Background

The DEIMOS spectroscopic throughput measurements shown here are the result of Thomas Lai's work as a Keck Visiting Scholar during November and December 2018. This measurements include the analysis of archival throughput observations of various standard stars taken between 2010 and 2018 for all DEIMOS gratings at several different central wavelength values. Follow the links below to access plots and tables with the results. The old spectroscopic throughput plots can be found here.

The throughput is defined as:

	throughput = Nd/Nt

where:

• Nd = Number of photons detected
• Nt = Number of photons hitting the telescope's primary mirror, computed as Nt = Nst * 10 ** (-0.4*airmass*ext(lambda))
• Nst is the star's photon flux, in photon/cm**2/s, taken from the HST/CALSPEC database of standard star fluxes.
• ext(lambda) is the mean monochromatic extinction coefficient for Mauna Kea.

Data

Throughput data for various central wavelengths and order-blocking filters are available for the following DEIMOS gratings:

• 600ZD
• 830G
• 900ZD
• 1200G
• 1200B

Grating 600ZD

Central Wavelength [Å]	Plot (click to enlarge)	Download	Filter	Table
5500		PNG	GG400	Table
6500		PNG	GG455	Table
7500		PNG	OG550	Table
All		PNG	--	--

Grating 830G

Central Wavelength [Å]	Plot (click to enlarge)	Download	Filter	Table
5000		PNG	GG400	Table
7000		PNG	GG455	Table
8000		PNG	OG550	Table
All		PNG	--	--

Grating 900ZD

Central Wavelength [Å]	Plot (click to enlarge)	Download	Filter	Table
5000		PNG	GG400	Table
7000		PNG	GG455	Table
8000		PNG	OG550	Table
All		PNG	--	--

Grating 1200G

Central Wavelength [Å]	Plot (click to enlarge)	Download	Filter	Table
5000		PNG	GG400	Table
7000		PNG	GG455	Table
8000		PNG	OG550	Table
All		PNG	--	--

Grating 1200B

Central Wavelength [Å]	Plot (click to enlarge)	Download	Filter	Table
5000		PNG	GG400	Table
7000		PNG	GG455	Table
8000		PNG	OG550	Table
All		PNG	--	--