Publication abstracts

Refereed Publications

48) ``The WiggleZ Dark Energy Survey: Survey Design and First Data Release'', Drinkwater, M.J., Jurek, R.J., Blake, C.A., Woods, D., Pimbblet, K.A., Glazebrook, K., Sharp, R., Pracy, M., Brough, S., Colless, M., Couch, W.J., Croom, S.M., Davis, T.M., Forbes, D., Forster, K., Gilbank, D.G., Gladders, M., Jelliffe, B., Jones, N., Li, I-h., Madore, B., Martin, D.C., Poole, G.B., Small, T., Wisnioski, E., Wyder, T., Yee, H.K.C., MNRAS, in press Postscript.

The WiggleZ Dark Energy Survey is a survey of 240,000 emission line galaxies in the distant universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The target galaxies are selected using ultraviolet photometry from the GALEX satellite, with a flux limit of NUV less than 22.8 mag. The redshift range containing 90 per cent of the galaxies is z=0.2--1.0. The primary aim of the survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4-8 Gyrs. Detailed forecasts indicate the survey will measure the BAO scale to better than 2% and the tangential and radial acoustic wave scales to approximately 3% and 5%, respectively. This paper provides a detailed description of the survey and its design, as well as the spectroscopic observations, data reduction, and redshift measurement techniques employed. It also presents an analysis of the properties of the target galaxies, including emission line diagnostics which show that they are mostly extreme starburst galaxies, and Hubble Space Telescope images, which show they contain a high fraction of interacting or distorted systems. In conjunction with this paper, we make a public data release of data for the first 100,000 galaxies measured for the project.

We present the QSO luminosity function of the completed 2dF-SDSS LRG and QSO (2SLAQ) survey, based on QSOs photometrically selected from Sloan Digital Sky Survey imaging data and then observed spectroscopically using the 2dF instrument on the Anglo-Australian Telescope. We analyse 10637 QSOs in the redshift range 0.4-z-2.6 to a g-band flux limit of 21.85 (extinction corrected) and an absolute continuum magnitude of Mg(z=2)-21.5. This sample covers an area of 191.9 sq deg. The binned QSO luminosity function agrees with that of the brighter SDSS main QSO sample, but extends 2.5 mags fainter, clearly showing the flattening of the luminosity function towards faint absolute magnitudes. 2SLAQ finds an excess of QSOs compared to the 2dF QSO Redshift Survey at g>20.0, as found previously by Richards et al. (2005). The luminosity function is consistent with other previous, much smaller, samples produced to the depth of 2SLAQ. By combining the 2SLAQ and SDSS QSO samples we produce a QSO luminosity function with an unprecedented combination of precision and dynamic range. With this we are able to accurately constrain both the bright and faint ends of the QSO LF. While the overall trends seen in the evolution of the QSO LF appear similar to pure luminosity evolution, the data show very significant departures from such a model. Most notably we see clear evidence that the number density of faint QSOs peaks at lower redshift than bright QSOs: QSOs with Mg>-23 have space densities which peak at z<1, while QSOs at Mg<-26 peak at z>2. By fitting simple luminosity function models in narrow Mg intervals we find that this downsizing is significant at the 99.98 per cent level

46) ``The Science Case for PILOT II: the Distant Universe'', Lawrence, J.S., Ashley, M.C.B., Bunker, A., Burgarlla, D., Burton, M.G., Gehrels, N., Glazebrook, K., Pimbblet, K.A., Quimby, R., Saunders, W., Storey, J.W.V., Wheeler, J.C., 2009, PASA, in press Postscript.

PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5 m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high photometric precision, wide-field, high spatial resolution, and high-cadence imaging capability to the PILOT telescope. These capabilities enable a unique scientificpotential for PILOT, which is addressed in this series of papers. The current paper presents a series of projects dealing with the distant (redshift greater than 1) Universe, that have been identified as key science drivers for the PILOT facility. The potential for PILOT to detect the first populations of stars to formin the early Universe, via infrared projects searching for pair-instability supernovae and gamma-ray burst afterglows, is investigated. Two projects are proposed to examine the assembly and evolution of structure in the Universe: an infrared survey searching for the first evolved galaxies at high redshift, and an optical survey aimed at characterising moderate-redshift galaxy clusters. Finally, a large-area weak-lensing survey and a program to obtain supernovae infrared light-curves are proposed to examine the nature and evolution of dark energy and dark matter.

45) ``The Science Case for PILOT I: Summary and Overview'', Lawrence, J.S., Ashley, M.C.B., Bailey, J., Barrado y Navascues, D., Bedding, T., Bland Hawthorn, J., Bond, I., Boulanger, F., Bouwens, R., Bruntt, H., Bunker, A., Burgarella, D., Burton, M.G., Busso, M., Coward, D., Cioni, M.-R., Durand, G., Eirona, C., Epchtein, N., Gehrels, N., Gillingham, P., Glazebrook, K., Haynes, R., Kiss, L., Lagage, P.O., Le Bertre, T., Mackay, C., Maillard, J.P., McGrath, A., Minier, V., Mora, A., Olsen, K., Persi, P., Pimbblet, K.A., Quimby, R., Saunders, W., Schmidt, B., Stello, D., Storey, J.W.V., Tinney, C., Tremblin, P., Wheeler, J.C., Yock, P., 2009, PASA, in press Postscript.

PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5 m optical/infrared telescope to be located at Dome C on the Antarctic plateau. Conditions at Dome C are known to be exceptional for astronomy. The seeing (above 30 m height), coherence time, and isoplanatic angle are all twice as good as at typical mid-latitude sites, while the water-vapour column, and the atmosphere and telescope thermal emission are all an order of magnitude better. These conditions enable a unique scientific capability for PILOT, which is addressed in this series of papers. The current paper presents an overview of the optical and instrumentation suite for PILOT and its expected performance, a summary of the key science goals and observational approach for the facility, a discussion of the synergies between the science goals for PILOT and other telescopes, and a discussion of the future of Antarctic astronomy. Paper II and Paper III present details of the science projects divided, respectively, between the distant Universe (i.e., studies of first light, and the assembly and evolution of structure) and the nearby Universe (i.e., studies of Local Group galaxies, the Milky Way, and the Solar System).

44) ``The Evolution of the Red Sequence Slope in Massive Galaxy Clusters'', Stott, J.P., Pimbblet, K.A., Edge, A.C., Smith, G.P., Wardlow, J.L., 2009, MNRAS, 394, 2098 Postscript.

We investigate the evolution of the optical and near-infrared colour-magnitude relation in an homogeneous sample of massive clusters from z = 1 to the present epoch. By comparing deep Hubble Space Telescope ACS imaging of X-ray selected MACS survey clusters at z = 0.5 to the similarly selected LARCS sample at z = 0.1 we find that the rest-frame d(U -V)/dV slope of the colour-magnitude relation evolves with redshift which we attribute to the build up of the red sequence over time. This rest frame slope evolution is not adequately reproduced by that predicted from semi-analytic models based on the Millennium Simulation despite a prescription for the build up of the red sequence by in-falling galaxies, 'strangulation'. We observe no strong correlation between this slope and the cluster environment at a given redshift demonstrating that the observed evolution is not due to a secondary correlation. Also presented are near-infrared UKIRT WFCAM observations of the LARCS clusters which confirm and improve on the the result from Stott et al. (2007) finding that there has been a two-fold increase in faint MV greater than -20 galaxies on the red sequence since z = 0.5 to a significance of 5sigma.

43) ``QSO-LRG 2-Point Cross-Correlation Function and Redshift-Space Distortions'', Mountrichas, G., Shanks, T., Croom, S.M., Sawangwit, U., Schneider, D.P., Myers, A.D., Pimbblet, K.A., 2009, MNRAS, 394, 2050 Postscript.

We have measured the bias of QSOs as a function of QSO luminosity at fixed redshift (z less than 1) by cross-correlating them with LRGs in the same spatial volume, hence breaking the degeneracy between QSO luminosity and redshift. We use three QSO samples from 2SLAQ, 2QZ and SDSS covering a QSO absolute magnitude range, M(bJ) between -24.5 to -21.5, and cross-correlate them with 2SLAQ (z=0.5) and AAOmega (z=0.7) photometric and spectroscopic LRGs in the same redshift ranges. The 2-D and 3-D cross-clustering measurements are generally in good agreement. Our (2SLAQ) QSO-LRG clustering amplitude (r_0=6.8_{-0.3}^{+0.1}h^{-1}Mpc) as measured from the semi-projected cross-correlation function appears similar to the (2SLAQ) LRG-LRG auto-correlation amplitude (r_0=7.45\pm0.35h^{-1}Mpc) and both are higher than the (2QZ+2SLAQ) QSO-QSO amplitude (r_0\simeq5.0h^{-1}Mpc). Our measurements show remarkably little QSO-LRG cross-clustering dependence on QSO luminosity. If anything, the results imply that brighter QSOs may be less highly biased than faint QSOs, the opposite direction expected from simple high peaks biasing models. Assuming a standard LCDM model and values for b_{LRG} measured from LRG autocorrelation analyses, we find b_Q=1.45\pm0.11 at M_{b_J}\approx-24 and b_Q=1.90\pm0.16 at M_{b_J}~-22. We also find consistent results for the QSO bias from a z-space distortion analysis of the QSO-LRG cross-clustering at z~0.55. The dynamical infall results give \beta _Q=0.55\pm0.10, implying b_Q=1.4\pm0.2. Thus both the z-space distortion and the amplitude analyses yield b_Q~1.5 at M_{b_J}~-23. The implied DM halo mass inhabited by QSOs at z~0.55 is \sim10^{13}h^{-1}M_{\sun}, again approximately independent of QSO luminosity.

