The Infrared detection of dueterated PAHS in HII regions

Doney, Kirstin D.

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https://hdl.handle.net/2142/91059 Copy

Description

Title

The Infrared detection of dueterated PAHS in HII regions

Author(s)

Doney, Kirstin D.

Contributor(s)

• Tielens, Xander
• Onaka, Takashi
• Mori, Tamami
• Candian, Alessandra

Issue Date

2016-06-23

Keyword(s)

Astronomy

Abstract

The amount of deuterium locked up in polycyclic aromatic hydrocarbons (PAHs) has to date been an uncertain value. A near-infrared (NIR) spectroscopic survey of HII regions in the Milky Way, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC), obtained with the AKARI satellite, was performed to search for features indicative of deuterated PAHs in order to better constrain the D/H ratio of PAHs. Through comparison of the observed spectra with a calculated spectrum of deuterated PAHs the aromatic and (a)symmetric aliphatic C-D stretch vibrational modes were identified. In only six out of fifty-three of the observed sources, all of which are located in the Milky Way, emission features are seen between 4.4-4.8 $\mu$m that can be unambiguously attributed to deuterated PAHs. In all cases the aromatic C-D stretching feature is weaker than the aliphatic C-D stretching feature, which indicates that deuterium addition is favored over substitution. In addition, based on the weak or absent PAD features in most of the observed spectra, it is suggested that the mechanism for PAH deuteration in the ISM is uncommon.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

En

Permalink

http://hdl.handle.net/2142/91059

Copyright and License Information

Copyright 2016 by the authors

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