Ultraviolet observations of M32, a cosmological comparison

The average spectral energy distribution for a sample of 3200 A. Spectral synthesis indicates that elliptical galaxies are most likely older than 9 Gyrs. The ultraviolet flux is consistent with a population of red horizontal branch stars, as those present in metal-rich globular clusters. Data for distant (Z approximately 1) first ranked cluster galaxies show indications of spectral evolution

Spectroscopy of Comet P/Encke in 1980 - 1981

Digital spectroscopic scans of P/Comets Encke, Stephan-Oterma, and Gunn were obtained with a sky-subtraction scanner system. Quantiative fluxes for the cometary emission bands of CN, C3, C2, NH2, and the 'D OI red auroral line are presented for P/Encke. The most straight-forward and model-independent line flux to interpret is the lambda lambda 6300, 6364 forbidden oxygen doublet. After an NH2 blending correction, the oxygen production rate may be directly measured from the Lick small-aperture fluxes. The oxygen production rates increased rapidly with decreasing heliocentric distance for both P/Encke and P/Stephan-Oterma. A rough power-law exponent in r with n = approximately -2.5 describes the change in oxygen production for P/Encke. Compared to the water production rates inferred from IUE satellite spectra showing the lambda 3080 OH band, these oxygen production rates are consistently lower by a factor of 11. This implies a common origin for the two species; H2O is the likely sole OI ID parent

Spatially resolved quantitative spectroscopy of comets

Because of their temporal and spatial variations, modern ground-based studies of comets within approximately 4 A.U. of the sun are observationally demanding tasks. Over the years, researchers have attempted resolved spectroscopy of comets covering a wide range of intrinsic luminosity. Recently this group has developed spectral and direct-imaging procedures to detect weak ion tails submerged into the comae of even fairly faint comets. Although the last year was devoid of any really bright comet, re-analysis of older dust and gas production data of the 1986 P/Halley apparition has been almost completed. The main changes are that the nucleus does make a significant contribution to continuum light, and that the gravity effect in the dust escape velocity is somewhat larger than previously assumed. On the direct observational side, spectral studies of the 1987's Comet Bradfield show it to be qualitatively carbon-rich, at least in the outer coma ratio of CO(+) and CO2(+), compared the H2O(+) with respect to Halley at similar heliocentric distances

Keck Observations of the Most Distant Galaxy: 8C1435+63 at z=4.25

We report on Keck observations and confirm the redshift of the most distant galaxy known: 8C1435+63 at z=4.25. The spectrum shows a strong Ly$\alpha$ line, a Ly$\alpha$ forest continuum break and a continuum break at $\lambda_{rest}=912$\AA. The Ly$\alpha$ emission is spatially extended and roughly aligned with the radio source. The galaxy shows a double structure in the $I$-band ($\lambda_{rest}\approx$1500\AA) which is aligned with the radio axis; the two $I$-band components spatially coincide with the nuclear and southern radio components. Some fraction of the $I$ band emission could be due to a nonthermal process such as inverse compton scattering. In the $K$-band ($\lambda_{rest}\approx$4200\AA), which may be dominated by starlight, the galaxy has a very low surface brightness, diffuse morphology. The $K$ morphology shows little relationship to the radio source structure, although the major axis of the $K$ emission is elongated roughly in the direction of the radio source axis. The galaxian continuum is very red ($I-K>4$) and if the $K$ continuum is due to starlight, implies a formation redshift of $z_f > 5$. We speculate that this galaxy may be the progenitor of a present day cD galaxy.Comment: 4 pages + 4 figures; uuencoded tar compressed PostScript files; figures and tables included. To appear in 1 Jan 1995 issue of The Astrophysical Journal, Letters. Please direct requests/questions/comments to [email protected]

Effects of Accounting Rules on Utility Choices of Energy Technologies in the United States

Standard presentations of electricity costs from alternate systems are on the basis of capital charge rates that explicitly include effects of inflation, and recurring charges computed and levelized only over a short time horizon. These practices distort perception of what is the "cheapest" system. Specifically, they ignore the future economic growth of the systems beyond the levelizing period. This worth is nevertheless an important factor in total economy. The worth is greatest for systems with high capital costs and low recurring costs, and they are therefore severely penalized. When systems are compared using self-consistent accounting methods that incorporate future value over entire plant history, fossil-fueled electric power, with low capital costs and high recurrent costs, becomes much less attractive, and solar power, with high capital costs and low recurrent costs, becomes much more attractive, both relative to nuclear power which occupies an intermediate position in both respects

A Generalized Model for Market Substitution

Market penetration by new technologies is an established fact. The form of the curves of penetration can be expressed by simple mathematical rules, and fit experience very well. However, it has not been able to argue rigorously that future market penetration will follow the same rules, because a theoretical basis for these rules is lacking. V. Peterka has proposed such a basis. It is shown here that it follows from detailed considerations of the investment practices of centrally planned economies. Another model, heuristically reasonable for market economies, is needed. This report offers such a model. The mathematical structure of the new model is identical with that of Peterka, but the models differ in one significant parameter, as well as in applicable rules for specifying costs. In spite of these differences, the two models each support the market penetration rules, and thus we can expect that prediction of future market penetrations can be more confidently expressed, both for centrally planned and for market economies

Market Substitution Models and Economic Parameters

Peterka's model for market penetration rests on pricing assumptions used by centrally planned economies and, on this basis, is not applicable in market economies. It is also a strategic principle rather than a strictly deterministic model, since less favored, as well as more favored, technologies continue to be adopted. Using related strategic principles, this paper explores several models that might be usable in market economies. Test application of models to a synthetic problem simulating market substitution in the electric utility industry favors the "price" model. In this model, the economic attractiveness of a technology is proportional to the inverse of the price that would have to be charged for a product