..483T
ADC_Keywords: QSOs ; Radio sources ; Photometry ; Polarization Keywords: galaxies: active - galaxies: quasars: general - radio continuum: galaxies Abstract: Gigahertz-peaked spectrum (GPS) sources and high frequency peakers (HFPs) are among the smallest of active galactic nuclei currently believed to represent the earliest phases in the evolution of extragalactic radio sources. Recently there has been evidence of contamination by other types of radio sources among the GPS and HFP samples, but the confirmed GPS sources or HFPs also seem to form a very heterogeneous population. We study the statistical clustering of the GPS sources and the HFPs by taking as many source parameters as possible to find homogeneous groups among the sources. We expect the clustering to give us insight into the physical parameters that play a role in different source populations. We have collected a sample of 206 GPS sources and HFPs from the literature and gathered a massive database of various source properties, such as the redshift, the size, the polarization, the magnitudes, and the properties of the radio continuum. To visualize and to cluster these multidimensional data we used self-organising maps (SOM), which are neural networks trained by an unsupervised algorithm. We have classified the sources with an auxiliary classification to trace the locations of different types of radio continuum spectra on the map. Description: Various properties of a sample of 206 gigahertz-peaked spectrum sources are presented together with their literature references. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table.dat 368 206 Data for each source refs.dat 74 64 References
Byte-by-byte Description of file: table.dat
Bytes Format Units Label Explanations
1- 10 A10 --- SRC Source name (HHMM+DDd/d) 12- 17 A6 --- ID Optical ID (1) 19- 25 A7 --- r_ID Reference for optical ID 26 A1 --- u_ID [)] Uncertainty flag on r_ID 27- 31 A5 --- OClass Original classification, as GPS or HFP (High- Frequency Peaker) 33- 39 A7 --- r_OClass Reference for original classification 41- 45 A5 --- Class Auxiliary classification (3) 47- 50 F4.2 --- z ?=9.99 Redshift 52- 57 A6 --- r_z Reference for redshift 58 A1 --- f_z [*] * for photometric redshift 60- 64 F5.2 kpc Szkpc ?=99.99 Size of the source 66- 71 A6 --- r_Szkpc Reference for size 72 A1 --- f_Szkpc [*] * for recalculated size (2) 74- 78 F5.2 [W/Hz] P5GHz ?=99.99 log(10) of source power at 5GHz (5) 80- 83 A4 --- r_P5GHz [calc] Reference for P5GHz 85- 89 F5.2 % polOpt ?=99.99 Optical polarization 91- 98 A8 --- r_polOpt Reference for optical polarization 100-104 F5.2 % polRad ?=99.99 Radio polarization 106-112 A7 --- r_polRad Reference for radio polarization 113 A1 --- f_polRad [*] * for zuk99 and step95 reference 114-119 A6 --- n_polRad Note on polRad 121-125 F5.2 mag Bmag ?=99.99 B magnitude 127-131 A5 --- r_Bmag Reference for B magnitude 133-137 F5.2 mag Vmag ?=99.99 V magnitude 139-144 A6 --- r_Vmag Reference for V magnitude 146-150 F5.2 mag Rmag ?=99.99 R magnitude 152-158 A7 --- r_Rmag Reference for R magnitude 159 A1 --- f_Rmag [*] * when calculated from r magnitude 161-165 F5.2 mag Imag ?=99.99 I magnitude 167-172 A6 --- r_Imag Reference for I magnitude 173 A1 --- f_Imag [*] * when calculated from i magnitude 175-179 F5.2 mag V-R ?=99.99 V-R colour index 181-185 A5 --- r_V-R Reference for V-R colour 187-191 F5.2 mag B-V ?=99.99 B-V colour index 193-196 A4 --- r_B-V Reference for B-V colour 198-202 F5.2 mag U-B ?=99.99 U-B colour index 204-207 A4 --- r_U-B [vv03] Reference for U-B colour 209-212 F4.2 mag R-I ?=9.99 R-I colour index 214-219 A6 --- r_R-I Reference for R-I colour 221-225 F5.2 GHz Freq ?=99.99 Rest-frame frequency of the turnover of the spectrum 227-231 F5.2 --- ab ?=99.99 Spectral index below the turnover 233-238 F6.2 --- aa ?=999.99 Spectral index above the turnover 240-245 F6.2 --- symm ?=999.99 Symmetry of the spectrum 247-251 F5.2 --- curv ?=99.99 Curvature of the spectrum 253-257 F5.2 --- FWHM ?=99.99 Full width at half maximum of the spectrum 259-264 F6.2 --- Mid ?=999.99 Mid-frequency of the bin used in calculations 266-270 F5.2 --- VI ?=99.99 Variability index 272-275 I4 --- o_VI ?=9999 Number of data points used for VI 277-283 F7.2 10+22cm-2 NHX ?=9999.99 Hydrogen column density in X-rays 285-289 A5 --- r_NHX Reference for NHX 291-294 F4.2 --- Gamma ?=9.99 Power-law slope in X-rays 296-300 A5 --- r_Gamma Reference for power-law slope in X-rays 302-306 F5.2 10+20cm-2 NH21 ?=99.99 Neutral hydrogen column density 308-313 A6 --- r_NH21 Reference for NH21 315-319 F5.2 mag Emag ?=99.99 E (photographic red) magnitude 321-327 A7 --- r_Emag reference for E magnitude 329-333 F5.2 mag Omag ?=99.99 O (photographic blue) magnitude 335-341 A7 --- r_Omag Reference for O magnitude 343-347 F5.2 mag O-E ?=99.99 O-E colour index 349-355 A7 --- r_O-E Reference for O-E colour 357-361 A5 --- Morph VLBI morphology (4) 363-368 A6 --- r_Morph Reference for VLBI morphology
Note (1): Optical identification as follows: BLO = BL Lac object BLO/G = BL Lac object/galaxy EF = empty field GAL = galaxy GA/QS = galaxy/QSO HPQ = high polarization quasar LPQ = low polarization quasar LPQ&bl = low polarization quasar and bl S = stellar QSO = quasar Note (2): Unless otherwise stated * means that the linear size has been recalculated from the angular size with H0=71km/s/Mpc, OmegaM=0.27, Omegavac=0.73 with Edward L. Wright's Cosmology Calculator (http://www.astro.ucla.edu/~wright/CosmoCalc.html). Note (3): Auxiliary classification as follows: n = not enough data for GPS identification s = steep spectrum f = flat spectrum f/s = flat at low frequencies, steep at high frequencies c = convex spectrum idb = inverted during bursts v = variability of Var_DeltaS>3 gps = gigahertz peaked spectrum Note (4): VLBI morphology as follows: cd = compact double cj = core-jet object cj/cd = core-jet object/compact double cso = compact symmetric object ct = compact triple cx = complex gl = gravitational lens ln = linear s = stellar unres = unresolved mr = marginally resolved p = point-like Note (5): Unit [W/Hz] was not specified in the paper.
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Ref Reference code 9- 27 A19 --- BibCode BibCode 29- 50 A22 --- Aut Author's name 52- 74 A23 --- Com Comments
Acknowledgements: I. Torniainen, ilo(at)kurp.hut.fi
(End) I. Torniainen [Metsahovi Radio Obs.], Patricia Vannier [CDS] 28-Feb-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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