29th Annual Report (2016-17)

210 School of Studies in Physics and Astrophysics, Pt. Ravishankar Shukla University, Raipur Research Highlights Ph.D. Thesis · · · · Sheetal Kumar Sahu has been working on his PhD thesis under the supervision of S.K. Pandey, The work comprised of analysis of multi-wavelength data of a sample of radio loud elliptical galaxies observed from 2m IGO Telescope, Girawali; 2m HCT, Hanle; and archival data from SDSS (ugriz), 2MASS (JHKs ), WISE, Spitzer (mid-IR), XMM, CHANDRA (X-ray), GALEX (UV), and VLA, IRAM (radio). Surface photometry was performed on the images obtained. The profiles of surface brightness, position angle, ellipticity and B4 coefficients of the galaxies were derived. Colour map, extinction map, H-alpha emission map, CO intensity map, diffuse X-ray emission map, and extinction curves of the galaxies were created in order to study the morphology, properties and physical correlations of different phases of Inter Stellar Medium, and to examine star formation processes in the galaxies. Spectra of the galaxies were analyzed. The flux of emission lines, temperature, electron density, and star formation rate for the galaxies were estimated. Based on spectral properties, the type ofAGNhosting galaxies were identified. Amit Tamrakar is continuing his Ph.D. work under the supervision of S.K. Pandey, on the thesis entitled, “Multi- wavelength Isophotal Shape Analysis of Early Type Galaxies”. By doing multiband isophotal shape analysis and ellipse fitting procedure, we are trying to find out correlations between the presence of dust and the other parameters. The workwill provide clues to the roll of dust, ISMand the formation of early-type galaxies. Mahendra Verma has registered for his Ph.D. degree, on the thesis entitled, “Central Region of Lenticular Galaxies” under the supervision of S.K. Pandey and Sudhanshu Barwey (SouthAfrican Observatory, Cape Town). The work is aimed to carry out detailed analysis of central (nuclear) regions of S0 galaxies observed with Hubble Space Telescope (HST). Volume limited sample of lenticular galaxies are selected fromRC3 catalogue depending on different selection parameters. We are working on HST WFC2 archival data to see the dust and other features on central regions of galaxies. It is found that most of the galaxies are power law dominated (gamma > 0.3). We also look for 2MASS galactic data for our sample to specify the K-band magnitude. We have explored the possible correlation between Pseudo bulge and Classical bulge. Kalyani Bagri has been working on her Ph.D. thesis entitled, “Study of Accretion Process and Jets in X-ray Binaries” under the supervision of J.S. Yadav (TIFR, Mumbai), S.K. Pandey, and Ranjeev Misra, (IUCAA). We have analyzed the RXTE observations of GX 339-4 during its four outbursts and identify the observations when the systemwas in the hard state and showed a broad Iron line. We have made an attempt to fit these observations with models, which include smeared reflection to understand whether the intrinsic photon index can indeed be large. We explored the correlations between spectral parameters such as the flux, ionization level, equivalent width of the line, etc. Title: Observational studies of type Ia supernovae. Student: N.K. Chakradhari Supervisors: D.K. Sahu (IIA, Bengaluru), and S.K. Pandey. (Pt. Ravishankar Shukla University, Raipur) Coordinator: Sheo K. Pandey, and Joint Coordinator: Rakesh C. Agrawal