• Size: 5 pc (in diameter)
• Distance: about 3.4 kpc
• Age: 322 years
• The supernova explosion was observed by the British astronomer John Flamsteed in 1680.

X-rays: The SNR was detected in X-rays with the Uhuru sattelite (1970-73); X-ray source was designated 3U 2321+58 (in the 3rd Uhuru catalog). Since then, Cas A has been studied extensively across the electromagnetic spectrum, from radio to gamma-rays. The Chandra X-ray image shows an expanding shell of hot gas produced by the explosion. This shell is about 10 light-years in diameter and has a temperature of 30-50 million degrees. Two shock fronts are visible: a faster outer shock and a slower inner shock. The outer shock is the blast wave from the SN explosion moving into the circumstellar medium. The inner shock is a reverse shock - a pressure wave expanding back into the ejecta. It is responsible for decelerating and compressing the outflowing ejecta. The SNR has a bright compact central source discovered with Chandra in August 1999 (Chandra "first light" image). Its nature is not yet understood. Likely, it is a neutron star with unusual properties.

Radio: Cas A was one of the first objects discovered in early years of radio astronomy. In the 1930s, Karl Jansky found that the Milky Way is a powerful radio emitter. His simple maps showed that several regions of the sky were emitting radio waves stronger than others. The brightest source was in the region of the constellation Cassiopeia and so was named Cassiopeia A. The radio image of Cas A shows a bright shell with bright spots and an extended plateau of emission.

Optical: Optical images of the Cas A show numerous filaments at large radii and fast moving knots.

Chandra ACIS image of Tycho SNR

Tycho, G120.1+1.4, 3C 10, SN1572

• Size: about 6 pc (in diameter)
• Distance: about 2.4 kpc.
• Age: 430 years.
• The SN was observed by the Danish astronomer Tycho Brahe in 1572.

X-rays: The Chandra X-ray image shows an expanding shell running into the interstellar environment with a speed 150 times the speed of sound. Most of the bright regions consist of clumps of metal-enriched material, ejected in the supernova explosion. This high resolution image (obtained with the ACIS camera) reveals the fine structure of the SNR. Most notable is the thin rim of emission around the entire remnant, which is believed to be the blast wave propagating through the surrounding circumstellar medium. Along with the thermal emission component, the spectrum of Tycho SNR has a non-thermal component with a power-law spectrum. It is interpreted as synchrotron emission from particles accelerated in the shocks.

Radio: Radio images show a shell, brightest to the north-east.

Optical: Faint filaments and knots are seen in the north-western, eastern parts of the remnant.

Chandra ACIS image of Kepler SNR

Kepler, G4.5+6.8, SN1604

• Size: about 4 pc (in diameter)
• Distance: 3-6 kpc
• Age: 398 years
• The supernova was observed by the German astronomer Johannes Kepler in 1604.

X-rays: The Chandra ACIS image shows X-ray emission from star fragments heated up to several million degrees. The emission comes from a reverse shock propagating in the ejecta and a forward shock propagating into the interstellar matter.

Radio: Radio maps show an incomplete shell which is the brightest to the north.

Optical: Optical images show faint filaments.

Chandra ACIS image of W49B.

W49B, G43.3-0.2

• Size: about 11 x 15 pc
• Distance: about 13 kpc.
• Age: 1,000 - 6,000 years

X-rays: The X-ray spectrum of this ejecta-dominated SNR shows strong emission lines from silicon (Si), sulfur (S) and iron (Fe). Fe K line has the highest equivalent width ever found in any SNR. Images of the supernova in narrow energy bands suggest that Fe is more centrally concentrated than the Si and S.

Radio: Radio maps show a shell, brightest to the south-east and west, near the HII region W49A.

Optical: No optical counterpart has been detected, probably due to obscuration by the interstellar medium.

Chandra ACIS image of SNR 0519-69.0

SNR 0519-69.0

• Size: about 7 pc (in diameter)
• Distance: LMC (50 kpc)
• Age:

X-rays: The young SNR 0519-69.0 in the Large Magellanic Cloud belongs to the class of objects typified by the Tycho supernova remnant, thought to be the remnants of Type Ia supernovae. Recent observations with the Chandra's Advanced CCD Imaging Spectrometer (ACIS) have shown the X-ray structure of the object in unprecedented details.

Chandra ACIS image of SNR 0540-69.3

SNR 0540-69.3

• Size: about 14 pc (in diameter)
• Distance: LMC (50 kpc)
• Age: 1000-2000 years

X-rays: SNR 0540-69.3 is one of the Crab-like supernova remnants. The SNR harbors a synchrotron nebula powered by a young energetic pulsar (characteristic age ~ 1660 yr). The structure of this pulsar-wind nebula is remarkably similar to that of the Crab. Along with the elongated bright core, the SNR has an incomplete shell. It has been suggested that the SN explosion was asymmetric.