42) ``The WiggleZ Dark Energy Survey: small-scale clustering of Lyman Break Galaxies at z less than 1'', Blake, C.A., Jurek, R.J., Brough, S., Colless, M., Couch, W., Croom, S., Drinkwater, M., Forbes, D., Glazebroook, K., Madore, B., Martin, C., Pimbblet, K.A., Poole, G.B., Pracy, M., Sharp, R.G., Small, T., Woods, D, Davis, T., 2009, MNRAS, 395, 240 Postscript.

The WiggleZ Dark Energy Survey is a large-scale structure survey of intermediate-redshift UV-selected emission-line galaxies scheduled to cover 1000 sq deg, spanning a broad redshift range 0.2 -- 1.0. The main scientific goal of the survey is the measurement of baryon acoustic oscillations (BAO) in the galaxy clustering pattern at a significantly higher redshift than previous studies. The BAO may be applied as a standard cosmological ruler to constrain dark energy models. Based on the first 20% of the dataset, we present initial results concerning the small-scale clustering of the WiggleZ targets, together with survey forecasts. The WiggleZ galaxy population possesses a clustering length r_0 = 5.23 +/- 0.15 Mpc/h, which is significantly larger than z=0 UV-selected samples, with a slope gamma = 1.82 +/- 0.07. This clustering length is comparable to z=3 Lyman Break Galaxies with similar UV luminosities. The full survey, scheduled for completion in 2010, will map an effective volume V_eff ~ 1 Gpc^3 (evaluated at a scale k = 0.15 h/Mpc) and will measure the angular-diameter distance and Hubble expansion rates in three redshift bins with accuracies ~ 5%. We will determine the value of a constant dark energy equation-of-state parameter, w, with a higher precision than existing supernovae observations using an entirely independent technique. The WiggleZ and supernovae measurements lie in highly complementary directions in the plane of w and the matter density Omega_m. The forecast using the full combination of WiggleZ, supernovae and CMB datasets is a marginalized error sigma(w) = 0.07, providing a robust and precise measurement of the properties of dark energy including cross-checking of systematic errors.

41) ``The 2dF-SDSS LRG and QSO Survey: The spectroscopic QSO catalogue'', Croom, S.M., Richards, G.T., Shanks, T., Boyle, B.J., Sharp, R.G., Bland-Hawthorn, J., Bridges, T., Brunner, R.J., Cannon, R., Carson, D., Chiu, K., Colless, M., Couch, W., De Propris, R., Drinkwater, M.J., Edge, A., Fine, S., Loveday, J., Miller, L., Myers, A.D., Nichol, R.C., Outram, P., Pimbblet, K.A., Roseboom, I., Ross, N., Schneider, D.P., Smith, A., Stoughton, C., Strauss, M.A., Wake, D., 2009, MNRAS, 392, 19-44 Postscript.

We present the final spectroscopic QSO catalogue from the 2dF-SDSS LRG and QSO (2SLAQ) Survey. This is a deep, 18

40) ``The WiggleZ Dark Energy Survey'', Blake, C., Brough, S., Couch, W., Glazebrook, K., Poole, G., Davis, T., Drinkwater, M., Jurek, R., Pimbblet, K.A., Colless, M., Sharp, R., Croom, S., Pracy, M., Woods, D., Madore, B., Martin, C., Wyder, T., 2008, A&G, 49, 5.19-5.24 PDF.

The accelerating expansion of the universe, attributed to ``dark energy'', has no accepted theoretical explanation. The origin of this phenomenon unambiguously implicates new physics via a novel form of matter exerting negative pressure or an alteration to Einstein's general relativity. These profound consequences have inspired a new generation of cosmological surveys that will measure the influence of dark energy using various techniques. One of the forerunners is the WiggleZ Survey at the Anglo-Australian Telescope, a new large-scale high-redshift galaxy survey that is now 50% complete and scheduled to finish in 2010. The WiggleZ project is aiming to map the cosmic expansion history using delicate features in the galaxy clustering pattern imprinted 13.7 billion years ago. In this article we outline the survey design and context, and predict the science highlights. Chris Blake and the WiggleZ team highlight the design and targets of this innovative survey.

39) ``Are Dumbbell Brightest Cluster Members Signposts to Galaxy Cluster Activity?'', Pimbblet, K.A., 2008, PASA, 25, 176-183 Postscript.

We assemble a sample of galaxy clusters whose brightest members are dumbbell galaxies and compare them with a control sample in order to investigate if they are the result of a recent mergers. We show that the dumbbell sample is no more likely than other clusters to exhibit subclustering. However, they are much more likely to have at least one dumbbell component possessing a significant peculiar velocity with respect to the parent cluster than a non-dumbbell brightest cluster member. We interpret this in the context of seeing the clusters at various stages of post-merger relaxation.

38) ``Constraining the quasar population with the broad-line width distribution'', Fine, S., Croom, S.M., Hopkins, P.F., Hernquist, L., Bland-Hawthorn, J., Colless, M., Hall, P.B., Miller, L., Myers, A.D., Nichol, R., Pimbblet, K.A., Ross, N.P., Schneider, D.P., Shanks, T., Sharp, R.G., 2008, MNRAS, 390, 1413-1429 Postscript.

We measure the width of the MgII lambda2799 line in quasar spectra from the SDSS, 2QZ and 2SLAQ surveys and, by invoking an unnormalised virial mass estimator, relate the scatter in line width to the scatter in mass in the underlying black hole population. We find conclusive evidence for a trend such that there is less scatter in line width, and hence black hole mass, in more luminous objects. However, the most luminous objects in our sample show such a low degree of scatter in line width that, when combined with measures for the intrinsic scatter in the radius-luminosity relation for the broad-line region in active galaxies, an inconsistency arises in the virial technique for estimating black hole masses. This analysis implies that, at least for the most luminous quasars, either there is little-to-no intrinsic scatter in the radius-luminosity relation or the MgII broad emission line region is not totally dominated by virial velocities. Finally we exploit the measured scatter in line widths to constrain models for the velocity field of the broad-line region. We show that the lack of scatter in broad line-widths for luminous quasars is inconsistent with a pure planar/disk-like geometry for the broad-line region... (abridged)

37) ``Star formation in galaxies falling into clusters along supercluster-scale filaments'', Porter, S., Raychaudhury, S., Pimbblet, K.A., Drinkwater, M.J., 2008, MNRAS, 388, 1152-1160 Postscript.

With the help of a statistical parameter derived from optical spectra, we show that the current star formation rate of a galaxy, falling into a cluster along a supercluster filament, is likely to undergo a sudden enhancement before the galaxy reaches the virial radius of the cluster. From a sample of 52 supercluster-scale filaments of galaxies joining a pair of rich clusters of galaxies within the two-degree Field Redshift Survey region, we find a significant enhancement of star formation, within a narrow range between 2-3 h/70 Mpc of the centre of the cluster into which the galaxy is falling. This burst of star formation is almost exclusively seen in the fainter dwarf galaxies (M_B> -20). The relative position of the peak does not depend on whether the galaxy is a member of a group or not, but non-group galaxies have on average a higher rate of star formation immediately before falling into a cluster. From the various trends, we conclude that the predominant process responsible for this rapid burst is the close interaction with other galaxies falling into the cluster along the same filament, if the interaction occurs before the gas reservoir of the galaxy gets stripped off due to the interaction with the intracluster medium.

36) ``The 2dF-SDSS LRG and QSO Survey: evolution of the clustering of luminous red galaxies since z = 0.6'', Wake, D.A., Sheth, R.K., Nichol, R.C., Baugh, C.M., Bland-Hawthorn, Joss, Colless, M., Couch, W.J., Croom, S.M., de Propris, R., Drinkwater, M.J., Edge, A.C., Loveday, J., Lam, T.Y., Pimbblet, K.A., Roseboom, I.G., Ross, N.P., Schneider, D.P., Shanks, T., Sharp, R.G., 2008, MNRAS, 387, 1045-1062 Postscript.

