Tomographic local 2D analyses of the WISExSuperCOSMOS all-sky galaxy catalogue

Abstract

The recent progress in obtaining larger and deeper galaxy catalogues is of fundamental importance for cosmological studies, especially to robustly measure the large scale density fluctuations in the Universe. The present work uses the Minkowski Functionals (MF) to probe the galaxy density field from the WISExSuperCOSMOS (WSC) all-sky catalogue by performing tomographic local analyses in five redshift shells (of thickness δz = 0.05) in the total range of 0.10 < z < 0.35. Here, for the first time, the MF are applied to 2D projections of the galaxy number count (GNC) fields with the purpose of looking for regions in the WSC catalogue with unexpected features compared to ΛCDM mock realisations. Our methodology reveals 1 -3 regions of the GNC maps in each redshift shell with an uncommon behaviour (extreme regions), i.e., p-value < 1.4%. Indeed, the resulting MF curves show signatures that suggest the uncommon behaviour to be associated with the presence of over-or underdensities there, but contamination due to residual foregrounds is not discarded. Additionally, even though our analyses indicate a good agreement among data and simulations, we identify 1 highly extreme region, seemingly associated to a large clustered distribution of galaxies. Our results confirm the usefulness of the MF to analyse GNC maps from photometric galaxy datasets.

The angular scale of homogeneity in the local Universe with the SDSS blue galaxies

“…The statistical isotropy of the universe is being tested for many extragalactic objects like Radio sources (Blake & Wall 2002;Ghosh et al 2016), Gamma-ray bursts (Bernui et al 2008a;Tarnopolski 2017;Řípa & Shafiello 2018), galaxy clusters (Bengaly et al 2017a), and galaxy datasets like the WISE (Yoon et al 2014;Bengaly et al 2017b;Novaes et al 2018) and the SDSS catalogues (Sarkar et al 2019), where all these analyses show a good concordance with the isotropy of the universe. The Planck Convergence and Cosmic Microwave Background temperature fluctuations maps have been examined and are also consistent with statistical isotropy at small angular scales (Ade et al 2016;Novaes et al 2016;Marques et al 2018), although some controversy remains at large angles (Bernui 2008b;Gruppuso et al 2013; Polase-mail: felipeavila@on.br tri, Gruppuso & Natoli 2015;Schwarz et al 2016;Aluri, Ralston & Weltman 2017;Rath et al 2017;Bernui et al 2018).…”

BAO angular scale at z_eff = 0.11 with the SDSS blue galaxies

“…In the 2D analysis, the 2PACF (Peebles & Yu 1970;Landy & Szalay 1993) estimates the angular correlation for data pairs projected on the celestial sphere (for alternative clustering analyses, see, e.g., Avila et al 2018Avila et al , 2019Bengaly et al 2017;Feldbrugge et al 2019;Novaes et al 2016Novaes et al , 2018Marques & Bernui 2020a;Marques et al 2020b;Pandey & Sarkar 2020;Sosa & Niz 2020).…”

Baryon acoustic oscillations signature in the three-point angular correlation function from the SDSS-DR12 quasar survey

“…The 3PCF is a complementary tool to characterize the clustering of cosmological tracers like galaxies, quasars, etc. For other applications of the 3PCF see, e.g., Fry & Seldner (1982) (2011); Marín et al (2013); for alternative statistical tools and clustering analyses see, e.g., Novaes et al (2014Novaes et al ( , 2016Novaes et al ( , 2018; Marques et al (2018Marques et al ( , 2019. Basically, the 3PCF compares the number of triplets of cosmic objects from a dataset that form a triangle configuration, to be called DDD, with respect to the number of triplets from a simulated random set of data, termed RRR.…”