Wavelength Coverage with Available Gratings and T2KB *

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Grating 1st Order -----Coverage in Å * ----
No. l/mm Blaze 1st.Order 2nd.Order 3rd.Order
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BL 250 158 4000Å <8200Å -- --
BL 400 158 7000 8200 <4100 --
KPC-10A 316 4000 <4100 -- --
BL 181 316 7500 4100 <2000 --

KPC-17B 527 5540Å 2500Å -- --
BL 420 600 7500 2300 1150 --
KPC-007 632 5200 2100 -- --
KPC-22B 632 8500 2100 1050 --

BL 450 632 11000Å -- 1050 700
KPC-18C 790 9500 1700 850 --
KPC-24 860 10800 1600 800 --
BL 380 1200 9000 1100 550 --
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* Coverage based on ~1500 pixels of spectrum (due to vignetting by the camera). UV coverage limited by response of the chip, grating and atmosphere

Spectral Resolution with Available Gratings

Below is a table of spectral resolution for a slit width of 300 microns or 2 arcseconds, assuming 2.5 pixels FWHM. Better resolution is available using smaller slit widths.

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Grating First Order | -----Resolution in Å * ----
No. l/mm Blaze Å/pixel | 1st.Order 2nd.Order 3rd.Order
-------------------------------------------------------------
BL 250 158 4000Å 5.52 | 14.5 -- --
BL 400 158 7000 5.52 | 14.5 7.3 --
KPC-10A 316 4000 2.75 | 7.2 -- --
BL 181 316 7500 2.78 | 7.2 3.6 --

KPC-17B 527 5540Å 1.68 | 4.4 -- --
BL 420 600 7500 1.52 | 4.0 2.0 --
KPC-007 632 5200 1.39 | 3.7 -- --
KPC-22B 632 8500 1.44 | 3.7 1.9 --

BL 450 632 11000Å 1.39 | -- 1.9 1.0
KPC-18C 790 9500 1.14 | 3.0 1.5 --
KPC-24 860 10800 1.07 | 2.7 1.4 --
BL 380 1200 9000 0.74 | 2.0 1.0 --
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deveny@noao.edu
Friday, August 4, 1995