An optical spectroscopic survey of the 3CR sample of radio galaxies with z<0.3. V. Implications for the unified model for FRIIs

We explore the implications of our optical spectroscopic survey of 3CR radio sources with z < 0.3 for the unified model (UM) for radio-loud AGN, focusing on objects with a "edge-brightened" (FR II) radio morphology. The sample contains 33 high ionization galaxies (HIGs) and 18 broad line objects (BLOs). According to the UM, HIGs, the narrow line sources, are the nuclearly obscured counterparts of BLOs. The fraction of HIGs indicates a covering factor of the circumnuclear matter of 65% that corresponds, adopting a torus geometry, to an opening angle of 50\ub0 \ub1 5. No dependence on redshift and luminosity on the torus opening angle emerges. We also consider the implications for a "clumpy" torus. The distributions of total radio luminosity of HIGs and BLOs are not statistically distinguishable, as expected from the UM. Conversely, BLOs have a radio core dominance, R, more than ten times larger with respect to HIGs, as expected in case of Doppler boosting when the jets in BLOs are preferentially oriented closer to the line of sight than in HIGs. Modeling the R distributions leads to an estimate of the jet bulk Lorentz factor of \u393 ~ 3-5. The test of the UM based on the radio source size is not conclusive due to the limited number of objects and because the size distribution is dominated by the intrinsic scatter rather than by projection effects. The [O II] line luminosities in HIGs and BLOs are similar but the [O III] and [O I] lines are higher in BLOs by a factor of ~2. We ascribe this effect to the presence of a line emitting region located within the walls of the obscuring torus, visible in BLOs but obscured in HIGs, with a density higher than the [O II] critical density. We find evidence that BLOs have broader [O I] and [O III] lines than HIGs of similar [O II] width, as expected in the presence of high density gas in the proximity of the central black hole. In conclusion, the radio and narrow line region (NLR) properties of HIGs and BLOs are consistent with the UM predictions when the partial obscuration of the NLR is taken into account. We also explored the radio properties of 21 3CR low ionization galaxies with a FR II radio morphology at z < 0.3. We find evidence that they cannot be part of the model that unifies HIGs and BLOs, but they are instead intrinsically different source, still reproduced by a randomly oriented population

Herschel -ATLAS: Extragalactic number counts from 250 to 500 microns

Aims. The Herschel-ATLAS survey (H-ATLAS) will be the largest area survey to be undertaken by the Herschel Space Observatory. It will cover 550 sq. deg. of extragalactic sky at wavelengths of 100, 160, 250, 350 and 500 μm when completed, reaching flux limits (5σ) from 32 to 145 mJy. We here present galaxy number counts obtained for SPIRE observations of the first ~14 sq. deg. observed at 250, 350 and 500 μm. Methods. Number counts are a fundamental tool in constraining models of galaxy evolution. We use source catalogs extracted from the H-ATLAS maps as the basis for such an analysis. Correction factors for completeness and flux boosting are derived by applying our extraction method to model catalogs and then applied to the raw observational counts. Results. We find a steep rise in the number counts at flux levels of 100–200 mJy in all three SPIRE bands, consistent with results from BLAST. The counts are compared to a range of galaxy evolution models. None of the current models is an ideal fit to the data but all ascribe the steep rise to a population of luminous, rapidly evolving dusty galaxies at moderate to high redshift

Herschel-ATLAS: Evolution of the 250 μm luminosity function out to z = 0.5

We have determined the luminosity function of 250 μm-selected galaxies detected in the ~14 deg2 science demonstration region of the Herschel-ATLAS project out to a redshift of z = 0.5. Our findings very clearly show that the luminosity function evolves steadily out to this redshift. By selecting a sub-group of sources within a fixed luminosity interval where incompleteness effects are minimal, we have measured a smooth increase in the comoving 250 μm luminosity density out to z = 0.2 where it is 3.6-0.9+1.4 times higher than the local value.S.D. Acknowledges the UK STFC for support

Herschel-ATLAS: The angular correlation function of submillimetre galaxies at high and low redshift

