Is there now in the end some believable theoretical foundation for the molecular origins and carriers of at the least a few of the most outstanding 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 (at the least in principle) in a peer-reviewed paper simply revealed in The Astrophysical Journal.
A staff 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 combo. It identifies extremely ionised species of the well-known soccer ball-shaped ‘Buckminsterfullerene’ C60 molecule as believable carriers of at the least a few of the most outstanding 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, through making use of first rules quantum chemical calculations, what theoretical mid-infrared signatures of those ionised types of fullerene might be anticipated. The outcomes are extraordinarily attention-grabbing and provocative and should eventually level the way in which ahead to at the least a partial decision of this enduring astrophysical thriller.
Professor Parker mentioned: “I’m extraordinarily honoured to have performed an element 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 outstanding Unidentified Infrared Emission options recognized. This could assist re-invigorate this space of analysis.”
The HKU lead staff discovered that a few of these positively charged fullerenes present robust emission bands that match extraordinarily effectively 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 presently 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 effectively separated from the 6.2 μm bands, which can be related to free/remoted fragrant hydrocarbon molecules (so referred to as PAH’s, one other potential service of UIE). This considerably aids of their identification from different potential carriers. This discovering is especially essential for discrimination and exploration of the coexistence of advanced hydrocarbon organics and fullerenes in astronomical sources.
Dr Sadjadi mentioned: “In our first paper we confirmed theoretically that extremely ionised fullerenes can exist and survive the cruel and chaotic setting 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.”