Ultra violet space instrumentation and studies of astronomical objects

Abstract

The Ultraviolet (UV) domain plays an important role in studying transient events, the atmosphere of stars and planets, characteristics of the interstellar medium, young stellar populations, physical properties of galaxies and quasars.

Despite the fact that a unique perspective may be gained from UV observa- tions, the observational capabilities in UV are severely limited. Significant

science can be achieved from small UV payloads which can be realized in a cost-effective way by launching them on a range of easily accessible space platforms, such as high-altitude balloons, sounding rockets, CubeSats, and piggybacking option on other space missions. In this thesis, we have explored the prospects for UV observations from these platforms. We have explored the prospects for UV observations from the Moon by flying a UV telescope as a piggyback payload on lunar landing mission. We have investigated the scientific outcomes and possible configuration of lunar Far UV and Near UV telescopes- Lunar Ultraviolet Cosmic Imager (LUCI). Due to launch weight constraints, we have opted for the development of an NUV telescope, which is an all spherical UV telescope with a field of view of 0.46◦×0.34◦ and would weigh around 1.2 Kg. It will observe at a fixed elevation angle and will perform the survey of the available sky in the near ultraviolet (200–320 nm) from the lunar surface. The payload has been assembled, tested and calibrated in a class 1000 clean room. We have designed and developed a lens based wide-field UV imager (WiFI) which has a 70 mm aperture with a circular field of view of 10.8 ◦ for UV sky survey (in the 280-340nm band) and transient detections. Here we will also

describe the instrumentation (attitude sensor and pointing system) for high al- titude balloon experiments with the aim of flying small scientific UV payloads.

A fiber fed UV telescope with a Czerny-Turner spectrograph was developed, to fly on balloon platform. Development of a CubeSat based Ultraviolet Bright Spectrograph (CUBS) to enable UV spectral observations in 200-300 nm using off-the-shelf items are described. A CubeSat version of a wide-field UV imager is also discussed.