Manchester Echelle Spectrometer-Aristarchos Telescope (MES-AT)

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.

Design

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.

Secondary modes

Several secondary modes 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.

Status: To be commissioned
Detector: e2V 2kx2k
FOV: 4′.8×4′.8
Scale (“/pixel): 0.27

Parameters on the Aristarchos 2.3 m telescope (first calculated values)

ECHELLE SPECTROMETER

Slit widths	Option 1	Option 2	Option 3
(μm)	70	150	300
(R=λ/Δλ)	60,000	30,000	15,000
(Δλ at 6500 Å)	0.1 Å	0.2 Å	0.4 Å
(km/s)	5	10	20
(arcsec)	0.8	1.8	3.5
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
	63.54 deg	31.6	128×254