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外文期刊>The Astrophysical journal
>COMPARING DYNAMICAL AND PHOTOMETRIC MASS ESTIMATES OF LOW- AND HIGH-REDSHIFT GALAXIES: RANDOM AND SYSTEMATIC UNCERTAINTIES
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COMPARING DYNAMICAL AND PHOTOMETRIC MASS ESTIMATES OF LOW- AND HIGH-REDSHIFT GALAXIES: RANDOM AND SYSTEMATIC UNCERTAINTIES
We determine the importance of redshift-dependent systematic effects in the determination of stellar masses from broadband spectral energy distributions (SEDs), using high-quality kinematic and photometric data of early-type galaxies at z ～ 1 and z ～ 0. We find that photometric masses of z ～ 1 galaxies can be systematically different, by up to a factor of 2, from photometric masses of z ～ 0 galaxies with the same dynamical mass. The magnitude of this bias depends on the choice of stellar population synthesis model and the rest-frame wavelength range used in the fits. The best result, i.e., without significant bias, is obtained when rest-frame optical SEDs are fitted with models from Bruzual & Chariot. When the SEDs are extended to the rest-frame near-IR, a bias is introduced: photometric masses of the z ～ 1 galaxies increase by a factor of 2 relative to the photometric masses of the z ～ 0 galaxies. When we use the Maraston models, the photometric masses of the z ～ 1 galaxies are low relative to the photometric masses of the z ～ 0 galaxies by a factor of ～ 1.8. This offset occurs both for fits based on rest-frame optical SEDs and fits based on rest-frame optical+near-IR SEDs. The results indicate that model uncertainties produce uncertainties as high as a factor of 2.5 in mass estimates from rest-frame near-IR photometry, independent of uncertainties due to unknown star formation histories.
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