English

Minivoids in the Local Volume

Astrophysics 2008-11-26 v1

Abstract

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. Besides them, 24 middle-size "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. 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 ellipsoide approximation). Being arranged by the size of their volume, local voids follow power law of volumes-rankes dependence. A correlation Gamma-function of the Local Volume galaxies follows a power low 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 on their luminosity, but have appreciably higher hydrogen mass-to-luminosity ratio and also higher star formation rate. We recognize an effect of local expansion of typical minivoid to be \Delta H/H_0~(25+-15)%.

Cite

@article{arxiv.astro-ph/0609109,
  title  = {Minivoids in the Local Volume},
  author = {A. V. Tikhonov and I. D. Karachentsev},
  journal= {arXiv preprint arXiv:astro-ph/0609109},
  year   = {2008}
}

Comments

23 pages, 18 figures. Astrophysical Journal, accepted

R2 v1 2026-07-22T09:12:25.380Z