Recovering dark-matter clustering from galaxies with Gaussianization

McCullagh, N.; Neyrinck, M.; Norberg, P.; Cole, S.

Abstract

The Gaussianization transform has been proposed as a method to remove the issues of scale-dependent galaxy bias and non-linearity from galaxy clustering statistics, but these benefits have yet to be thoroughly tested for realistic galaxy samples. In this paper, we test the effectiveness of the Gaussianization transform for different galaxy types by applying it to realistic simulated blue and red galaxy samples. We show that in real space, the shapes of the Gaussianized power spectra of both red and blue galaxies agree with that of the underlying dark matter, with the initial power spectrum, and with each other to smaller scales than do the statistics of the usual (untransformed) density field. However, we find that the agreement in the Gaussianized statistics breaks down in redshift space. We attribute this to the fact that red and blue galaxies exhibit very different fingers of god in redshift space. After applying a finger-of-god compression, the agreement on small scales between the Gaussianized power spectra is restored. We also compare the Gaussianization transform to the clipped galaxy density field and find that while both methods are effective in real space, they have more complicated behaviour in redshift space. Overall, we find that Gaussianization can be useful in recovering the shape of the underlying dark-matter power spectrum to k ∼ 0.5 h Mpc−1 and of the initial power spectrum to k ∼ 0.4 h Mpc−1 in certain cases at z = 0.

Citation

McCullagh, N., Neyrinck, M., Norberg, P., & Cole, S. (2016). Recovering dark-matter clustering from galaxies with Gaussianization. Monthly Notices of the Royal Astronomical Society, 457(4), 3652-3665. https://doi.org/10.1093/mnras/stw223

• Journal Article Type: Article
• Acceptance Date: Jan 23, 2016
• Online Publication Date: Jan 27, 2016
• Publication Date: Apr 21, 2016
• Deposit Date: Apr 5, 2016
• Publicly Available Date: Apr 7, 2016
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 457
• Issue: 4
• Pages: 3652-3665
• DOI: https://doi.org/10.1093/mnras/stw223
• Public URL: https://durham-repository.worktribe.com/output/1387610