We present an analysis of the small-to-intermediate scale clustering of samples of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) and the 2dF-SDSS LRG and QSO Survey (2SLAQ) survey carefully matched to have the same rest-frame colours and luminosity. We study the spatial two-point autocorrelation function in both redshift space and real space of a combined sample of over 10000 LRGs, which represent the most massive galaxies in the universe with stellar masses >10^11h-1Msolar and space densities ~=10-4h3Mpc-3. We find no significant evolution in the amplitude (r0) of the correlation function with redshift, but do see a slight decrease in the slope with increasing redshift over 0.19 < z < 0.55 and scales of 0.32 < r < 32h-1Mpc. We compare our measurements with the predicted evolution of dark matter clustering and use the halo model to interpret our results. We find that our clustering measurements are inconsistent (>99.9 per cent significance) with a passive model whereby the LRGs do not merge with one another; a model with a merger rate of 7.5 +/- 2.3 per cent from z = 0.55 to 0.19 (i.e. an average rate of 2.4 per cent Gyr-1) provides a better fit to our observations. Our clustering and number density measurements are consistent with the hypothesis that the merged LRGs were originally central galaxies in different haloes which, following the merger of these haloes, merged to create a single brightest cluster galaxy. In addition, we show that the small-scale clustering signal constrains the scatter in halo merger histories. When combined with measurements of the luminosity function, our results suggest that this scatter is sub-Poisson. While this is a generic prediction of hierarchical models, it has not been tested before.

35) ``Luminous Red Galaxies in hierarchical cosmologies'', Almeida, C., Baugh, C.M., Wake, D.A., Lacey C.G., Benson, A.J., Bower R.G., Pimbblet, K.A., 2008, MNRAS, 386, 2145-2160 Postscript.

Luminous red galaxies (LRGs) are much rarer and more massive than L* galaxies. Coupled with their extreme colours, LRGs therefore provide a demanding testing ground for the physics of massive galaxy formation. We present the first self-consistent predictions for the abundance and properties of LRGs in hierarchical structure formation models. We test two published models which use quite different mechanisms to suppress the formation of massive galaxies: the Bower et al. (2006) model, which invokes ``AGN-feedback'' to prevent gas from cooling in massive haloes, and the Baugh et al. (2005) model which relies upon a ``superwind'' to eject gas before it is turned into stars. Without adjusting any parameters, the Bower et al. model gives an excellent match to the observed luminosity function of LRGs in the SDSS (with a median redshift of z=0.24) and to their clustering; the Baugh et al. model is less successful in these respects. Both models fail to match the observed abundance of LRGs at z=0.5 to better than a factor of 2. In the models, LRGs are typically bulge dominated systems with M* of 2x10^11 h^{-1} M_sun and velocity dispersions of 250 km s^{-1}. Around half of the stellar mass in the model LRGs is already formed by z=2.2 and is assembled into one main progenitor by z=1.5; on average, only 25 per cent of the mass of the main progenitor is added after z=1. LRGs are predicted to be found in a wide range of halo masses, a conclusion which relies on properly taking into account the scatter in the formation histories of haloes. Remarkably, we find that the correlation function of LRGs is predicted to be a power law down to small pair separations, in excellent agreement with observational estimates. Neither the Bower et al. nor the Baugh et al. model is able to reproduce the observed radii of LRGs.

34) ``Using a complete spectroscopic survey to find red quasars and test the KX method'', Jurek, R.J., Drinkwater, M.J., Francis, P., Pimbblet, K.A., 2008, MNRAS, 383, 673-682 Postscript.

We present an investigation of quasar colour-redshift parameter space in order to search for radio-quiet red quasars and to test the ability of a variant of the KX quasar selection method to detect quasars over a full range of colour without bias. This is achieved by combining IRIS2 imaging with the complete Fornax Cluster Spectroscopic Survey to probe parameter space unavailable to other surveys. We construct a new sample of 69 quasars with measured bJ - K colours. We show that the colour distribution of these quasars is significantly different from that of the Large Bright Quasar Survey's quasars at a 99.9 per cent confidence level. We find 11 of our sample of 69 quasars have signifcantly red colours (bJ - K greater than 3.5) and from this, we estimate the red quasar fraction of the K less than 18.4 quasar population to be 31 per cent, and robustly constrain it to be at least 22 per cent. We show that the KX method variant used here is more effective than the UVX selection method, and has less colour bias than optical colour-colour selection methods.

33) ``The 2dF-SDSS LRG and QSO survey: QSO clustering and the L-z degeneracy'', da Ângela, J., Shanks, T., Croom, S.M., Weilbacher, P., Brunner, R.J., Couch, W.J., Miller, L., Myers, A.D., Nichol, R.C., Pimbblet, K.A., de Propris, R., Richards, G.T., Ross, N.P., Schneider, D.P., Wake, D., 2008, MNRAS, 383, 565-580 Postscript.

We combine the quasi-stellar object (QSO) samples from the 2dF QSO Redshift Survey (2QZ) and the 2dF-Sloan Digital Sky Survey luminous red galaxy (LRG) and QSO Survey (2dF-SDSS LRG and QSO, hereafter 2SLAQ) in order to investigate the clustering of z = 1.5 QSOs and measure the correlation function. The clustering signal in redshift-space and projected along the sky direction is similar to that previously obtained from the 2QZ sample alone. By fitting functional forms for the correlation function(sigma, pi), the correlation function measured along and across the line of sight, we find, as expected, that Beta, the dynamical infall parameter and Omega M, the cosmological density parameter, are degenerate. However, this degeneracy can be lifted by using linear theory predictions under different cosmological scenarios. Using the combination of the 2QZ and 2SLAQ QSO data, we obtain: Beta QSO(z = 1.5) = 0.60+0.14-0.11, Omega M = 0.25+0.09-0.07 which imply a value for the QSO bias, b(z = 1.4) = 1.5 +/-0.2.

The combination of the 2QZ with the fainter 2SLAQ QSO sample further reveals that QSO clustering does not depend strongly on luminosity at fixed redshift. This result is inconsistent with the expectation of simple `high peaks' biasing models where more luminous, rare QSOs are assumed to inhabit higher mass haloes. The data are more consistent with models which predict that QSOs of different luminosities reside in haloes of similar mass. By assuming ellipsoidal models for the collapse of density perturbations, we estimate the mass of the dark matter haloes which the QSOs inhabit as ~3 × 1012h-1Msolar. We find that this halo mass does not evolve strongly with redshift nor depend on QSO luminosity. Assuming a range of relations which relate halo to black hole mass, we investigate how black hole mass correlates with luminosity and redshift, and ascertain the relation between Eddington efficiency and black hole mass. Our results suggest that QSOs of different luminosities may contain black holes of similar mass.

32) ``Intrinsic galaxy alignments from the 2SLAQ and SDSS surveys: luminosity and redshift scalings and implications for weak lensing surveys'', Hirata, C.M., Mandelbaum, R., Ishak, M., Seljak, U., Nichol, R., Pimbblet, K.A., Ross, N.P., Wake, D.A., 2007, MNRAS, 381, 1197-1218 Postscript.

Correlations between intrinsic shear and the density field on large scales, a potentially important contaminant for cosmic shear surveys, have been robustly detected at low redshifts with bright galaxies in SDSS data. Here we present a more detailed characterization of this effect, which can cause anti-correlations between gravitational lensing shear and intrinsic ellipticity (GI correlations). This measurement uses 36278 Luminous Red Galaxies (LRGs) from the SDSS spectroscopic sample with 0.15-z-0.35, split by redshift and luminosity; 7758 LRGs from the 2SLAQ Survey at 0.4-z-0.8; and a variety of other SDSS samples from previous, related work. We find 3sigma detections of the effect for all galaxy subsamples within the SDSS LRG sample; for the 2SLAQ sample, we find a 2sigma detection for a bright subsample, and no detection for a fainter subsample. Fitting formulae are provided for the scaling of the GI correlations with luminosity, transverse separation, and redshift. We estimate contamination in the measurement of sigma8 for future cosmic shear surveys on the basis of the fitted dependence of GI correlations on galaxy properties. We find contamination to the power spectrum ranging from -1.5 (optimistic) to -33 per cent (pessimistic) for a toy cosmic shear survey using all galaxies to a depth of R=24 using scales l~500. This corresponds to a bias in sigma8 of Delta sigma8=-0.004 (optimistic), -0.02 (central), or -0.10 (pessimistic). We provide a prescription for inclusion of this error in cosmological parameter estimation codes. The principal uncertainty is in the treatment of the fainter than L* blue galaxies. Characterization of the tidal alignments of these galaxies, especially at redshifts relevant for cosmic shear, should be a high priority for the cosmic shear community. (Abridged)

31) ``The 2dF-SDSS LRG and QSO Survey: The 2-Point Correlation Function and Redshift-Space Distortions'', Ross, N.P., da Angela, J., Shanks, T., Wake, D.A., Cannon, R.D., Edge, A.C., Nichol, R.C., Outram, P.J., Colless, M., Couch, W.J., Croom, S.M., De Propris, R., Drinkwater, M.J., Eisenstein, D.J., Loveday, J., Pimbblet, K.A., Roseboom, I.G., Schneider, D.P., Sharp, R.G., Strauss, M.A., Weilbacher, P.M., 2007 MNRAS, 381, 573-588 Postscript.

