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431.
We estimate the contribution of millisecond pulsars to the diffuse gamma-ray background of the Galaxy, and show that a significant
fraction of the Galactic background may originate from them. A small number of the unidentified COS-B point sources may, in
fact, be millisecond pulsars. It is argued that several hundred millisecond pulsars may be detectable as point sources by
the GRO satellite
A preliminary version of these results was presented at the NATO Advanced Study Institute on Neutron stars, AGNs and Jets,
Erice, September 5–17, 1988.
On leave from Raman Research Institute, Bangalore, India. 相似文献
432.
Reviving a calculation made by Eddington in the 1920s, and using the most recent and comprehensive databases available on
stars and galaxies, including more than 2,500,000 stars and around 20,000 galaxies we have computed their total radiation
received at the Earth just outside its atmosphere. This radiation density, if thermalized, would be equivalent to a temperature
of 4.212 K. The comparability of this temperature to that of the cosmic microwave background (2.723 K) may either be a pure
coincidence or may hold a key to some as yet unknown, aspect of the universe. 相似文献
433.
434.
We review recent findings that the universe on its largest scales shows hints of violations of statistical isotropy, in particular alignment with the geometry and direction of motion of the solar system, and missing power at scales greater than 60°. We present the evidence, attempts to explain it using astrophysical, cosmological or instrumental mechanisms, and prospects for future understanding. 相似文献
435.
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439.
We have calculated the distortions of the cosmic microwave background (CMB) spectrum in the wavelength range 2–50 cm due to the superposition of the CMB hydrogen recombination radiation in subordinate lines. The level populations were determined by numerically solving the equation of recombination kinetics together with the statistical equilibrium equations for a 60-level model hydrogen atom. The relative distortions are ≈10?7–10?6, with their wavelength dependence having a low-contrast, wavy pattern. However, the contrast increases severalfold and becomes pronounced when passing to the differential distortion spectrum. We study the dependence of the distortions on cosmological parameters. 相似文献
440.