Astrophysical jets

Astrophysical jets
ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R · CC BY 4.0 · source
Name	Astrophysical jets
Type	Astrophysical phenomenon
First discovered	1918
Discovered by	Heber D. Curtis; later observations by Antony Hewish; theoretical work by Martin Rees
Location	Milky Way; M87; Centaurus A

Contents

Astrophysical jets Astrophysical jets are collimated outflows of plasma observed emanating from compact or active astrophysical objects and interacting with surrounding media. They are studied across electromagnetic regimes by teams at institutions such as European Southern Observatory, NASA, Max Planck Society, and Harvard–Smithsonian Center for Astrophysics using facilities like Very Large Array, Hubble Space Telescope, Chandra X-ray Observatory, and Event Horizon Telescope. Observationally important sources include Quasars, Pulsars, Microquasars, and objects in the Orion Nebula.

Introduction

Jets were first inferred in early radio maps of objects like Centaurus A and later imaged in systems such as M87 and 3C 273, linking them to compact sources like Sagittarius A* and accreting objects studied by teams from University of Cambridge and California Institute of Technology. Historical milestones involve personnel such as Antony Hewish, Roger Blandford, and Martin Rees, and facilities like Very Long Baseline Array and observatories including Mount Wilson Observatory. Early theoretical frameworks were influenced by work associated with Princeton University and Cambridge University groups.

Jet launching models invoke interactions between accretion disks around compact objects like Stellar-mass black holes in systems such as Cygnus X-1, and magnetic fields described in papers from Princeton Plasma Physics Laboratory and Max Planck Institute for Radio Astronomy. Mechanisms include magnetohydrodynamic (MHD) processes like those in the Blandford–Znajek process and the Blandford–Payne mechanism, developed by researchers at Stanford University and Cambridge University. Plasma acceleration and collimation involve concepts tested in laboratories like Lawrence Livermore National Laboratory and modelled with codes originating at Los Alamos National Laboratory and Zurich University. Relativistic effects require frameworks from Albert Einstein’s relativity and work by Roger Penrose and Stephen Hawking on black hole energetics. Particle acceleration to produce synchrotron and inverse Compton emission is connected to studies at CERN and collaborations including Fermi Gamma-ray Space Telescope teams.

Observations across bands—from radio surveys by Very Large Array and LOFAR to optical imaging from Hubble Space Telescope and X-ray detections by Chandra X-ray Observatory—reveal knotty, sometimes superluminal motions as in 3C 273 and variability documented by researchers at Johns Hopkins University and University of Oxford. Polarization studies linked to work at Max Planck Society and spectral energy distributions analyzed by groups at Space Telescope Science Institute and Harvard College Observatory constrain magnetic field geometries and particle populations, relating to sources like Mrk 421 and PKS 0637-752. High-energy gamma-ray detections by Fermi Gamma-ray Space Telescope and VERITAS tie jets to blazar categories cataloged by teams from University of Chicago and Columbia University.

Jet-producing systems include active galactic nuclei (AGN) in galaxies like M87 and Centaurus A observed by European Southern Observatory; microquasars such as SS 433 and GRS 1915+105 studied by MIT groups; young stellar objects in regions like Orion Nebula and T Tauri stars observed by National Radio Astronomy Observatory; and pulsar wind nebulae exemplified by the Crab Nebula investigated by teams at Princeton University and Cornell University. Radio galaxies (e.g., Cygnus A), blazars (e.g., BL Lacertae), and Seyfert galaxies (e.g., NGC 1068) represent AGN subclasses identified in surveys by Sloan Digital Sky Survey and catalogs compiled at Max Planck Institute for Astronomy.

Jets interact with interstellar and intergalactic media producing features such as lobes and hot spots in radio galaxies like Cygnus A and Fornax A mapped by Very Large Array and modeled in work at National Astronomical Observatory of Japan. Feedback processes implicated in galaxy evolution have been proposed in studies from Institut d'Astrophysique de Paris and ETH Zurich, affecting cooling flows in clusters like Perseus Cluster examined by Chandra X-ray Observatory teams. Shock interaction and entrainment involve turbulence research linked to Los Alamos National Laboratory and observational campaigns coordinated by European Space Agency.

Numerical simulations of jets employ general relativistic MHD codes developed at Princeton Plasma Physics Laboratory, Max Planck Institute for Astrophysics, and Kavli Institute for Cosmological Physics; major contributors include research groups at University of Maryland, University of California, Berkeley, and Rutgers University. Simulations reproduce features seen in Event Horizon Telescope images of M87, and multi-scale models link black hole spin theories from Roger Blandford and Roman Blandford-affiliated work to large-scale jet propagation studies at Los Alamos National Laboratory and Argonne National Laboratory. Computational advances leverage supercomputers at Oak Ridge National Laboratory and code bases from CEA Saclay.

Jets provide feedback regulating star formation in galaxies studied by teams from Max Planck Institute for Extraterrestrial Physics, Harvard–Smithsonian Center for Astrophysics, and Institute for Advanced Study. Observational programs at Atacama Large Millimeter/submillimeter Array and theoretical analyses at Columbia University link jet-driven outflows to suppression of cooling in massive halos like those in the Virgo Cluster and to triggered star formation in regions cataloged by Spitzer Space Telescope surveys. Studies of protostellar jets in Orion Nebula and Taurus Molecular Cloud by National Radio Astronomy Observatory and Jet Propulsion Laboratory teams illuminate accretion–ejection coupling relevant to models from Caltech.