Remnant of Kepler's Supernova, SN 1604

Remnant of Tycho's Nova, SN 1572

A supernova remnant (SNR) is the structure resulting from the gigantic explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. Download high resolution version (750x750, 53 KB)Remnants of Keplers Supernova (SN 1604). ... Download high resolution version (750x750, 53 KB)Remnants of Keplers Supernova (SN 1604). ... Supernova 1604, also known as Keplers Supernova or Keplers Star, was a supernova in the Milky Way, in the constellation Ophiuchus. ... Image File history File links Download high resolution version (2400x2400, 609 KB) Summary Tychos Supernova Remnant. ... Image File history File links Download high resolution version (2400x2400, 609 KB) Summary Tychos Supernova Remnant. ... X-ray image of the expanding cloud of debris and high energy electrons from Tychos supernova. ... This article is about the astronomical object. ... For other uses, see Supernova (disambiguation). ... Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...

There are two possible routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accumulate (accrete) material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. For the story by Larry Niven, see Neutron Star (story). ... For other uses, see Black hole (disambiguation). ... This article or section does not adequately cite its references or sources. ... In astrophysics, the term accretion is used for at least two distinct processes. ...

In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 1% the speed of light, some 3,000 km s^-1. When this material collides with the surrounding circumstellar or interstellar gas, it forms a shock wave that can heat the gas up to temperatures as high as 10 million K, forming a plasma. For other uses, see Plasma. ...

Perhaps the most famous and best-observed young SNR was formed by SN 1987A, a supernova in the Large Magellanic Cloud that was discovered in 1987. Other well-known, older, supernova remnants include Tycho (SN 1572), a remnant named after Tycho Brahe, who recorded the brightness of its original explosion (AD 1572) and Kepler (SN 1604), named after Johannes Kepler. Beaded ring brightens from 2003 and 2005 SN 1987A was a supernova in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, a nearby dwarf galaxy. ... The Large Magellanic Cloud (LMC) is a nearby satellite galaxy of our own galaxy, the Milky Way. ... X-ray image of the expanding cloud of debris and high energy electrons from Tychos supernova. ... Monument of Tycho Brahe and Johannes Kepler in Prague Tycho Brahe, born Tyge Ottesen Brahe (December 14, 1546 – October 24, 1601), was a Danish nobleman from the region of Scania (in modern-day Sweden), best known today as an early astronomer, though in his lifetime he was also well known... January 16 - Thomas Howard, 4th Duke of Norfolk is tried for treason for his part in the Ridolfi plot to restore Catholicism in England. ... Supernova 1604, also known as Keplers Supernova or Keplers Star, was a supernova in the Milky Way, in the constellation Ophiuchus. ... Kepler redirects here. ...

Summary of stages

A SNR passes through the following stages as it expands:

1. Free expansion of the ejecta, until they sweep up their own weight in circumstellar or interstellar medium. This can last tens to a few hundred years depending on the density of the surrounding gas.
2. Sweeping up of a shell of shocked circumstellar and interstellar gas. This begins the Sedov-Taylor phase, which can be well modeled by a self-similar analytic solution. Strong X-ray emission traces the strong shock waves and hot shocked gas.
3. Cooling of the shell, to form a thin (< 1 pc), dense (1-100 million atoms per cubic metre) shell surrounding the hot (few million kelvin) interior. This is the pressure-driven snowplow phase. The shell can be clearly seen in optical emission from recombining ionized hydrogen and ionized oxygen atoms.
4. Cooling of the interior. The dense shell continues to expand from its own momentum, in a momentum-driven snowplow. This stage is best seen in the radio emission from neutral hydrogen atoms.
5. Merging with the surrounding interstellar medium. When the supernova remnant slows to the speed of the random velocities in the surrounding medium, after roughly a million years, it will merge into the general turbulent flow, contributing its remaining kinetic energy to the turbulence.

The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ... A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ...

Types of supernova remnant

There are three types of supernova remnant:

• Shell-like, such as Cassiopeia A
• Composite, in which a shell contains a central pulsar wind nebula, such as G11.2-0.3 or G21.5-0.9.
• Mixed-morphology (also called "thermal composite") remnants, in which central thermal X-ray emission is seen, enclosed by a radio shell. The thermal X-rays are primarily from swept-up interstellar material, rather than supernova ejecta. Examples of this class include the SNRs W28 and W44. (Confusingly, W44 additionally contains a pulsar and pulsar wind nebula; so it is simultaneously both a "classic" composite and a thermal composite.)

3C461, Cassiopeia A, in X-rays 3C461, Cassiopeia A, observed by the Spitzer Space Telescope Cassiopeia A (Cas A) is a supernova remnant in the constellation Cassiopeia and the brightest extra solar radio source in the sky, with a flux of 2720 janskies at 1 GHz. ... A pulsar wind nebula (also known as a plerion, Greek for full) is a synchrotron nebula powered by the relativistic wind of an energetic pulsar. ...

Origin of cosmic rays

Supernova remnants are the major source of Galactic cosmic rays.^[1][2][3] In 1949 Enrico Fermi proposed a model for the acceleration of cosmic rays through particle collisions with magnetic clouds in the interstellar medium.^[4] This process, known as the "Second Order Fermi Mechanism", increases particle energy during head-on collisions, resulting in a steady gain in energy. A later model to produce Fermi Acceleration was generated by a powerful shock front moving through space. Particles that repeatedly cross the front of the shock can gain significant increases in energy. This became known as the "First Order Fermi Mechanism".^[5] Galactic cosmic rays are high-energy charged particles that enter the solar system from the outside. ... Enrico Fermi (September 29, 1901 – November 28, 1954) was an Italian physicist most noted for his work on the development of the first nuclear reactor, and for his contributions to the development of quantum theory, particle physics and statistical mechanics. ... The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ...

Supernova remnants can provide the energetic shock fronts required to generate ultra-high energy cosmic rays. Observation of the SN 1006 remnant in the X-ray has shown synchrotron emission consistent with it being a source of cosmic rays^[1]. However, for energies higher than about 10¹⁵ eV a different mechanism is required as supernova remnants cannot provide sufficient energy.^[5] ... Synchrotron radiation is electromagnetic radiation, similar to cyclotron radiation, but generated by the acceleration of ultrarelativistic (i. ...

See also

• List of supernova remnants
• Local Bubble
• Nova remnant
• Planetary nebula

Cassiopeia A Crab Nebula Gum Nebula SN 1604 SN 1987A Veil Nebula Vela Supernova Remnant W49B See also Supernova remnant Supernova Categories: | | ... The Local Bubble is a cavity in the local interstellar medium (ISM) at least 300 light years across containing a neutral hydrogen density that is approximately one tenth of that of the average ISM in the Milky Way (approximately 0. ... A nova remnant is made up of the materials left behind by the gigantic explosion of a star in a nova. ... NGC 6543, The Cats Eye Nebula NGC 6853, The Dumbbell Nebula A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives. ...

References

is the 308th day of the year (309th in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 332nd day of the year (333rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 39th day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 222nd day of the year (223rd in leap years) in the Gregorian calendar. ...

External links

• Galactic SNR Catalogue (D. A. Green, University of Cambridge)
• Magellanic Cloud SNR Catalogues (R. Williams, University of Illinois at Urbana)
• NASA: Introduction to Supernova Remnants.
• NASA's Imagine: Supernova Remnants
• Supernova Remnant (UOttawa)
• Afterlife of a Supernova
• 2MASS images of Supernova Remnants
• An Article Discussing Ring Formation around certain Supernova