INVESTIGADORES
PAZ Dante Javier
congresos y reuniones científicas
Título:
Clues on void evolution-II. Measuring density and velocity profiles on SDSS galaxy redshift space distortions
Autor/es:
DANTE J. PAZ; LARES, MARCELO; CECCARELLI, LAURA; LAMBAS, DIEGO GARCÍA; PADILLA, NELSON D.
Lugar:
Ohio
Reunión:
Workshop; Cosmic Voids in the Next Generation of Galaxy Surveys Workshop; 2014
Institución organizadora:
The Center for Cosmology and Astro-Particle Physics (CCAPP) at The Ohio State University (OSU)
Resumen:
Using the redshift space distortions of void-galaxy cross-correlation
function we analyse the dynamics of voids embedded in different
environments. We compute the void-galaxy cross-correlation function in
the Sloan Digital Sky Survey (SDSS) in terms of distances taken along
the line of sight and projected into the sky. We analyse the distortions
on the cross-correlation isodensity levels and find anisotropic
isocontours consistent with expansion for large voids with smoothly
rising density profiles and collapse for small voids with overdense
shells surrounding them. Based on the linear approach of gravitational
collapse theory we developed a parametric model of the void-galaxy
redshift space cross-correlation function. We show that this model can
be used to successfully recover the underlying velocity and density
profiles of voids from redshift space samples. By applying this
technique to real data, we confirm the twofold nature of void dynamics:
large voids typically are in an expansion phase whereas small voids tend
to be surrounded by overdense and collapsing regions. These results are
obtained from the SDSS spectroscopic galaxy catalogue and also from
semi-analytic mock galaxy catalogues, thus supporting the viability of
the standard Lambdacold dark matter model to reproduce large-scale
structure and dynamics.