Supernova remnants are the primary source of X-ray emission in our galaxy. When a massive star explodes as a supernova, it releases a tremendous amount of energy, which heats the surrounding gas and dust to extremely high temperatures, causing them to emit X-rays.

Cataclysmic variable stars are a type of binary star system that consists of a white dwarf and a companion star. The white dwarf accretes material from the companion star, which heats up and emits X-rays.

Cosmic rays are the primary source of gamma-ray emission in our galaxy. Cosmic rays are high-energy particles that originate from outside our solar system and interact with the interstellar medium, producing gamma-rays.

Sagittarius A* is the brightest persistent gamma-ray source in the Milky Way. It is located at the center of our galaxy and is associated with the supermassive black hole at the galactic center.

GRB 780325A was the first detected gamma-ray burst. It was observed on March 25, 1978, by the Vela satellites, which were originally designed to detect nuclear explosions.

Gamma-ray bursts typically last for a few seconds, although some can last for up to a few minutes. The duration of a gamma-ray burst is related to the amount of energy released and the distance to the source.

The collapse of a massive star is the most common mechanism responsible for producing gamma-ray bursts. When a massive star reaches the end of its life, it collapses under its own gravity, forming a black hole. This process releases a tremendous amount of energy, which is converted into gamma-rays.

Swift is a satellite that was launched in 2004 to study gamma-ray bursts. It is designed to rapidly slew to the location of a gamma-ray burst and observe it in multiple wavelengths, from X-rays to gamma-rays.

The BATSE catalog is the largest catalog of gamma-ray bursts. It contains over 2,700 gamma-ray bursts detected by the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory.

The typical redshift of gamma-ray bursts is between 2 and 3. This means that gamma-ray bursts are typically located at very large distances from Earth.

Gamma-ray bursts are often followed by an afterglow, which can be detected in X-rays, optical light, and radio waves. The afterglow is produced by the interaction of the gamma-ray burst jet with the surrounding medium.

The neutron star merger model is a theory that explains the production of gamma-ray bursts by the merger of two neutron stars. When two neutron stars merge, they release a tremendous amount of energy, which is converted into gamma-rays.

GW170817 was the first detected gravitational wave signal from a neutron star merger. It was observed on August 17, 2017, by the Laser Interferometer Gravitational-Wave Observatory (LIGO).

GRB 170817A, AT 2017gfo, and SSS17a were all detected as electromagnetic counterparts to the gravitational wave signal GW170817 from a neutron star merger.

Chandra X-ray Observatory, XMM-Newton, and NuSTAR are all satellites that have been launched to study X-ray emission from black holes.