A variables IMF slope to fit the LCDM picture to observed high-z submillimeter sources

A. M. MUÑOZ; F. NAVARRETE; C. DEL P. LAGOS; N. D. PADILLA; CORA S. A.; T. E. TECCE

Distrito Federal

Conferencia; XIII Reunión Regional Latinoamericana de Astronomía; 2010

Using a Salpeter initial mass function (IMF) allows to describe fairly well a large variety of properties in galaxies. However, some studies have found that it is necessary to change it for a top-heavy IMF in starbursts to give an adequate prediction in the abundance of submillimeter galaxies (SMGs) at high redshifts. We show preliminary results of an implementation of a star formation intensity dependent IMF slope in a semi-analytic model of galaxy formation, which has been connected with a spectrophotometric code that provides an adequate treatment of reprocessed starlight by dust. We also explore systematic effects on the counts of submm sources coming from the beamsize of the receiver taking into account the spatial correlation of sources and foreground objects. This helps alleviate the discrepancies found between the model and the observations.