The LSS instrument is the Chinese contribution to the WSO-UV space telescope. Update information on the progress of the instrument development should be accessed through the LSS team website. LSS will provide low resolution (R~1500-2500) spectra in the 102-320 nm spectral range with a design that emphasizes sensitivity for observing faint objects.

1. LSS outline:
2. More information on LSS: 

1. LSS outline

According to preliminary results of phase A study on-going at NAOC (China), the most promising design for this instrument is to have two channels working in 102-161 nm (FUV) and 160-320 nm (NUV) ranges, respectively, as shown in the figure below. Each channel has its own entrance slit, the arrangement of which is described in the HIRDES instrument section above. Both slits are 1"´75" wide that allows 1 arcsec spatial resolution. In order to maximize sensitivity both LSS channels use holographic gratings to minimize the number of reflecting surfaces in optical path, and to enhance overall spatial resolution along the slit. Both channels use microchannel plates working in photon-counting modes as detectors. A slit-viewer similar to that is used in HIRDES, internal calibrator, and detector redundancy are being studied.

The two LSS channels can be operated independently. To obtain spectra of full spectral range of the same source the telescope is required to re-point when switching channel. Besides normal integration mode, special observing modes including high time-resolution mode (up to 1 second) and "windowed mode". whereas only photons detected by specific part of the detector surface are recorded, are envisaged.

Schematic layout of main optical and detector elements in LSS Phase A study

2. More information on LSS

• A Proposal of Long Slit Spectrograph for WSO-UV (presentation by Zhongwen Hu, Nanjing Institute of Astronomical Optics and Technology, National Astronomical Observatory of China, CAS)