Mid-infrared diagnostics to distinguish AGNs from starbursts

We present new mid-infrared (MIR) diagnostics to distinguish emission of active galactic nuclei (AGN) from that originating in starburst regions. Our method uses empirical spectroscopic criteria based on the fact that MIR emission from star forming or active galaxies arises mostly from HII regions,...

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Detalles Bibliográficos
Publicado: 2000
Materias:
Galaxies: active
Galaxies: starburst
Infrared: galaxies
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v359_n3_p887_Laurent
http://hdl.handle.net/20.500.12110/paper_00046361_v359_n3_p887_Laurent
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00046361_v359_n3_p887_Laurent
record_format dspace
spelling paper:paper_00046361_v359_n3_p887_Laurent2025-07-30T17:10:56Z Mid-infrared diagnostics to distinguish AGNs from starbursts Galaxies: active Galaxies: starburst Infrared: galaxies We present new mid-infrared (MIR) diagnostics to distinguish emission of active galactic nuclei (AGN) from that originating in starburst regions. Our method uses empirical spectroscopic criteria based on the fact that MIR emission from star forming or active galaxies arises mostly from HII regions, photo-dissociation regions (PDRs) and AGNs. The analysis of the strength of the 6.2 μm Unidentified Infrared Band (UIB) and the MIR continuum shows that UIBs are very faint or absent in regions harboring the intense and hard radiation fields of AGNs and pure HII regions, where the UIB carriers could be destroyed. The MIR signature of AGNs is the presence of an important continuum in the 3-10 μm band which originates from very hot dust heated by the intense AGN radiation field. Using these two distinct spectral properties found in our MIR templates, we build diagnostic diagrams which provide quantitative estimates of the AGN, PDR and HII region contribution in a given MIR spectrum. This new MIR classification can be used to reveal the presence of AGNs highly obscured by large columns of dust. 2000 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v359_n3_p887_Laurent http://hdl.handle.net/20.500.12110/paper_00046361_v359_n3_p887_Laurent
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Galaxies: active
Galaxies: starburst
Infrared: galaxies
spellingShingle Galaxies: active
Galaxies: starburst
Infrared: galaxies
Mid-infrared diagnostics to distinguish AGNs from starbursts
topic_facet Galaxies: active
Galaxies: starburst
Infrared: galaxies
description We present new mid-infrared (MIR) diagnostics to distinguish emission of active galactic nuclei (AGN) from that originating in starburst regions. Our method uses empirical spectroscopic criteria based on the fact that MIR emission from star forming or active galaxies arises mostly from HII regions, photo-dissociation regions (PDRs) and AGNs. The analysis of the strength of the 6.2 μm Unidentified Infrared Band (UIB) and the MIR continuum shows that UIBs are very faint or absent in regions harboring the intense and hard radiation fields of AGNs and pure HII regions, where the UIB carriers could be destroyed. The MIR signature of AGNs is the presence of an important continuum in the 3-10 μm band which originates from very hot dust heated by the intense AGN radiation field. Using these two distinct spectral properties found in our MIR templates, we build diagnostic diagrams which provide quantitative estimates of the AGN, PDR and HII region contribution in a given MIR spectrum. This new MIR classification can be used to reveal the presence of AGNs highly obscured by large columns of dust.
title Mid-infrared diagnostics to distinguish AGNs from starbursts
title_short Mid-infrared diagnostics to distinguish AGNs from starbursts
title_full Mid-infrared diagnostics to distinguish AGNs from starbursts
title_fullStr Mid-infrared diagnostics to distinguish AGNs from starbursts
title_full_unstemmed Mid-infrared diagnostics to distinguish AGNs from starbursts
title_sort mid-infrared diagnostics to distinguish agns from starbursts
publishDate 2000
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v359_n3_p887_Laurent
http://hdl.handle.net/20.500.12110/paper_00046361_v359_n3_p887_Laurent
_version_ 1840324081436590080

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