Probing evolutionary population synthesis models in the near infrared with early-type galaxies

We performed a near-infrared (NIR; ~1.0 -2.4 μm) stellar population study in a sample of early-type galaxies. The synthesis was performed using five different evolutionary population synthesis libraries of models. Our main results can be summarized as follows: low-spectral-resolution libraries are not able to produce reliable results when applied to the NIR alone, with each library finding a different dominant population. The two newest higher resolution models, on the other hand, perform considerably better, finding consistent results to each other and to literature values. We also found that optical results are consistent with each other even for lower resolution models. We also compared optical and NIR results and found out that lower resolution models tend to disagree in the optical and in the NIR, with higher fraction of young populations in the NIR and dust extinction ~1 mag higher than optical values. For higher resolution models, optical and NIR results tend to agree much better, suggesting that a higher spectral resolution is fundamental to improve the quality of the results.© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
LGDH thanks CAPES and CNPq. RR thanks CNPq and FAPERGS for partial funding of this project. ARA thanks CNPq for partial support to this work. LPM thanks CNPQ and FAPESP for partial funding of this project. CK acknowledges support through the research project AYA2017-79724-C4-4-P from the Spanish PNAYA. This research made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This study uses data provided by the Calar Alto Legacy Integral Field Area (CALIFA) survey (http://califa.caha.es/). Based on observations collected at the Centro Astronomico Hispano Aleman (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut fur Astronomie and the Instituto de Astrofisica de Andalucia (CSIC). We thank the referee Reynier Peletier for carefully reading our paper and for giving such constructive comments which substantially helped improving the quality of the paper.