Chandra X-ray Observatory in the context of "SN 2006gy"

A quasar (/ˈkweɪzɑːr/ KWAY-zar) is an extremely luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by accretion onto a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way. Quasars are usually categorized as a subclass of the more general category of AGN. The redshifts of quasars are of cosmological origin.

A pulsar (pulsating star, on the model of quasar) is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth (similar to the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays (see also centrifugal mechanism of acceleration).

Pulsars’ highly regular pulses make them very useful tools for astronomers. For example, observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered in 1992 around a pulsar, specifically PSR B1257+12. In 1983, certain types of pulsars were detected that, at that time, exceeded the accuracy of atomic clocks in keeping time.

In astronomy, a deep field is an image of a portion of the sky taken with a very long exposure time, in order to detect and study faint objects. The depth of the field refers to the apparent magnitude or the flux of the faintest objects that can be detected in the image. Deep field observations usually cover a small angular area on the sky, because of the large amounts of telescope time required to reach faint flux limits. Deep fields are used primarily to study galaxy evolution and the cosmic evolution of active galactic nuclei, and to detect faint objects at high redshift. Numerous ground-based and space-based observatories have taken deep-field observations at wavelengths spanning radio to X-rays.

The first deep-field image to receive a great deal of public attention was the Hubble Deep Field, observed in 1995 with the WFPC2 camera on the Hubble Space Telescope. Other space telescopes that have obtained deep-field observations include the Chandra X-ray Observatory, the XMM-Newton Observatory, the Spitzer Space Telescope, and the James Webb Space Telescope.

An astrophysical jet is an astronomical phenomenon where ionised matter is expelled at high velocity from an astronomical object, in a pair of narrow streams aligned with the object's axis of rotation. When the matter in the beam approaches the speed of light, astrophysical jets become relativistic jets as they show effects from special relativity.

Astrophysical jets are associated with many types of high-energy astronomical sources, such as black holes, neutron stars and pulsars. Their causes are not yet fully understood, but they are believed to arise from dynamic interactions within accretion disks. One explanation is that as an accretion disk spins, it generates a rotating, tangled magnetic field which concentrates material from the disk into the jets and then drives it away from the central object. Jets may also be influenced by a general relativity effect known as frame-dragging.

XMM-Newton, also known as the High Throughput X-ray Spectroscopy Mission and the X-ray Multi-Mirror Mission, is an X-ray space observatory launched by the European Space Agency in December 1999 on an Ariane 5 rocket. It is the second cornerstone mission of ESA's Horizon 2000 programme. Named after physicist and astronomer Sir Isaac Newton, the spacecraft is tasked with investigating interstellar X-ray sources, performing narrow- and broad-range spectroscopy, and performing the first simultaneous imaging of objects in both X-ray and optical (visible and ultraviolet) wavelengths.

Initially funded for two years, with a ten-year design life, the spacecraft remains in good health and has received repeated mission extensions, most recently in March 2023 and is scheduled to operate until the end of 2026. ESA plans to succeed XMM-Newton with the Advanced Telescope for High Energy Astrophysics (ATHENA), the second large mission in the Cosmic Vision 2015–2025 plan, to be launched in 2035. XMM-Newton is similar to NASA's Chandra X-ray Observatory, also launched in 1999.

The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 keV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle Atlantis during STS-37 on April 5, 1991, and operated until its deorbit on June 4, 2000. It was deployed in low Earth orbit at 450 km (280 mi) to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at 16,300 kilograms (35,900 lb).

Costing $617 million, the CGRO was part of NASA's Great Observatories series, along with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. It was the second of the series to be launched into space, following the Hubble Space Telescope. The CGRO was named after Arthur Compton, an American physicist and former chancellor of Washington University in St. Louis who received the Nobel Prize for work involved with gamma-ray physics. CGRO was built by TRW (now Northrop Grumman Aerospace Systems) in Redondo Beach, California. CGRO was an international collaboration and additional contributions came from the European Space Agency and various universities, as well as the U.S. Naval Research Laboratory.

Space Shuttle Columbia (OV-102) was a Space Shuttle orbiter manufactured by Rockwell International and operated by NASA. Named after the first American ship to circumnavigate the globe, and the female personification of the United States, Columbia was the first of five Space Shuttle orbiters to fly in space, debuting the Space Shuttle launch vehicle on its maiden flight on April 12, 1981 and becoming the first spacecraft to be re-used after its first flight when it launched on STS-2 on November 12, 1981. As only the second full-scale orbiter to be manufactured after the Approach and Landing Test vehicle Enterprise, Columbia retained unique external and internal features compared with later orbiters, such as test instrumentation and distinctive black chines. In addition to a heavier aft fuselage and the retention of an internal airlock throughout its lifetime, these made Columbia the heaviest of the five spacefaring orbiters: around 1,000 kilograms (2,200 pounds) heavier than Challenger and 3,600 kilograms (7,900 pounds) heavier than Endeavour when originally constructed. Columbia also carried ejection seats based on those from the SR-71 during its first six flights until 1983, and from 1986 onwards carried an imaging pod on its vertical stabilizer.

During its 22 years of operation, Columbia was flown on 28 missions in the Space Shuttle program, spending over 300 days in space and completing over 4,000 orbits around Earth. NASA's flagship orbiter, Columbia often flew flights dedicated to scientific research in orbit following the loss of Challenger in 1986. Columbia was used for eleven of the fifteen flights of Spacelab laboratories, all four United States Microgravity Payload missions, and the only flight of Spacehab's Research Double Module. Columbia flew many of the longest duration space shuttle missions, all dedicated to scientific research. The only space shuttle that could rival Columbia's long missions was Endeavour, which flew the STS-67 mission that lasted for nearly 17 days. In 1992, NASA modified Columbia to be able to fly some of the longest missions in the Shuttle Program history using the Extended Duration Orbiter pallet. The orbiter used the pallet in thirteen of the pallet's fourteen flights, which aided lengthy stays in orbit for scientific and technological research missions. The longest duration flight of the Shuttle Program, STS-80, was flown with Columbia in 1996, at over 17 days in orbit. Columbia was also used to deploy the first ever satellites into orbit by the Shuttle on STS-5, retrieve the Long Duration Exposure Facility and deploy the Chandra observatory, which was the heaviest payload ever carried by the Space Shuttle. Columbia also carried into space the first female commander of an American spaceflight mission, the first ESA astronaut, the first female astronaut of Indian origin, and the first Israeli astronaut.

STS-93 in 1999 marked the 95th launch of the Space Shuttle, the 26th launch of Columbia, and the 21st night launch of a Space Shuttle. Eileen Collins became the first female shuttle Commander on this flight. Its primary mission was to launch the Chandra X-ray Observatory, the heaviest payload ever carried by the Space Shuttle system, at 22,780 kilograms (50,222 lb).

STS-93 would be Columbia's last mission until March 2002. During the interim, Columbia would be out of service for upgrading and would only fly again on STS-109. The launch was originally scheduled for 20 July, but it was aborted at T−7 seconds. The successful launch of the flight occurred three days later.