Yogesh Wadadekar

Distant obscured galaxies with Herschel and GMRT:

A large number of star-forming and active galaxies are obscured by dust and are invisible in optical surveys. To identify, characterise and understand the physical properties of such objects far-infrared (FIR) and radio data are very useful. Our group has obtained FIR data from the HerMES survey on the Herschel telescope with our own 325 MHz radio observations with GMRT. We have also obtained new observations of the XMMLSS field (9 sq. degrees), the Lockman Hole (18 sq. degrees) and ELAIS-N1 (9 sq. degrees) with GMRT. Besides identifying distant obscured star-forming galaxies, we are using the data to identify distant radio galaxies (z>3) and study the radio-FIR correlation from normal galaxies at redshifts lower than 1. We are also using stacking techniques to characterise the radio properties of a variety of source populations, such as X-ray sources, normal galaxies, quasars, star-forming galaxies, etc.


Formation of lenticular galaxies:

Over the last few years, we have used near-ultraviolet, optical and near-infrared observations of lenticular galaxies to demonstrate that these objects belong to two subclasses, differentiated by stellar mass or luminosity. More luminous lenticulars seem to have a predominantly old stellar population like elliptical galaxies, while less luminous lenticulars have a stellar population with a wide variety of ages like in spiral galaxies. A number of observational probes such as star-formation history, bar fraction, bulge disk size correlations have been used to show that the formation history of more luminous lenticulars is similar to that of ellipticals while less luminous lenticulars are essentially spirals whose star formation has been quenched by environmental or secular effects.


Document Actions