Voids and superstructures: correlations and induced large-scale velocity flows

CECCARELLI, LAURA; MALDONADO, VICTORIA; GARCIA LAMBAS, DIEGO; RUIZ, ANDRÉS N.; LARES, MARCELO; PAZ, DANTE J.; LUPARELLO, HELIANA E.; CECCARELLI, LAURA; MALDONADO, VICTORIA; GARCIA LAMBAS, DIEGO; RUIZ, ANDRÉS N.; LARES, MARCELO; PAZ, DANTE J.; LUPARELLO, HELIANA E.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2017 vol. 470 p. 85 - 94

0035-8711

The expanding complex pattern of filaments, walls and voids build theevolving cosmic web with material flowing from underdense on to highdensity regions. Here, we explore the dynamical behaviour of voids andgalaxies in void shells relative to neighbouring overdensesuperstructures, using the Millenium simulation and the main galaxycatalogue in Sloan Digital Sky Survey data. We define a correlationmeasure to estimate the tendency of voids to be located at a givendistance from a superstructure. We find voids-in-clouds (S-types)preferentially located closer to superstructures than voids-in-voids(R-types) although we obtain that voids within ?40 h-1Mpc of superstructures are infalling in a similar fashion independentlyof void type. Galaxies residing in void shells show infall towards theclosest superstructure, along with the void global motion, with adifferential velocity component depending on their relative position inthe shell with respect to the direction to the superstructure. Thiseffect is produced by void expansion and therefore is stronger forR-types. We also find that galaxies in void shells facing thesuperstructure flow towards the overdensities faster than galaxieselsewhere at the same relative distance to the superstructure. Theresults obtained for the simulation are also reproduced for the SkySurvey Data Release data with a linearized velocity fieldimplementation.