Bibcode
Patiri, Santiago G.; Prada, Francisco; Holtzman, Jon; Klypin, Anatoly; Betancort-Rijo, J. E.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 372, Issue 4, pp. 1710-1720.
Advertised on:
11
2006
Citations
107
Refereed citations
98
Description
We present a comparison of the properties of galaxies in the most
underdense regions of the Universe, where the galaxy number density is
less than 10 per cent of the mean density, with galaxies from more
typical regions. We have compiled a sample of galaxies in 46 large
nearby voids that were identified using the Sloan Digital Sky Survey
DR4, which provides the largest coverage of the sky. We study the u - r
colour distribution, morphology, specific star formation rate (SFR) and
radial number density profiles for a total of 495 galaxies fainter than
Mr = -20.4 + 5 logh located inside the voids and compare
these properties with a control sample of field galaxies. We show that
there is an excess of blue galaxies inside the voids. However,
inspecting the properties of blue and red galaxies separately, we find
that galaxy properties such as colour distribution, bulge-to-total
ratios and concentrations are remarkably similar between the void and
overall sample. The void galaxies also show the same specific SFR at
fixed colour as the control galaxies. We compare our results with the
predictions of cosmological simulations of galaxy formation using the
Millennium Run semi-analytic galaxy catalogue. We show that the
properties of the simulated galaxies in large voids are in reasonably
good agreement with those found in similar environments in the real
Universe. To summarize, in spite of the fact that galaxies in voids live
in the least dense large-scale environment, this environment makes very
little impact on the properties of galaxies.