Abstract Details

Name: Rahul Kumar Anand
Affiliation: D.D.U. Gorakhpur University, Gorakhpur, 273009
Conference ID: ASI2016_679
Title : Infrared emission bands in some late carbon stars and correlation with other archival data
Authors and Co-Authors : Shantanu Rastogi Department of Physics, D.D.U. Gorakhpur University, Gorakhpur - 273009 Brijesh Kumar ARIES, Manora Peak, Nainital (Uttarakhand) - 263002
Abstract Type : Poster
Abstract Category : Stars, The Milky Way Galaxy and its neighbours
Abstract : Observations from space telescopes, particularly infrared telescopes (IRAS, ISO and Spitzer), indicate ubiquitous presence of the mid infrared emission features at 3.3, 6.2, 7.7, 8.6, 11.2 and 12.7 µm in nebular spectra. These features are attributed to Polycyclic Aromatic Hydrocarbon (PAH) molecules pumped by background UV radiations and are popularly known as Aromatic Infrared Bands (AIBs). In order to understand the origin and variation of these features in different objects, a study is performed on late type stars: IRC+10216, NGC7027 and BD30°3639, which are well known for their mid-infrared excess. Analysis of the information available in archival data for these objects in different wavelength windows is made. Attempt is made to identify any correlation that may exist between the AIB features and other bands. IRC+10216, also known as CW Leonis, is a carbon-rich evolved star in the AGB phase and is one of the most prominent and best-studied near-infrared (NIR) sources in the sky. NGC7027 and BD30°3639 are planetary nebulae. Due to its proximity, NGC7027 has a high surface brightness at all wavelengths. It has a very rich atomic and molecular spectrum. BD30°3639 is an optically bright, round, highly symmetric low-excitation nebulae. The AIB features in these objects have been classified as close to ‘B’ class feature, related to benign conditions, which are considered to be locations for PAH formation and evolution. Study of the HST and other Space Telescope archival data in visible and UV regions is also done for these objects. Understanding of variations in band features and their correlations can be related to the different chemistry of PAH formation and evolution in the circumstellar medium.