We analyse the large‐scale correlation function of the 6dF Galaxy Survey (6dFGS) and detect a baryon acoustic oscillation (BAO) signal at 105 h−1 Mpc. The 6dFGS BAO detection allows us to constrain the distance–redshift relation at zeff= 0.106. We achieve a distance measure of DV(zeff) = 457 ± 27 Mpc and a measurement of the distance ratio, rs(zd)/DV(zeff) = 0.336 ± 0.015 (4.5 per cent precision), where rs(zd) is the sound horizon at the drag epoch zd. The low‐effective redshift of 6dFGS makes it a competitive and independent alternative to Cepheids and low‐z supernovae in constraining the Hubble constant. We find a Hubble constant of H0= 67 ± 3.2 km s−1 Mpc−1 (4.8 per cent precision) that depends only on the Wilkinson Microwave Anisotropy Probe‐7 (WMAP‐7) calibration of the sound horizon and on the galaxy clustering in 6dFGS. Compared to earlier BAO studies at higher redshift, our analysis is less dependent on other cosmological parameters. The sensitivity to H0 can be used to break the degeneracy between the dark energy equation of state parameter w and H0 in the cosmic microwave background data. We determine that w=−0.97 ± 0.13, using only WMAP‐7 and BAO data from both 6dFGS and Percival et al. (2010). We also discuss predictions for the large‐scale correlation function of two future wide‐angle surveys: the Wide field ASKAP L‐band Legacy All‐sky Blind surveY (WALLABY) blind H i survey (with the Australian Square Kilometre Array Pathfinder, ASKAP) and the proposed Transforming Astronomical Imaging surveys through Polychromatic Analysis of Nebulae (TAIPAN) all‐southern‐sky optical galaxy survey with the UK Schmidt Telescope. We find that both surveys are very likely to yield detections of the BAO peak, making WALLABY the first radio galaxy survey to do so. We also predict that TAIPAN has the potential to constrain the Hubble constant with 3 per cent precision.

The definitive version can be found at: http://onlinelibrary.wiley.com/ Copyright Royal Astronomical SocietyThe Galaxy and Mass Assembly (GAMA) survey has been operating since 2008 February on the 3.9-m Anglo-Australian Telescope using the AAOmega fibre-fed spectrograph facility to acquire spectra with a resolution of R approximate to 1300 for 120 862 Sloan Digital Sky Survey selected galaxies. The target catalogue constitutes three contiguous equatorial regions centred at 9h (G09), 12h (G12) and 14.5h (G15) each of 12 x 4 deg2 to limiting fluxes of r(pet) < 19.4, r(pet) < 19.8 and r(pet) < 19.4 mag, respectively (and additional limits at other wavelengths). Spectra and reliable redshifts have been acquired for over 98 per cent of the galaxies within these limits. Here we present the survey footprint, progression, data reduction, redshifting, re-redshifting, an assessment of data quality after 3 yr, additional image analysis products (including ugrizYJHK photometry, Sersic profiles and photometric redshifts), observing mask and construction of our core survey catalogue (GamaCore). From this we create three science-ready catalogues: GamaCoreDR1 for public release, which includes data acquired during year 1 of operations within specified magnitude limits (2008 February to April); GamaCoreMainSurvey containing all data above our survey limits for use by the GAMA Team and collaborators; and GamaCoreAtlasSV containing year 1, 2 and 3 data matched to Herschel-ATLAS science demonstration data. These catalogues along with the associated spectra, stamps and profiles can be accessed via the GAMA website: http://www.gama-survey.org/

