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Quasar 3C298: a test-case for meteoritic nanodiamond 3.5 microns emission

J. A. de Diego·L. Binette·P. Ogle·A. C. Andersen·S. Haro Corzo·M. Wold
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Abstract

We calculate the dust emission expected at 3.43 and 3.53 microns if meteoritic (i.e. hydrogenated) nanodiamonds are responsible for most of the far-UV break observed in quasars. We integrate the UV flux that hydrogenated nanodiamonds must absorb to reproduce the far-UV break. Based on laboratory spectra of H-terminated diamond surfaces, we analyse the radiative energy budget and derive theoretically the IR emission profiles expected for possible C-H surface stretch modes of the diamonds. Using as test case a spectrum of 3C298 provided by the Spitzer Observatory, we do not find evidence of these emission bands. While diamonds without surface adsorbates remain a viable candidate for explaining the far-UV break observed in quasars, hydrogenated nanodiamonds appear to be ruled out, as they would giverise to IR emission bands, which have not been observed so far.

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J. A. de Diego, L. Binette, P. Ogle, A. C. Andersen, S. Haro Corzo, M. Wold. 2007-03-05. Quasar 3C298: a test-case for meteoritic nanodiamond 3.5 microns emission. https://doi.org/10.1051/0004-6361%3A20077081

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