科研之友
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摘要
It remains challenging to detect the low surface brightness structures of faint high-z galaxies, which are key to understanding the structural evolution of galaxies. The technique of image stacking allows us to measure the averaged light profile beneath the detection limit and probe the extended structure of a group of galaxies. We carry out simulations to examine the recovery of the averaged surface brightness profile through stacking model Hubble Space Telescope/Advanced Camera for Surveys images of a set of galaxies as functions of the Sersic index (n), effective radius (R-e) and axis ratio (AR). The Sersic profile best fitting the radial profile of the stacked image is taken as the recovered profile, in comparison with the intrinsic mean profile of the model galaxies. Our results show that, in general, the structural parameters of the mean profile can be properly determined through stacking, though systematic biases need to be corrected when spreads of R-e and AR are counted. We find that the Sersic index is slightly overestimated and R-e is underestimated at AR < 0.5 because the stacked image appears to be more compact due to the presence of inclined galaxies; the spread of Re biases the stacked profile to have a higher Sersic index. We stress that the measurements of structural parameters through stacking should take these biases into account. We estimate the biases in the recovered structural parameters from stacks of galaxies when the samples have distributions of R-e, AR and n seen in local galaxies.
- 出版日期2016-12
- 单位中国科学院大学; 南京大学; 中国科学院紫金山天文台
