Properties of LSB galaxies at void walls

L. CECCARELLI; R. HERRERA-CAMUS; D. LAMBAS; G. GALAZ; N. PADILLA

Mar del Palta

Congreso; Reunión Anual de la Asociación Argentina de Astronomía; 2012

We study the relative abundance of low and high surface brightness galaxies (LSBGs and HSBGs) at void walls in the SDSS DR7.  We focus on galaxies of similar luminosity in equal local density environments. This analysis allows to distinguish the effect of the large-scale environment defined by the void geometry on galaxy. We compare galaxy fractions in the field, and in the void walls; the latter are defined as the volume of void shells of radius equal to that of the void.  We find a significant decrement, a factor ~ 4, of the relative fraction of blue, active star-forming LSBGs in equal mass groups at the void walls and the field. This decrement is  consistent with an increase of the fraction of blue, active star-forming HSBGs. By contrast, red LSBGs and HSBGs show  negligible changes. We argue that these results are consistent with a scenario where LSBGs with blue colors and strong star formation activity at the void walls are fueled by gas from the expanding void regions. This process could lead to LSBG to HSBG transformations.