Optical: Optical structure resembles that seen in X-rays.

Chandra ACIS image of RCW103.

RCW 103, G332.4-0.4

• Size: about 10 pc (in diameter)
• Distance: about 3.3 kpc.
• Age: about 2000 years

X-rays: As in the case of the Cas A SNR, the Chandra ACIS image reveales an enigmatic central source. This source shows pulsations with a period of 6.4 hours and variations of source brightness by a factor of 50. Most probably, it is a neutron star in a binary system; its X-ray emission is powered by accretion of matter from a subluminous companion.

Radio: Radio maps show a shell, brightest to the south.

Optical: The filaments seen in the optical images coincide well with the radio shell.

Chandra ACIS image of SNR 509.0-68.7

SNR 0509-68.7, N103B (LMC)

• Size: about 7 pc (in diameter)
• Distance: LMC (50 kpc)
• Age: about 1,500 years

X-rays: The Chandra ACIS image reveals a fine structure of the SNR at an arc-second level, including several bright knots and filamentary structures. The remnant shows a characteristic spectrum of a Type Ia SNR, with strong lines of Fe, Si, S, Ar, and Ca. The asymmetric morphology of the SNR suggests that the surrounding medium is nonuniform.

Chandra ACIS image of 3C58.

SN 1181, G130.7+3.1, 3C58

• Size: about 8×6 pc
• Distance: about 3.2 kpc
• Age: 821 years
• The SN explosion was observed by the ancient Chineese and Japaneese astronomers in the year 1181AD.

X-rays: The Chandra ACIS image reveals a pulsar-wind nebula in the center of this SNR. The nebula is powered by the pulsar, PSR J0205+6449, which rotates about 15 times per second and slows down at the rate of about 10 microseconds per year. Despite the pulsar's young age, the total X-ray luminosity of the pulsar and its wind nebula is a factor of thousand weaker than that of the Crab.

Radio: Radio maps show a center-filled nebula. The radiation is highly polarized.

Optical: Faint filaments are seen in the optical images.

Chandra ACIS image of SN1006

The ROSAT image of SN1006

SN1006, G327.6+14.6, PKS 1459-41

• Size: about 20 pc (in diameter)
• Distance: about 2 kpc
• Age: 996 years
• The supernova explosion was seen by astronomers in several Asian and European countries in the year 1006AD. It is probably the brightest supernova in historical records.

X-rays: The Chandra image reveals the fine structure of the shocks produced by the collision of the expanding gas from the SN explosion with the surrounding material. The spectra of the shocks are non-thermal, providing evidence for particle acceleration in the shocks. This proves that SNRs are the sources of cosmic rays.

Radio: A shell with two bright arcs is seen in the radio images.

Optical: Optical images show filaments to the north-west, with broad Hα component in their spectra.

Chandra HRC image of SNR 0538-69.1

SNR 0538-69.1, N157B (LMC)

• Size: about 7×3 pc
• Distance: LMC (50 kpc)
• Age:

X-rays: This Crab-like SNR harbors the fastest (16 millisecond period) pulsar, PSR J0537-6910, ever associated with SNR. The Chandra image reveals a pulsar-wind nebula, wich consists of an elongated bright core and a fainter diffused tail. The diffused emission is thought to be trailing the motion of the pulsar (the head of the "comet").

Chandra ACIS image of Kes 75

Kes 75, G29.7-0.3

• Size: about 13 pc (in diameter)
• Distance: uncertain, 9-20 kpc.
• Age: about 700 years.

X-rays: Kes 75 belongs to the so-called "composite" class of SNRs which show, in radio, both a shell and a central core. Kes 75 contains an X-ray pulsar (period 0.3 seconds) and a pulsar-wind nebula found with Chandra.

Radio: Radio maps show a shell filled with a diffuse emission with a flatter spectrum.

Chandra ACIS image of MSH 15-52

G320.4-1.2, MSH 15-52, RCW 89

• Size: about 15×10 pc
• Distance: about 5.2 kpc
• Age: 1817 years (?)

X-rays: The Chandra ACIS image reveals a very unusual structure of the pulsar-wind nebula inside MSH 15-52. The X-rays are emitted by high-energy particles ejected by the pulsar (the bright white source at the center of the nebula). A huge jet, almost 20 light years in length, extends to the lower left and traces a beam of particles being shot out along the pulsar's rotation axis at speeds close to the speed of light. Just above the pulsar a small arc of X-ray emission is seen. It is thought to be associated with a shock produced by particles flowing away from the pulsar in the equatorial plane.

