Ultraviolet Space Astronomy : UVIT and Beyond (WS2)

Background:
We propose to conduct a workshop at ASI 2021 meeting, to discuss the planning of a dedicated Ultraviolet (UV) space mission that will provide high resolution deep imaging and spectroscopy over a large area of the sky, with the larger community. A UV space mission with a deep imaging and spectroscopic capability along with a wide field of view is the need of the hour, as there are several large optical facilities that will come online in the coming years, including the Large Synoptic Survey Telescope (LSST) that will survey the entire visible sky every three days and provide deep optical images and discover a variety of optical transient objects in the sky. It is also more appropriate than ever to conduct a workshop on this topic, as we have just completed the five years of ASTROSAT in orbit this year. ASTROSAT team was quite successful in reaching out to colleges and universities that helped wide use of the ASTROSAT data.

A dedicated UV mission is in the pre-project phase. We would like to initiate an engagement during the conceptual phase of the planned mission. This will broaden the science goals of the mission and hence help to optimize the design. The mission team will also benefit from the large student community both from science and engineering colleges and universities. The proposed workshop will provide a forum to discuss the lessons learned from Ultra-Violet Imaging Telescope (UVIT) on the aspects of design, assembly, calibration, operation and user training during the mission. ASI offers the best possible platform for community explorations:
bringing experts in the area of astronomical observations, theory, modelling/simulations, instrumentation, data calibration and software and efficiently integrating the technical expertise from the universities on one forum.

The main goals of the proposed workshop are:

  1. to bring together scientists and engineers who worked in the design, fabrication, assembly, launch, operation and post launch calibration of the UVIT and discuss the challenges faced while manoeuvring the instrument for the last five years in space successfully. Also, this opportunity will be utilized to showcase some of the excellent science results that have come from the UVIT.
  2. to discuss the UVIT in the context of future missions as what additional capabilities would be required in a future mission to have an even more scientific impact.
  3. Other technical challenges, in design, fabrication, assembly, launch, operation and post launch calibration of a future UV mission that would be capable of conducting not only high spatial resolution deep imaging but also would be capable of making low-medium resolution spectroscopy.

In the next decade, astronomy will enter the era of large-scale surveys in the optical wavelengths, with the commissioning of the LSST. In space, we will have the multi-mirror James Webb Space Telescope (JWST), followed by WFIRST (NASA mission planned for 2025) and EUCLID (an ESA mission scheduled for launch in 2022) missions. To complement the IR wavelength range, a deep imaging instrument with a wide field-of-view in the UV range is lacking for both the Indian and the International astronomical community.
Indian Spectroscopic and Imaging Space Telescope (INSIST) was proposed as a dedicated UV mission in response to the call for future astronomy missions by the ISRO in April 2018. After a review of all proposals, INSIST project was awarded a seed funding of 30 Lakh, for a year of pre-project phase, in March 2019.

The proposed mission will produce high spatial resolution (0.1”/pixel) deep (~26 ABmag) UV-optical images, UV (150-300 nm), u (300-400 nm) and g (400-550 nm), of a relatively wider field-of-view (FOV; ~0.25 sq. deg) from space. The INSIST will also have the capabilities to carry out medium-resolution (R~2000) spectroscopy of astronomical sources in UV in multi-object mode of a smaller FOV (~3’x3’) and low-resolution (R~500) spectroscopy of the imaging FOV, simultaneously in UV- and g-band, in slitless mode. Combining a large focal area with an efficient optical design, INSIST is expected to produce HST-quality deep images and moderate resolution multi object spectra of astronomical sources. The main science drivers for this mission span a wide range of topics, starting from evolution of galaxies in groups and clusters, chemo-dynamics and demographics of the nearby universe, stellar systems with accretions, to stars with planetary systems, to cosmology near and far.

During the workshop we propose to review

  1. Some of the results obtained with the UVIT and some of the compelling science cases for a future UV space mission.
  2. Maturity of a conceptual optical/mechanical design for the telescope and discuss any additional capabilities that are required in INSIST other than those proposed.
  3. Design and fabrication of a prototype spectrograph to demonstrate the usage of the Digital Micro-mirror Device (DMD) as a MOS.
  4. Capacity building and challenges ahead.

Tentative Program list:

  1. UVIT - flagship UV facility - lessons learned
  2. Results from UVIT and Science cases for future mission
  3. INSIST:Proposed UV mission (status update of optical and mechanical designs)
  4. Digital Micromirror Device prototyping of spectrograph
  5. Panel discussion

Proposers: INSIST Team (IIA, IUCAA, PRL, TIFR, ARIES, IISER (Tirupati), IIST, CU, CUHP)