2006/09/05 by A. V. Tikhonov, Anton V. Tikhonov, I. D. Karachentsev +1 · 77 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Local Group #Power law #SPHERES #Statistical Mechanics and Entropy #Void (composites) #Volume (thermodynamics) #astro-ph
paper · pdf · doi:10.1086/508981
published in The Astrophysical Journal 653(2), 969-976 (IOP Publishing) · 23 pages, 18 figures. Astrophysical Journal, accepted
arxiv created 2006/09/05 · openalex publication_date 2006/12/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider a sphere of 7.5 Mpc radius, which contains 355 galaxies with accurately measured distances, to detect the nearest empty volumes. Using a simple void detection algorithm, we found six large (mini)voids in Aquila, Eridanus, Leo, Vela, Cepheus, and Octans, each of more than 30 Mpc 3 . In addition, 24 middle-sized "bubbles" of more than 5 Mpc 3 volume are detected, as well as 52 small "pores." The six largest minivoids occupy 58% of the considered volume. The addition of the bubbles and pores to them increases the total empty volume up to 75% and 81%, respectively. The detected local voids look like oblong potatoes with typical axial ratios b / a = 0.75 and c / a = 0.62 (in the triaxial ellipsoid approximation). Being arranged by the size of their volume, local voids follow a power law for volume-rank dependence. A correlation Gamma function of the Local Volume galaxies follows a power law with a formally calculated fractal dimension D = 1.5. We found that galaxies surrounding the local minivoids do not differ significantly from other nearby galaxies in their luminosity, but have appreciably higher hydrogen mass-to-luminosity ratios and also higher star formation rates. We recognize an effect of the local expansion of a typical minivoid to be Δ H / H 0 ~ (25 ± 15)%.