Orientation of Galactic Disks Around Illustris Voids

GARCIA LAMBAS, DIEGO; LARES, MARCELO; DÁVILA KURBÁN, FEDERICO

Mendoza

Congreso; Reunión Anual de la AAA 2017; 2017

The alignments of galactic disks with respect to the surrounding structures stores informationabout their formation and dynamical evolution. There is not a clear consensus on whether disks in voids have apreferential orientation with respect to the void?centric direction. Here we present an analysis of the orientationsof galactic disks near void walls in the Illustris simulation. Voids are identified as spherical underdense regionswith a threshold integrated density of at most 10 per cent the mean density in the simulation. We divide thegalaxy sample in high and low spin according to a Spin-Mass linear regression. The excess of disks oriented in agiven position with respect to the void?centric direction is computed with a novel statistical procedure. We findfive voids with radii of about 10 Mpc, out of which three present a significant excess of high?spin disks to reachthe void walls at an edge?on position. Also, disks with low spin show no significant signal for any of the voids inthe sample.