Investigating structure and spectral energy distribution of galaxies using uvit and multi-wavelength archival data

Title

Investigating structure and spectral energy distribution of galaxies using uvit and multi-wavelength archival data

Creator

Rahna, P T.

Contributor

Gudennavar, Shivappa B

Description

This thesis deals with the multi-wavelength investigation of the different aspects of galaxy formation and evolution. The first part of this thesis deals with the studies on the characteristics of the in-orbit performance of the Ultraviolet Imaging Telescope (UVIT) on-board AstroSat. We have written a UVIT pipeline (JUDE ) to convert the Level 1 data from the Indian Space Science Data Centre (ISSDC) into scientifically useful photon lists and images. We have also performed an independent calibration of the FUV and NUV channels of the UVIT using JUDE. We found that the photometric sensitivity is about 35% that of the Galaxy Evolution Explorer (GALEX ) in the FUV broadband filter, and about the same as GALEX in the NUV broadband filter. The point spread function (PSF) of the instrument is of the order of 1.2 1.6and#8242;and#8242;. We found that the performance is close to that expected from the ground-based calibrations. We studied the recent star formation in the nearby face-on spiral galaxy NGC 2336 using the UVIT imaging. We have identified 78 bright star-forming complexes in the disk and derived their positions and estimated their properties such as luminosities, sizes, star formation rates (SFRs), colors, and ages. The FUV-NUV colors of the complexes are found to be redder in the inner region of the galaxy and become progressively bluer as the radius increases. The last part of this thesis is devoted to a model-based study of galaxies using physically motivated Code Investigating Galaxy Emission (CIGALE) package. We have studied 10,000 galaxies from GALEX SDSS merged catalog using CIGALE and estimated their properties such as stellar masses, SFRs, stellar populations, dust luminosities etc. We have classified this set of galaxies into the star-forming, intermediate and quiescent type of galaxies based on their specific SFR. We also studied the properties of dust-lane spheroidal galaxies (DLSGs) drawn from the multi-wavelength archival data in 18 bands from FUV to FIR using GALEX, SDSS, 2MASS, WISE, and AKARI surveys.

Source

Author's Submission

Date

2018-01-01

Publisher

Christ(Deemed to be University)

Subject

Physics and Electronics

Rights

Open Access

Relation

61000099

Format

PDF

Language

English

Type

PhD

Identifier

http://hdl.handle.net/10603/394294