Spectroscopy is the basic tool employed in astronomy to derive physical parameters, like temperature, density, chemical composition, velocity and magnetic fields that give insights into the physical processes that are operative in the celestial objects. Much of our understanding of stellar atmospheres and even low-density collisionally excited plasma, such as supernova remnants, is based on the understanding of plasma processes in the solar atmosphere. Although some of these processes can be studied by high spatial resolution images of the sun, our knowledge of the temperature, densities and dynamics of different regions of the solar atmosphere is based on the high resolution spectroscopy in the X-ray, UV and optical spectral regions.

The atomic and molecular spectroscopy plays a key role in understanding astrochemistry. For example, the carbon bearing molecules, such as polycyclic aromatic hydrocarbons (PAHs), are now thought to be widespread in the interstellar medium in their neutral and ionized forms. Identifying the carriers responsible for several observed interstellar bands will allow us to derive important information on cosmic elemental abundance as well as on the physical conditions reigning in specific interstellar environments. The identifications of these carriers are the key for a correct understanding of the energetic mechanisms that govern the origin and evolution of the interstellar medium.

In the last two decades great progress has been made in our understanding of the physics of molecules, and neutral and ionized atoms, and the application of physics to develop spectroscopic diagnostics to analyze the spectra of sun, stars and other celestial objects.

Comprehensive and accurate transition probability data are needed to determine the abundances of a neutral atom and all of its ions in different astrophysical environments. Determination of radiative lifetimes can provide the absolute scale for converting the branching fractions into atomic transition probabilities and vice versa. Since the derivation of the physical parameters of the prevailing astrophysical conditions is an inverse problem, accurate theories of line formation under widely varying conditions that one encounters in celestial objects have to be developed.

Hence a multi-disciplinary approach, by combining astrophysical observation with laboratory simulations and theoretical modelings, is essential to address the complex issues involved in interpreting the data for the ultimate aim of understanding the physical conditions prevalent in celestial objects. Also for a proper interpretation of the high resolution data that we obtain from space missions, it has become necessary to improve the accuracy of the theory of line formation to a great extent.

We have scientists who are actively working in various fields, like observational astronomy, theoretical astrophysics, theoretical and experimental atomic and molecular spectroscopy. The purpose of this conference is to bring them together to discuss their research activities and to plan new collaborations among scientists working in related fields which would yield better scientific results. For young researchers and Ph. D. students, the conference would give a great opportunity to interact with experts and learn different aspects of spectroscopy.