The Rowland Spectrograph
Spectrographs in the Rowland mounting are characterized by a high photon
throughput since there is only one single internal reflection. The Rowland
spectrograph of SPECTRUM UV is designed to work in three channels with
different resolving power:
The selection of the channels is made by the rotating turret with different
- The Lyman Channel
Spectral range; 90 - 120 nm with R = 10000,
divided in the two subchannels 90 - 105 nm and 105 - 120 nm
- The Medium Resolution Channel
Spectral range; 120 - 300 nm with R = 3000,
divided in the two subchannels 120 - 190 nm and 190 - 300 nm
- The Low Resolution Channel
Spectral range; 120 - 400 nm with R = 500
The Lyman Channel allows to study the extremely interesting Lyman spectral
region with a resolution corresponding to 30 km/sec.
The Medium Resolution Channel is able to resolve the C IV (154.8 nm, 155.1 nm)
and Mg II (279.6 nm, 280.3 nm) doublets for faint objects.
With the Low Resolution Channel it will be possible to reach a magnitude of
V = 19 with SNR = 100 and 10000 sec exposure time for an unreddened star with
an effective temperature of 40000 K.
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firstname.lastname@example.org - T. Bloecker - 28. Jan. 1996