This high resolution spectrometer is dedicated to the investigation of extended line-emission phenomena (i.e. Supernova remnants, Planetary nebulae, HII regions, Luminous blue variable star’s nebulae etc). The instrument is not currently available to the observers.
In its primary mode a single order of its echelle grating nominally δ=63.54˚ with 31.6 grooves/mm is isolated by a broad, efficient, three period interference filter eliminating the need of cross-dispersion. Consequently, its primary use, is to obtain spatially-resolved profiles of individual emission lines from faint extended sources emitting in the range 3900-7500 Å with a spectral resolving power of λ/Δλ ≤105.
Several secondary mode are available:
A direct image of the field can be obtained by both the insertion of a clear to replace the slit and of a mirror before the grating (slit positions against images of extended sources can be obtained using this facility). The insertion of a grism along with the plane mirror permits long-slit, low dispersion (76.3 Å/mm) spectra to be obtained.
|Slit widths||Option 1||Option 2||
|(Δλ at 6500 Å)||0.1 Å||0.2 Å||0.4 Å|
|multi-slits||number of slits||free spectral range||sky separation|
|10||1.65 mm = 138 km/s||=19.2 arcsec|
|5||3.3 mm = 138 km/s||=38.4 arcsec|
|3||6.6 mm = 138 km/s||=76.9 arcsec|
|slit length||linear||on sky||comments|
|30 mm||5.8 arcmin||curent max.|
|60 mm||11.6 arcmin|
|Other isolatator filter||center (bandwidth)||centre (bandwidth)||centre (bandwidth)|
|6730 (100) Å||6580 (100) Å||5020 (70) Å|
|echelle grating||blaze angle||grooves/mm||ruled area|
|Field area (max)||Linear||On sky||Scale|
|Current||24.6x24.6 mm||4.8x4.8 arcmin2||0.3 arcsec/pixel|
|max||25x30 mm||4.9x5.8 arcmin2|