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. =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=-[log_10_(S1400)-log_10_(S151)]/[log_10_(1400)-log_10_(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. , 1990, Cat. ), 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