GIRAFFE High Resolution Mode

High resolution mode 316 lines/mm, 63.5 blaze grating

These are the setups for the grating currently in used, which is a higher-efficiency version (installed October 10th 2003) of the original one. The numbers for the OLD grating are given here.

From P84 in ARGUS/GIRAFFE, the settings HR01, HR02 and HR03 are available in VISITOR MODE ONLY due to the problem of obtaining sufficient counts in blue attached flats. For Medusa and IFU all settings are available in service and visitor mode.

From P73 a number of new settings were introduced. These are H447.1B,H484.5B, H525.8B, H651.5B, H737.0B and H836.6B. These have higher resolution but LOWER THROUGHPUT compared with the 'A' setups as they work in higher order where the diffraction grating diffraction angle is not matched to the peak efficiency of the grating. Additionally, a new setting H665.0 has been introduced that covers both H-alpha and Li6707. Bluewards of about 649 nm the response of this setting is only 50% of the peak.

Approximate efficiency ratios comparing the higher and lower-order settings with the same central wavelength are as follows;H447.1B/H447.1A=0.6, H484.5B/H484.5A=0.7, H525.8B/H525.8A=0.7,H651.5B/H651.5A=0.5, H737.0B/H737.0A=0.3, H805.3B/H805.3A=0.7, H836.6B/H836.6A=0.25, H920.5B/H920.5A=0.7

These values were measured by comparing the strength of flatfield data in the two settings and refer to the central wavelength only.They have been corrected for the fact that the 'B' settings have a lower wavelength coverage than the 'A' settings.

Filter Theta Order p2pp name ETC name Wl start Wl center Wl end Band R IFU/Argus R MEDUSA Comments
1 61.1 15 H379.0 HR1 370.0 379.0 386.7 16.7 36000 22500  
2 58.2 14 H395.8 HR2 385.4 395.8 404.9 19.5 31300 19600  
3 63.0 14 H412.4 HR3 403.3 412.4 420.1 16.8 39000 24800  
4 59.1 13 H429.7 HR4 418.8 429.7 439.2 20.5 32500 20350  
5 55.1 12 H447.1A HR5A 434.0 447.1 458.7 24.7 29481 18470  
5 63.9 13 H447.1B HR5B 437.6 447.1 455.2 17.6 41500 26000  
6 59.1 12 H465.6 HR6 453.8 465.6 475.9 22.2 32500 20350  
7 54.5 11 H484.5A HR7A 470.0 484.5 497.4 27.4 29632 18529  
7 63.9 12 H484.5B HR7B 474.2 484.5 493.2 19.0 42700 26700  
8 58.5 11 H504.8 HR8 491.7 504.8 516.3 24.6 32000 20000  
9 53.3 10 H525.8A HR9A 509.5 525.8 540.4 31.0 28372 17750  
9 63.2 11 H525.8B HR9B 514.3 525.8 535.6 21.3 41400 25900  
10 57.3 10 H548.8 HR10 533.9 548.8 561.9 28.0 31600 19800  
11 62.0 10 H572.8 HR11 559.7 572.8 584.0 24.3 38700 24200  
12 55.6 9 H599.3 HR12 582.1 599.3 614.6 32.5 29900 18700  
13 60.3 9 H627.3 HR13 612.0 627.3 640.5 28.5 36000 22500  
14 52.6 8 H651.5A HR14A 630.8 651.5 670.1 39.4 28334 17740  
14 65.1 9 H651.5B HR14B 638.3 651.5 662.6 24.3 46000 28800  
15 -- 8 H665.0 HR15N 647 665.0 679 32 28000 17000 Covers H-alpha and Li6707.
15 56.4 8 H679.7 HR15 660.7 679.7 696.5 35.9 30800 19300  
16 61.1 8 H710.5 HR16 693.7 710.5 725.0 31.3 38000 23900  
17 51.7 7 H737.0A HR17A 712.9 737.0 758.7 45.9 27869 17425  
17 65.9 8 H737.0B HR17B 722.5 737.0 749.0 26.5 48300 30200  
18 55.4 7 H769.1 HR18 746.8 769.1 788.9 42.0 29400 18400  
19 46.9 6 H805.3A HR19A 774.5 805.3 833.5 59.0 22175 13867  
19 60.1 7 H805.3B HR19B 785.6 805.3 822.5 36.9 35500 22200  
20 49.6 6 H836.6A HR20A 807.3 836.6 863.2 56.0 25511 16036  
20 64.9 7 H836.6B HR20B 819.5 836.6 850.9 31.4 45500 28600  
21 53.2 6 H875.7 HR21 848.4 875.7 900.1 51.7 25900 16200  
22 43.7 5 H920.5A HR22A 881.6 920.5 956.5 74.9 18628 11642  
22 57.9 6 H920.5B HR22B 896.0 920.5 941.9 45.9 30400 19000  

Legend

Filter is the filter number;
Theta is the angle of diffraction with the grating normal;
Order is the working echelle order;
Wl start, center, end are wavelengths at the edges and center of the CCD;
Band is the covered spectral passband;
resolving power, R, obtained in IFU/Argus mode;
resolving power, R, obtained in MEDUSA mode.

Note that these are the setups used by the currently used grating, which is a higher-efficiency version (installed October 10th2003). The numbers for the OLD grating are given here.