In the past I worked on the evolution of galaxy morphology in cluster environment using HST data. We use 2D bulge-disk decomposition method to quantify the morphology of galaxies. Our results are described here.

We also developed one automatic program, PyMorph, to estimate morphological parameters of galaxies. PyMorph is written in Python and uses SExtractor and GALFIT. The methods implemented in PyMorph are described here. You can find a user manual for PyMorph here. PyMorph is available freely on request.

My current projects include testing gravity using dwarf galaxies and stars, dark energy survey and morphological evolution of galaxies based on SDSS spectroscopic sample. We developed a method to isolate screened regions in the local Universe based on N-body simulations. This helps us to search for the 'fifth force' in the unscreened objects. Follow this link for more details.

To test modified gravity you need to identify whether a galaxy is screened by its own potential or by the environment. Here you may find some more details of the work.

Another interesting project I am currently working on is related to the evolution of galaxy morphology over cosmic time. The evolution of size gives some important clues about the formation mechanism of different galaxy mprphology. It is now widely believed that minor or major merger between galaxies play the crucial role in the evolution. The merger theory offers some observational signatures on the size evolution of galaxies. We, therefore, use nearly 600,000 galaxies from SDSS to look for these signatures. We have are in a process of generating the structural parameters of these galaxies and some of the priliminary results can be found here.




Publications