ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808

We present results of mid-infrared λ = 5.0-16.5 μm spectrophotometric imaging of the starburst galaxies M 82, NGC 253, and NGC 1808 from the ISOCAM instrument on board the Infrared Space Observatory. The mid-infrared spectra of the three galaxies are very similar in terms of features present. The λ...

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Autores principales: Förster Schreiber, N.M., Sauvage, M., Charmandaris, V., Laurent, O., Gallais, P., Mirabel, I.F., Vigroux, L.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00046361_v399_n3_p833_ForsterSchreiber
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spelling todo:paper_00046361_v399_n3_p833_ForsterSchreiber2023-10-03T14:00:02Z ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808 Förster Schreiber, N.M. Sauvage, M. Charmandaris, V. Laurent, O. Gallais, P. Mirabel, I.F. Vigroux, L. Galaxies: individual: M 82, NGC 253, NGC 1808 Galaxies: ISM Galaxies: starburst Infrared: galaxies Infrared: ISM Aromatic hydrocarbons Galaxies Infrared imaging Light emission Observatories Spectrophotometry Infrared emission Infrared space observatory Nuclear starburst Starburst galaxies Astrophysics We present results of mid-infrared λ = 5.0-16.5 μm spectrophotometric imaging of the starburst galaxies M 82, NGC 253, and NGC 1808 from the ISOCAM instrument on board the Infrared Space Observatory. The mid-infrared spectra of the three galaxies are very similar in terms of features present. The λ ≳ 11 μm continuum attributed to very small dust grains (VSGs) exhibits a large spread in intensity relative to the short-wavelength emission. We find that the 15 μm dust continuum flux density correlates well with the fine-structure [Ar II] 6.99 μm line flux and thus provides a good quantitative indicator of the level of star formation activity. By contrast, the λ = 5-11 μm region dominated by emission from polycyclic aromatic hydrocarbons (PAHs) has a nearly invariant shape. Variations in the relative intensities of the PAH features are nevertheless observed, at the 20%-100% level. We illustrate extinction effects on the shape of the mid-infrared spectrum of obscured starbursts, emphasizing the differences depending on the applicable extinction law and the consequences for the interpretation of PAH ratios and extinction estimates. The relative spatial distributions of the PAH, VSG, and [Ar II] 6.99 μm emission between the three galaxies exhibit remarkable differences. The ≲1 kpc size of the mid-infrared source is much smaller than the optical extent of our sample galaxies and 70%-100% of the IRAS 12 μm flux is recovered within the ISOCAM ≤ 1.5 arcmin2 field of view, indicating that the nuclear starburst dominates the total mid-infrared emission while diffuse light from quiescent disk star formation contributes little. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00046361_v399_n3_p833_ForsterSchreiber
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: individual: M 82, NGC 253, NGC 1808
Galaxies: ISM
Galaxies: starburst
Infrared: galaxies
Infrared: ISM
Aromatic hydrocarbons
Galaxies
Infrared imaging
Light emission
Observatories
Spectrophotometry
Infrared emission
Infrared space observatory
Nuclear starburst
Starburst galaxies
Astrophysics
spellingShingle Galaxies: individual: M 82, NGC 253, NGC 1808
Galaxies: ISM
Galaxies: starburst
Infrared: galaxies
Infrared: ISM
Aromatic hydrocarbons
Galaxies
Infrared imaging
Light emission
Observatories
Spectrophotometry
Infrared emission
Infrared space observatory
Nuclear starburst
Starburst galaxies
Astrophysics
Förster Schreiber, N.M.
Sauvage, M.
Charmandaris, V.
Laurent, O.
Gallais, P.
Mirabel, I.F.
Vigroux, L.
ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
topic_facet Galaxies: individual: M 82, NGC 253, NGC 1808
Galaxies: ISM
Galaxies: starburst
Infrared: galaxies
Infrared: ISM
Aromatic hydrocarbons
Galaxies
Infrared imaging
Light emission
Observatories
Spectrophotometry
Infrared emission
Infrared space observatory
Nuclear starburst
Starburst galaxies
Astrophysics
description We present results of mid-infrared λ = 5.0-16.5 μm spectrophotometric imaging of the starburst galaxies M 82, NGC 253, and NGC 1808 from the ISOCAM instrument on board the Infrared Space Observatory. The mid-infrared spectra of the three galaxies are very similar in terms of features present. The λ ≳ 11 μm continuum attributed to very small dust grains (VSGs) exhibits a large spread in intensity relative to the short-wavelength emission. We find that the 15 μm dust continuum flux density correlates well with the fine-structure [Ar II] 6.99 μm line flux and thus provides a good quantitative indicator of the level of star formation activity. By contrast, the λ = 5-11 μm region dominated by emission from polycyclic aromatic hydrocarbons (PAHs) has a nearly invariant shape. Variations in the relative intensities of the PAH features are nevertheless observed, at the 20%-100% level. We illustrate extinction effects on the shape of the mid-infrared spectrum of obscured starbursts, emphasizing the differences depending on the applicable extinction law and the consequences for the interpretation of PAH ratios and extinction estimates. The relative spatial distributions of the PAH, VSG, and [Ar II] 6.99 μm emission between the three galaxies exhibit remarkable differences. The ≲1 kpc size of the mid-infrared source is much smaller than the optical extent of our sample galaxies and 70%-100% of the IRAS 12 μm flux is recovered within the ISOCAM ≤ 1.5 arcmin2 field of view, indicating that the nuclear starburst dominates the total mid-infrared emission while diffuse light from quiescent disk star formation contributes little.
format JOUR
author Förster Schreiber, N.M.
Sauvage, M.
Charmandaris, V.
Laurent, O.
Gallais, P.
Mirabel, I.F.
Vigroux, L.
author_facet Förster Schreiber, N.M.
Sauvage, M.
Charmandaris, V.
Laurent, O.
Gallais, P.
Mirabel, I.F.
Vigroux, L.
author_sort Förster Schreiber, N.M.
title ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
title_short ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
title_full ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
title_fullStr ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
title_full_unstemmed ISOCAM view of the starburst galaxies M 82, NGC 253 and NGC 1808
title_sort isocam view of the starburst galaxies m 82, ngc 253 and ngc 1808
url http://hdl.handle.net/20.500.12110/paper_00046361_v399_n3_p833_ForsterSchreiber
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