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 resolving powers listed here also correspond to the most up-to-date measurements, after the intervention in the focussing procedure on February 2nd 2015. The corresponding values for the old focussing procedure (i.e. for observations taken between Oct 10 2003 and Feb 1 2015) are given here. 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 43350 26750
2 58.2 14 H395.8 HR2 385.4 395.8 404.9 19.5 34800 22700
3 63.0 14 H412.4 HR3 403.3 412.4 420.1 16.8 48750 31400
4 59.1 13 H429.7 HR4 418.8 429.7 439.2 20.5 35550 24000
5 55.1 12 H447.1A HR5A 434.0 447.1 458.7 24.7 30250 20250
5 63.9 13 H447.1B HR5B 437.6 447.1 455.2 17.6 50530 33000  
6 59.1 12 H465.6 HR6 453.8 465.6 475.9 22.2 35150 24300  
7 54.5 11 H484.5A HR7A 470.0 484.5 497.4 27.4 27850 19500  
7 63.9 12 H484.5B HR7B 474.2 484.5 493.2 19.0 51150 33500  
8 58.5 11 H504.8 HR8 491.7 504.8 516.3 24.6 37000 23500  
9 53.3 10 H525.8A HR9A 509.5 525.8 540.4 31.0 28000 18000  
9 63.2 11 H525.8B HR9B 514.3 525.8 535.6 21.3 50500 31750  
10 57.3 10 H548.8 HR10 533.9 548.8 561.9 28.0 33700 21500  
11 62.0 10 H572.8 HR11 559.7 572.8 584.0 24.3 46500 29500  
12 55.6 9 H599.3 HR12 582.1 599.3 614.6 32.5 32000 20250  
13 60.3 9 H627.3 HR13 612.0 627.3 640.5 28.5 42200 26400  
14 52.6 8 H651.5A HR14A 630.8 651.5 670.1 39.4 27900 18000  
14 65.1 9 H651.5B HR14B 638.3 651.5 662.6 24.3 58350 36900  
15 -- 8 H665.0 HR15N 647 665.0 679 32 30600 19200 Covers H-alpha and Li6707.
15 56.4 8 H679.7 HR15 660.7 679.7 696.5 35.9 35500 21350  
16 61.1 8 H710.5 HR16 693.7 710.5 725.0 31.3 45500 27400  
17 51.7 7 H737.0A HR17A 712.9 737.0 758.7 45.9 29250 17350  
17 65.9 8 H737.0B HR17B 722.5 737.0 749.0 26.5 65100 38100  
18 55.4 7 H769.1 HR18 746.8 769.1 788.9 42.0 32350 20150  
19 46.9 6 H805.3A HR19A 774.5 805.3 833.5 59.0 23250 14500  
19 60.1 7 H805.3B HR19B 785.6 805.3 822.5 36.9 43700 26500  
20 49.6 6 H836.6A HR20A 807.3 836.6 863.2 56.0 25400 15800  
20 64.9 7 H836.6B HR20B 819.5 836.6 850.9 31.4 57100 34900  
21 53.2 6 H875.7 HR21 848.4 875.7 900.1 51.7 28000 18000  
22 43.7 5 H920.5A HR22A 881.6 920.5 956.5 74.9 17100 11800  
22 57.9 6 H920.5B HR22B 896.0 920.5 941.9 45.9 34200 23550  

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 values corresponding to the currently used grating and focussing procedure, i.e. for observations after February 2 2015. The corresponding values for the old focussing procedure (i.e. for observations taken between Oct 10 2003 and Feb 1 2015) are given here

The numbers for the OLD grating (i.e. for observations taken before Oct 10 2003) are given here.