We present a clustering analysis of Luminous Red Galaxies (LRGs) using nearly 9 000 objects from the final catalogue of the 2dF-SDSS LRG And QSO (2SLAQ) Survey. We measure the redshift-space two-point correlation function, xi(s), at the mean LRG redshift of z=0.55. A single power-law fits the deprojected correlation function, xi(r), with a correlation length of r_0=7.45+-0.35 Mpc and a power-law slope of gamma=1.72+-0.06 in the r=0.4--70 Mpc range. But it is in the LRG angular correlation function that the strongest evidence for non-power-law features is found where a slope of gamma=-2.17+-0.07 is seen at r=1--10 Mpc with a flatter gamma=-1.67+-0.03 slope apparent at r<~1 Mpc scales. We use the simple power-law fit to the galaxy xi(r) to model the redshift space distortions in the 2-D redshift-space correlation function, xi(sigma,pi). We fit for the LRG velocity dispersion, w_z, Omega_m and beta, where beta=Omega_m^0.6/b and b is the linear bias parameter. We find values of w_z=330kms^-1, Omega_m= 0.10+0.35-0.10 and beta=0.40+-0.05. These high redshift results, which incorporate the Alcock-Paczynski effect and the effects of dynamical infall, start to break the degeneracy between Omega_m and beta found in low-redshift galaxy surveys. This degeneracy is further broken by introducing an additional external constraint, the value of beta(z=0.1)=0.45 from 2dFGRS, and then considering the evolution of clustering from z~0 to z_LRG~0.55. With these combined methods we find Omega_m(z=0)=0.30+-0.15 and beta(z=0.55)=0.45+-0.05. Assuming these values, we find a value for b(z=0.55)=1.66+-0.35. We show that this is consistent with a simple ``high peaks'' bias prescription which assumes that LRGs have a constant co-moving density and their clustering evolves purely under gravity.

30) ``Radio galaxies in the 2SLAQ Luminous Red Galaxy Survey - I. The evolution of low-power radio galaxies to z ~ 0.7'', Sadler, E.M., Cannon, R.D., Mauch, T., Hancock, P.J., Wake, D.A., Ross, N., Croom, S.M., Drinkwater, M.J., Edge, A.C., Eisenstein, D., Hopkins, A.M., Johnston, H.M., Nichol, R., Pimbblet, K.A., de Propris, R., Roseboom, I.G., Schneider, D.P., Shanks, T., 2007, MNRAS, 381, 211-227 Postscript.

We have combined optical data from the 2dF-SDSS (Sloan Digital Sky Survey) LRG (Luminous Red Galaxy) and QSO (quasi-stellar object) (2SLAQ) redshift survey with radio measurements from the 1.4GHz VLA (Very Large Array) FIRST (Faint Images of the Radio Sky at Twenty-cm) and NVSS (NRAO VLA Sky Survey) surveys to identify a volume-limited sample of 391 radio galaxies at redshift 0.4 - z - 0.7. By determining an accurate radio luminosity function for luminous early-type galaxies in this redshift range, we can investigate the cosmic evolution of the radio-galaxy population over a wide range in radio luminosity. The low-power radio galaxies in our LRG sample (those with 1.4GHz radio luminosities in the range 1024 to 1025WHz-1, corresponding to Fanaroff-Riley I (FRI) radio galaxies in the local Universe) undergo significant cosmic evolution over the redshift range 0 - z - 0.7, consistent with pure luminosity evolution of the form (1 + z)k, where k = 2.0 +/- 0.3. Our results appear to rule out (at the 6-7\u03c3 level) models in which low-power radio galaxies undergo no cosmic evolution. The most powerful radio galaxies in our sample (with radio luminosities above 1026WHz-1) may undergo more rapid evolution over the same redshift range. The evolution seen in the low-power radio-galaxy population implies that the total energy input into massive early-type galaxies from active galactic nucleus (AGN) heating increases with redshift, and was at least 50 per cent higher at z = 0.55 (the median redshift of the 2SLAQ LRG sample) than in the local universe.

29) ``An Increase in the Faint Red Galaxy Population in Massive Clusters since z=0.5'', Stott, J.P., Smail, I., Edge, A.C., Ebeling, H., Smith, G.P., Kneib, J.-P., Pimbblet, K.A., 2007, ApJ, 661, 95-101 Postscript.

We compare the luminosity functions for red galaxies lying on the restframe (U-V) color-magnitude sequence in a homogeneous sample of ten X-ray luminous clusters from the MACS survey at z=0.5 to a similarly selected X-ray cluster sample at z=0.1. We exploit deep Hubble Space Telescope ACS imaging in the F555W and F814W passbands of the central 1.2-Mpc diameter regions of the distant clusters to measure precise colors for the galaxies in these regions and statistically correct for contamination by field galaxies using observations of blank fields. We apply an identical analysis to ground-based photometry of the z=0.1 sample. This comparison demonstrates that the number of faint, MV=-19, red galaxies relative to the bright population seen in the central regions of massive clusters has roughly doubled over the 4 Gyrs between z=0.5 and z=0.1. We quantify this difference by measuring the dwarf to giant ratio on the red sequence which increases by a factor of at least 2.2 +/- 0.4 since z=0.5. This is consistent with the idea that many faint, blue star-forming galaxies in high density environments are transforming onto the red sequence in the last half of the Hubble time.

28) ``MegaZ-LRG: A photometric redshift catalogue of one million SDSS Luminous Red Galaxies'', Collister, A., Lahav, O., Blake, C.A., Cannon, R., Croom, S., Drinkwater, M.J., Edge, A.C., Eisenstein, D., Loveday, J., Nichol, R., Pimbblet, K.A., De Propris, R., Roseboom, I.G., Ross, N., Schneider, D.P., Shanks, T., Wake, D., 2007, MNRAS, 375, 68-76 Postscript.

We describe the construction of MegaZ-LRG, a photometric redshift catalogue of over one million luminous red galaxies (LRGs) in the redshift range z = 0.4 - 0.7 with limiting magnitude i = 20. The catalogue is selected from the imaging data of the Sloan Digital Sky Survey Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ) spectroscopic redshift catalogue of 13,000 intermediate-redshift LRGs provides a photometric redshift training set, allowing use of ANNz, a neural network-based photometric-redshift estimator. The rms photometric redshift accuracy obtained for an evaluation set selected from the 2SLAQ sample is sigma_z = 0.049 averaged over all galaxies, and sigma_z = 0.040 for a brighter subsample (i less than 19.0). The catalogue is expected to contain about 5 per cent stellar contamination. The ANNz code is used to compute a refined star/galaxy probability based on a range of photometric parameters; this allows the contamination fraction to be reduced to 2 per cent with negligible loss of genuine galaxies.

27) ``Mathematical Morphology: Star/Galaxy Differentiation & Galaxy Morphology Classification'', Moore, J.A., Pimbblet, K.A., Drinkwater, M.J., 2006, PASA, 23, 135-146 Postscript.

We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3 +/- 3.8 % of galaxies can be separated from stars using MM, with 19.4 +/- 7.9 % of the stars being misclassified. We demonstrate that, for photographic plate images, the number of galaxies correctly separated from the stars can be increased using our MM diffraction spike tool, which allows 51.0 +/- 6.0 % of the high-brightness galaxies that are inseparable in current techniques to be correctly classified, with only 1.4 +/- 0.5 % of the high-brightness stars contaminating the population. We demonstrate that elliptical (E) and late-type spiral (Sc-Sd) galaxies can be classified using MM at an accuracy of 91.4 +/- 7.8 %. It is a method involving less `free parameters' than current techniques, especially automated machine learning algorithms. The limitation of MM galaxy morphology based on seeing and distance is also presented. We examine various star/galaxy differentiation and galaxy morhpology classification techniques commonly used today, and show that the above MM techniques compare very favourably.

26) ``The 2dF-SDSS LRG and QSO Survey: The Star Formation Histories of Luminous Red Galaxies'', Roseboom, I.G., Pimbblet, K.A., Drinkwater, M.J., Cannon, R.D., De Propris, R., Edge, A.C., Eisenstein, D.J., Nichol, R.C., Smail, I., Wake, D.A., Bland Hawthorn, J., Bridges, T.J., Carson, D., Colless, M., Couch, W.J., Croom, S.M., Driver, S.P., Hewett, P.C., Loveday, J., Ross, N., Schneider, D.P., Shanks, T., Sharp, R.G., Weilbacher, P., 2006, MNRAS, 373, 349-360 Postscript.