We use the catalogue of 4315 extragalactic H i 21‐cm emission‐line detections from the H i Parkes All Sky Survey (HIPASS) to calculate the most accurate measurement of the H i mass function (HIMF) of galaxies to date. The completeness of the HIPASS sample is well characterized, which enables an accurate calculation of space densities. The HIMF is fitted with a Schechter function with parameters α=−1.37 ± 0.03 ± 0.05, log (M* H I/M⊙) = 9.80 ± 0.03 ± 0.03 h−275, and θ*= (6.0 ± 0.8 ± 0.6) × 10−3 h375 Mpc−3 dex−1 (random and systematic uncertainties at 68 per cent confidence limit), in good agreement with calculations based on the HIPASS Bright Galaxy Catalogue, which is a complete, but smaller, sub‐sample of galaxies. The cosmological mass density of H i in the local Universe is found to be ΩH i= (3.5 ± 0.4 ± 0.4) × 10−4 h−175. This large homogeneous sample allows us to test whether the shape of the HIMF depends on local galaxy density. We find tentative evidence for environmental effects in the sense that the HIMF becomes steeper toward higher density regions, ranging from α≈−1.2 in the lowest density environments to α≈−1.5 in the highest density environments probed by this blind H i survey. This effect appears stronger when densities are measured on larger scales.

We are performing a uniform and unbiased imaging survey of the Large Magellanic Cloud (LMC; $7 ; 7) using the IRAC (3.6, 4.5, 5.8, and 8 m) and MIPS (24, 70, and 160 m) instruments on board the Spitzer Space Telescope in the Surveying the Agents of a Galaxy's Evolution (SAGE) survey, these agents being the interstellar medium (ISM) and stars in the LMC. This paper provides an overview of the SAGE Legacy project, including observing strategy, data processing, and initial results. Three key science goals determined the coverage and depth of the survey. The detection of diffuse ISM with column densities >1:2 ; 10 21 H cm À2 permits detailed studies of dust processes in the ISM. SAGE's point-source sensitivity enables a complete census of newly formed stars with masses >3 M that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass-loss rates >1 ; 10 À8 M yr À1 will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are nonproprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point-source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data for a region near N79 and N83. The MIPS 70 and 160 m images of the diffuse dust emission of the N79/N83 region reveal a similar distribution to the gas emissions, especially the H i 21 cm emission. The measured point-source sensitivity for the epoch 1 data is consistent with expectations for the survey. The point-source counts are highest for the IRAC 3.6 m band and decrease dramatically toward longer wavelengths, A

We combine new Parkes telescope observations of neutral hydrogen (Hi) in the Small Magellanic Cloud (SMC) with an Australia Telescope Compact Array (ATCA) aperture synthesis mosaic to obtain a set of images sensitive to all angular (spatial) scales between 98 arcsec (30 pc) and 4° (4 kpc). The new data are used to study the HI spatial power spectrum over a range of contiguous scale sizes wider than those previously achieved in any other galaxy, including our own. The spatial power spectrum closely obeys the relation P(k) ∝ kγ, with γ =‐3.04 ± 0.02, similar to values obtained by other authors for our own Galaxy which are in the range γ =‐3.0 to ‐2.8. This is surprising given the very different morphology, gas‐richness, star‐formation rate and evolution of the two systems, and may imply similar mechanisms for structure formation. One interpretation of the P(k) power‐law is that the interstellar medium (ISM) of the SMC is fractal in nature, consisting of a hierarchy of HI cloud structures created, for example, by homogeneous turbulence. The projected fractal dimension of Dp=1.5 is similar to values obtained by other authors for molecular clouds in the Galaxy in the size range ∼ 0.05 to 100 pc. Such a model is consistent with a low space‐filling factor for the neutral gas. A kinematic study of the HI data reveals the existence of three supergiant shells which were previously undetectable in the ATCA data alone. These shells have diameters up to 1.8 kpc and require energies (in the standard supernova‐driven models) up to 2×1054 erg. The structure and evolution of the ISM in the SMC are heavily influenced by the formation of these supergiant shells.

