Observation ģC 273 is visible in May in both the northern and southern hemispheres. Host galaxy ģC 273 lies at the center of a giant elliptical galaxy with an apparent magnitude of 16 and an apparent size of 30 arcseconds. VLBI radio observations of 3C 273 have revealed proper motion of some of the radio emitting regions, further suggesting the presence of relativistic jets of material.
Such jets are believed to be created by the interaction of the central black hole and the accretion disk. Polarization with coincident orientation has been observed in radio, infrared, and optical light being emitted from the large-scale jet these emissions are therefore almost certainly synchrotron in nature, radiation that is created by a jet of charged particles moving at relativistic speeds. The luminosity is variable at nearly every wavelength from radio waves to gamma rays on timescales of a few days to decades. However, even to this day, the process which gives rise to the X-ray emissions is controversial. Credit: NASA/ ESAģC 273 is a radio-loud quasar, and was also one of the first extragalactic X-ray sources discovered in 1970. Light from the bright quasar nucleus is blocked by a coronagraph so that the surrounding host galaxy can be more easily seen. 3C 273 was the first object to be identified as a quasar-an extremely luminous object at an astronomical distance.ģC 273 as imaged by the Hubble Space Telescope's Advanced Camera for Surveys. Its spectrum did not resemble that of any normal stars with typical stellar elements. However, it was not understood what these objects were, since their spectra were unlike those of any known stars. Also, many active galaxies had been misidentified as variable stars, including the famous BL Lac, W Com and AU CVn.
Prior to the discovery of 3C 273, several other radio sources had been associated with optical counterparts, the first being 3C 48. In 1963, Maarten Schmidt and Bev Oke published a pair of papers in Nature reporting that 3C 273 has a substantial redshift of 0.158, placing it several billion light-years away. After accurate positions were obtained using lunar occultation by Cyril Hazard at the Parkes Radio Telescope, the radio source was quickly associated with an optical counterpart, an unresolved stellar object. The name signifies that it was the 273rd object (ordered by right ascension) of the Third Cambridge Catalog of Radio Sources ( 3C), published in 1959. In 1995, optical imaging of the jet using the Hubble Space Telescope revealed a structured morphology evidenced by repeated bright knots interlaced by areas of weak emission. The quasar has a large-scale visible jet, which measures ~200 kilolight-years (60 kpc) long, having an apparent size of 23″. The mass of its central black hole has been measured to be 886 ± 187 million solar masses through broad emission-line reverberation mapping. Since the Sun's absolute magnitude is 4.83, it means that the quasar is over 4 trillion times more luminous than the Sun at visible wavelengths. It is also one of the most luminous quasars known, with an absolute magnitude of −26.7, meaning that if it were only as distant as Pollux (~10 parsecs) it would appear nearly as bright in the sky as the Sun. A luminosity distance of D L = 749 megaparsecs (2.4 gigalight-years) may be calculated from z. It is the optically brightest quasar in the sky from Earth ( m ~12.9), and one of the closest with a redshift, z, of 0.158. It was the first quasar ever to be identified. Optically brightest quasar, first spectrum of a quasarģC 273 is a quasar located in the constellation of Virgo. Quasar 3C 273 taken by Hubble Space Telescope Ģ.443 Gly (749 Mpc) (luminosity distance)