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Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/Be environment

Itsuki Sakon·Yoshiko K. Okamoto·Hirokazu Kataza·Takashi Onaka·Hidehiro Kaneda·Mitsuhiko Honda
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Abstract

We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and 12.7um is detected throughout the system and we find a clear increase in the UIR 11.0um/11.2um ratio in the vicinity of the central star. Since the UIR 11.0um feature is attributed to a solo-CH out-of-plane wagging mode of cationic PAHs while the UIR 11.2um feature to a solo-CH out-of-plane bending mode of neutral PAHs, the large 11.0um/11.2um ratio directly indicates a promotion of the ionization of PAHs near the central star.

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Itsuki Sakon, Yoshiko K. Okamoto, Hirokazu Kataza, Takashi Onaka, Hidehiro Kaneda, Mitsuhiko Honda. 2007-01-09. Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/Be environment. https://doi.org/10.1142/9789812708922_0014

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