Testing different stellar mass estimators at 1<z<2

TL;DR

This study evaluates the accuracy of stellar mass estimations for early-type galaxies at redshifts 1<z<2 using simulated data, highlighting the limitations of optical band measurements and the potential of near-IR data.

Contribution

It provides a quantitative assessment of how well different stellar mass estimators recover true galaxy parameters at high redshift using simulated SEDs.

Findings

Optical band stellar masses have larger uncertainties and often underestimate true values.

Near-IR bands yield more accurate stellar mass estimates.

The V-band M/L ratio is strongly underestimated even with recent color-based recipes.

Abstract

Physical parameters of galaxies (as luminosity, stellar mass, age) are often derived by means of the model templates which best fit their spectro-photometric data. We have performed a quantitative test aimed at exploring the ability of this procedure in recovering the physical parameters of early-type galaxies at 1<z<2. A wide range of simulated SEDs, reproducing those of early-type galaxies at 1<z<2 with assigned age and mass, are used to build mock photometric catalogs with wavelength coverage and photometric uncertainties similar to those of two topical surveys (i.e. VVDS and GOODS). The best fitting analysis of the simulated photometric data allows to study the differences among the recovered parameters and the input ones. Results indicate that the stellar masses measured by means of optical bands are affected by larger uncertainties with respect to those obtained from near-IR bands, and they frequently underestimate the real values. The M/L ratio in the V band results strongly underestimated, even when derived from the recently proposed recipe based on rest-frame optical colours (e.g. (B-V)).