- Characterization of solid state array cameras for the mid-IR
Abstract
The authors present a characterization of some processes affecting the performance of
solid state array cameras designed for ground based astronomical imaging in the 8-13 um
atmospheric window. The discussion includes a novel model for electron-hole generation - recombination
noise based on the probable pathlength of an electron in a photoconductor. The authors use the
Berkeley mid-IR Array Camera as an example. For this camera, the results show that the total
optical system composed of the camera, a 3 m telescope, and the atmosphere has an efficiency of
about 3%, a 1 sigma noise equivalent flux density of 25 mJy / min^0.5 arcsec^2 measured over a 10% band
width, and a noise equivalent expressed as the ambient temperature thermal black body noise of 23%.
Eric Keto, Roger Ball, J.F. Arens, Garrett Jernigan & Margaret Meixner, 1992, Int. J. Infrared Millimeter Waves, 13, 1709
- A Super-Star Cluster in NGC 253: Mid-Infrared Properties
Abstract
We observed the nearby starburst galaxy NGC 253 in the mid-infrared to
obtain a three-dimensional data set with arcsecond angular resolution
and 0.2 um spectral resolution. The observations show the major spectral
features in the upper half of the mid-IR window: the 11.3 um polycyclic
aromatic hydrocarbon (PAH) line and the 12.8 um [Ne II] line as well
as the broad silicate absorption feature at 9.7 um. We use
the [Ne II] line to determine the emission measure of the ionized
gas, and in combination with radio observations to predict the thermal
and nonthermal contributions to the radio continuum. The amount of
ionized gas is related to the rate of star formation. Based on the
mid-IR spectra, we identify three major components in the nucleus
of NGC 243: an AGN in the center of the galaxy, a super-star cluster
also seen in optical images, and a larger scale diffuse envelope
composed of an older population of supernova remnants and lower mass stars.
Eric Keto, Joseph L. Hora, G.G. Fazio,
William Hoffmann, Lynne Deutsch, ApJ, 518, 183
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