Engineering topics
Publications and source records attributed to Matthews, K..
An absorption feature at 2.3 microns attributed to CO molecules in stellar atmospheres has been found in some, but not all, of the infrared sources within 20 arcsec of the galactic center. The absorption is characteristic of that found in M-type giant and supergiant stars. The infrared source coincident with the sub-arcsecond nonthermal radio source does not show CO absorption.
Infrared photometric measurements of 19 normal and giant elliptical galaxies are reported which were made with apertures having diameters 0.1 to 1.3 times the visual galactic diameters. The derived V (2.2 micron) colors, ranging from 3.15 to 3.60 magnitudes, are compared with the results of Grasdalen (1975) for 28 spiral and elliptical galaxies. All but one of the present magnitudes are found to be systematically brighter than Grasdalen's by 0.07 to 0.46 magnitude, and no significant radial color gradient is observed.
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Observations of Cygnus X-3 were carried out at 2.5 - 7.5 keV, 2.2 micron, 8.1 GHz and 2.7 GHz over a two week period. The X-ray data show the periodic structure which is typical of Cyg X-3. At times the X-ray and infrared measurements show very similar periodic structure, both in phase and shape, while at other times the infrared data show no periodic variability. The radio fluxes were usually low during the period of observation; both the daily average radio flux levels and spectral index remained nearly constant.
Infrared observations of Cyg X-3 are presented along with X-ray and radio data. A study of the data shows evidence for several types of behavior in the infrared flux variations of Cyg X-3. It is pointed out that a lack of periodic variations observed can be due either to a real absence of these variations or to a masking by an outburst preceding the observation time. There is no simple radio-infrared correlation, although both radio and infrared emissions were observed during the same period of time.
The extent of the long-period variable infrared-emitting object IRC+10011 has been measured at 2.2, 10, and 20 microns, taking advantage of two lunar occultation this object has recently undergone. At 10 and 20 microns, the bulk of the radiation is found to come from an optically thick dust region about 0.1 sec in diameter. At 2.2 microns, the dominant source of radiation is the central Mira star, but the inner part of the dust shell is also visible.
A new complex of infrared sources about one minute across has been discovered in Orion. Associated with this cluster is an extended molecular cloud producing intense CO emission. Its measured infrared luminosity is less than 500 times the luminosity of the sun. The complex is hypothesized to be composed of pre-main-sequence sources. Several arguments suggest that these stars heat dust in the larger molecular cloud and thus cause the strong CO emission. The complex is not associated with a known visible or radio continuum feature, and searches over a 0.7 x 0.7-deg field show no other comparable unknown 2.2-micron sources.
Several hundred five-micron 'video' pictures of Jupiter, with 1-sec resolution, made during September, October, and December 1973 and compared with color photographs, are shown to exhibit direct, detailed correlations with the darker 'purple' features. Forty-four of these pictures were made just before the Pioneer-10 encounter.
Observations of the luminosity sensitive CO absorption band at 2.3 micron are presented for the nuclei of 16 epsilon and SO galaxies. Preliminary data on the radial variation of the CO index in 6 galaxies are also given. The data show that the 2-u radiation from the nuclei is dominated by high luminosity stars of integrated spectral type later than K5. There is only a small variation in the CO absorption from galaxy to galaxy, and only a slight variation with measuring aperture size from 17.5 in. to 59 in. The data can be used to synthesize stellar populations for elliptical galaxy nuclei.
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The data presented show that a majority of the 10-micron emission from NGC 1068 comes from an area with a diameter of about 60 pc. The measurements described were made at 10 microns on two nights at the 200-inch Hale telescope. The data obtained agree with the results obtained by Stein et al. (1973). An approach to reconcile the new data with the variability observed by Rieke and Low (1972) is also discussed.
Coordinated X-ray and IR observations of Cyg X-3 indicate the presence of a 4.8-hr periodicity in the IR flux density which is synchronized with the previously discovered 4.8-hr periodicity in X-ray emission intensity. This uniquely associates the X-ray source with the IR source, and hence, through the positional coincidence, with the radio object. In addition, short-term variability in the IR flux of Cyg X-3 is described which may be related to the flares seen at radio wavelengths. An improved estimate of the X-ray position is also given.