We present a detailed investigation into the recent star formation histories of 5,697 Luminous Red Galaxies (LRGs) based on the Hdelta (4101A) and [OII] (3727A) lines. LRGs are luminous (L greater than 3L*), galaxies which have been selected to have photometric properties consistent with an old, passively evolving stellar population. For this study we utilise LRGs from the recently completed 2dF-SDSS LRG and QSO survey (2SLAQ). Equivalent widths of the Hdelta and [OII] lines are measured and used to define three spectral types, those with only strong Hdelta absorption (k+a), those with strong [OII] in emission (em) and those with both (em+a). All other LRGs are considered to have passive star formation histories. The vast majority of LRGs are found to be passive (~80 per cent), however significant numbers of k+a (2.7 per cent), em+a (1.2 per cent) and em LRGs (8.6 per cent) are identified. An investigation into the redshift dependence of the fractions is also performed. A sample of SDSS MAIN galaxies with colours and luminosities consistent with the 2SLAQ LRGs is selected to provide a low redshift comparison. While the em and em+a fractions are consistent with the low redshift SDSS sample, the fraction of k+a LRGs is found to increase significantly with redshift. This result is interpreted as an indication of an increasing amount of recent star formation activity in LRGs with redshift. By considering the expected life time of the k+a phase, the number of LRGs which will undergo a k+a phase can be estimated. A crude comparison of this estimate with the predictions from semi-analytic models of galaxy formation shows that the predicted level of k+a and em+a activity is not sufficient to reconcile the predicted mass growth for massive early-types in a hierarchical merging scenario.

25) ``The 2dF-SDSS LRG and QSO (2SLAQ) Luminous Red Galaxy Survey'', Cannon, R., Drinkwater, M., Edge, A., Eisenstein, D., Nichol, R.C., Outram, P., Pimbblet, K.A., De Propris, R., Roseboom, I.G., Wake, D., Allen, P., Bland-Hawthorn, J., Bridges, T., Carson, D., Chiu, K., Colless, M., Couch, W., Croom, S., Driver, S., Fine, S., Hewett, P., Loveday, J., Ross, N., Sadler, E.M., Shanks, T., Sharp, R., Allyn Smith, J., Stoughton, C., Weilbacher, P., Brunner, R.J., Meiksin, A., Schneider, D.P., 2006, MNRAS, 372, 425-442 Postscript.

24) ``The 2dF-SDSS LRG and QSO survey: Evolution of the Luminosity Function of Luminous Red Galaxies to z=0.6'', Wake, D.A., Nicol, R.C., Eisenstein, D.J., Loveday, J., Edge, A.C., Cannon, R., Smail, I., Schneider, D.P., Scranton, R., Carson, D., Ross, N.P., Brunner, R.J., Colless, M., Couch, W.J., Croom, S.M., Driver, S.P., da Angela, J., Jester, S., De Propris, R., Drinkwater, M., Bland-Hawthorn, J., Pimbblet, K.A., Roseboom, I.G., Shanks, T., Sharp, R.G., Brinkmann, J., 2006, MNRAS, 372, 537-550 Postscript.

23) ``Matching of Catalogues by Probabilistic Pattern Classification'', Rohde, D.J., Gallagher, M.R., Drinkwater, M.J., Pimbblet, K.A., 2006, MNRAS, 369, 2-14 Postscript.

We consider the statistical problem of catalogue matching from a machine learning perspective with the goal of producing probabilistic outputs, and using all available information. A framework is provided that unifies two existing approaches to producing probabilistic outputs in the literature, one based on combining distribution estimates and the other based on combining probabilistic classifiers. We apply both of these to the problem of matching the HIPASS radio catalogue with large positional uncertainties to the much denser SuperCOSMOS catalogue with much smaller positional uncertainties. We demonstrate the utility of probabilistic outputs by a controllable completeness and efficiency trade-off and by identifying objects that have high probabilities of being rare. Finally, possible biasing effects in the output of these classifiers are also highlighted and discussed.

22) ``The Large Peculiar Velocity of the cD Galaxy in Abell 3653'', Pimbblet, K.A., Roseboom, I.G., Doyle, M.T., 2006, MNRAS, 368, 651-658 Postscript.

We present a catalogue of galaxies in Abell 3653 from observations made with the 2dF spectrograph at the Anglo-Australian Telescope. Of the 391 objects observed, we find 111 are bone-fide members of Abell 3653. We show that the cluster has a velocity of cz = 32214 +/- 83 km/s (z=0.10738 +/- 0.00027), with a velocity dispersion typical of rich, massive clusters of sigma_{cz} = 880^{+66}_{-54}. We find that the cD galaxy has a peculiar velocity of 683 +/- 96 km/s in the cluster restframe - some 7sigma away from the mean cluster velocity, making it one of the largest and most significant peculiar velocities found for a cD galaxy to date. We investigate the cluster for signs of substructure, but do not find any significant groupings on any length scale. We consider the implications of our findings on cD formation theories.

21) ``The Las Campanas/AAT Rich Cluster Survey: III. Spectroscopic Studies of X-ray Bright Galaxy Clusters at z=0.1'', Pimbblet, K.A., Smail, I., Edge, A.C., O'Hely, E., Couch, W.J., Zabludoff, A.I., 2006, MNRAS, 366, 645-666 Postscript | Press Release.

We present the analysis of the spectroscopic and photometric catalogues of 11 X-ray luminous clusters at z=0.07-0.16 from the Las Campanas / Anglo-Australian Telescope Rich Cluster Survey. Our spectroscopic dataset consists of over 1600 galaxy cluster members, of which two thirds are outside r_200. These spectra allow us to assign cluster membership using a detailed mass model and expand on our previous work on the cluster colour-magnitude relation where membership was inferred statistically. We confirm that the modal colours of galaxies on the colour magnitude relation become progressively bluer with increasing radius d(B-R) / dr_p = -0.011 +/- 0.003 and with decreasing local galaxy density d(B-R) / dlog(Sigma) = -0.062 +/- 0.009. Interpreted as an age effect, we hypothesize that these trends in galaxy colour should be reflected in mean Hdelta equivalent width. We confirm that passive galaxies in the cluster increase in Hdelta line strength as dHdelta / d r_p = 0.35 +/- 0.06. Therefore those galaxies in the cluster outskirts may have younger luminosity-weighted stellar populations; up to 3 Gyr younger than those in the cluster centre assuming d(B-R)/dt=0.03 mag per Gyr (Kodama \& Arimoto 1997). A variation of star formation rate, as measured by [OII], with increasing local density of the environment is discernible and is shown to be in broad agreement with previous studies from the 2dF Galaxy Redshift Survey and the Sloan Digital Sky Survey. We divide our spectra into a variety of types based upon the MORPHs classification scheme. We find that clusters at z=0.1 are less active than their higher redshift analogues: about 60 per cent of the cluster galaxy population is nonstarforming, with a further 20 per cent in the post-starburst class and 20 per cent in the currently active class, demonstrating that evolution is visible within the past 2-3 Gyr. We also investigate unusual populations of blue and very red nonstarforming galaxies and we suggest that the former are likely to be the progenitors of galaxies which will lie on the colour-magnitude relation, while the colours of the latter possibly reflect dust reddening. We show that the cluster galaxies at large radii consist of both backsplash ones and those that are infalling to the cluster for the first time. We make a comparison to the field population at z=0.1 and examine the broad differences between the two populations. Individually, the clusters show significant variation in their galaxy populations which we suggest reflects their recent infall histories.

20) ``Diffuse Optical Light in Galaxy Clusters I: Abell 3888'', Krick, J.E., Bernstein, R.A., Pimbblet, K.A., 2006, AJ, 131, 168-184 Postscript.

We are undertaking a program to measure the characteristics of the intracluster light (total flux, profile, color, and substructure) in a sample of 10 galaxy clusters with a range of cluster mass, morphology, and redshift. We present here the methods and results for the first cluster in that sample, A3888. We have identified an intracluster light (ICL) component in A3888 in V and r that contains 13\pm5% of the total cluster light and extends to 700h_{70}^{-1}kpc (~0.3 r_{200}) from the center of the cluster. The ICL color in our smallest radial bin is V-r = 0.3 \pm 0.1, similar to the central cluster ellipticals. The ICL is redder than the galaxies at 400 < r < 700h_{70}^{-1}kpc although the uncertainty in any one radial bin is high. Based on a comparison of V-r color with simple stellar models, the ICL contains a component which formed more than 7 Gyr ago (at z > 1), coupled with a high metallicity (1.0Z_{\odot} < Z_{ICL} \la 2.5Z_{\odot}), and a more centralized component which contains stars formed within the past 5 Gyr (at z ~ 1). The profile of the ICL can be roughly fit by a shallow exponential in the outer regions and a steeper exponential in the central region. We also find a concentration of diffuse light around a small group of galaxies 1.4h_{70}^{-1}Mpc from the center of the cluster. In addition, we find 3 low surface brightness features near the cluster center which are blue (V-r = 0.0) and contain a total flux of 0.1M*. Based on these observations and X-ray and galaxy morphology, we suggest that this cluster is entering a phase of significant merging of galaxy groups in the core, whereupon we expect the ICL fraction to grow significantly with the formation of a cD galaxy as well as the in-fall of groups.

