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Astrophysical jet

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Thestarburst galaxyCentaurus A,with its plasma jets extending over a millionlight years,is considered as the closestactiveradio galaxytoEarth.The 870-micronsubmillimetredata, fromLABOCAon APEX, are shown in orange.X-raydata from theChandra X-ray Observatoryare shown inblue.Visible lightdata from theWide Field Imager(WFI) on the MPG/ESO 2.2 m telescope located at La Silla,Chile,show the backgroundstarsand the galaxy's characteristicdust lanein close to "true colour".

Anastrophysical jetis anastronomicalphenomenon where outflows ofionisedmatter are emitted as extended beams along theaxis of rotation.[1]When this greatly accelerated matter in the beam approaches thespeed of light,astrophysical jets becomerelativistic jetsas they show effects fromspecial relativity.

The formation and powering of astrophysical jets are highly complex phenomena that are associated with many types of high-energy astronomical sources. They likely arise from dynamic interactions withinaccretion disks,whose active processes are commonly connected with compact central objects such asblack holes,neutron starsorpulsars.One explanation is that tangledmagnetic fieldsare organised to aim two diametrically opposing beams away from the central source by angles only several degrees wide(c. > 1%).[2]Jets may also be influenced by ageneral relativityeffect known asframe-dragging.[3]

Most of the largest and most active jets are created bysupermassive black holes(SMBH) in the centre ofactive galaxiessuch asquasarsandradio galaxiesor within galaxy clusters.[4]Such jets can exceed millions ofparsecsin length.[2]Other astronomical objects that contain jets includecataclysmic variable stars,X-ray binariesandgamma-ray bursts(GRB). Jets on a much smaller scale (~parsecs) may be found in star forming regions, includingT Tauri starsandHerbig–Haro objects;these objects are partially formed by the interaction of jets with theinterstellar medium.Bipolar outflowsmay also be associated withprotostars,[5]or with evolvedpost-AGBstars,planetary nebulaeandbipolar nebulae.

Relativistic jets[edit]

Elliptical galaxy M87emitting a relativistic jet, as seen by theHubble Space Telescope

Relativistic jets are beams of ionised matter accelerated close to the speed of light. Most have been observationally associated with central black holes of someactive galaxies,radio galaxiesorquasars,and also by galacticstellar black holes,neutron starsorpulsars.Beam lengths may extend between several thousand,[6]hundreds of thousands[7]or millions of parsecs.[2]Jet velocities when approaching the speed of light show significant effects of thespecial theory of relativity;for example,relativistic beamingthat changes the apparent beam brightness.[8]

Massive central black holes in galaxies have the most powerful jets, but their structure and behaviours are similar to those of smaller galacticneutron starsandblack holes.These SMBH systems are often calledmicroquasarsand show a large range of velocities.SS 433jet, for example, has a mean velocity of 0.26c.[9]Relativistic jet formation may also explain observedgamma-ray bursts,which have the most relativistic jets known, beingultrarelativistic.[10]

Mechanisms behind the composition of jets remain uncertain,[11]though some studies favour models where jets are composed of an electrically neutral mixture ofnuclei,electrons,andpositrons,while others are consistent with jets composed of positron–electron plasma.[12][13][14]Trace nuclei swept up in a relativistic positron–electron jet would be expected to have extremely high energy, as these heavier nuclei should attain velocity equal to the positron and electron velocity.

Rotation as possible energy source[edit]

Because of the enormous amount of energy needed to launch a relativistic jet, some jets are possibly powered by spinningblack holes.However, the frequency of high-energy astrophysical sources with jets suggests combinations of different mechanisms indirectly identified with the energy within the associated accretion disk and X-ray emissions from the generating source. Two early theories have been used to explain how energy can be transferred from a black hole into an astrophysical jet:

  • Blandford–Znajek process.[15]This theory explains the extraction of energy from magnetic fields around an accretion disk, which are dragged and twisted by the spin of the black hole. Relativistic material is then feasibly launched by the tightening of the field lines.
  • Penrose mechanism.[16]Here energy is extracted from a rotating black hole byframe dragging,which was later theoretically proven byReva Kay Williamsto be able to extract relativistic particle energy and momentum,[17]and subsequently shown to be a possible mechanism for jet formation.[18]This effect includes using general relativisticgravitomagnetism.

