Compiled by S. M. Faber
November 2, 1995

**DEIMOS Grating Data**
Grating	alpha	beta_0	betamin	betamax	lambda_0	lambdamin	lambdamax	anamor	bratio	Scale		Raw slitwidth		Eff slitwidth
[l/mm]	[°]	[°]	[°]	[°]	[Å]	[Å]	[Å]	anamor	bratio	[none]	[Å/mm]	[px]	[Å]	[px]	[Å]	[px]	[Å]
Mirror, image centered on detector (not at nominal imaging point).
Mirror	22.226	-22.226						1.00	1.080			6.29		6.52
Mirror, image at nominal imaging point, which puts 4.5' at 0.472-in to right on detector.
Mirror	23.127	-23.127						1.00	1.087			6.29		6.52
1200-line grating
1200.	62.628	18.177	9.016	27.338	10000.000	8706.238	11227.310	2.066	2.175	0.312	20.781	3.04	0.95	3.50	1.09
1200.	57.912	13.461	4.300	22.622	9000.000	7685.008	10265.603	1.831	1.882	0.319	21.271	3.43	1.10	3.85	1.23
1200.	53.459	9.008	-0.153	18.169	8000.000	6673.023	9293.781	1.659	1.680	0.324	21.602	3.79	1.23	4.17	1.35
1200.	49.207	4.756	-4.405	13.917	7000.000	5668.989	8313.337	1.525	1.531	0.327	21.797	4.12	1.35	4.47	1.46
1200.	45.111	0.660	-8.501	9.821	6000.000	4672.051	7325.362	1.417	1.417	0.328	21.871	4.44	1.46	4.76	1.56
1200.	41.135	-3.316	-12.477	5.845	5000.000	3681.656	6330.700	1.326	1.328	0.328	21.836	4.74	1.55	5.05	1.65
1200.	39.183	-5.268	-14.429	3.893	4500.000	3188.605	5830.885	1.285	1.290	0.327	21.780	4.89	1.60	5.19	1.70
900-line grating
900.	51.311	6.860	-2.301	16.021	10000.000	8226.668	11739.321	1.588	1.600	0.434	28.954	3.96	1.72	4.32	1.88
900.	48.171	3.720	-5.441	12.881	9000.000	7225.620	10756.149	1.496	1.499	0.437	29.102	4.20	1.83	4.54	1.98
900.	45.111	0.660	-8.501	9.821	8000.000	6229.402	9767.149	1.417	1.417	0.437	29.161	4.44	1.94	4.76	2.08
900.	42.120	-2.331	-11.492	6.830	7000.000	5238.333	8773.387	1.347	1.348	0.437	29.139	4.67	2.04	4.98	2.18
900.	39.183	-5.268	-14.429	3.893	6000.000	4251.474	7774.514	1.285	1.290	0.436	29.040	4.89	2.13	5.19	2.26
900.	36.293	-8.158	-17.319	1.003	5000.000	3268.991	6771.166	1.228	1.241	0.433	28.868	5.12	2.22	5.40	2.34
900.	34.861	-9.590	-18.751	-0.429	4500.000	2779.311	6267.852	1.202	1.219	0.431	28.755	5.23	2.26	5.51	2.38
830-line grating
830.	47.433	2.982	-6.179	12.143	9500.000	7576.483	11407.654	1.476	1.478	0.474	31.580	4.26	2.02	4.60	2.18
830.	46.021	1.570	-7.591	10.731	9000.000	7078.359	10913.284	1.440	1.440	0.474	31.611	4.37	2.07	4.70	2.23
830.	43.243	-1.208	-10.369	7.953	8000.000	6085.447	9920.959	1.372	1.373	0.474	31.615	4.58	2.17	4.90	2.32
830.	40.515	-3.936	-13.097	5.225	7000.000	5096.784	8924.099	1.312	1.315	0.473	31.548	4.79	2.27	5.09	2.41
830.	37.829	-6.622	-15.783	2.539	6000.000	4112.300	7923.074	1.258	1.266	0.471	31.412	5.00	2.36	5.29	2.49
830.	35.179	-9.272	-18.433	-0.111	5000.000	3131.611	6917.848	1.207	1.223	0.468	31.209	5.21	2.44	5.49	2.57
830.	33.864	-10.587	-19.748	-1.426	4500.000	2642.679	6413.740	1.184	1.204	0.466	31.084	5.31	2.48	5.59	2.60
600-line grating
600.	39.183	-5.268	-14.429	3.893	9000.000	6377.210	11661.771	1.285	1.290	0.653	43.560	4.89	3.20	5.19	3.39
600.	37.252	-7.199	-16.360	1.962	8000.000	5394.024	10659.158	1.246	1.256	0.651	43.400	5.04	3.28	5.33	3.47
600.	35.337	-9.114	-18.275	0.047	7000.000	4413.637	9653.616	1.210	1.226	0.648	43.192	5.19	3.37	5.48	3.55
600.	33.438	-11.013	-20.174	-1.852	6000.000	3435.962	8645.198	1.176	1.198	0.644	42.939	5.34	3.44	5.62	3.62
600.	31.551	-12.900	-22.061	-3.739	5000.000	2460.931	7633.956	1.144	1.173	0.640	42.640	5.50	3.52	5.76	3.69
600.	30.611	-13.840	-23.001	-4.679	4500.000	1974.391	7127.291	1.128	1.162	0.637	42.474	5.57	3.55	5.84	3.72

Notes

Spectrograph angle is 44.451 deg, and imaging position is displaced by 0.472-in.
Central beta_0 and lambda_0 are for wavelength at center of detector, which is the nominal spectroscopy zeropoint.
Max and Min values are for wavelengths falling at edges of ±4096 px detector with 15 µ px, not allowing for any gaps.
Maxangle (for edges of detector) is 9.161 deg.
The slitwidth is 0.75" on sky. Raw slitwidth (FWHM) is for no aberrations, effective slitwidth (FWHM) includes collimator and camera aberrations.
Anamor is the anamorphic factor defined as the dimensionless ratio between pixel scale in the dispersion direction (arcsec/pix) and the pixel scale in the spatial direction (arcsec/pix). As the grating tilt angle increases "more arcseconds fit within each pixel", and therefore the slit becomes narrower in the dispersion direction:
```
slit_width_eff [Å] = (slit_width ["] / 0.1185 ["/pix]) x (disp [Å/pix] / anamor)
```
Bratio is the beam elongation on flat or grating.
Spectrograph angle of 44.51 degrees corresponds to middle of detector on the optical axis of the camera on the one hand and 4.5 arc min off axis from the center of the telescope FOV on the other. The latter point is the nominal field field center for each DEIMOS beam.
November 1997: Correct Eff slitw using updated design and fabrication errors from Camera CDR.
Narrow-band imaging: To move center of FOV at 4.5' to LHS of detector needs alpha = 17.65 deg for mirror. To move center of FOV at 4.5' to RHS of detector needs alpha = 26.81 deg for mirror.

Compiled by S. M. Faber November 2, 1995

Notes

Compiled by S. M. Faber
November 2, 1995