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Owen, J. R.

Publications and source records attributed to Owen, J. R..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

The diffuse gamma-ray background in the Hoyle-Narlikar cosmology

The paper analyzes the contributions of QSOs, BL-Lac objects and Seyfert galaxies to the diffuse gamma-ray background within the framework of the Hoyle-Narlikar theory. It is shown that the inconsistency reported in standard theory, namely that the evolutionary function needed to explain the gamma-ray data is very different from the one derived from the optical part of the spectrum, is no longer present. It is also shown that the contribution of a variable gravitational 'constant' to the expression for the diffuse background is the same as that of a density evolution function.

Canuto, V. M.↗
NASA NTRS1980

Cosmological considerations on the diffuse gamma-ray isotropic background

Bignami et al (1979) have recently studied the problem of the origin of the diffuse gamma-ray isotropic radiation. They have concluded that within standard cosmology with Lambda = 0 and p = 0, BL Lacertae objects and Seyfert galaxies can account for most of the diffuse radiation if they have not evolved in time. For QSOs, an evolutionary factor is allowed by the data. From the study of radio data, however, it is known that strong evolutionary effects are expected. The discrepancy cannot be explained by changing the geometry of the universe. Contrary to the case of standard cosmology, it is found that in order to fit the diffuse gamma-ray background, the evolutionary function required is almost identical to the one previously determined from the study of the log N-log S relation.

Canuto, V. M.↗
NASA NTRS1979

Scale covariance and G-varying cosmology. III - The /m, z/, /theta sub m, z/, /theta sub i, z/, and /N/m/, m/ tests

The Einstein gravitational equations in atomic units are fully solved for a matter-dominated universe in the context of a recently proposed scale-covariant cosmology. The magnitude-redshift relation for elliptical galaxies is studied, the evolutionary parameter used in such a study is derived, and the relation between isophotal angular diameters and redshifts is investigated, along with the relation between metric angular diameters and redshifts, the N(m)-magnitude relation for QSOs, and the magnitude-redshift relation for QSOs. Results are presented for four gauges (i.e., relations between G and the scale function beta (t)), and no contradictions are found between the proposed theory and the observational data. It is shown that only an open universe can fit the data if certain gauges suggested by a recent analysis of the time variation of the moon's period are selected and that observations made with atomic instruments do not necessarily yield geometrical parameters unless specific assumptions are made regarding the relation between atomic and gravitational dynamics.

Canuto, V. M.↗
NASA NTRS1979

Scale covariance and G-varying cosmology. IV - The log N-log S relation

The traditional radio counts N(S) and radio source models are studied within the framework of the scale-covariant cosmology developed to investigate whether the relative strength of the gravitational and electromagnetic constants is a function of cosmological epoch. It is found that a gravitational constant G varying as the inverse of t, where t is the epoch in atomic units, is consistent with all the data analyzed. For a wide class of models the present cosmology allows a finer discrimination of the deceleration parameter than does standard theory. The results, when combined with those of previous papers, namely, those from radio and optical flux and angular-diameter data analysis, favor an open universe.

Canuto, V. M.↗
NASA NTRS1979

Varying G

The problem of the variation of the gravitational constant with cosmological time is critically analyzed. Since Einstein's equation does not allow G to vary on any time scale, no observational data can be analyzed within the context of the standard theory. The recently proposed scale covariant theory, which allows (but does not demand) G to vary, and which has been shown to have passed several standard cosmological tests, is employed to discuss some recent nonnull observational results which indicate a time variation of G.

Canuto, V.↗
NASA NTRS1973

Determine the utility of ERTS-1 imagery in the preparation of hydrologic atlases of arid land watersheds

The author has identified the following significant results. The 9x9-inch transparencies from the ERTS-1 system seem to have better contrast in vegetation and drainage features than the 70-mm transparencies. This imagery can be magnified about eight times before it becomes excessively grainy. Imagery in band 7 appears to be the best single band product for viewing landform-water complexes. Band 5 best defines vegetation patterns. Multispectral color-additive viewing would appear to improve the separation of vegetation types where the vegetation exhibits moderate to strong infrared reflectance. Multispectral viewing did not appear to improve relief of drainage channel detail. False-color aerial infrared photographs at a scale of 1:120,000 for the Utah test site are excellent quality and can be magnified as much as 15 times without serious loss of contrast or excessive fuzziness. In desert areas with sparse to moderate shrub cover, the contrast between the soil background and the plant cover is so low that texture cannot be seen, even under high magnification. In areas of higher rainfall during the summer it is possible to discriminate coniferous and deciduous trees, grass, and shrub communities and to identify different rangeland treatment practices.

Shown, L. M.↗