Sample Overview

    The original 2Jy sample (Wall and Peacock 1985) includes all the radio sources with flux density above 2Jy at 2.7GHz . We have studied a sub-sample of this that encompasses the southern part (delta<+10 degrees; z<0.7) of this catalogue to study in detail the relationship between the radio, optical, infrafed and X-ray properties of the sample. The 2Jy full sample consists of 88 objects: 68 galaxies, 18 quasars and 2 BL Lac objects and outlined with the optical spectroscopic data in Tadhunter et al. (1993) and with the radio data in Morganti et al. (1993).

The full 2Jy sample

The full 2Jy sample of 88 objects has the following database available:

1) radio data: data from the VLA and the Australia Telescope Compact Array (ATCA) have been obtained at 5 GHz (resolution ~3 arcsec, see Morganti et al. 1993 and 1999 for details). These data, together with some collected from literature, have allowed a morphological classification of the sources according to Fanaroff & Riley (1974). An estimate of the core flux densities was obtained from PTI observations (Morganti et al. 1997). This is important because it allows us to derive the parameter R (ratio of the core to the extended radio flux density) that is believed to be an important indicator of orientation. VLBI observations have been taken for a number of objects including all the Compact Steep Spectrum (CSS) sources (Venturi et al. 1996, Tzioumis et al. 1996).

2) optical (spectroscopic) data: all the objects in the sample have a measurement (either a detection or an upper limit) for the [OIII]5007 emission line (Tadhunter et al. 1993 and 1998). The [OII]3727 was measured in 47 objects, and a measurement of Hbeta is available for 40 objects. Measurements of the flux and colour of the optical continuum have also been obtained. We also have broad-band polarimetry for the radio galaxies with redshift between 0.15 and 0.7 (Tadhunter et al. 1997).

3) X-ray data: ROSAT data in the 0.1--2.4 keV energy band from the survey and from (public) pointed observations have been retrieved in order to determine the soft X-ray luminosities (Siebert et al. 1996). Using a maximum- likelihood source-detection algorithm we could detect 50 out of the 88 sources in the sample and a reliable upper limit could be set for the remaining 38.Observations were also done on some objects using the italian-dutch X-ray satellite SAX.

The steep-spectrum sub-sample

    In order to maximize the potential of our investigations we have focused our recent observation campaigns on a sub-sample of 46 objects. This sample was originally selected for our Spitzer campaign in order to avoid objects with strong flat-spectrum radio cores: the steep-spectrum selection for the quasars rules out objects dominated by emission from the beamed relativistic jet and core components. The sample comprises all 46 steep-spectrum powerful radio galaxies and quasars with redshifts 0:05 < z < 0:7 and flux densities S2.7 GHz > 2 Jy from the sample of Tadhunter et al. (1993). We define the steep-spectrum selection as α4.82.7 GHz > 0.5 (Fν   ν), which excludes 16 objects within the redshift range. We have also included PKS 0347+05, which has since proved to fulfill the same selection criteria (di Serego- Alighieri et al. 1994). The lower redshift limit has been set to ensure that these galaxies are genuinely powerful sources. Including the data described above the 2Jy sub-sample of 46 objects has the following database available:

  1. 1)Chandra (complete z<0.3) and XMM X-ray observations - (Mingo et al. 2014, In press)

  2. 2)Optical imaging with GEMINI G-MOS-S - (Ramos Almeida et al. 2011a)

  3. 3)Near-IR imaging with UKIRT UFTI - (Inskip et al. 2010)

  4. 4)Infrared Spitzer MIPS imaging and IRS spectroscopy - (Dicken et al. 2008; Dicken et al. 2012)

  5. 5)Far-infrared Herschel PACS and SPIRE photometry - (Dicken et al. 2014 in preperation)

  6. 6)Sub-mm observations with LABOCA - (Dicken et al. 2014 in preperation)

  7. 7)complete, high-frequency (15-25 GHz), radio core observations -

See data page for further details