Severo Ochoa Seminar by Prof. A. Rodríguez Ardila

On Tuesday December 9th, the Severo Ochoa visitor Prof. Alberto Rodríguez Ardila, from the Laboratório Nacional de Astrofísica and Universidade Federal de Itajubá (Itajubá, Brazil), will give a Severo Ochoa Seminar, entitled FeII emission in active galactic nuclei: results from NIR Spectroscopy.

Start date: 9 Dec, 2014 - 10:30
End date: 9 Dec, 2014 - 12:00
Location: Aula, IAC Headquarters, Tenerife.
Organizer: IAC

Abstract:

FeII comprises up to one third of the line emission in AGNs. For that reason it is an important coolant that needs to be taken into account to fully understand the energetics of the broad line region (BLR). In this talk I will discuss new approaches to study the excitation mechanisms of the FeII based on a semi-empirical template we derived in the near-infrared region (NIR). We correlate the strength of the NIR and optical iron lines to assess the relative contribution of the different mechanisms that produces that emission. We found that in all cases Ly_alpha fluorescence plays an important role, being a process that needs to be considered in any approach aimed at understanding this complex emission. We also compare the width of the individual FeII lines with that of other lines emitted in BLR. Our results confirm previous assumptions and results from variability studies that the gas responsible for the FeII emission is the outer portion of the BLR.