Access to Astronomical Catalogues

← Click to display the menu
J/MNRAS/438/796     Local radio-galaxy population at 20GHz  (Sadler+, 2014)

The local radio-galaxy population at 20GHz. Sadler E.M., Ekers R.D., Mahony E.K., Mauch T., Murphy T. <Mon. Not. R. Astron. Soc., 438, 796-824 (2014)> =2014MNRAS.438..796S (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galaxies, radio Keywords: catalogues - surveys - galaxies: active - radio continuum: galaxies - radio continuum: general Abstract: We have made the first detailed study of the high-frequency radio-source population in the local Universe, using a sample of 202 radio sources from the Australia Telescope 20GHz (AT20G) survey identified with galaxies from the 6dF Galaxy Survey (6dFGS). The AT20G-6dFGS galaxies have a median redshift of z=0.058 and span a wide range in radio luminosity, allowing us to make the first measurement of the local radio luminosity function at 20GHz. Our sample includes some classical Fanaroff-Riley type I (FR I) and FR II radio galaxies, but most of the AT20G-6dFGS galaxies host compact (FR 0) radio active galactic nuclei which appear to lack extended radio emission even at lower frequencies. Most of these FR 0 sources show no evidence for relativistic beaming, and the FR 0 class appears to be a mixed population which includes young compact steep-spectrum and gigahertz peaked-spectrum radio galaxies. We see a strong dichotomy in the Wide-field Infrared Survey Explorer (WISE) mid-infrared colours of the host galaxies of FR I and FR II radio sources, with the FR I systems found almost exclusively in WISE 'early-type' galaxies and the FR II radio sources in WISE 'late-type' galaxies. The host galaxies of the flat- and steep-spectrum radio sources have a similar distribution in both K-band luminosity and WISE colours, though galaxies with flat-spectrum sources are more likely to show weak emission lines in their optical spectra. We conclude that these flat-spectrum and steep-spectrum radio sources mainly represent different stages in radio-galaxy evolution, rather than beamed and unbeamed radio-source populations. Description: We assembled the galaxy sample studied in this paper by matching radio sources from the AT20G survey catalogue (Murphy et al. 2010, Cat. J/MNRAS/402/2403) with nearby galaxies from the Third Data Release of the 6dF Galaxy Survey (6dFGS DR3; Jones et al., 2009, Cat. VII/259). The 6dFGS was chosen because it is a large-area survey well matched to the area covered by AT20G, and shallow enough in redshift that the effects of cosmic evolution within the sample volume can be neglected. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 157 202 6dFGS galaxies detected as AT20G radio sources.
See also: VII/250 : 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003) VIII/78 : Sydney University Molonglo Sky Survey (SUMSS) (Mauch+ 2006) VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998) J/MNRAS/329/227 : 2dF Galaxy Redshift Survey. II. (Sadler+, 2002) J/MNRAS/375/931 : Radio sources in the 6dFGS (Mauch+, 2007) J/MNRAS/402/2403 : Australia Tel. 20GHz Survey Catalog, AT20G (Murphy+, 2010) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1 A1 --- n_Name [ab] Note on Sources (1) 3- 16 A14 --- Name Source name from the AT20G catalogue (2) 19- 20 I2 h RAh Right ascension (J2000) (3) 22- 23 I2 min RAm Right ascension (J2000) (3) 25- 29 F5.2 s RAs Right ascension (J2000) (3) 32 A1 --- DE- Declination sign (J2000) (3) 33- 34 I2 deg DEd Declination (J2000) (3) 36- 37 I2 arcmin DEM Declination (J2000) (3) 39- 42 F4.1 arcsec DEm Declination (J2000) (3) 44- 48 I5 mJy S20 The catalogued 20 GHz flux density (4) 49- 52 I4 mJy e_S20 ?=- rms uncertainty on S20 54- 57 I4 mJy S8.4 ?=- Catalogued 8.4 GHz flux density (5) 58- 61 I4 mJy e_S8.4 ?=- rms uncertainty on S8.4 63- 66 I4 mJy S5 ?=- Catalogued 5 GHz flux density (5) 68- 70 I3 mJy e_S5 ?=- rms uncertainty on S5 72- 78 F7.1 mJy S1.4 ?=- For sources north of declination -40°, the total 1.4GHz flux density (6) 79- 86 F8.1 mJy S843 ?=- For sources south of declination -30°, the total 843MHz flux density (7) 89-103 A15 ---- 6dFGS 6dFGS name (gHHMMSSs+DDMMSS) 104 A1 --- l_Offset Limit flag on Offset 105-108 F4.1 arcsec Offset ?=- Offset between the AT20G and 6dFGS position 111-115 F5.2 mag Kmag 2MASS total infrared K-band magnitude Ktot (8) 118-123 F6.4 --- z Optical redshift, as listed in the 6dFGS catalogue (Jones et al. 2009, Cat. VII/259) 126 A1 --- q_z [234J-] 6dFGS redshift quality (9) 129-131 A3 --- Class Spectral classification for galaxies with a good-quality 6dFGS spectrum (10) 134-157 A24 --- Notes Notes
Note (1): Note as follows: a = 6dFGS galaxies identified with AT20G point sources b = 6dFGS galaxies identified with extended or multiple AT20G sources Note (2): For galaxies which are identified with two or more AT20G sources, we list a commonly-used source name instead. Note (3): The 20GHz radio position (J2000) as catalogued by Murphy et al. (2010, Cat. J/MNRAS/402/2403). Note (4): From (Murphy et al. 2010, Cat. J/MNRAS/402/2403). For sources with multiple AT20G components, we list the sum of the component flux densities. Note (5): From (Murphy et al. 2010, Cat. J/MNRAS/402/2403). Note (6): measured from the NVSS catalogue (Condon et al. 1998, Cat. VIII/65). For sources with more than one NVSS component the listed flux is the sum of the components, as described by Mauch & Sadler (2007, Cat. J/MNRAS/375/931). Note (7): measured from the SUMSS catalogue (Mauch et al. 2003, Cat. VIII/70). For sources with more than one SUMSS component the listed flux is the sum of the components. Note (8): from the 2MASS extended source catalogue (Jarrett et al., 2000AJ....120..298J), as listed in the 6dFGS database. Note (9): Quality code (Jones et al., 2004MNRAS.355..747J) as follows: 2 = possible, but doubtful redshift estimate 3 = probable redshift 4 = represents a reliable redshift J = SDSS and ZCAT sources (not a measure of quality) Note (10): Spectral classification code as follows: Aa = absorption-line spectrum, Aae = absorption lines plus weak emission lines, Ae = strong emission lines (see Sadler et al. 1999, Cat. VII/250; 2002, Cat. J/MNRAS/329/227)
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Jul-2017
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

catalogue service

© UDS/CNRS

Contact