19) ``The Afterglows, Redshifts, and Properties of Swift Gamma-Ray Bursts'', Berger, E., Kulkarni, S.R., Fox, D.B., Soderberg, A.M., Harrison, F.A., Nakar, E., Kelson, D.D., Gladders, M.D., Mulchaey, J.S., Oemler, A., Dressler, A., Cenko, S.B., Price, P.A., Schmidt, B.P., Frail, D.A., Morrell, N., Gonzalez, S., Krzeminski, W., Sari, R., Gal-Yam, A., Moon, D.-S., Penprase, B.E., Jayawardhana, R., Scholz, A., Rich, J., Peterson, B.A., Anderson, G., McNaught, R., Minezaki, T., Yoshii, Y., Cowie, L.L., Pimbblet, K.A., 2005, ApJ, 634, 501-508 Postscript

We present optical, near-IR, and radio follow up of sixteen Swift bursts, including our discovery of nine afterglows and a redshift determination for three. These observations, supplemented by data from the literature, provide an afterglow recovery rate of 60% in the optical/near-IR, much higher than in previous missions (BeppoSAX, HETE-2, INTEGRAL, and IPN). The optical/near-IR afterglows of Swift events are on average 1.7 mag fainter at t=12 hr than those of previous missions. The X-ray afterglows are similarly fainter compared to those of pre-Swift bursts. In the radio the limiting factor is the VLA threshold and the detection rate for Swift bursts is similar to that for past missions. The redshift distribution of pre-Swift bursts peaked at z~1, whereas the five Swift bursts with measured redshifts are distributed evenly between 1.3 and 3.2. From these results we conclude that (i) the pre-Swift distributions were biased in favor of bright events and low redshift events, (ii) the higher sensitivity and accurate positions of Swift result in a better representation of the true burst redshift and brightness distributions (which are higher and dimmer, respectively), and (iii) as many as 1/3 of the bursts can be optically dark, as a result of a high redshift and/or dust extinction. We remark that the apparent lack of low redshift, low luminosity Swift bursts, and the lower event rate compared to pre-launch estimates (90 vs. 150 per year), are the result of a threshold that is similar to that of BATSE. In view of these inferences, afterglow observers may find it advisable to make significant changes in follow up strategies of Swift events. The faintness of the afterglows means that large telescopes should be employed as soon as the burst is localized. Sensitive observations in RIz and near-IR bands will be needed to discriminate between a typical z=2 burst with modest extinction and a high redshift event. Radio observations will be profitable for a small fraction (10%) of events. Finally, we suggest that a search for bright host galaxies in untriggered BAT localizations may increase the chance of finding nearby low luminosity GRBs.

18) ``Evaluation of Cosmic Ray Rejection Algorithms on Single-shot Exposures'', Farage, C.L., Pimbblet, K.A., 2005, PASA, 22, 249-256 Postscript

To maximise data output from single-shot astronomical images, the rejection of cosmic rays is important. We present the results of a benchmark trial comparing various cosmic ray rejection algorithms. The procedures assess relative performances and characteristics of the processes in cosmic ray detection, rates of false detections of true objects and the quality of image cleaning and reconstruction. The cosmic ray rejection algorithms developed by Rhoads (2000), van Dokkum (2001), Pych (2004) and the IRAF task \textsc{xzap} by Dickinson are tested using both simulated and real data. It is found that detection efficiency is independent of the density of cosmic rays in an image, being more strongly affected by the density of real objects in the field. As expected, spurious detections and alterations to real data in the cleaning process are also significantly increased by high object densities. We find the Rhoads' linear filtering method to produce the best performance in detection of cosmic ray events, however, the popular van Dokkum algorithm exhibits the highest overall performance in terms of detection and cleaning.

17) ``The HIPASS Catalogue: III. Optical Counterparts and Isolated Dark Galaxies'', Doyle, M.T., Drinkwater, M.J., Rohde, D.J., Pimbblet, K.A., Read, M., Meyer, M.J., Zwaan, M.A., Ryan-Weber, E., Stevens, J., Koribalski, B.S., Webster, R.L., Staveley-Smith, L., Barnes, D.G., Howlett, M., Kilborn, V.A., Waugh, M., Pierce, M.J., Bhathal, R., de Blok, W.J.G., Disney, M.J., Ekers, R.D., Freeman, K.C., Garcia, D.A., Gibson, B.K., Harnett, J., Henning, P.A., Jerjen, H., Kesteven, M.J., Knezek, P.M., Mader, S., Marquarding, M., Minchin, R.F., O'Brien, J., Oosterloo, T., Price, R.M., Putman, M.E., Ryder, S.D., Sadler, E.M., Stewart, I.M., Stootman, F., Wright, A.E., 2005, MNRAS, 361, 34-44 Postscript.

We present the largest catalogue to date of optical counterparts for HI radio-selected galaxies, Hopcat. Of the 4315 HI radio-detected sources from the HI Parkes All Sky Survey (Hipass) catalogue, we find optical counterparts for 3618 (84%) galaxies. Of these, 1798 (42%) have confirmed optical velocities and 848 (20%) are single matches without confirmed velocities. Some galaxy matches are members of galaxy groups. From these multiple galaxy matches, 714 (16%) have confirmed optical velocities and a further 258 (6%) galaxies are without confirmed velocities. For 481 (11%), multiple galaxies are present but no single optical counterpart can be chosen and 216 (5%) have no obvious optical galaxy present. Most of these 'blank fields' are in crowded fields along the Galactic plane or have high extinctions.
Isolated 'Dark galaxy' candidates are investigated using an extinction cut of ABj < 1 mag and the blank fields category. Of the 3692 galaxies with an ABj extinction < 1 mag, only 13 are also blank fields. Of these, 12 are eliminated either with follow-up Parkes observations or are in crowded fields. The remaining one has a low surface brightness optical counterpart. Hence, no isolated optically dark galaxies have been found within the limits of the Hipass survey.

16) ``The 2dF-SDSS LRG and QSO Survey: The z less than 2.2 Quasar Luminosity Function from 5645 Quasars to g less than 21.85'', Richards, G.T., Croom, S.M., Anderson, S.F., Boyle, B.J., De Propris, R., Drinkwater, M.J., Fan, X., Gunn, J.E., Ivezic, Z., Jester, S., Loveday, J., Meiksin, A., Miller, L., Myers, A., Nichol, R.C., Outram, P.J., Pimbblet, K.A., Roseboom, I.G., Ross, N., Schneider, D.P., Shanks, T., Sharp, R.G., Stoughton, C., Strauss, M.A., Szalay, A.S., Vanden Berk, D.E., York, D.G., 2005, MNRAS, 360, 839-852 Postscript

We have used the 2-degree Field (2dF) instrument on the Anglo-Australian Telescope to obtain redshifts of a sample of z<3, 18.021 deep surveys for quasars. The 2SLAQ data exhibit no well defined ``break'' in the number counts or luminosity function, but do clearly flatten with increasing magnitude. Finally, we find that the shape of the quasar luminosity function derived from 2SLAQ is in good agreement with that derived from type I quasars found in hard X-ray surveys.

15) ``Pulling out Threads from the Cosmic Tapestry: Defining Filaments of Galaxies'', Pimbblet, K.A., 2005, PASA, 22, 136-143. Postscript

Filaments of galaxies are the dominant feature of modern large scale redshift surveys. They can account for up to perhaps half of the baryonic mass budget of the Universe and their distribution and abundance can help constrain cosmological models. However, there remains no single, definitive way in which to detect, describe and define what filaments are and their extent. This work examines a number of physically motivated, as well as statistical, methods that can be used to define filaments and examines their relative merits.

14) ``Calibrating Photometric Redshifts of Luminous Red Galaxies'', Padmanabhan, N., Budavari, T., Schlegel, D.J., Bridges, T., Brinkmann, J., Cannon, R., Connolly, A.J., Croom, S.C., Csabai, I., Drinkwater, M., Eisenstein, D.J., Hewett, P.C., Loveday, J., Nichol, R.C., Pimbblet, K.A., De Propris, R., Schneider, D.P., Scranton, R., Seljak, U., Shanks, T., Szapudi, I., Szalay, A.S., Wake, D., 2005, MNRAS, 359, 237-250. Postscript

We discuss the construction of a photometric redshift catalogue of Luminous Red Galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue -- (i) photometrically selecting the sample, (ii) measuring photometric redshifts and their error distributions, (iii) and estimating the true redshift distribution. We compare two photometric redshift algorithms for these data and find that they give comparable results. Calibrating against the SDSS and SDSS-2dF spectroscopic surveys, we find that the photometric redshift accuracy is $\sigma \sim 0.03$ for redshifts less than 0.55 and worsens at higher redshift ($\sim 0.06$). These errors are caused by photometric scatter, as well as systematic errors in the templates, filter curves, and photometric zeropoints. We also parametrize the photometric redshift error distribution with a sum of Gaussians, and use this model to deconvolve the errors from the measured photometric redshift distribution to estimate the true redshift distribution. We pay special attention to the stability of this deconvolution, regularizing the method with a prior on the smoothness of the true redshift distribution. The methods we develop are applicable to general photometric redshift surveys.

