A new mid-infrared diagnostic between agn and starbursts

We present a new set of diagnostics which allow us to trace and classify in a statistical manner the mid-IR emission produced by active galactic nuclei (AGN) and star-forming regions. We construct a diagram based on the strength of the unidentified infrared band (UIB) at 6.2 μm, and the intensity of...

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Publicado: 2001
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v276_n2-4_p569_Laurent
http://hdl.handle.net/20.500.12110/paper_0004640X_v276_n2-4_p569_Laurent
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_0004640X_v276_n2-4_p569_Laurent
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spelling paper:paper_0004640X_v276_n2-4_p569_Laurent2023-06-08T14:29:31Z A new mid-infrared diagnostic between agn and starbursts We present a new set of diagnostics which allow us to trace and classify in a statistical manner the mid-IR emission produced by active galactic nuclei (AGN) and star-forming regions. We construct a diagram based on the strength of the unidentified infrared band (UIB) at 6.2 μm, and the intensity of the continuum at short (6 μm) and long wavelengths (15 μm). We interpret the integrated mid-IR emission in late-type galaxies as resulting from three individual contributions coming from HII regions, diffuse/photodissociation regions (PDRs), and AGN. Based on this assumption, our diagnostic diagram provides a quantitative estimate of the AGN and starburst contribution to an observed mid-IR spectrum. We show that UIB emission is very faint or absent in regions harbouring intense and hard radiation fields as in the case of AGN or 'pure' HII starburst regions where UIB carriers can be destroyed by photodissociation. However, contrary to starburst spectra, typical AGN spectra present a strong hot continuum below 9 μm originating from hot dust heated by the AGN radiation field. An extrapolation of this diagnostic towards other mid-IR observations should improve our knowledge of the AGN/starburst connection. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v276_n2-4_p569_Laurent http://hdl.handle.net/20.500.12110/paper_0004640X_v276_n2-4_p569_Laurent
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description We present a new set of diagnostics which allow us to trace and classify in a statistical manner the mid-IR emission produced by active galactic nuclei (AGN) and star-forming regions. We construct a diagram based on the strength of the unidentified infrared band (UIB) at 6.2 μm, and the intensity of the continuum at short (6 μm) and long wavelengths (15 μm). We interpret the integrated mid-IR emission in late-type galaxies as resulting from three individual contributions coming from HII regions, diffuse/photodissociation regions (PDRs), and AGN. Based on this assumption, our diagnostic diagram provides a quantitative estimate of the AGN and starburst contribution to an observed mid-IR spectrum. We show that UIB emission is very faint or absent in regions harbouring intense and hard radiation fields as in the case of AGN or 'pure' HII starburst regions where UIB carriers can be destroyed by photodissociation. However, contrary to starburst spectra, typical AGN spectra present a strong hot continuum below 9 μm originating from hot dust heated by the AGN radiation field. An extrapolation of this diagnostic towards other mid-IR observations should improve our knowledge of the AGN/starburst connection.
title A new mid-infrared diagnostic between agn and starbursts
spellingShingle A new mid-infrared diagnostic between agn and starbursts
title_short A new mid-infrared diagnostic between agn and starbursts
title_full A new mid-infrared diagnostic between agn and starbursts
title_fullStr A new mid-infrared diagnostic between agn and starbursts
title_full_unstemmed A new mid-infrared diagnostic between agn and starbursts
title_sort new mid-infrared diagnostic between agn and starbursts
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v276_n2-4_p569_Laurent
http://hdl.handle.net/20.500.12110/paper_0004640X_v276_n2-4_p569_Laurent
_version_ 1768544757408071680

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