Radio: Radio maps show the ragged shell.

Optical: RCW 89 is the Hα emitting region north-west of the pulsar. It is also seen in the X-ray image (at the top). This hot gas was possibly produced during the supernova explosion. It also can be heated via collisions of the gas particles with high-energy particles produced by the pulsar.

Chandra ACIS image of DEM 71

DEM 71, SNR 0505-67.9 (LMC)

• Size: about 1 kpc (in diameter)
• Distance: LMC (50 kpc)
• Age:

X-rays: The Chandra ACIS image of DEM 71 shows that the X-ray and optical morphologies are remarkably similar. Both X-ray and optical components are dominated by emission from the forward shock. The fainter X-ray emission near the center of DEM 71 may be attributed to the reverse shock.

Optical: Optical images show a shell (brighter to the west and east) and central diffuse emission. SNR 0505-67.9 shows Balmer-line dominated spectrum.

Chandra ACIS image of SNR 0509-67.5

SNR 0509-675 (LMC)

• Size: about 360 pc (in diameter)
• Distance: LMC (50 kpc)
• Age:

X-rays: As in the case of DEM 71, the Chandra images of SNR 0509-67.5 show remarkably similar X-ray and optical morphologies.

Optical: Optical images show a shell, brightest to the south-west. SNR 0509-675 has Balmer-line dominated spectrum.

Chandra ACIS image of N63A

Composite image of N63A

SNR 0535-660, N63A (LMC)

• Size: about 290 pc (in diameter)
• Distance: LMC (50 kpc)
• Age:

X-rays: The size of the SNR, indicated by the X-ray and radio emission, is much larger than the size determined from optical images. Most of the radio and X-ray emission does not seem to have optical counterparts. In the composite image, blue represents X-ray data taken with the Chandra X-ray Observatory. Red and green are from optical images taken with the Hubble Space Telescope.

Optical: N63A is expanding within a bubble produced by its progenitor within the N63 HII complex. The Hubble Space Telescope images reveal not only shocked clouds but also small shocked bullets evaporating in the SNR interior.

Chandra ACIS image of G11.2-0.3

G11.2-0.3

• Size: about 6 pc (in diameter)
• Distance: about 5 kpc.
• Age: 1616 years (?)
• Chineese records indicate that the remnant may be associated with the SN of 386AD.

X-rays: The Chandra ACIS image shows a pulsar exactly at the geometric center of the supernova remnant. The Chandra observations have also revealed the presence of a pulsar-wind nebula. Its cigar-like shape is in contrast to the graceful arcs observed around the Crab and Vela pulsars.

Radio: Radio maps show a symmetrical clumpy shell, with a a core exibiting a flatter spectrum.

Optical: Optical images show a shell, with a brightened region around the pulsar.

Chandra HRC image of Crab Nebula

Crab Nebula in visible light

Crab Nebula with HST

Crab Nebula in infrared

Crab Nebula in radio

Crab Nebula, SN1054, G184.6-5.8, 3C144

• Size: 4×3 pc
• Distance: 2 kpc
• Age: 948 years
• The supernova explosion was observed by the Chineese (5 texts, 4 independent) and Japaneese astronomers (3 texts, 2 independent) in the year 1054AD.

X-rays: At the center of the nebula there is the famous Crab pulsar, a rapidly spinning neutron star pulses of radiation 30 times a second. The X-ray image shows the pulsar surrounded by a torus of high-energy particles that appear to have been flung outward over a distance of more than a light year from the pulsar. Perpendicular to the torus, jet-like structures produced by high-energy particles which blast away from the pulsar. The inner diameter of the torus is about a tenth of a light year, more than 200 times the diameter of our solar system. The X-rays from the Crab nebula are produced by high-energy particles spiraling around magnetic field lines and emitting synchrotron radiation. Chandra observations revealed the dynamic structure of the inner Crab Nebula. The inner edge of the torus (`inner ring') shows temporal variations in structure; the knots located along the ring change in both morphology and brightness on a timescale of weeks. The bell-shaped appearance of the Nebula could be due to the interaction and/or obscuration of this huge bubble of relativistic particles with/by clouds of gas and dust.

Radio: Radio images show center-filled remnant around the pulsar and a jet extending north-west from the pulsar.

