Showing papers by "G. Neugebauer published in 1980"
TL;DR: The effective temperature of Saturn, 94.4 + 3 K, implies a total emission greater than two times the absorbed sunlight, and the infrared data alone give an atmospheric abundance of H2 relative to H2 + He of 0.85 � 0.15.
Abstract: The effective temperature of Saturn, 94.4 + 3 K, implies a total emission greater than two times the absorbed sunlight. The infrared data alone give an atmospheric abundance of H_2 relative to H_2 + He of 0.85 ± 0.15. Comparison of infrared and radio occultation data will give a more precise estimate. Temperature at the 1-bar level is 137 to 140 K, and 2.5 K differences exist between belts and zones up to the 0.06-bar level. Ring temperatures range from 60 to 70 K on the south (illuminated) side and from < 60 to 67 K in the planet's shadow. The average temperature of the north (unilluminated) side is ~ 55 K. Titan's 45-micrometer brightness temperature is 80 ± 10 K.
56 citations
TL;DR: The face-on Scd galaxy IC 342 has been studied at infrared wavelengths between 1.2 and 250 μm and at centimeter radio wavelengths as discussed by the authors, and the radio emission comes from a region with many of the same spatial features as the 10 μm source.
Abstract: The face-on Scd galaxy IC 342 has been studied at infrared wavelengths between 1.2 μm and 250 μm and at centimeter radio wavelengths. At 10 μm the nucleus is bright and extended on a scale of 200 pc, with a double structure unlike that of the stars seen at 2 μm. The infrared emission between 8 and 250 μm probably arises from heated dust grains in star formation regions in the disk of the galaxy. The radio emission comes from a region with many of the same spatial features as the 10 μm source; it appears to include both thermal and nonthermal sources. IC 342 is intermediate in luminosity between the Galaxy and NGC 253; the difference can probably be accounted for by a difference in the current rate of star formation at their centers.
53 citations
TL;DR: In this article, it is argued that dust grain growth was inhibited because of the low mass of condensable atoms in the shell, which is similar to the radius of the grains which grow in the optically thick shells of the DQ Herculis type novae.
Abstract: Nova Cygni 1978 was monitored photometrically from V to 19.5 microns for 120 days after the eruption. Following the initial expansion of the hot gas shell, an optically thin dust shell formed and reached a maximum visual optical depth of about 0.1 by day 60. No visible transition phase of the type observed in the very dusty DQ Herculis novae occurred in Nova Cygni 1978. It is argued that dust grain growth was inhibited because of the low mass of condensable atoms in the shell. Although the dust shell in Nova Cygni 1978 was optically thin at visual and infrared wavelengths, the grains grew to a radius of 0.3 micron which is comparable to the radius of the grains which grow in the optically thick shells of the DQ Herculis type novae.
37 citations
TL;DR: In this article, a simple model where the emission lines are formed in an H II region, and the line ratios are consistent with those predicted by standard radiative recombination theory and reddening corresponding to 0.4 mag.
Abstract: Measurements of the emission-line intensities of NGC 1068 have been made over the wavelength range extending from rest wavelengths equal to 1216 A to 1.875 micron. The data, plus other available emission-line data, can be explained in terms of a simple model where the emission lines are formed in an H II region, and the line ratios are consistent with those predicted by standard radiative recombination theory and reddening corresponding to 0.4 mag. The continuum flux is seen to consist of a galaxy component plus a nonstellar component which dominates the observed flux in the ultraviolet. The observed ultraviolet continuum does not show an absorption dip caused by the intertellar 2200 A feature nor does it contain enough energy to power the observed infrared flux.
31 citations
TL;DR: New spectrophotometric observations of Pluto from 1.5-2.5 micron with a resolution of 0.05 are reported in this article, which confirm the presence of methane frost on the surface of Pluto.
Abstract: New spectrophotometric observations of Pluto from 1.5-2.5 micron with a resolution of 0.05 are reported. The new observations confirm the presence of methane frost on the surface of Pluto.
27 citations
TL;DR: A 2 x 3 arcmin region surrounding the W3 cluster of near-infrared sources and compact H II regions has been mapped at 30, 50, and 100 microns with an angular resolution of about 30 arcsec as mentioned in this paper.
Abstract: A 2 x 3 arcmin region surrounding the W3 cluster of near-infrared sources and compact H II regions has been mapped at 30, 50, and 100 microns with an angular resolution of about 30 arcsec The data have been used to produce maps of the distribution of luminosity, color temperature, and opacity in the far-infrared which are used to analyze the properties and evolutionary states of the individual compact sources in the cluster and of the molecular cloud in which they are embedded The total luminosity of the near-infrared source W3-IRS 5 is estimated on the basis of these observations to be 200,000 solar luminosities, and it is identified as a forming O star
16 citations
TL;DR: In this paper, the spatial distribution of the emission in the v = 1-0 S(1) line of H2 in the planetary nebula NGC 7027 is presented.
Abstract: The spatial distribution of the emission in the v = 1-0 S(1) line of H2 in the planetary nebula NGC 7027 is presented. The excited H2 molecules do not fill the same volume as the ionized gas and most likely reside near the outer edge of the nebula. The spatial resolution of the data, 5 arcsec, is insufficient to define the location of the molecules precisely. An upper limit to the strength of the v = 2-1 S(1) line is given; it is low enough to preclude simple ultraviolet fluorescence as the source of excitation. A simple shock model can fit the line ratio data, however, and there is enough energy in the expanding nebula to sustain such a shock. A rough estimate of 1 M_⊙ to 4 M_⊙ for the mass in the molecular cloud surrounding NGC 7027 is derived.
11 citations
TL;DR: In this paper, it was shown that the double quasars are a pair of images of a single object and that the quasar has an energy distribution that is unusual, and the intervening galaxy is shown to be highly luminous with a bolometric luminosity of about 2 × 10^(11) L.
Abstract: The properties of the remarkable double quasar 0957 + 561 were first described by Walsh et al. Recently Young et al. have described CCD observations of a distant galaxy associated with the quasar pair, and have identified this galaxy as a gravitational lens forming a double image of a single quasar. We report here 1.2–2.2-µm observations of the system that support the conclusion that the twin quasars are a pair of images of a single object; the quasar has an energy distribution that is unusual. The intervening galaxy is shown to be highly luminous with a bolometric luminosity of about 2 × 10^(11) L.
7 citations