Is there now in the end some believable theoretical foundation for the molecular origins and carriers of no less than a few of the most distinguished so-called ‘UIE’ (Unidentified Infrared Emission) bands which have mystified astronomers for many years?
The theoretical astrophysicists and astrochemists on the Laboratory for Area Analysis (LSR) and Division of Physics at The College of Hong Kong (HKU) appear to assume so (no less than in principle) in a peer-reviewed paper simply revealed in The Astrophysical Journal.
A workforce led by Dr SeyedAbdolreza Sadjadi, member of the LSR, and Professor Quentin Parker, Director of the LSR within the Division of Physics, has now positioned some attention-grabbing theoretical work into the combination. It identifies extremely ionised species of the well-known soccer ball-shaped ‘Buckminsterfullerene’ C60 molecule as believable carriers of no less than a few of the most distinguished and enigmatic UIE bands which have challenged astronomers since they have been first found and studied over 30 years in the past.
First, Dr Sadjadi and Professor Parker proved theoretically that C60 might survive, in steady states, from being ionised as much as +26 (i.e. 26 of the 60 electrons within the buckyball being eliminated) earlier than the buckyball disintegrates (Sadjadi & Parker 2021). Now they’ve proven, by way of making use of first ideas quantum chemical calculations, what theoretical mid-infrared signatures of those ionised types of fullerene may be anticipated. The outcomes are extraordinarily attention-grabbing and provocative and will finally level the best way ahead to no less than a partial decision of this enduring astrophysical thriller.
Professor Parker stated: “I’m extraordinarily honoured to have performed a component within the astonishingly advanced quantum chemistry investigations undertaken by Dr Sadjadi which have led to those very thrilling outcomes. They concern first the theoretical proof that Fullerene — Carbon 60 — can survive to very excessive ranges of ionisation and now this work reveals the infrared emission signatures from such species are a wonderful match for a few of the most distinguished Unidentified Infrared Emission options recognized. This could assist re-invigorate this space of analysis.”
The HKU lead workforce discovered that a few of these positively charged fullerenes present robust emission bands that match extraordinarily nicely the place of key astronomical UIE emission options at 11.21, 16.40 and 20-21 micrometers (μm). This makes them key goal species for identification of the at present unidentified UIE options and gives robust motivation for future astronomical observations throughout the mid infrared wavelength vary to check these theoretical findings. Additionally they discovered that the IR signatures of the group of those C60 cations with q = 1 − 6 are nicely separated from the 6.2 μm bands, which might be related to free/remoted fragrant hydrocarbon molecules (so known as PAH’s, one other potential service of UIE). This considerably aids of their identification from different potential carriers. This discovering is especially vital for discrimination and exploration of the coexistence of advanced hydrocarbon organics and fullerenes in astronomical sources.
Dr Sadjadi stated: “In our first paper we confirmed theoretically that extremely ionised fullerenes can exist and survive the cruel and chaotic atmosphere of area. It’s like asking how a lot air you possibly can push out of a soccer ball and the ball nonetheless maintains its form. On this paper we labored with two different main astrophysicists and planetary scientists Professor Yong Zhang and Dr Chih-Hao Hsia, each ex-HKU workers however nonetheless affiliated to the LSR, to find out the molecular vibrational notes of a celestial symphony, i.e. the spectral options that these ionised buckyballs would play/produce. We then hunted for them in area exhibiting their notes/signatures are simply distinguishable from PAHs.”