Relativistic jets from neutron stars[edit]

The pulsar IGR J11014-6103 with supernova remnant origin, nebula and jet

Jets may also be observed from spinning neutron stars. An example is pulsarIGR J11014-6103,which has the largest jet so far observed in theMilky Way,and whose velocity is estimated at 80% the speed of light (0.8c). X-ray observations have been obtained, but there is no detected radio signature nor accretion disk.[19][20]Initially, this pulsar was presumed to be rapidly spinning, but later measurements indicate the spin rate is only 15.9 Hz.[21][22]Such a slow spin rate and lack of accretion material suggest the jet is neither rotation nor accretion powered, though it appears aligned with the pulsar rotation axis and perpendicular to the pulsar's true motion.

Other images[edit]

  • Illustration of the dynamics of a proplyd, including a jet
    Illustration of the dynamics of aproplyd,including a jet
  • Centaurus A in x-rays showing the relativistic jet
    Centaurus Ain x-rays showing the relativistic jet
  • The M87 jet seen by the Very Large Array in radio frequency (the viewing field is larger and rotated with respect to the above image.)
    The M87 jet seen by theVery Large Arrayinradio frequency(the viewing field is larger and rotated with respect to the above image.)
  • Hubble Legacy Archive Near-UV image of the relativistic jet in 3C 66B
    Hubble Legacy Archive Near-UVimage of the relativistic jet in3C 66B
  • Galaxy NGC 3862, an extragalactic jet of material moving at nearly the speed of light can be seen at the three o'clock position.
    GalaxyNGC 3862,an extragalactic jet of material moving at nearly the speed of light can be seen at the three o'clock position.
  • Some of the jets in HH 24-26, which contains the highest concentration of jets known anywhere in the sky
    Some of the jets inHH 24-26,which contains the highest concentration of jets known anywhere in the sky

See also[edit]

References[edit]