Optical: Strongly polarized filaments, diffuse synchrotron emission and `a jet are seen in the optical images. Observations with the Hubble Space Telescope have shown the dynamic nature of the pulsar wind nebula. In the HST images the equatorial wind appears as a series of wisp-like features moving away from the pulsar at speeds of about half a speed of light.

Vela SNR observed with Chandra and ROSAT.

Vela, G263.9-3.3

• Size: 30 pc (in diameter)
• Distance: 350 pc
• Age: About 20,000 years.

X-rays: The ROSAT PSPC (Position Sensitive Proportional Counter) image reveals a complex structure of hot gas caused by non-uniformity of the interstellar gas and dust surrounding the explosion. The high angular resulution of Chandra reveals the fine detailes of the Vela pulsar-wind nebula (PWN). The Vela pulsar emits a relativistic wind comprised of particles and electromagnetic field. This wind cannot be directly observed until it is shocked in the ambient medium. Beyond the shock, the motion of the individual particles (hence, the angular distribution of their synchrotron radiation) becomes nearly isotropic, and the post-shock region manifests itself as a pulsar wind nebula whose spectrum and surface brightness are determined by the particle spectrum, the post-shock magnetic field, and the properties of the ambient SNR medium. If the pulsar has a high spatial velocity, the ram pressure caused by its motion can dominate the ambient gas pressure, resulting in a bow-shock PWN. Chandra ACIS observations led to the discovery of a remarkable dynamic jet (bottom-right pannel of the image) extending 0.3 pc away from the pulsar (about twice the radius of the PWN).

Radio: Radio images show a large shell with filaments and a central diffuse component with a harder spectrum.

Optical: Numerous filaments are seen in the optical images.

Chandra images of G21.5-0.9

G21.5-0.9

• Size: about 6 pc (in diameter)
• Distance: about 5 kpc.
• Age:

X-rays: The Chandra ACIS image shows a bright pulsar wind nebula surrounded by a much larger diffuse halo. Inside the inner nebula there is a bright central source most probably a magnetized neutron star. At both radio and x-ray wavelengths, this SNR appears as a round patch in the sky.

Radio: Center-filled morphology of the SNR is clearly seen in the radio maps.

Optical: Optical images show a shell, with a centrally brightened region.

Chandra ACIS image of E0102-72

E0102-72, SNR 0102-72.3

• Size: 15 pc (in diameter)
• Distance: 60 kpc (SMC).
• Age: several thousand years

X-rays: E0102-72 is a supernova remnant in the Small Magellanic Cloud, a satellite galaxy of the Milky Way. This galaxy is about 180,000 light years from Earth. E0102 -72, which is several thousand years old, was produced by the explosion of a massive star. The X-ray data show that this gas is rich in oxygen and neon. These elements were created by nuclear reactions inside the star and ejected into space by the supernova.

Radio: Radio maps show a shell, slightly larger than that in X-rays.

Chandra image of N132D

N132D in optical

N132D in radio

SNR 0525-69.6, N132D (LMC)

• Size: 30 pc (in diameter)
• Distance: 50 kpc (LMC)
• Age: about 3,000 years

X-rays: N132D is the brightest SNR in the Large Magellanic Cloud, the galaxy located about 180,000 light-years from Earth. The Chandra X-ray image of N132D shows a highly structured remnant, filled with a 10 million degree gas, which is 80 light years across. The estimated age of the remnant is about 3000 years. The N132D supernova remnant appears to be colliding with a giant molecular cloud, which brightens the southern rim of the remnant. The relatively weak X-ray radiation on the upper left shows that the shock wave is expanding into a less dense region of the edge of the molecular cloud. A number of small circular structures are visible in the central regions, and a hint of a large circular loop can be seen in the upper part of the remnant.

Radio: Radio maps show a clumpy structure.

Optical: Optical images show a shell and filaments.

Chandra "true-color" image of G292.0+1.8.

G292.0+1.8, MSH 11-54

• Size: about 7 pc (in diameter)
• Distance: about 3.5 kpc
• Age: about 1,500 years

X-rays: The Chandra X-ray image of G292.0+1.8, a young supernova remnant with a pulsar (PSR J1124-5916 with a period of 135 milliseconds) at its center, shows rapidly expanding shell of gas that is 36 light years across and contains large amounts of elements such as oxygen, neon, magnesium, silicon and sulfur. In the Chandra "true-color" image color change from red to green to blue corresponds to an increase in the photon energy. The blue region close to the center show the location of the pulsar and its wind nebula comprised of highly energetic electrons emitting synchrotron radiation.

Radio: Radio maps show a centrally brightened source surrounded by a plateau of faint emission.

Optical: Optical images show oxygen-rich filaments.