The scale of homogeneity in the local Universe with the ALFALFA catalogue

Abstract

We use the scaled counts in spherical caps $\mathcal{N}(<\theta )$ and the fractal correlation dimension ${\mathcal{D}}_2(\theta )$ procedures to search for a transition scale to homogeneity in the local universe as given by the ALFALFA catalogue (a sample of extragalactic HI line sources, in the redshift range $0<z<0.06$). Our analyses, in the 2-dimensional sky projected data, show a transition to homogeneity at ${\theta }_H=16.49^{\circ }\pm 0.29^{\circ }$, in remarkable accordance with the angular scale expected from simulations, a result that strengthens the validity of the cosmological principle in the local universe. We test the robustness of our results by analysing the data sample using three versions of the $\mathcal{N}(<\theta )$ estimator, which show a well agreement between them. These statistical estimators were validated using mock realizations generated assuming a fractal distribution of points, successfully recovering the input information. In addition, we perform further analyses showing that our approach is also able to indicate the presence of under- and over-densities in the data. Finally, we verify the influence of the sample size to the ${\theta }_H$ estimates by using segment Cox processes of different projected areas, confirming the suitability of the ALFALFA surveyed area for the current analyses.

15 pages, 7 figures

References in corpus (21)

• The Arecibo Legacy Fast ALFA Survey: The ALFALFA Extragalactic HI Source Catalog
• Planck 2018 results. VII. Isotropy and Statistics of the CMB
• The ALFALFA HI mass function: A dichotomy in the low-mass slope and a locally suppressed 'knee' mass
• The Extended Virgo Cluster Catalog
• Angular Baryon Acoustic Oscillation measure at z=2.225 from the SDSS quasar survey
• Homogeneity and isotropy in the 2MASS Photometric Redshift catalogue
• Dipolar modulation in number counts of WISE-2MASS sources
• Large scale structure in the HI Parkes All-Sky Survey: Filling the Voids with HI galaxies?
• Testing Isotropic Universe Using the Gamma-Ray Burst Data of Fermi / GBM
• Cosmic homogeneity: a spectroscopic and model-independent measurement
• Measuring the scale of cosmic homogeneity with SDSS-IV DR14 quasars
• On the large-scale angular distribution of short-Gamma ray bursts
• Isotropy analyses of the Planck convergence map
• Probing statistical isotropy of cosmological radio sources using SKA
• The scale of cosmic homogeneity as a standard ruler
• North-South non-Gaussian asymmetry in PLANCK CMB maps
• HI gas content of SDSS galaxies revealed by ALFALFA: implications for the mass-metallicity relation and the environmental dependence of HI in the local Universe
• Tomographic local 2D analyses of the WISExSuperCOSMOS all-sky galaxy catalogue
• CMB low multipole alignments in the $\mathbf{\Lambda }$CDM and Dipolar models
• Topology and the suppression of CMB large-angle correlations
• The many scales to cosmic homogeneity: Use of multiple tracers from the SDSS

Cited by in corpus (21)

• BAO angular scale at z_eff = 0.11 with the SDSS blue galaxies
• Inferring $S_8(z)$ and $\gamma (z)$ with cosmic growth rate measurements using machine learning
• The growth rate of cosmic structures in the local Universe with the ALFALFA survey
• Exploring galaxy colour in different environments of the cosmic web with SDSS
• Baryon acoustic oscillations signature in the three-point angular correlation function from the SDSS-DR12 quasar survey
• The angular scale of homogeneity in the Local Universe with the SDSS blue galaxies
• The homogeneity scale and the growth rate of cosmic structures
• Update on Testing the Isotropy of the Properties of Gamma-Ray Bursts
• The scale of cosmic homogeneity as a standard ruler
• Probing cosmic isotropy in the Local Universe
• HI gas content of SDSS galaxies revealed by ALFALFA: implications for the mass-metallicity relation and the environmental dependence of HI in the local Universe
• Cosmological homogeneity scale estimates are dressed
• Unravelling the Cosmic Web: An analysis of the SDSS DR14 with the Local Dimension
• Reconstructing the growth index $\gamma$ with Gaussian Processes
• The bulk flow motion and the Hubble-Lema\^ıtre law in the Local Universe with the ALFALFA survey
• Measuring the matter fluctuations in the Local Universe with the ALFALFA catalog
• The BINGO project VIII: On the recoverability of the BAO signal on HI intensity mapping simulations
• Baryon acoustic scale at $z_{\eff} = 0.166$ with the SDSS blue galaxies
• All-sky angular power spectra from cleaned WISE$\times$SuperCOSMOS galaxy number counts
• Probing large-scale structures with the two-point function and the power spectrum: insights into cosmic clustering evolution
• Cosmological constraints from cosmic homogeneity