IRCS Wavelength Coverage of Echelle Orders

The configuration of the IRCS echelle is adjustable to most user requirements. The following tables list 'standard' configurations which should satisfy most applicants.

zJ-band
J-band
H-band
K-band
L-band
Echelle simulator
Response functions

zJ-band orders 48-55

The zJ setting of the echelle provides continuous wavelength coverage from 1.0146 - 1.1912 μm.

Order	Wavelength (μm)	Dispersion (A/pixel)
48	1.1629 - 1.1912	0.276
49	1.1391 - 1.1670	0.273
50	1.1163 - 1.1437	0.269
51	1.0943 - 1.1214	0.264
52	1.0732 - 1.0998	0.260
53	1.0529 - 1.0791	0.256
54	1.0334 - 1.0591	0.251
55	1.0146 - 1.0398	0.245

J-band: orders 41-48

The J setting of the echelle provides continuous wavelength coverage from 1.1626 - 1.3946 μm.

Order	Wavelength (μm)	Dispersion (A/pixel)
41	1.3613 - 1.3946	0.326
42	1.3289 - 1.3615	0.319
43	1.2979 - 1.3299	0.313
44	1.2684 - 1.2998	0.307
45	1.2402 - 1.2709	0.301
46	1.2132 - 1.2434	0.295
47	1.1874 - 1.2170	0.289
48	1.1626 - 1.1916	0.283

H-band: orders 31-38

Complete coverage of the H-band requires two settings of the echelle, H^- and H⁺.

	H^-		H⁺
Order	Wavelength (μm)	Dispersion (A/pixel)	Wavelength (μm)	Dispersion (A/pixel)
31	1.7926 - 1.8376	0.440
32	1.7365 - 1.7802	0.427	1.7485 - 1.7910	0.416
33	1.6838 - 1.7263	0.415	1.6955 - 1.7368	0.404
34	1.6343 - 1.6756	0.404	1.6455 - 1.6858	0.394
35	1.5875 - 1.6278	0.393	1.5985 - 1.6377	0.384
36	1.5434 - 1.5826	0.383	1.5540 - 1.5923	0.374
37	1.5016 - 1.5399	0.374	1.5120 - 1.5493	0.365
38	1.4621 - 1.4994	0.365	1.4721 - 1.5086	0.357

K-band: orders 23-29

Complete coverage of the K-band requires two echelle settings, K^- and K⁺. In addition, a third setting, K*, is offered which includes most of the important astronomical emission lines.

	K^-		K⁺		K^*
Order	Wavelength (μm)	Dispersion (A/pixel)	Wavelength (μm)	Dispersion (A/pixel)	Wavelength (μm)	Dispersion (A/pixel)
23	2.4023 - 2.4656	0.619	2.4456 - 2.5038	0.569	2.3930 - 2.4545	0.602
24	2.3021 - 2.3627	0.592	2.3437 - 2.3997	0.547	2.2931 - 2.3525	0.581
25	2.2098 - 2.2679	0.568	2.2500 - 2.3039	0.527	2.2012 - 2.2587	0.562
26	2.1247 - 2.1805	0.546	2.1634 - 2.2154	0.508	2.1165 - 2.1720	0.543
27	2.0458 - 2.0995	0.525	2.0833 - 2.1335	0.491	2.0380 - 2.0917	0.525
28	1.9726 - 2.0244	0.506	2.0089 - 2.0575	0.475	1.9652 - 2.0172	0.508
29	1.9044 - 1.9544	0.488	1.9397 - 1.9867	0.460	1.8974 - 1.9477	0.492

L-band: orders 14-19

Complete coverage of the L window requires 6 echelle settings. The A^-, A⁰, and A⁺ settings include orders 15-19 only, while the B^-, B⁰, and B⁺ settings include orders 14-17 only.

	A^-/B^-		A⁰/B⁰		A⁺/B⁺
Order	Wavelength (μm)	Dispersion (A/pixel)	Wavelength (μm)	Dispersion (A/pixel)	Wavelength (μm)	Dispersion (A/pixel)
14	3.8807 - 3.9891	1.058	3.9838 - 4.0843	0.981	4.0682 - 4.1614	0.910
15	3.6220 - 3.7231	0.987	3.7183 - 3.8120	0.914	3.7969 - 3.8840	0.850
16	3.3956 - 3.4904	0.926	3.4859 - 3.5738	0.858	3.5596 - 3.6412	0.797
17	3.1958 - 3.2851	0.872	3.2808 - 3.3636	0.809	3.3502 - 3.4270	0.750
18	3.0183 - 3.1026	0.823	3.0986 - 3.1767	0.763	3.1641 - 3.2366	0.708
19	2.8594 - 2.9393	0.780	2.9355 - 3.0095	0.722	2.9976 - 3.0663	0.670

Echelle Simulator

The angle of the echelle grating and the cross disperser can be set to optimize the wavelength coverage. Echelle simulator (web app) can be used to figure out the appropriate configuration.

A detailed simulator is also available (IDL/IDL VM is needed).

Response Functions

See the page below for the response functions of IRCS echelle calculated with the echelle simulator. This can be used as the atlas of the emission lines such as OH and Ar for wavelength calibration.