Herschel-ATLAS/GAMA: SDSS cross-correlation induced by weak lensing

We report a highly significant (>10σ) spatial correlation between galaxies with S350 μm ≥ 30 mJy detected in the equatorial fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) with estimated redshifts ≳ 1.5, and Sloan Digital Sky Survey (SDSS) or Galaxy And Mass Assembly (G...

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Bibliographic Details
Main Authors: Gonzalez-Nuevo, J., Lapi, A., Negrello, M., Danese, L., De Zotti, G., Amber, S., Baes, M., Bland-Hawthorn, J., Bourne, N., Brough, S., Bussmann, R.S., Cai, Z-Y., Cooray, A., Driver, S.P., Dunne, L., Dye, S., Eales, S., Ibar, E., Ivison, R., Liske, J., Loveday, J., Maddox, S., Micha owski, M.J., Robotham, A.S.G., Scott, D., Smith, M.W.L., Valiante, E., Xia, J-Q.
Format: Article
Published: Oxford University Press 2014
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Online Access:https://eprints.nottingham.ac.uk/42378/
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Summary:We report a highly significant (>10σ) spatial correlation between galaxies with S350 μm ≥ 30 mJy detected in the equatorial fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) with estimated redshifts ≳ 1.5, and Sloan Digital Sky Survey (SDSS) or Galaxy And Mass Assembly (GAMA) galaxies at 0.2 ≤ z ≤ 0.6. The significance of the cross-correlation is much higher than those reported so far for samples with non-overlapping redshift distributions selected in other wavebands. Extensive, realistic simulations of clustered sub-mm galaxies amplified by foreground structures confirm that the cross-correlation can be explained by weak gravitational lensing (μ < 2). The simulations also show that the measured amplitude and range of angular scales of the signal are larger than can be accounted for by galaxy–galaxy weak lensing. However, for scales ≲ 2 arcmin, the signal can be reproduced if SDSS/GAMA galaxies act as signposts of galaxy groups/clusters with halo masses in the range 1013.2–1014.5 M⊙. The signal detected on larger scales appears to reflect the clustering of such haloes.