J. G. Jernigan

Monte Carlo Methods for X-ray Dispersive Spectrometers

We discuss multivariate Monte Carlo methods appropriate for X-ray dispersive spectrometers. Dispersive spectrometers have many advantages for high resolution spectroscopy in the X-ray band. Analysis of data from these instruments is complicated by the fact that the instrument response functions are multi-dimensional and relatively few X-ray photons are detected from astrophysical sources. Monte Carlo methods are the natural solution to these challenges, but techniques for their use are not well developed. We describe a number of methods to produce a highly efficient and flexible multivariate Monte Carlo. These techniques include multi-dimensional response interpolation and multi-dimensional event comparison. We discuss how these methods have been extensively used in the XMM-Newton Reflection Grating Spectrometer in-flight calibration program. We also show several examples of a Monte Carlo applied to observations of clusters of galaxies and elliptical galaxies with the XMM-Newton observatory.

Long wavelength infrared camera (LWIRC): a 10 micron camera for the Keck Telescope

The long wavelength IR camera is a facility instrument for the Keck Observatory designed to operate at the f/25 forward Cassegrain focus of the Keck I telescope. The camera operates over the wavelength band 7-13 micrometers using ZnSe transmissive optics. A set of filters, a circular variable filter, and a mid-IR polarizer are available, as are three plate scales: 0.05 inch, 0.10 inch, 0.12 inch per pixel. The camera focal plane array and optics are cooled using liquid helium. The system has been refurbished with a 128 X 128 pixel Si:As detector array. The electronics readout system used to clock the array is compatible wit both the hardware and software of the other Keck IR instruments NIRC and LWS. A new pre-amplifier/A-D converter has been designed and constructed which decreases greatly the system susceptibility to noise.