ACIS Absolute QE the
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چکیده
منابع مشابه
A Comparison of Continuous Clocking 1x3 Mode to Timed Exposure Mode E ciencies of ACIS
In this document we compare event detection e ciencies in the TE mode to the ones expected in the CC(1x3) mode in the ACIS-S detector array of the HETG spectrometer on board the Chandra X-ray Observatory. Data taken in TE mode have pulse heights determined from the charge in a 3x3 pixel event island. In CC(1x3) mode, events are read out on a row by row basis, and therefore the pulse height for ...
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ACIS observations of astronomical sources as well as its own external calibration source (ECS) have shown that molecular contamination has been building up on the optical/UV blocking filters since launch. Early LETG/ACIS observations of Ton S180 in Nov. 1999 and 3C 273 in Jan. 2000 showed that there was a slight reduction in the low energy ACIS QE1. A nearsimultaneous LETG/HRC-S observation of ...
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In this paper we present our system design and methodology for making absolute quantum efficiency (QE) measurements through the vacuum ultraviolet (VUV) and verify the system with delta-doped silicon CCDs. Delta-doped detectors provide an excellent platform to validate measurements through the VUV due to their enhanced UV response. The requirements for measuring QE through the VUV are more stre...
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The absolute flux calibration of the standard WFC and HRC filters is derived from the available constraining observations of spectrophotometric standard stars. Values for the encircled energy (EE) of one arcsec radius relative to an infinite aperture radius are derived for hot stars and compared to the EE for cooler stars. The sensitivity degradation for the five year ACS lifetime is defined an...
متن کاملThe zeaxanthin-independent and zeaxanthin-dependent qE components of nonphotochemical quenching involve common conformational changes within the photosystem II antenna in Arabidopsis.
The light-harvesting antenna of higher plant photosystem II (LHCII) has the intrinsic capacity to dissipate excess light energy as heat in a process termed nonphotochemical quenching (NPQ). Recent studies suggest that zeaxanthin and lutein both contribute to the rapidly relaxing component of NPQ, qE, possibly acting in the minor monomeric antenna complexes and the major trimeric LHCII, respecti...
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