supernova remnant

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supernova remnant

(SNR) The expanding shell of gas from a supernova explosion, consisting of the supernova ejecta and ‘swept-up’ interstellar gas. Young (< 1000 year old) supernova remnants are generally optically faint but are fairly strong radio and X-ray sources; the Crab nebula is exceptionally bright because it is energized by a central pulsar. Older supernova remnants appear as rings of bright filaments, again with associated radio and X-ray emission. Supernova remnants that have been observed at sufficiently high resolution can be loosely classified into two types. In shell SNRs, which constitute about 90% of all SNRs (including Tycho and Kepler), most of the observed radiation comes from a filamentary, often spherical shell; they seem to have no central power source and their luminosity is exclusively derived from the interaction of the supernova shell with the external medium. Plerions (or filled or filled-center SNRs) are now widely thought to be powered by a central pulsar – the Crab nebula is the archetypal example – and the observed radiation originates from the whole of the remnant. Compression by an expanding supernova remnant can trigger star formation in interstellar clouds. See also emission nebula.

supernova remnant

[¦sü·pər′nō·və ′rem·nənt]
(astronomy)
A nebula consisting of an expanding shell of gas that has been ejected by a supernova. Abbreviated SNR.
References in periodicals archive ?
Collectively, through their powerful stellar winds and later their supernova remnants, these massive stellar populations blow huge superbubbles into the surrounding interstellar medium.
It would also be interesting to discuss which objects give off ultraviolet emission lines or more UV light in general, like maybe some supernova remnants.
Many of the other gamma ray emission sources, in this very high energy band, have so far been linked to pulsars or supernova remnants (the remains of an exploding star).
The scientists now plan to continue their search to see if other supernova remnants also lack phosphorus.
Greaves and her colleague Phil Sigan started their work by taking a close look at two different supernova remnants, the left-over rubble from the&nbsp;explosions which is later used for the formation of new planets.
These accelerators include supernova remnants and active galaxies known as blazars that shoot out blasts of particles.
This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material.
Launched in 2008, Fermi continues to give astronomers a unique tool for exploring high-energy processes associated with solar flares, spinning neutron stars, outbursts from black holes, exploding stars, supernova remnants and energetic particles to gain insight into how the universe works.
Topics include the relation between magnetic energy and helicity, the hydrodynamics of colliding circumstellar bubbles, the stability of cosmic ray precursors, supernova remnants as the source of galactic cosmic rays, and polarimeters for HARPS and X-shooter.
ISLAMABAD -- NASA's Swift satellite has discovered one of the youngest-known supernova remnants - believed to be less than 2,500 years old - in our Milky Way galaxy.
Among the topics featured are water in the solar system, supernova remnants at high energy, the Crab Nebula, evolution of debris disks, and nuclear activity in nearby galaxies.
One of the youngest supernova remnants known, a glowing dust ball created by the explosion of a super-massive star in the Small Magellanic Cloud galaxy, exhibits the same problem as those in our galaxy: too little dust, according to measurements by University of California, Berkeley, astronomers.