We present measurements of the angular correlation function of galaxies selected from the first field of the H-ATLAS survey. Careful removal of the background from galactic cirrus is essential, and currently dominates the uncertainty in our measurements. For our 250 μm-selected sample we detect no significant clustering, consistent with the expectation that the 250 μm-selected sources are mostly normal galaxies at z <∼ 1. For our 350 μm and 500 μm-selected samples we detect relatively strong clustering with correlation amplitudes A of 0.2 and 1.2 at 1’, but with relatively large uncertainties. For samples which preferentially select high redshift galaxies at z ∼ 2−3 we detect significant strong clustering, leading to an estimate of r0 ∼ 7−11 h−1 Mpc. The slope of our clustering measurements is very steep, δ ∼ 2. The measurements are consistent with the idea that sub-mm sources consist of a low redshift population of normal galaxies and a high redshift population of highly clustered star-bursting galaxie

Herschel-ATLAS: Dust temperature and redshift distribution of SPIRE and PACS detected sources using submillimetre colours

We present colour-colour diagrams of detected sources in the Herschel-ATLAS science demonstration field from 100 to 500μm using both PACS and SPIRE. We fit isothermal modified black bodies to the spectral energy distribution (SED) to extract the dust temperature of sources with counterparts in Galaxy And Mass Assembly (GAMA) or SDSS surveys with either a spectroscopic or a photometric redshift. For a subsample of 330 sources detected in at least three FIR bands with a significance greater than 3σ, we find an average dust temperature of (28±8) K. For sources with no known redshift, we populate the colour-colour diagram with a large number of SEDs generated with a broad range of dust temperatures and emissivity parameters, and compare to colours of observed sources to establish the redshift distribution of this sample. For another subsample of 1686 sources with fluxes above 35 mJy at 350μm and detected at 250 and 500μm with a significance greater than 3σ we find an average redshift of 2.2 ±0.6Amblard, Barton, Cooray, Leeuw, Serra and Temi acknowledge support from NASA funds for US participants in Herschel through JPL. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Web Site is http://www.sdss.org/. The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The UKIDSS project is defined in Lawrence et al. (2007)

Herschel -ATLAS: The dust energy balance in the edge-on spiral galaxy UGC 4754

We use Herschel PACS and SPIRE observations of the edge-on spiral galaxy UGC 4754, taken as part of the H-ATLAS SDP observations, to investigate the dust energy balance in this galaxy. We build detailed SKIRT radiative models based on SDSS and UKIDSS maps and use these models to predict the far-infrared emission. We find that our radiative transfer model underestimates the observed FIR emission by a factor of two to three. Similar discrepancies have been found for other edge-on spiral galaxies based on IRAS, ISO, and SCUBA data. Thanks to the good sampling of the SED at FIR wavelengths, we can rule out an underestimation of the FIR emissivity as the cause for this discrepancy. Instead we support highly obscured star formation that contributes little to the optical extinction as a more probable explanation.This work used data from the UKIDSS DR5 and SDSS DR7. The UKIDSS project is defined in Lawrence et al. (2007) and uses the UKIRT Wide Field Camera (WFCAM; Casali et al. 2007). Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England

Herschel*-ATLAS: deep HST/WFC3 imaging of strongly lensed submillimetre galaxies

We report on deep near-infrared observations obtained with the Wide Field Camera-3 (WFC3) onboard the Hubble Space Telescope (HST) of the first five confirmed gravitational lensing events discovered by the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We succeed in disentangling the background galaxy from the lens to gain separate photometry of the two components. The HST data allow us to significantly improve on previous constraints of the mass in stars of the lensed galaxy and to perform accurate lens modelling of these systems, as described in the accompanying paper by Dye et al. We fit the spectral energy distributions of the background sources from near-IR to millimetre wavelengths and use the magnification factors estimated by Dye et al. to derive the intrinsic properties of the lensed galaxies. We find these galaxies to have star-formations rates (SFR) ∼ 400–2000 M⊙ yr−1, with ∼(6–25) × 1010 M⊙ of their baryonic mass already turned into stars. At these rates of star formation, all remaining molecular gas will be exhausted in less than ∼100 Myr, reaching a final mass in stars of a few 1011 M⊙. These galaxies are thus proto-ellipticals caught during their major episode of star formation, and observed at the peak epoch (z ∼ 1.5–3) of the cosmic star formation history of the Universe