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We present a detailed analysis of redshift‐space distortions in the two‐point correlation function of the 6dF Galaxy Survey (6dFGS). The K‐band selected subsample which we employ in this study contains 81 971 galaxies distributed over 17 000 degree2 with an effective redshift zeff= 0.067. By modelling the 2D galaxy correlation function, , we measure the parameter combination f(zeff)σ8(zeff) = 0.423 ± 0.055, where is the growth rate of cosmic structure and σ8 is the rms of matter fluctuations in 8 h−1 Mpc spheres. Alternatively, by assuming standard gravity we can break the degeneracy between σ8 and the galaxy bias parameter b. Combining our data with the Hubble constant prior from Riess et al., we measure σ8= 0.76 ± 0.11 and Ωm= 0.250 ± 0.022, consistent with constraints from other galaxy surveys and the cosmic microwave background data from Wilkinson Microwave Anisotropy Probe 7 (WMAP7). Combining our measurement of fσ8 with WMAP7 allows us to test the cosmic growth history and the relationship between matter and gravity on cosmic scales by constraining the growth index of density fluctuations, γ. Using only 6dFGS and WMAP7 data we find γ= 0.547 ± 0.088, consistent with the prediction of General Relativity. We note that because of the low effective redshift of the 6dFGS our measurement of the growth rate is independent of the fiducial cosmological model (Alcock–Paczynski effect). We also show that our conclusions are not sensitive to the model adopted for non‐linear redshift‐space distortions. Using a Fisher matrix analysis we report predictions for constraints on fσ8 for the Wide‐field Australian SKA Pathfinder telescope L‐band Legacy All‐sky Blind surveY (WALLABY) and the proposed Transforming Astronomical Imaging surveys through Polychromatic Analysis of Nebulae (TAIPAN) survey. The WALLABY survey will be able to measure fσ8 with a precision of 4–10 per cent, depending on the modelling of non‐linear structure formation. This is comparable to the predicted precision for the best redshift bins of the Baryon Oscillation Spectroscopic Survey, demonstrating that low‐redshift surveys have a significant role to play in future tests of dark energy and modified gravity.

Abstract. We present the first fully and uniformly sampled, spatially complete H  survey of the entire Magellanic System with high velocity resolution (∆v = 1.0 km s −1 ), performed with the Parkes Telescope . Approximately 24 percent of the southern sky was covered by this survey on a ≈5 grid with an angular resolution of HPBW = 14. 1. A fully automated data-reduction scheme was developed for this survey to handle the large number of H  spectra (1.5 × 10 6 ). The individual Hanning smoothed and polarization averaged spectra have an rms brightness temperature noise of σ = 0.12 K. The final data-cubes have an rms noise of σ rms ≈ 0.05 K and an effective angular resolution of ≈16 . In this paper we describe the survey parameters, the datareduction and the general distribution of the H  gas. , if all H  gas is at the same distance of 55 kpc. Approximately two thirds of this H  gas is located close to the Magellanic Clouds (Magellanic Bridge and Interface Region), and 25% of the H  gas is associated with the Magellanic Stream. The Leading Arm has a four times lower H  mass than the Magellanic Stream, corresponding to 6% of the total H  mass of the gaseous features.We have analyzed the velocity field of the Magellanic Clouds and their neighborhood introducing a LMC-standard-of-rest frame. The H  in the Magellanic Bridge shows low velocities relative to the Magellanic Clouds suggesting an almost parallel motion, while the gas in the Interface Region has significantly higher relative velocities indicating that this gas is leaving the Magellanic Bridge building up a new section of the Magellanic Stream. The Leading Arm is connected to the Magellanic Bridge close to an extended arm of the LMC. The clouds in the Magellanic Stream and the Leading Arm show significant differences, both in the column density distribution and in the shapes of the line profiles. The H  gas in the Magellanic Stream is more smoothly distributed than the gas in the Leading Arm. These morphological differences can be explained if the Leading Arm is at considerably lower z-heights and embedded in a higher pressure ambient medium.