13) ``A New Algorithm for the Detection of Inter-cluster Galaxy Filaments using Galaxy Orientation Alignments'', Pimbblet, K.A., 2005, MNRAS, 358, 256-262. Postscript.

We present a new algorithm to detect inter-cluster galaxy filaments based upon the assumption that the orientations of constituent galaxies along such filaments are non-isotropic. We apply the algorithm to the 2dF Galaxy Redshift Survey catalogue and find that it readily detects many straight filaments between close cluster pairs. At large inter-cluster separations (more than 15 Mpc), we find that the detection efficiency falls quickly, as it also does with more complex filament morphologies. We explore the underlying assumptions and suggest that it is only in the case of close cluster pairs that we can expect galaxy orientations to be significantly correlated with filament direction.

12) ``Discovery of a Large-scale Wall in the Direction of Abell 22'', Pimbblet, K.A., Edge, A.C., Couch, W.J., 2005, MNRAS Letters, 357, L45-L49. Postscript.

We report on the discovery of a large-scale wall in the direction of Abell 22. Using photometric and spectroscopic data from the Las Campanas Observatory and Anglo--Australian Telescope Rich Cluster Survey, Abell 22 is found to exhibit a highly unusual and striking redshift distribution. We show that Abell 22 exhibits a foreground wall-like structure by examining the galaxy distributions in both redshift space and on the colour-magnitude plane. A search for other galaxies and clusters in the nearby region using the 2dF Galaxy Redshift Survey database suggests that the wall-like structure is a significant large-scale, non-virialized filament which runs between two other Abell clusters either side of Abell 22. The filament stretches over at least 40 Mpc in length and 10 Mpc in width at the redshift of Abell 22.

11) ``Random Numbers from Astronomical Imaging'' , Pimbblet, K.A., Bulmer, M., 2005, PASA, 22, 1-5 Postscript | Press Release

This article describes a method to turn astronomical imaging into a random number generator by using the positions of incident cosmic rays and hot pixels to generate bit streams. We subject the resultant bit streams to a battery of standard benchmark statistical tests for randomness and show that these bit streams are statistically the same as a perfect random bit stream. Strategies for improving and building upon this method are outlined.

10)`Inter-cluster filaments of galaxies programme: Abundance and Distribution of Filaments in the 2dFGRS Catalogue', Pimbblet, K.A., Drinkwater, M.J., Hawkrigg, M.C., 2004, MNRAS Letters, 354, L61-L65 Postscript.

Filaments of galaxies are known to stretch between galaxy clusters at all redshifts in a complex manner. In this Letter, we present an analysis of the frequency and distribution of inter-cluster galaxy filaments selected from the 2dF Galaxy Redshift Survey. Out of 805 cluster-cluster pairs, we find at least 40 per cent have bone-fide filaments. We introduce a filament classification scheme and cast the filaments into several types according to their visual morphology: straight (lying on the cluster-cluster axis; 37 per cent), warped or curved (lying off the cluster-cluster axis; 33 per cent), sheets (planar configurations of galaxies; 3 per cent), uniform (1 per cent) and irregular (26 per cent) We find that straight filaments are more likely to reside between close cluster pairs and they become more curved with increasing cluster separation. This curving is toward a larger mass concentration in general. We also show that the more massive a cluster is, the more likely it is to have a larger number of filaments. Our results are found to be consistent with a Lambda cold dark matter cosmology.

9) ``Inter-cluster Filaments of Galaxies Programme: Pilot Study Survey and Results'', Pimbblet, K.A. and Drinkwater, M.J., 2004, MNRAS, 347, 137-143 Postscript.

We present results from a pilot study of a new wide-field, multicolour (BVR) CCD imaging project, designed to examine galaxy evolution along large scale filaments that connect clusters of galaxies at intermediate redshifts (0.08 < z < 0.20). Our pilot dataset is based on 0.56 square degree of observations targeted on Abell 1079 and Abell 1084 using the Wide Field Imager on the Anglo-Australian Telescope. We describe our data reduction pipeline and show that our photometric error is 0.04 mags. By selecting galaxies that lie on the colour-magnitude relation of the two clusters we verify the existence of a low density (3-4 square Mpc) filament population conjoining them at a distance greater than 3 Abell radii from either cluster. By applying a simple field correction, we characterize this filament population by examining their colour distribution on a (V-R)-(B-V) plane. We confirm the galaxian filament detection at a 7.5 sigma level using a cut at M(V)=-18 and we discuss their broad properties.

8) ``At the Vigintennial of the Butcher-Oemler Effect'', Pimbblet, K.A., 2003, PASA, 20, 294-299. Postscript.

In their study of the evolution of galaxies within clusters, Butcher and Oemler discovered evidence for a strong evolution in star-formation rate with redshift. Later studies confirmed this conclusion and uncovered several aspects of the effect: photometric, spectroscopic, and morphological. This article reviews a broad sample of these works and discusses selection effects, biases, and driving mechanisms that might be responsible for the changes in star-formation rate.

7) ``Defining Civilization utilizing Anthropic Reasoning'', Pimbblet, K.A., 2003, The Observatory, 123 (No. 1177), 341-343. Postscript

We utilize anthropic reasoning to demonstrate that we are typical observers of our reference class under a self-sampling assumption by investigating the definition of what a civilization is. With reference to the conflict between such reasoning and the observational lack of extra-terrestrial intelligent life, we conclude that a part of our theoretical understanding of the Universe will be at fault.

6) ``Ex-nihilo II: Examination Syllabi and the Sequencing of Cosmology Education'', Pimbblet, K.A., Newman, J.C., 2003, Physics Education, 38, 243-247. Postscript. PDF.

Cosmology education has become an integral part of modern physics courses. Directed by National Curricula, major UK examination boards have developed syllabi that contain explicit statements about the model of the Big Bang and the strong observational evidence that supports it. This work examines the similarities and differences in these specifications and addresses when cosmology could be taught within a physics course, what should be included in this teaching and in what sequence it should be taught at different levels.

5) ``Ex-nihilo: Obstacles Surrounding Teaching the Standard Model'', Pimbblet, K.A., 2002, Physics Education, 37, 512-515. Postscript. PDF.

The model of the Big Bang is an integral part of the national curriculum for England. Previous work (e.g. Baxter 1989) has shown that pupils often come into education with many and varied prior misconceptions emanating from both internal and external sources. Whilst virtually all of these misconceptions can be remedied, there will remain (by its very nature) the obstacle of ex-nihilo, as characterised by the question `how do you get something from nothing?' There are two origins of this obstacle: conceptual (i.e. knowledge-based) and cultural (e.g. deeply held religious viewpoints). The article shows how the citizenship section of the national curriculum, coming `online' in England from September 2002, presents a new opportunity for exploiting these.

4) ``The Las Campanas/AAT Rich Cluster Survey: II. The Environmental Dependance of Galaxy Populations in Rich Clusters of Galaxies around z=0.1'' , Pimbblet, K.A., Smail, I., Kodama, T., Couch, W.J., Edge, A.C., Zabludoff, A.I., O'Hely, E., 2002, MNRAS, 331, 333-350. Postscript.

We investigate the variation in galaxy colour with environment in 11 X-ray luminous clusters at $0.07\leq z \leq 0.16$ taken from the Las Campanas/AAT Rich Cluster Survey. We study the properties of the galaxy populations in individual clusters and also take advantage of the homogeneity of the sample to combine the clusters together to investigate weaker trends in the combined sample. We find that modal colours of galaxies lying on the colour-magnitude relation in the clusters becomes bluer by $d(B-R) / d r_p = -0.021 \pm 0.004$ between the cluster core out to a radius of $\sim 6$\,Mpc. We also examine the variation in modal galaxy colour with local density for galaxies lying close to the colour-magnitude relation and find that the median colour shifts bluewards by $d(B-R) / d {\rm log}_{10}(\Sigma) = -0.043 \pm 0.009$ with decreasing local density across three orders of magnitude. We show that the position of the red envelope of galaxies in the colour-magnitude relation does not vary as a function of radius or density within the clusters, suggesting that the change in the modal colour results from an increasing fraction of bluer galaxies within the colour-magnitude relation, rather than a change in the colours of the {\it whole} population. We show that this shift in the modal colour of the colour-magnitude relations with radius and local-density is greater than expected from the changing morphological mix based on the local morphology--density relation. We therefore conclude that we are seeing a blueing of the galaxies lying close to the colour-magnitude relation in the outskirts of clusters. The simplest interpretation of this result (and similar constraints in local clusters) is that an increasing fraction of galaxies in the lower density regions at large radii within clusters exhibit signatures of having experienced star formation in the recent past, signatures which are not seen in the evolved galaxies in the highest density regions.

