Proposals

Images Slicer:

UHRF uses an image slicer of 1.5×1.5 arcsec entrance, but not fully transmitted. Throughput depends on seeing and telescope pointing. 

Signal to Noise Estimates:

Approximate sensitivities for UHRF using the EEV CCD is such that at B=3.0 at 4232Å, V=3.3 at 5890Å and I=2.4 at 7700Å give 100 electrons/sec per 0.01Å in 1.8" seeing. 

Gratings and Resolution modes:

UHRF used a 31.6 lines/mm echelle grating plus a range of cross-dispersing gratings to achieve high resolution. The various available resolution modes are:

R=300 000 (0.3M)

R=600 000 (0.6M)

R=940 000 (1.0M)

Wavelength coverage:

1.0M: 4Å (@3000Å) - 13Å (@11000Å) 

0.6M: 6Å (@3000Å) - 22Å (@11000Å) 

0.3M: 13Å (@3000Å) - 45Å (@11000Å)

Detectors:

The same detectors as for UCLES are available for UHRF. The EEV2 2kx4k 13.5um pixels is used, usually binned x 8. The EEV suffers from fringing in the red, but the MITLL3 is not ideal for most programs as it doesn't support on-chip binning.

1. Blue sensitive E2V 2K x 4K (13.5 micro pixels)

Image scale: 0.16 arcsec per spatial pixel

On chip binning in both spatial and spectral direction is possible.

SPEED READ OUT TIME (s) GAIN (e-/ADU) READ OUT NOISE (e-) SATURATION (e-) NON-LINEARITY (ALPHA x10-6)
SLOW 445 (403) 0.37 2.45 (2.3) 24,000 (ADC) 0.14
NORMAL 178 (158) 1.30 3.15 (3.2) 85,000 (ADC) 0.60
FAST 132 (132) 2.80 5.27 (5.35) 183,000 (ADC) 0.78
NONASTRO 89 (74) 6.67 9.74 (9.8) 437,000 (ADC) 1.92

2. Red sensitive MITLL3 2K x 4K (15 micro pixels)

Image scale: 0.18 arcsec per spatial pixel

No binning possible.

SPEED READ OUT TIME (s) GAIN (e-/ADU) READ OUT NOISE (e-) SATURATION (e-) NON-LINEARITY (ALPHA x10-6)
XTRASLOW (936) 0.074 (1.16) 5,000 (ADC) -0.23
SLOW 300 (296) 0.37 1.84 (1.7) 24,000 (ADC) 0.23
NORMAL 163 (154) 1.1 2.38 (2.4) 72,000 (ADC) 0.36
FAST 127 (120) 2.2 3.47 (3.3) 141,000 (ADC) 0.19
NONASTRO 85 (75) 4.5 6.55 (6.3) 178,000 0.02