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Galactic X-rays: Variable Sources in Hydromagnetic Waves.
Science (New York, N.Y.)
|June 28, 1968
Summary
Galactic X-ray sources are small, dense gas regions emitting kiloelectron-volt thermal bremsstrahlung. Hydromagnetic waves compress gas clouds, creating these sources, estimated at 10^16 cm, too small for radio telescopes.
Area of Science:
- Astrophysics and plasma physics.
- Study of high-energy celestial phenomena.
Background:
- Galactic X-ray sources exhibit intensity fluctuations.
- These sources are theorized to be localized regions of high gas density and temperature.
Purpose of the Study:
- To explain the origin and characteristics of fluctuating galactic X-ray sources.
- To estimate the physical size of these X-ray emitting regions.
Main Methods:
- Analysis of thermal Coulomb bremsstrahlung emission from ionized gas clouds.
- Modeling of hydromagnetic wave compression of galactic gas clouds.
- Estimation of source size based on fluctuation periods and bremsstrahlung calculations.
Main Results:
- Identified fluctuating galactic X-ray sources as small regions (approx. 10^16 cm) of enhanced gas density and temperature.
- Determined that hydromagnetic wave motions in galactic spiral arms compress ionized gas clouds, creating these sources.
- Calculated source sizes using fluctuation periods and bremsstrahlung formulas, yielding consistent estimates.
Conclusions:
- The observed X-ray emissions originate from small, compressed gas regions within the galaxy.
- These regions are too small to be detected by current radio telescope technology.
- Hydromagnetic waves play a crucial role in the formation of these energetic X-ray sources.
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