Instruments: HRC

Abstract

HRC operations continue smoothly with no major problems, anomalies, or interruptions. Routine monitoring observations show no significant charge extraction from the detectors. There may be some evidence of a decrease in the low energy (below 400 eV) QE of the HRC-S, probably indicative of the chemical evolution of the CsI photocathode. This is being monitored by the CXC Cal team and the HRC instrument team, but this phenomenon currently is not significant for scientific observations. There has been no significant change in the HRC-I quantum efficiency during the past year. One HRC observation was made using one of the shutters during the past year, an HRC+LETG observation of the Crab Nebula. The shutter was used to block the zeroth order image in order to reduce the overall instrument rate from this bright source below the telemetry limit. There were some anomalies in inserting and withdrawing the shutter in the past. Overall another quiet year from an HRC perspective. A wide variety of scientific investigations have been carried out over the past year with the HRC instruments. This year we highlight an HRC-I observation of the Mouse nebula, a pulsar wind nebula, demonstrating the HRC's imaging and timing capabilities.