3C 273

3C 273
Hubble ESA · CC BY 2.0 · source
Name	3C 273
Type	Quasar
Ra	12h 29m 06.7s
Dec	+02° 03′ 09″
Redshift	0.158
Magnitude	12.9
Constellation	Virgo
Discovery	1963

3C 273 is a luminous quasar and one of the first quasistellar objects identified, notable for its bright optical magnitude and prominent radio jet; it played a decisive role in establishing the extragalactic nature of quasars and linking radio sources to optical counterparts. The object’s identification connected work by radio surveys, optical spectroscopy, and space-based observatories, influencing research at institutions such as Harvard College Observatory, Mount Wilson Observatory, Palomar Observatory, and Arecibo Observatory. Its prominence has made it a calibration target for instruments on platforms including Hubble Space Telescope, Chandra X-ray Observatory, Very Large Array, and Fermi Gamma-ray Space Telescope.

Discovery and early observations

The source was first catalogued in the Third Cambridge Catalogue of Radio Sources during surveys led by teams associated with Cambridge University and subsequently observed in radio interferometry projects by groups at Jodrell Bank Observatory, Cambridge, and National Radio Astronomy Observatory. Optical identification was achieved through work by observers at Yerkes Observatory, Palomar Observatory, and Harvard College Observatory, with spectroscopy by instrumentalists influenced by methods from Maarten Schmidt and contemporaries tied to Mount Wilson Observatory that revealed a high redshift. Early X-ray detections connected programs at Uhuru (satellite) and High Energy Astronomy Observatory to the radio and optical data, prompting debate among researchers from Caltech, Cambridge, and Princeton University about cosmological redshifts versus local models advocated by proponents linked to Harvard and University of Cambridge.

Properties and classification

As a prototype of the radio-loud quasar class, it has been classified within frameworks developed at IAU meetings and discussed in reviews by researchers from Max Planck Institute for Radio Astronomy, Cavendish Laboratory, and Space Telescope Science Institute. Spectroscopic campaigns using equipment from Palomar Observatory and European Southern Observatory measured broad emission lines consistent with the high-ionization spectra studied by groups at Smithsonian Astrophysical Observatory and Los Alamos National Laboratory. Photometric and polarimetric studies involving teams at Kitt Peak National Observatory and Rutherford Appleton Laboratory placed it among objects exhibiting strong non-thermal continua similar to sources analyzed by Vera Rubin Observatory planners and researchers associated with Sloan Digital Sky Survey consortium work. The source’s radio-loudness, optical luminosity, and X-ray to radio flux ratios match criteria used by classifiers at International Astronomical Union symposia and in reviews from Harvard-Smithsonian Center for Astrophysics.

Jet and radio structure

High-resolution imaging using the Very Large Array, Very Long Baseline Array, and European networks coordinated with MERLIN and European VLBI Network revealed a one-sided relativistic jet whose morphology and superluminal motion were interpreted using models from groups at CERN and Princeton University. Radio maps produced by teams at National Radio Astronomy Observatory and Max Planck Institute show knots and hotspots comparable to those studied in Cygnus A and M87, and the jet’s polarization has been analyzed by collaborations including researchers from University of Cambridge and Caltech. Multi-epoch VLBI campaigns led by scientists at JIVE and Yebes Observatory measured apparent speeds and bending consistent with Doppler boosting scenarios discussed by theorists from Cambridge University, Harvard, and Columbia University.

Host galaxy and environment

Deep optical and infrared imaging by Hubble Space Telescope and ground-based facilities such as Keck Observatory and Gemini Observatory resolved the host galaxy and its stellar population, with analyses by groups at Institute of Astronomy, Cambridge and Max Planck Institute for Astronomy characterizing morphology and merger signatures. Observations with Spitzer Space Telescope and instruments at European Southern Observatory probed dust and star-formation rates, connecting to environmental studies conducted by teams from University of California, Berkeley and Yale University. Surrounding large-scale structure has been mapped in redshift surveys associated with Sloan Digital Sky Survey and compared to cluster studies by researchers at Harvard-Smithsonian Center for Astrophysics and University of Chicago to assess galaxy density and interactions.

Variability and multiwavelength studies

Intensive monitoring campaigns involving Fermi Gamma-ray Space Telescope, Chandra X-ray Observatory, XMM-Newton, and optical programs at Palomar Observatory and Las Cumbres Observatory documented variability from radio through gamma rays, with coordination among groups at NASA, ESA, and institutions such as Max Planck Institute for Extraterrestrial Physics. Correlated flares analyzed by teams from Caltech, Stanford University, and Columbia University informed models of particle acceleration used by theorists affiliated with Princeton University and University of Cambridge. Long-term photometric and spectroscopic monitoring projects connected work at University of Arizona and University of Oxford to reverberation mapping approaches developed by researchers at Space Telescope Science Institute and Carnegie Institution for Science.

Black hole and accretion physics

Estimates of the central black hole mass and accretion rate derived from broad-line region dynamics, continuum fitting, and reverberation mapping were produced by groups at Harvard-Smithsonian Center for Astrophysics, Max Planck Institute for Astrophysics, and University of Cambridge, applying methods comparable to those used for NGC 5548 and NGC 4151. Models of relativistic jet launching and magnetohydrodynamic accretion have been advanced by teams at Princeton University, MIT, and Kavli Institute for Theoretical Physics with comparisons to simulations from NASA Goddard Space Flight Center and Los Alamos National Laboratory. Studies involving general relativistic magnetohydrodynamics conducted by researchers at University of Chicago and Perimeter Institute relate the source’s energetics to frameworks developed in work on Event Horizon Telescope targets and theoretical programs at Institut d'Astrophysique de Paris.

Category:Quasars