4 research outputs found
Stellar populations in local AGNs: evidence for enhanced star formation in the inner 100 pc
Galaxie
The AGNIFS survey: distribution and excitation of the hot molecular and ionized gas in the inner kpc of nearby AGN hosts
Galaxie
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
Gemini NIFS survey of feeding and feedback processes in nearby active galaxies – II. The sample and surface mass density profiles
We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14–195 keV luminosities LX ≥ 1041.5 erg s−1, redshift z ≤ 0.015, being accessible for observations with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended [O III]λ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H II) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS. We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density (Σ) profiles for H II and H2 in their inner ∼500  pc, showing that H II emission presents a steeper radial gradient than H2. This can be attributed to the different excitation mechanisms: ionization by AGN radiation for H II and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ ΣH II ≤ 35.9) M⊙ pc−2, and (0.2 ≤ ΣH2 ≤ 13.9)× 10−3 M⊙ pc−2, while the ratios between the H II and H2 masses range between ∼200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity