A Method For Mapping The Aliphatic Hydrocarbon Content Of Interstellar Dust Towards The Galactic Centre

Map of the aliphatic hydrocarbon column density is presented in the left panel for the Galactic Centre in galactic coordinates. Colour bar and contours indicate the column density (×1018 cm−2 ) levels. Map of the aliphatic hydrocarbon abundance relative to H abundance (AV ∼30 mag) is presented in the right panel for the Galactic Centre in galactic coordinates. Colour bar and contours indicate the aliphatic hydrocarbon abundance levels (ppm).

In the interstellar medium, the cosmic elemental carbon abundance includes the total carbon in both gas and solid phases.

The aim of the study was to trial a new method for measuring the amount and distribution of aliphatic carbon within interstellar dust over wide fields of view of our Galaxy. This method is based on measurement of the 3.4 μm absorption feature from aliphatic carbonaceous matter. This can readily be achieved for single sources using IR spectrometers.

However, making such measurements over wide fields requires an imaging IR camera, equipped with narrow-band filters that are able to sample the spectrum. While this cannot produce as good a determination of the spectra, the technique can be applied to potentially tens to hundreds of sources simultaneously, over the field of view of the camera. We examined this method for a field in the centre of the Galaxy, and produced a map showing the variation of 3.4 μm optical depth across it.

B. Günay, M. G. Burton, M. Afşar, T. W. Schmidt
(Submitted on 11 Feb 2020)
Subjects: Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
DOI: 10.1093/mnras/staa288
Cite as: arXiv:2002.04610 [astro-ph.GA] (or arXiv:2002.04610v1 [astro-ph.GA] for this version)
Submission history
From: Burcu Günay
[v1] Tue, 11 Feb 2020 12:09:07 UTC (1,231 KB)
Astrobiology, Astrochemistry

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