J/MNRAS/493/2841 Faint radio source population at 15.7GHz - IV (Whittam+, 2020) ================================================================================ The faint radio source population at 15.7 GHz IV. The dominance of core emission in faint radio galaxies. Whittam I.H., Green D.A., Jarvis M.J., Riley J.M. =2020MNRAS.493.2841W (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Galaxies, radio ; Radio continuum ; Active gal. nuclei ; Photometry, ugriz ; Photometry, infrared ; Redshifts Keywords: catalogues - surveys - galaxies: active - radio continuum: galaxies Abstract: We present 15-GHz Karl G. Jansky Very Large Array observations of a complete sample of radio galaxies selected at 15.7GHz from the Tenth Cambridge (10C) survey. 67 out of the 95 sources (71 per cent) are unresolved in the new observations and lower frequency radio observations, placing an upper limit on their angular size of ~2arcsec. Thus, compact radio galaxies, or radio galaxies with very faint jets, are the dominant population in the 10C survey. This provides support for the suggestion in our previous work that low-luminosity (L<10^25^WHz^-1^) radio galaxies are core dominated, although higher resolution observations are required to confirm this directly. The 10C sample of compact, high-frequency selected radio galaxies is a mixture of high-excitation and low-excitation radio galaxies and displays a range of radio spectral shapes, demonstrating that they are a mixed population of objects. Description: This work is based on a sample selected from the 10C survey at 15.7GHz. The 10C survey was observed with the Arcminute Microkelvin Imager (AMI; Zwart et al. 2008MNRAS.391.1545Z) Large Array and covers 27deg^2^ complete to 1mJy in 10 different fields, and a further 12deg^2^ complete to 0.5mJy contained within these fields. Here, we use a complete sample of 96 sources selected from a region of the 10C survey in the Lockman Hole with particularly good low-frequency data available. There is a wealth of multiwavelength data available in the Lockman Hole, most of which is contained in the 'SERVS Data Fusion' catalogue (Vaccari 2015fers.confE..27V), a multiwavelength catalogue selected in the mid-infrared. In the Lockman Hole, this catalogue contains data from the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE; see Lonsdale et al. 2003PASP..115..897L), the Spitzer Extragalactic Representative Volume Survey (SERVS; see Mauduit et al. 2012PASP..124..714M), and the United Kingdom Infrared Telescope Infrared Deep Sky Survey (see Lawrence et al. 2007MNRAS.379.1599L, Cat. II/314). The new data were taken with the Karl G. Jansky VLA in C configuration in the Ku band. Pointed observations were made of the 96 sources in the sample. The 75 sources with S_10C_>0.75mJy (S_10C_ is the 15-GHz peak flux density from the 10C catalogue) were observed for 50s on source. The fainter sources with S_10C_<0.75mJy (21 sources) were observed for a time scaled according to the 10C peak flux density of each source. The observations were split into two scheduling blocks (SBs) containing 42 and 54 sources, and these were observed on 2017 May 31 and 2017 June 11, respectively. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 99 95 Properties of the sources in this sample based on the new VLA observations tableb1.dat 180 95 Host galaxy catalogue -------------------------------------------------------------------------------- See also: J/MNRAS/429/2080 : Lockman Hole 10C sources radio spectral indices (Whittam+ 2013) J/MNRAS/453/4244 : Faint radio source population at 15.7GHz (Whittam+, 2015) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 19 A19 --- Name Source name (10C JHHMMSS+DDMMSS) 21- 22 I2 h RAh Right ascension (J2000) 24- 25 I2 min RAm Right ascension (J2000) 27- 32 F6.3 s RAs Right ascension (J2000) 34 A1 --- DE- Declination sign (J2000) 35- 36 I2 deg DEd Declination (J2000) 38- 39 I2 arcmin DEm Declination (J2000) 41- 45 F5.2 arcsec DEs Declination (J2000) 47- 53 F7.4 mJy Speak Peak flux density in VLA image 55- 59 F5.3 mJy e_Speak Error on Speak 61- 66 F6.3 mJy Sint Integrated flux density in VLA image 68- 72 F5.3 mJy e_Sint Error on Sint 74 I1 --- Ncomp