LRIS r400_8500 Throughput Measurements

Summary

Date	Standard	RA (J2000)	DEC (J2000)	Grating	Block	Cent. Wave	Slit	Airmass	Conditions	Figures	Tables
16DEC2010	G191B2B	05:05:30.60	+52:49:54.0	400/8500	560	7883	10.00	1.08	Clear,<1",direct	ZP_pix ZP_Ang Efficiency	ZP_pix ZP_Ang Efficiency

The above table summarizes the set of standard stars that have been processed. They should have all been observed in photometric conditions. You may note, however, that the slitwidth and airmass vary consdierably. The efficiency calculations have made an estimated correction for the airmass, but NO correction for slit losses. If you have a standard star to contribute, please contact the Keck staff or JXP. Here is a summary of the standards observed:

ZP_pix: Zero point (AB magnitude) to give one electron per second per pixel. This does NOT include an airmass correction. ZP_Ang: Zero point (AB magnitude) to give one electron per second per Angstrom. This does NOT include an airmass correction. Efficiency: Total efficiency of the telescope+instrument. This does include an airmass correction.

Current ZP and Efficiency Curves

The following figures show the most recent measurements of the ZeroPoint and efficiency measurements hopefully observed through a sufficiently large slit (usually >2 arcsec).