PKS 0637−752

PKS 0637−752 is a quasar located six billion light years in the constellation of Mensa. It is noted for having a bright and largest astrophysical jet at redshift of z = 0.651. Discovered by Einstein Observatory in 1980 through X-rays, PKS 0637−752 was the first celestial object to be observed by Chandra X-ray Observatory upon its commissioning in July 23, 1999.

Characteristics

PKS 0637−752 contains an active galactic nucleus. It is classified a blazar, a type of an active galaxy with a relativistic jet pointing towards Earth's direction. Like other quasars, PKS 0637−752 is considered luminous, powering up 10 trillion times the sun, with a supermassive black hole in its center.

PKS 0637−752 contains a high γ-ray flux X-ray jet studied by Hubble Space Telescope and Spitzer. The jet extends ≥100 kiloparsecs wide and has a luminosity of ~10^44.6 ergs⁻¹. It produces X-ray emission through inverse Compton scattering from the cosmic microwave background.
Further observations from Hubble also found three small knots occurring concurrently with the X-ray emission and peak radio. According to observations made by Australia Telescope Compact Array, these knots are shown to be quasi-periodic with a separation gap of ~1.1 arcsecs. Using two class models, astronomers calculated the jet power of PKS 0637−752 to be Q ~ 10⁴⁶ erg/s and the jet engine modulation to be 2 x 10³ yr < \tau < 3x 10⁵ yr. Such evidence, proves the jet structure in the quasar might result from an unstable accretion disk, causing limit cycle behavior.