Abstract Details
| Name: Akant Vats Affiliation: Banaras Hindu University,Varansi Conference ID: ASI2019_340 Title : Theoretical vibrational study of Nitrogenated PAHs: Astrophysical implications Authors and Co-Authors : Ekant Vats, Gauri Devi, Mridusmita Buragohain, Amit Pathak Abstract Type : Poster Abstract Category : Stars, ISM and Galaxy Abstract : Infrared fluorescence in large aromatic molecules known as Polycyclic Aromatic Hydrocarbon (PAH) results in infrared emission features that dominate the spectra of the interstellar medium (ISM) of most Galactic and extra galactic objects (Tielens 208). Interstellar PAHs show ubiquitous infrared (IR) spectrum from 3 to 20 μm and this spectrum is full of intricate features. Strong emission features are observed at 3.3, 6.2, 7.7, 8.6, and 11.2 μm. The bands in the 6-9 μm range are dominated by the emission of ionized PAHs. There are spectral variations in the peak position and profile of the 6.2 μm C-C stretch feature because this band is not a single band but two or more bands, one centered near 6.2 μm and the other near 6.3 μm or beyond (Peeters et al., 2002). The 6.3 μm band is explained by varying the size of the PAH molecule but the 6.2 μm remains unexplained. The substitution of one or more nitrogen atoms within the interior of PAH cation (replacing one or more carbon atoms) induces a blue shift in the position of the C-C stretch feature and this feature now appears at 6.2 μm (Hudgins et al., 2005). Here we present the vibrational spectra of PANH, HPANH and DPANH molecules in their various ionized forms. Apart from discussing the 6.2 μm feature, we try to explore new features that are contributed by these molecules. We also discuss the dipole moment of these species and whether these are feasible to be detected by radio astronomy techniques. Standard density functional theory (DST) is used for calculating various physical parameters of these molecules. |