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J/MNRAS/373/1531    6C** sample of steep-spectrum radio sources   (Cruz+, 2006)
The 6C** sample of steep-spectrum radio sources -
I. Radio data, near-infrared imaging and optical spectroscopy.
    Cruz M.J., Jarvis M.J., Blundell K.M., Rawlings S., Croft S.,
    Klockner H.-R., McLure R.J., Simpson C., Targett T.A., Willott C.J.
   <Mon. Not. R. Astron. Soc., 373, 1531-1562 (2006)>
   =2006MNRAS.373.1531C
ADC_Keywords: Radio sources

Keywords: galaxies: active - galaxies: evolution - galaxies: high-redshift -
          radio continuum: galaxies

Abstract:
    We present basic observational data on the 6C** sample. This is a new
    sample of radio sources drawn from the 151-MHz 6C survey, which was
    filtered with radio criteria chosen to optimize the chances of finding
    radio galaxies at z>4. The filtering criteria are a steep-spectral
    index and a small angular size. The final sample consists of 68
    sources from a region of sky covering 0.421sr. We present Very Large
    Array radio maps, and the results of K-band imaging and optical
    spectroscopy.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
tablea1.dat       88       68   The survey flux densities of the 6C** sources
                              and the spectral indices derived from these


See also:
    VIII/18 : 6C Survey of radio sources - I. (Baldwin+ 1985)
    VIII/21 : 6C Survey of radio sources - II. (Hales+ 1988)
    VIII/22 : 6C Survey of Radio Sources - III. (Hales+ 1990)
    VIII/23 : 6C Survey of radio sources - IV. (Hales+ 1991)
    VIII/24 : 6C Survey of Radio Sources - V. (Hales+ 1993)
    VIII/25 : 6C Survey of radio sources - VI. (Hales+ 1993)


Byte-by-byte Description of file: tablea1.dat

   Bytes Format Units   Label     Explanations

   1- 11  A11   ---     6C        6C source name (6CHHMM+DDMM, B1950)
  13- 14  I2    h       RAh       6C right ascension (J2000)
  16- 17  I2    min     RAm       6C right ascension (J2000)
  19- 22  F4.1  s       RAs       6C right ascension (J2000)
      24  A1    ---     DE-       6C declination sign (J2000)
  25- 26  I2    deg     DEd       6C declination (J2000)
  28- 29  I2    arcmin  DEm       6C declination (J2000)
  31- 32  I2    arcsec  DEs       6C declination (J2000)
  34- 35  I2    h       RAN.h     NVSS right ascension (J2000)
  37- 38  I2    min     RAN.m     NVSS right ascension (J2000)
  40- 43  F4.1  s       RAN.s     NVSS right ascension (J2000)
      45  A1    ---     DEN.-     NVSS declination sign (J2000)
  46- 47  I2    deg     DEN.d     NVSS declination (J2000)
  49- 50  I2    arcmin  DEN.m     NVSS declination (J2000)
  52- 53  I2    arcsec  DEN.s     NVSS declination (J2000)
  55- 59  F5.2  Jy      S151MHz   6C flux density at 151MHz
  61- 64  F4.2  Jy     e_S151MHz  rms uncertainty on S151MHz
  66- 71  F6.4  Jy      S1.4GHz   NVSS flux density at 1.4GHz
  73- 78  F6.4  Jy     e_S1.4GHz  rms uncertainty on S1.4GHz
  80- 83  F4.2  ---     alpha     Spectral index 1400MHz to 151MHz (1)
  85- 88  F4.2  ---     e_alpha   rms uncertainty on alpha

Note (1): Spectral indices are determined by:
           alpha=-[log10(S1400)-log10(S151)]/[log10(1400)-log10(151)]
    Error analysis on Parts II and III of the 6C catalogue shows that ∼60%
    of the sources have flux densities within ±40mJy of their true value
    (Hales et al. 1988, Cat. VIII/21, 1990, Cat. VIII/22), thus we
    take 40mJy as the typical error for the 6C flux densities quoted here.


History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    14-Aug-2007