Number of components source is resolved into 76- 78 I3 uJy/beam rms Local rms noise in VLA image (measured in a 100x100 pixel box away from the source) 80- 84 F5.3 mJy Score ? Flux density of core component 86- 90 F5.1 arcsec theta Angular size of source measured at 15 GHz 92 A1 --- f_theta [0/1] Flag on theta (1) 94- 99 A6 --- FRclass Morphological classification (2) -------------------------------------------------------------------------------- Note (1): Flag as follows: 0 = True value 1 = Upper limit Note (2): Classification as follows: FR0/I = Compact radio galaxy or Fanaroff and Riley type I source (3/95) FR0c = Candidate compact steep spectrum (CSS) source (13/95) FR0g = Candidate GHz-peaked spectrum (GPS) source (8/95) FR0u = Uncertain compact source (46/95) FRI = Fanaroff and Riley type I source (6/95) FRI/II = FRI or FRII source (1/95) FRII = Fanaroff and Riley type II source (17/95) SFG = Star-forming galaxy (1/95) -------------------------------------------------------------------------------- Byte-by-byte Description of file: tableb1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 19 A19 --- Name Source name (10C JHHMMSS+DDMMSS) 21- 25 F5.2 mag gmag ? g-band magnitude 27- 31 F5.3 mag e_gmag ? Error on gmag 33- 37 F5.2 mag imag ? i-band magnitude 39- 43 F5.3 mag e_imag ? Error on imag 45- 49 F5.2 mag rmag ? r-band magnitude 51- 55 F5.3 mag e_rmag ? Error on rmag 57- 60 F4.1 mag zmag ? z-band magnitude 62- 66 F5.3 mag e_zmag ? Error on zmag 68- 72 F5.2 mag Jmag ? J-band magnitude 74- 77 F4.2 mag e_Jmag ? Error on Jmag 79- 83 F5.2 mag Kmag ? K-band magnitude 85- 88 F4.2 mag e_Kmag ? Error on Kmag 90- 96 F7.2 uJy SERVS1 ? SERVS 3.6um magnitude 98-101 F4.2 uJy e_SERVS1 ? Error on SERVS1 103-108 F6.2 uJy SERVS2 ? SERVS 4.5um magnitude 110-113 F4.2 uJy e_SERVS2 ? Error on SERVS2 115-121 F7.2 uJy SWIRE1 ? SWIRE 3.6um magnitude 123-126 F4.2 uJy e_SWIRE1 ? Error on SWIRE1 128-133 F6.2 uJy SWIRE2 ? SWIRE 4.5um magnitude 135-138 F4.2 uJy e_SWIRE2 ? Error on SWIRE2 140-145 F6.2 uJy SWIRE3 ? SWIRE 5.8um magnitude 147-150 F4.2 uJy e_SWIRE3 ? Error on SWIRE3 152-158 F7.2 uJy SWIRE4 ? SWIRE 8.0um magnitude 160-163 F4.2 uJy e_SWIRE4 ? Error on SWIRE4 165-168 F4.2 --- z ? Final redshift value 170 I1 --- r_z [1/4]? Reference for z (1) 172 A1 --- Optcomp [EP ] Source extension (2) 174 A1 --- Lacy [YN ] Indicates if the source is located inside the Lacy et al. (2004ApJS..154..166L) area (3) 176 A1 --- Xray [YN ] Indicates if the source is detected by an X-ray survey (4) 178 A1 --- SpClass [HL ] Spectral classification (5) 180 A1 --- Class [HL ] Overall HERG (H) or LERG (L) classification -------------------------------------------------------------------------------- Note (1): Flag as follows: 1 = Spectroscopic redshift 2 = Rowan-Robinson et al. (2013MNRAS.428.1958R, Cat. II/326) 3 = Fotopoulou et al. (2012ApJS..198....1F, Cat. J/ApJS/198/1) 4 = Photometric redshift obtained using LE PHARE code (Arnouts et al. 1999MNRAS.310..540A) Note (2): Extension as follows: E = Extended source (58/95) P = Point-like (8/95) Note (3): Classification as follows: Y = The source is located inside the Lacy et al. (2004ApJS..154..166L) area on the mid-infrared colour-colour diagram (23/95) N = The source is located outside this region (including sources with limits that must lie outside this region) (38/95) Note (4): X-ray detection as follows: Y = The source is detected by an X-ray survey (15/95) N = The source lies inside X-ray survey area but is not detected (16/95) Note (5): Spectral class as follows: H = The source is classified as a high-excitation radio galaxy (HERG) based on its optical spectrum (7/95) L = The source is classified as a low-excitation radio galaxy (LERG) based on its optical spectrum (15/95) -------------------------------------------------------------------------------- History: From electronic version of the journal References: Whittam et al., Paper I 2013MNRAS.429.2080W, Cat. J/MNRAS/429/2080 Whittam et al., Paper II 2015MNRAS.453.4244W, Cat. J/MNRAS/453/4244 Whittam et al., Paper III 2016MNRAS.462.2122W ================================================================================ (End) Ana Fiallos [CDS] 19-Apr-2023