  1. ^ Beall, J. H. (2015)."A Review of Astrophysical Jets"(PDF).Proceedings of Science:58.Bibcode:2015mbhe.confE..58B.doi:10.22323/1.246.0058.Retrieved19 February2017.
  2. ^abcKundt, W. (2014)."A Uniform Description of All the Astrophysical Jets"(PDF).Proceedings of Science:58.Bibcode:2015mbhe.confE..58B.doi:10.22323/1.246.0058.Retrieved19 February2017.
  3. ^Miller-Jones, James (April 2019)."A rapidly changing jet orientation in the stellar-mass black-hole system V404 Cygni"(PDF).Nature.569(7756): 374–377.arXiv:1906.05400.Bibcode:2019Natur.569..374M.doi:10.1038/s41586-019-1152-0.PMID31036949.S2CID139106116.
  4. ^Beall, J. H (2014)."A review of Astrophysical Jets".Acta Polytechnica CTU Proceedings.1(1): 259–264.Bibcode:2014mbhe.conf..259B.doi:10.14311/APP.2014.01.0259.
  5. ^"Star sheds via reverse whirlpool".Astronomy.com.27 December 2007.Retrieved26 May2015.
  6. ^ Biretta, J. (6 Jan 1999)."Hubble Detects Faster-Than-Light Motion in Galaxy M87".
  7. ^ "Evidence for Ultra-Energetic Particles in Jet from Black Hole".Yale University – Office of Public Affairs. 20 June 2006. Archived fromthe originalon 2008-05-13.
  8. ^ Semenov, V.; Dyadechkin, S.; Punsly, B. (2004)."Simulations of Jets Driven by Black Hole Rotation".Science.305(5686): 978–980.arXiv:astro-ph/0408371.Bibcode:2004Sci...305..978S.doi:10.1126/science.1100638.PMID15310894.S2CID1590734.
  9. ^Blundell, Katherine (December 2008)."Jet Velocity in SS 433: Its Anticorrelation with Precession-Cone Angle and Dependence on Orbital Phase".The Astrophysical Journal.622(2): 129.arXiv:astro-ph/0410457.doi:10.1086/429663.Retrieved15 January2021.
  10. ^Dereli-Bégué, Hüsne; Pe’er, Asaf; Ryde, Felix; Oates, Samantha R.; Zhang, Bing; Dainotti, Maria G. (2022-09-24)."A wind environment and Lorentz factors of tens explain gamma-ray bursts X-ray plateau".Nature Communications.13(1): 5611.arXiv:2207.11066.Bibcode:2022NatCo..13.5611D.doi:10.1038/s41467-022-32881-1.ISSN2041-1723.PMC9509382.PMID36153328.
  11. ^ Georganopoulos, M.; Kazanas, D.; Perlman, E.; Stecker, F. W. (2005). "Bulk Comptonization of the Cosmic Microwave Background by Extragalactic Jets as a Probe of Their Matter Content".The Astrophysical Journal.625(2): 656–666.arXiv:astro-ph/0502201.Bibcode:2005ApJ...625..656G.doi:10.1086/429558.S2CID39743397.
  12. ^ Hirotani, K.; Iguchi, S.; Kimura, M.; Wajima, K. (2000). "Pair Plasma Dominance in the Parsec-Scale Relativistic Jet of 3C 345".The Astrophysical Journal.545(1): 100–106.arXiv:astro-ph/0005394.Bibcode:2000ApJ...545..100H.doi:10.1086/317769.S2CID17274015.
  13. ^Electron–positron Jets Associated with Quasar 3C 279
  14. ^Naeye, R.; Gutro, R. (2008-01-09)."Vast Cloud of Antimatter Traced to Binary Stars".NASA.
  15. ^ Blandford, R. D.; Znajek, R. L. (1977). "Electromagnetic extraction of energy from Kerr black holes".Monthly Notices of the Royal Astronomical Society.179(3): 433.arXiv:astro-ph/0506302.Bibcode:1977MNRAS.179..433B.doi:10.1093/mnras/179.3.433.
  16. ^ Penrose, R. (1969). "Gravitational Collapse: The Role of General Relativity".Rivista del Nuovo Cimento.1:252–276.Bibcode:1969NCimR...1..252P.Reprinted in:Penrose, R. (2002). ""Golden Oldie": Gravitational Collapse: The Role of General Relativity ".General Relativity and Gravitation.34(7): 1141–1165.Bibcode:2002GReGr..34.1141P.doi:10.1023/A:1016578408204.S2CID117459073.
  17. ^ Williams, R. K.(1995). "Extracting X-rays, Ύ-rays, and relativistic e−e+pairs from supermassive Kerr black holes using the Penrose mechanism ".Physical Review.51(10): 5387–5427.Bibcode:1995PhRvD..51.5387W.doi:10.1103/PhysRevD.51.5387.PMID10018300.
  18. ^ Williams, R. K. (2004). "Collimated Escaping Vortical Polar e−e+Jets Intrinsically Produced by Rotating Black Holes and Penrose Processes".The Astrophysical Journal.611(2): 952–963.arXiv:astro-ph/0404135.Bibcode:2004ApJ...611..952W.doi:10.1086/422304.S2CID1350543.
  19. ^ "Chandra:: Photo Album:: IGR J11014-6103:: June 28, 2012".
  20. ^ Pavan, L.; et al. (2015). "A closer view of the IGR J11014-6103 outflows".Astronomy & Astrophysics.591:A91.arXiv:1511.01944.Bibcode:2016A&A...591A..91P.doi:10.1051/0004-6361/201527703.S2CID59522014.
  21. ^ Pavan, L.; et al. (2014)."The long helical jet of the Lighthouse nebula, IGR J11014-6103"(PDF).Astronomy & Astrophysics.562(562): A122.arXiv:1309.6792.Bibcode:2014A&A...562A.122P.doi:10.1051/0004-6361/201322588.S2CID118845324.Long helical jet of Lighthouse nebula page 7
  22. ^ Halpern, J. P.; et al. (2014). "Discovery of X-ray Pulsations from the INTEGRAL Source IGR J11014-6103".The Astrophysical Journal.795(2): L27.arXiv:1410.2332.Bibcode:2014ApJ...795L..27H.doi:10.1088/2041-8205/795/2/L27.S2CID118637856.

External links[edit]

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