20–28 Mar 2025
Emperors Palace Hotel Casino Convention Resort
Africa/Johannesburg timezone

Emission line properties of type-2 AGN in the Lockman-SpReSO survey

27 Mar 2025, 11:30
15m
Emperors Palace Hotel Casino Convention Resort

Emperors Palace Hotel Casino Convention Resort

64 Jones Rd, Kempton Park, Johannesburg, 1620
Talk Galaxies Science

Speaker

Ms Bereket Assefa (Debre Berhan University, Ethiopia)

Description

Context. Active galactic nuclei (AGN) are some of the brightest sources in the Universe, emitting light at all wavelengths due to their complex structure. Deep multiwavelength extragalactic surveys are therefore important for understanding the full physics of AGN and their role in the formation and evolution of galaxies. The Lockman-SpReSO survey is one of the deepest multiwavelength spectroscopic surveys in the far-infrared (FIR). It is a unique sample of AGN with deep FIR and optical spectroscopic data obtained using Herschel and the GTC 10m telescopes, respectively. Using Lockman-SpReSO, it is possible to study the relationship between the fundamental FIR and optical properties of galaxies.
Aims. To better understand the optical spectroscopic properties of type-2 FIR AGN by characterizing the emission line properties and comparing them with the FIR properties.
Methods. We first obtain the emission spectra of AGN by running the Starlight code and by subtracting the continuum plus absorption spectra. Using the strong emission lines, we measure the line intensity, full width at half maximum (FWHM), and the equivalent width (EW) of all identified lines.
Results. Our analysis revealed that FIR-detected type-2 AGN exhibit similar strong emission lines to optically-selected AGN. We constructed a comprehensive catalog of emission line measurements for 71 sources, which will be made publicly available. We found correlations between emission line luminosities and AGN luminosity, SFR, and IR luminosity, suggesting connections between the AGN, surrounding gas, star formation, and dust properties. We also show that for the FIR-detected AGN, there is a relation between type-2 AGN luminosity and SFR.

Stream Science

Primary author

Ms Bereket Assefa (Debre Berhan University, Ethiopia)

Co-author

Prof. Mirjana Povi'c (Space Science and Geospatial Institute (SSGI), Ethiopia)

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