ionization front

ionization front

See Strömgren sphere.

ionization front

[‚ī·ə·nə′zā·shən ‚frənt]
(astronomy)
A transition region that separates interstellar gas in which a given atomic species (usually hydrogen) is mostly ionized from interstellar gas in which it is mostly neutral.
References in periodicals archive ?
The ionization front known as the "Bright Bar" is the strikingly straight edge running from the northeast to the southwest border of the Huygens region.
This cool observation technique also helps convince me the orangepink color is real, because I saw color along the outer edge of the Bright Bar ionization front and in the small patch just southwest of the Trapezium in the shrouded star-forming area, Orion S, exactly where color exists.
The Sandia concept, called the Ionization Front Accelerator (IFA), does not suffer this disadvantage.
To accelerate the electron-beam front, the physicists provide an accelerated, moving ionization front in the cesium.
The famous Pelican Nebula, IC 5070, is an ionization front illuminated by young, energetic stars within a vast molecular cloud in Cygnus.
Within the next 20,000 years or so, the advancing ionization front will overrun the nearby newly forming star, slowing or stopping its growth by destroying the materials it needs to continue coalescing.
Wen's calculations reveal that the Orion Nebula is a very thin emitting layer lying on top of a highly irregular ionization front.
For almost two decades the bar was believed, qualitatively, to result from the nebula's ionization front tilting up until it became nearly perpendicular to the plane of the sky.
This bar region is very useful for determining the structure of the nebula because the compressed gas on the neutral side of the ionization front -- not luminous at visible wavelengths but detectable in the infrared and radio -- is also seen edge on.
New visible-light Hubble images of the Bright Bar show this tilted ionization front in unprecedented detail.
1] C are being photoionized just like the main ionization front of Orion.
Severe ionization fronts are often generated in the course of ionospheric storms which are driven by space weather conditions (Ho et al.