A spectrograph was designed and constructed to provide a new capability for measuring spectrum of extended emission line sources, but it has the versatility to work well on stellar bright moving sources for example emission nebulae and comets. The spectrograph uses high-speed lens system. It projects the incoming wide field light through a horizontal moving slit assembly onto a reflective grating based on a rotary platform that is synchronised with the slit mechanism. The slit width is adjustable, as is the case in conventional spectrographs. An important part of the design is the lateral movement of the entire slit assembly (in addition to the movement of the slit itself), so that the narrow beam passing through the slit will reflect off different parts of the diffraction grating and be received by the camera in a scanning mode. As a result, this single device can cover a wide field of view across the range of spectra in a short duration of time. In fact it can obtain a spectrum of sky 3 x 3 degrees in a short timescale depending on the quantum efficiency and format size of the CCD detector.

Date Published: 30 September 2004
PDF: 5 pages
Proc. SPIE 5492, Ground-based Instrumentation for Astronomy, (30 September 2004);

Published in SPIE Proceedings Vol. 5492:
Ground-based Instrumentation for Astronomy
Alan F. M. Moorwood; Masanori Iye, Editor(s)