3) ``Software and Sociology in UK Astronomy'' , Pimbblet, K.A., 2002, Astronomy & Geophysics, 43, 1.25. Postscript.

I discuss the remit of Starlink's software strategy groups and a particular item on the agenda of a meeting of the image processing software strategy group held on 26th January 2001: `Why don't people use Starlink software?'. The answer to this question was speculated to be primarily a sociological effect: those people supervising UK astronomy Ph.D. students are largely people who had learnt their trade at a time when Starlink had a less than perfect reputation. I report on the recommendations made to Starlink to counter this effect.

2) ``Stellar Populations of X-Ray Luminous Clusters at z=0.1'' , Pimbblet, K.A., PhD Thesis, Univ. of Durham, 2001. Postscript.

This thesis presents new and unique wide-field imaging and spectroscopic observations of 21 X-ray selected rich clusters of galaxies in the redshift range 0.07 - 0.16 from the Las Campanas Observatory (LCO) / Anglo-Australian Telescope (AAT) Rich Cluster Survey (LARCS). Mosaic two colour broad-band CCD imaging extending to 10 Mpc at the mean redshift of the survey have been taken at LCO; comprising over 50Gb of raw data. A reduction pipeline is developed for these data and catalogues are constructed for these clusters. Four of these fields are compared to the APM catalogue (Maddox et al. 1990) to confirm their photometric accuracy. In making the comparison several populations of galaxies are discovered to be absent from the APM. A statistical background correction technique is developed to examine the photometric properties of cluster members. Eleven clusters are combined together to investigate environmental trends in the stellar populations of the combined sample. It is found that the modal colours of galaxies lying on the colour-magnitude relation in the clusters become bluer by d(B-R) / d r_p = -0.022 +/- 0.004 with radius or d(B-R) / d log(\Sigma) = -0.076 +/- 0.009 with local galaxy density. The 2dF spectroscope at the AAT is used to make spectroscopic follow-up observations of three clusters. A reduction pipeline for these data is developed and redshifts for the galaxies are determined. The spectral catalogues are used to define cluster membership and confirm the photometric environmental trends. Spectral line strengths are used to classify the galaxy population and examine environmental trends across the clusters. The cluster cores are found to be predominantly passive compared to the field. A comparison of the two cluster membership assignment techniques underscores the need for spectroscopy to define the cluster population.

1) ``The Las Campanas/AAT Rich Cluster Survey: I. Precision and Reliability of the Photometric Catalogue'', Pimbblet, K.A., Smail, I., Edge, A.C., Couch, W.J., O'Hely, E., Zabludoff, A.I., 2001, MNRAS, 327, 588-601. Postscript.

The Las Campanas Observatory and Anglo-Australian Telescope Rich Cluster Survey (LARCS) is a panoramic imaging and spectroscopic survey of an X-ray luminosity-selected sample of 21 clusters of galaxies at 0.07 < z < 0.16. CCD imaging was obtained in B and R of typically 2-degree wide regions centred on the 21 clusters, and the galaxy sample selected from the imaging is being used for an on-going spectroscopic survey of the clusters with the 2dF spectrograph on the Anglo-Australian Telescope. This paper presents the reduction of the imaging data and the photometric analysis used in the survey. Based on an overlapping area of 12.3 square degrees we compare the CCD-based LARCS catalogue with the photographic-based galaxy catalogue used for the input to the 2dF Galaxy Redshift Survey (2dFGRS) from the APM, to the completeness of the GRS/APM catalogue, b_J=19.45. The stellar contamination in the GRS/APM galaxy catalogue is confirmed as around 5-10 percent, as originally estimated. However, using the superior sensitivity and spatial resolution in the LARCS survey evidence is found for four distinct populations of galaxies which are systematically omitted from the GRS/APM catalogue. The characteristics of the `missing' galaxy populations are described, reasons for their absence examined and the impact they will have on the conclusions drawn from the 2dF Galaxy Redshift Survey are discussed.

Conference Proceedings and Other Non-refereed publications

6) ``The WiggleZ project: AAOmega and Dark Energy'', Glazebrook, K., Blake, C., Couch, W., Forbes, D., Drinkwater, M., Jurek, J., Pimbblet, K.A.,, Madore, B., Martin, C., Small, T., Forster, K., Colless, M., Sharp, R., Croom, S., Woods, D., Pracy, M., Gilbank, D., Yee, H., Gladders, M., 2007, To appear in the Proceedings of the Durham "Cosmic Frontiers" ASP conference eds. Metcalfe & Shanks Postscript.

We describe the `WiggleZ' spectroscopic survey of 400,000 star-forming galaxies selected from a combination of GALEX ultra-violet and SDSS + RCS2 optical imaging. The fundamental goal is a detection of the baryonic acoustic oscillations in galaxy clustering at high-redshift (0.5 < z < 1) and a precise measurement of the equation of state of dark energy from this purely geometric and robust method. The survey has already started on the 3.9m Anglo-Australian Telescope using the AAOmega spectrograph, and planned to complete during 2009.

5) ``The WiggleZ Dark Energy Survey: 1000 redshifts and beyond'', Drinkwater, M.J., Pimbblet, K.A., Jurek, R.J., Blake, C.A., Glazebrook, K., Woods, D., Couch, W.J., Colless, M., Forbes, D., Madore, B., Martin, C., Small, T., 2006, Anglo-Australian Observatory Newsletter, 110, 3-5

Here we outline design aspects and first results of the WiggleZ Dark Energy Survey that has recently been awarded long-term status on the AAT from the 2006B semester. The primary aim of the WiggleZ Dark Energy Survey is to use baryonic acoutic oscillations (BAOs) as a standard ruler to measure w(z), the parametrization of the equation of state of the Universe, and hence determine if dark energy is described by the cosmological constant.

4)``The SDSS-DR3 and 2dF-SDSS Quasar Luminosity Functions'', Richards, G.T., Strauss, M.A., Croom, S.M., Colless, M., Bland-Hawthorn, J., Sharp, R.G., Boyle, B.J., Fan, X., York, D.G., Outram, P.J., Shanks, T., Ross, N., Meiksin, A., Jester, S., Stoughton, C., Szalay, A., Miller, L., Schneider, D.P., Vanden Berk, D.E., Nichol, R.C., Myers, A.D., Anderson, S.F., Ivezic, Z., Drinkwater, M., Pimbblet, K.A., Roseboom, I.G., SDSS, 2SLAQ, 2005, American Astronomical Society Meeting 205, #167.03

We present two complementary determinations of the quasar luminosity function (QLF) based on over 50,000 bright quasars from the SDSS-DR3 quasar catalog and over 5000 faint quasars from the 2dF-SDSS LRG and QSO survey (2SLAQ). With a limiting magnitude of i=19.1 (i=20.2 for z>3) the SDSS-DR3 sample does not reach the "break" in the z<2.2 QLF, but the data allow, for the first time, the determination of the QLF from z=0 to z=5 in a single survey. For z<2.2 the SDSS-DR3 number counts and QLF are in good agreement with the bright end of the QLF from the 2dF QSO Redshift Survey (2QZ). The 2SLAQ sample, on the other hand, is limited to UVX sources (z<3), but with a limit of g=21.85 extends over 2 magnitudes fainter than the "break" and 1 magnitude fainter than the 2QZ sample. We find good agreement with previous results from 2QZ except at the faint end, where the 2SLAQ data indicate a higher density of quasars and thus a steeper QLF slope.

3) ``HETE 3557: Optical observations'', Pimbblet, K.A., Price, P.A., 2004, Gamma Ray Bursts Coordinates Network, 2702, 1

We have observed the error circle of HETE trigger #3557 with the 40-inch telescope + Wide Field Imager in poor seeing conditions (~ 3 arcsec) with an R filter at 2004 Sep 12.703 UTC. Preliminary reduction involved coaddition of 3 x 300 sec exposures, which cover most of the 22 arcmin diameter error circle (missing the South-most 2 arcmin, and reduced sensitivity in a mosaic gap) to a limiting magnitude of approximately 20 mag. We do not identify any optical afterglow candidate after visually comparing with the Digitised Sky Survey 2 F plate. We plan to reduce and inspect further images, with an integration time of approximately an hour.

2) ``The SDSS-2dF LRG and QSO surveys'', Cannon, R., Croom, S., Pimbblet, K.A. for the SDSS-2dF Team, 2003 AAO Newsletter Postscript.

No abstract available.

1) ``On the Merit of Observations Beyond the Cluster Core'' , Pimbblet, K.A., APS Conf. Ser. Vol. 283, ``A New Era in Cosmology'' Univ. of Durham, 2002, p.240. Postscript.

I discuss recent seminal work on the LARCS dataset: a panoramic study of rich clusters of galaxies at $z\sim0.12$. The importance of observing beyond the cluster core is illustrated by exploiting these data to examine colour gradients across the clusters. (Contributed talk)

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