Nearby active and starburst galaxies as seen with ISOCAM
We present a set of spectral characteristics distinguishing optically selected active galactic nuclei (AGNs) from starbursts in the mid-IR. In AGN spectra, the Unidentified Infrared Bands (UIBs) are not detected which is probably due to the destruction of their carriers by the UV-X radiation field....
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1999
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v269-270_n1-4_p357_Laurent http://hdl.handle.net/20.500.12110/paper_0004640X_v269-270_n1-4_p357_Laurent |
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paper:paper_0004640X_v269-270_n1-4_p357_Laurent2023-06-08T14:29:30Z Nearby active and starburst galaxies as seen with ISOCAM We present a set of spectral characteristics distinguishing optically selected active galactic nuclei (AGNs) from starbursts in the mid-IR. In AGN spectra, the Unidentified Infrared Bands (UIBs) are not detected which is probably due to the destruction of their carriers by the UV-X radiation field. In addition, a non-negligible continuum below 10 μm commonly associated with emission from very hot dust is exclusively present in AGNs. On the contrary, starburst spectra present clearly detected UIBs with a faint underlying continuum between 5-10 μm. Based on these features, we build a mid-IR diagnostic diagram to identify emission induced by the AGN and that associated with the star formation activity. This diagnostic based on the mid-IR continuum and the UIB intensity allows us to estimate the relative importance of the three components (HII regions, photo-dissociation regions (PDRs), and AGN) contained in the integrated mid-IR emission of galaxies. Our diagnostic diagram can be applied to reveal the presence of very obscured active nuclei behind large columns of dust. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v269-270_n1-4_p357_Laurent http://hdl.handle.net/20.500.12110/paper_0004640X_v269-270_n1-4_p357_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 set of spectral characteristics distinguishing optically selected active galactic nuclei (AGNs) from starbursts in the mid-IR. In AGN spectra, the Unidentified Infrared Bands (UIBs) are not detected which is probably due to the destruction of their carriers by the UV-X radiation field. In addition, a non-negligible continuum below 10 μm commonly associated with emission from very hot dust is exclusively present in AGNs. On the contrary, starburst spectra present clearly detected UIBs with a faint underlying continuum between 5-10 μm. Based on these features, we build a mid-IR diagnostic diagram to identify emission induced by the AGN and that associated with the star formation activity. This diagnostic based on the mid-IR continuum and the UIB intensity allows us to estimate the relative importance of the three components (HII regions, photo-dissociation regions (PDRs), and AGN) contained in the integrated mid-IR emission of galaxies. Our diagnostic diagram can be applied to reveal the presence of very obscured active nuclei behind large columns of dust. |
title |
Nearby active and starburst galaxies as seen with ISOCAM |
spellingShingle |
Nearby active and starburst galaxies as seen with ISOCAM |
title_short |
Nearby active and starburst galaxies as seen with ISOCAM |
title_full |
Nearby active and starburst galaxies as seen with ISOCAM |
title_fullStr |
Nearby active and starburst galaxies as seen with ISOCAM |
title_full_unstemmed |
Nearby active and starburst galaxies as seen with ISOCAM |
title_sort |
nearby active and starburst galaxies as seen with isocam |
publishDate |
1999 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004640X_v269-270_n1-4_p357_Laurent http://hdl.handle.net/20.500.12110/paper_0004640X_v269-270_n1-4_p357_Laurent |
_version_ |
1768543305199517696 |