Spectroscopic Investigation Of Nebular Gas (SING): a dedicated NUV spectrograph to study extended objects from a stable space platform

Abstract

One of the most exciting parts of the astrophysical spectrum is the ultraviolet, with a greater density of absorption and emission lines than any other part of the electromagnetic spectra. Our primary science objective is to study the physical conditions in extended regions of the sky. These encompass many phases of the ISM, from the hot gas in supernova remnants (SNR) to the warm gas in planetary nebulae to cold gas in molecular clouds including emission lines from hot gas (CIV 1548/1550 ˚A) and warm gas (NIII 1750 ˚A). SING is a near ultraviolet (NUV) spectrograph which operates in the wavelength range from 1400 ˚A to 2700 ˚A, with a spectral resolution of about 2 ˚A at 2200 ˚A. The spectrograph is intended to map nebulae and other extended objects at moderate spatial and spectral resolution in the NUV from a stable platform of the space station – Chinese modular space station (CSS). As the event rate in the UV is low, the spectrograph employs a photon-counting detector because of its low noise performance. In this work, we present the overview of the opto-mechanical design of SING and the estimates of its performance.