Infrared and Optical Astronomy

The Infrared Astronomy Group specializes in the observational studies of star and planet formation, physics and chemistry of the interstellar medium, the Galactic structure and kinematics of stellar populations in the Galaxy. The group also specializes in astronomi- cal instrumentation for ground-based and space-based (balloon- and satellite-borne) infrared astronomy.

Observational Programs

  1. Star formation and its impact on the ISM in our Galaxy and nearby Galaxies

    The primary goals of this program are:

    • Understand the local (and subsequently) global conditions which lead to the onset of star formation in molecular clouds
    • Study the physical processes and mechanisms that regulate the evolution of the newly born stars
    • Impact of the newly born stars on the surrounding molecular cloud since this decides the evolution of the ISM in a galaxy and determines the rate of formation of stars in future

    The program involves multiwavelength (optical to radio) continuum and spectroscopic observations using ground- and space-based telescopes. In-house modeling capabilities have also been developed for the interpretation of the data.

  2. Astrochemistry using spectroscopic observations

    In spite of the extremely low number density of particles in the interstellar medium (ISM), a surprisingly large number of molecules have been detected in the outer space. In this program we observe spectral lines from complex molecules and ions in space, both in emission and absorption in the infrared to millimeter wavelengths using space- and ground-based telescopes. The primary goals of this program are:

    • Detection of new molecules
    • Estimation of density, temperature and abundance of chemical species in dense and diffuse regions in the matter between the stars (ISM)
    • Probing important gas-phase & grain-surface chemical pathways in the rarified environment of the ISM
    • Use temperatures and chemical reactions as probes of heating mechanisms viz., stellar photons, dissipation of turbulence, which are of general relevance to our understanding of the ISM evolution and the process of star formation.
  3. Protoplanetary Disk Evolution & Planet formation

    Coagulation of dust plays an important role in the formation of planets and this program studies evolution of protoplanetary disks in order to study physical processes such as grain growth, sedimentation and crystallization. The program obtains observations of infrared spectra of tracers of the onset of planet formation in protoplanetary disks and confronts the state-of-the art models of planet formation in disks.

  4. Galactic Structure & Stellar kinematics

    The primary goal of this program is to investigate in detail the observed ultraviolet (UV) star counts obtained by Galaxy Evolution Explorer (GALEX) vis-a-vis the model simulated catalogues produced by the Besançon model of stellar population synthesis in various Galactic directions, and to explore the potential for studying the structure of our Galaxy from images in multiple near-UV (NUV) and far-UV (FUV) filters of the forthcoming Ultraviolet Imaging Telescope (UVIT) to be flown onboard ASTROSAT.

Instrumentation Programs

The group has a long tradition of development of Near and Far infrared instruments for ground and space-based Indian observing facilities. The current programs in instrumentation include development of a Near Infrared imaging camera as well as spectrometers particularly sensitive to the Near infrared wavelengths. Some of the currently operational and under development instruments are: