We investigate the emission properties of polycyclic aromatic hydrocarbons (PAHs) in various metallicity environments with the Infrared Spectrograph on board Spitzer. Local giant H II regions are used as references as they enable access to the distinct interstellar medium components that contribute to the mid-infrared spectrum of star-forming galaxies: photodissociation regions (PDRs), photoionized gas, stellar clusters, and embedded regions. Three objects are considered: NGC 3603 in the Milky Way, 30 Doradus in the Large Magellanic Cloud, and N 66 in the Small Magellanic Cloud. From the variations of the PAH/14 μm ratio, we find that PAHs are destroyed in the ionized gas for a radiation field such that [Neiii]/[Neii] ≳ 3. From the variations of the PAH/Huα ratio, we find that the PAH emission sources in the giant H II regions follow the same photodestruction law regardless of metallicity. We then compare these results with observations of starburst galaxies, H II galaxies, and blue compact dwarf galaxies (BCDs). While the integrated mid-infrared spectra of BCDs are reminiscent of a warm dusty ionized gas, we observe a significant contribution to the PAH emission in starburst galaxies that is not arising from PDRs. © 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A.
CITATION STYLE
Lebouteiller, V., Bernard-Salas, J., Whelan, D. G., Brandl, B., Galliano, F., Charmandaris, V., … Kunth, D. (2011). Influence of the environment on polycyclic aromatic hydrocarbon emission in star-forming regions. Astrophysical Journal, 728(1). https://doi.org/10.1088/0004-637X/728/1/45
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