Abstract Details
| Name: Shantanu Rastogi Affiliation: DDU Gorakhpur University Conference ID: ASI2016_518 Title : Study of astrophysically relevant phenyl substituted aromatic phenanthrene Authors and Co-Authors : Rashmi Singh, DDU Gorakhpur University Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : Polycyclic Aromatic Hydrocarbons (PAHs) have been considered as an essential, ubiquitous species of the interstellar medium (ISM). PAHs are responsible for mid-IR emission bands that are most prominent at 3.3, 6.2, 7.7, 8.6, 11.2 and 12.6 micron (3030, 1610, 1300, 1160, 890 and 790 cm-1). These bands are called Aromatic infrared bands (AIBs) because of aromatic nature of carrier molecules. The profile of these emission bands exhibit definite variations from source to source. The composite model spectra of mixtures of PAHs show uncertainty in matching the 6.2 micron feature. This emphasizes the need to consider a larger varieties of PAHs and PAH derivatives for simultaneous match of all AIBs. In this work, we illustrate the theoretical IR spectra of neutral and ionised PAH, phenanthrene substituted on the side with a phenyl group at different positions. The aim is to study their suitability, in terms of intensity, peak position and profile, for explaining the astrophysical AIBs. In particular, the optimized structures and vibrational spectra of 1-,2-,3-,4-, and 9-phenylphenanthrene are obtained using DFT/B3LYP functional in conjugation with 6-31Gd basis expansion. The moderation in the principle PAH features and additional bands that appear due to the phenyl group addition are studied. The feasibility of incorporating phenyl substituted PAHs in modelling astrophysical spectra is discussed. |