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Home , Astrophysical jet, Wolfgang Kundt

PoS(FRAPWS2014)025 al Hz, 26 10 . http://pos.sissa.it/ http://pos.sissa.it/ . Clearly, this 2 ± 2 = 10 γ ce. ”. ill try to penetrate into the jet -negligible density, most notably l spectral lines), but likewise in our , still inside its deLaval nozzle, the oth stellar and galactic scales, also ng of the universal working scheme the streaming, extremely relativistic pensible pair is generated in entz-factor uum, as “bare jets”. New in this pre- -drifts through self-rammed channels, annel-wall material. In this way, bare lock will be their medium: extremely . Already for this reason, black holes B tic Maxwellian distribution (almost) to dressed jets x nating ‘hotspots’, or ‘heads’. These elec- e deLaval nozzle – is not loss-free; it turns E ), see page 120 of Kundt & Krishna [2004]. 6 10 . γ -fields convect the electric potential necessary for eventu B ive Commons Attribution-NonCommercial-ShareAlike Licen -ray emitter, with photon frequencies reaching up to γ - and E ∗ -pair plasma performing quasi loss-free ± [email protected] Copyright owned by the author(s) under the terms of the Creative Commons transition in velocity distribution – in transit through th the jet engine into a powerful single-step post-acceleration, at their ‘knots’ and termi magnetospheric reconnections of the heavycannot central serve rotator as jet engines. During its passage from subsonic to supersonic propagation that of a (mono-energetic) Deltafunction, of (uniform) Lor tromagnetic fields convect half of the jet’s power. The indis escaping relativistic pair-plasma passes from a relativis channels, but will instead be expelled, andpair dragged plasma, along in by the form ofjets subrelativistically are comoving converted ch into (line- and continuum-) emitting “ So far, all the jets weresentation treated will as be though an propagating allowance in for vac anencountered embedding in medium SS of 433 non (with itsGalactic fast-moving X-ray twin and jet. optica Such an embedding medium, gas or plasma, w In this talk (at Mondello)of I attempt all to the sketch astrophysical my understandi jet sources, or ‘bipolar flows’, on b called ‘’, and ‘’. A crucial building b relativistic e (corresponding to Lorentz factors Speaker. whose guiding equi-partition © Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). ∗ Copyright owned by the author(s) under the terms of the Creat c Frontier Research in , 26-31 May 2014 Mondello (Palermo), Italy Argelander Institut of Bonn University, Germany E-mail: A Uniform Description of All the Astrophysical Jets

PoS(FRAPWS2014)025 rela- Wolfgang Kundt still increases with PeV energies at their ter- f Active Galactic Nuclei . t SBHs, rather (nuclear-) Burn- es of the Universe: The engines tions are thought to result from [Kulsrud et al 1972] – and gnetosphere; it can only swallow. ever since 1978, I have convinced cretion disk, with a spin period of his constraint is optimised by e lifetime of a jet engine. We know mals; like cells, hearts, lungs, in- a necessary though not a sufficient at almost luminal speeds, to astro- s? As is known since the 1970s, a which serves as a heavy and sharp- well as neutron stars surrounded by erical gravitational potential of their plasma must be post-accelerated, and ntum space, and their significant post- he above-listed engines, the funneling rrounding medium – for confinement that. But in astrophysics we deal with tgoing low-frequency electromagnetic me & Kundt 1988, Kundt 2005, Kundt jet without abundant jet substance, or mbient medium, as was first proposed us size and mass scales? After years of of relativistic pair plasma (than YSOs), tion rate has been estimated to have well ns of this kind. How does non-animated ncy, further by (ii) their scattering on the all the jet engines follow one and the same 2 uses reliable molecular engines with stable working yr nonstop, in two antipodal directions, in a beamed 7 10 & -pairs, at a low rate, even nowadays, in its hot corona. When ± biology 1%, whereby particles arrive with & Mpc, for . , the lightest medium in the Universe; whereby its lightness sources are among the most delicate engin Note that for its multiple tasks, This jet plasma must be supplied continually, throughout th Continual supply of abundant (relativistic) pair plasma is And what is the working pattern of the Central Engines (CEs) o manner, aimed within an angle of A Uniform Description of All the Astrophysical Jets 1. How to make jets? can eject charges atnomical Very-High Energies distances (VHE), of order continually mination sites. Militaries would appreciate availing of gu matter achieve such a difficult task, time and again, on vario intense deliberation, it is my distinct understanding that universal working pattern. patterns that can be easily reproduced by both plants and ani testines, muscles, nerves, a largelifeless, number of inorganic senses, matter! and all Howrather to jet ‘plasma’, achieve which reliability? should No bepurposes much lighter – than its i.e., su muchtivistic smaller pair in plasma rest mass, and much hotter. T that our Sun can generate relativistic e the height of its Lorentz factor. ambient photon gas, via (iii) phase-riding on the strong, ou the Sun was young, born3.6 at hours the (instead of inner the edge present ofsufficed 27.3 to its days), power its (planetary) its pair-forma Young-Stellar-Object ac (YSO) stage& [Blo Marggraf, 2014].‘magnetic Whereby spanking’ the of necessary the magneticedged inner reconnec obstacle. edge of Correspondingly, its forming accretionaccretion white disks disk, are dwarfs, expected as to bein even perfect stronger generators agreement with the observations. condition on a jet engine tofunneled into function: two The antipodal freshly channels. generated Weof maintain their that for twin-jets t iscentral achieved rotator, by and that buoyancy, the in bunching of theacceleration the take quasi-sph charges place in via mome (i) their just-mentioned buoya waves (LFW) of the centralvia rotator (iv) – profiting like from by the theby deLaval-nozzle Crab Blandford structure & nebula’s of Rees in its 1974, a see [Kundt & Krishna 1980, 2004]. (AGN), during their – quitesupermassive black similar-looking hole (SBH) – cannotNo anchor jet pair a formation, formation corotating no buoyant ma myself escape, (and no even a LFWs. few of Fortunately, my referees) that the CEs of AGN are no PoS(FRAPWS2014)025 , = = 1 . − 3 ˙ γ N s / (2.1) 4 2 − of /10 ω := Wolfgang Kundt of order f ping is expected 4 − γ generator ω G, 3 magnetosphere of angular ds a heavy the rare, gigantic, supersoft X- hearing) against the inner edge := B/10 functional regularities in micro- s, the buoyant escape, the post- longer to be considered as poten- 3 e-sketched universal jet model in on [1981], and by Peter Scheuer 4 t engines, their dynamics, stabili- gged out of its convection zone by − with the stellar CEs, thus creating rotators, via their strongly shearing nt Sun, pair formation at its surface ted as caused by innermost stars on n effect will be to narrow the energy ihilations in neutron-star jet sources 8], and that earlier interpretations of ω s available here. The reader can find 1, 2005, 2009a,b; 2011a,b,c, Kundt tic Lorentz factor e its earlier versions by allowing for not wanted for other reasons. on losses to blow jets, the rest of them her hand, only 10% of all AGN have / e of magnetic reconnection should not their . 3 atory experiments where atomic beams per second, of mean Lorentz factor 2013] has reminded us that BHs form a B rmation via magnetic reconnections have pse solutions: Expected during collapse – 2 d by dense surroundings. of (large) strength parameter f : . 14 10 = 3 , insufficient for jet formation. ˙ ω N c e m / eB = electron- pairs : f 4 γ / 44 L 1 − s 7 . 45 strong, low-frequency spherical waves , in the absence of damping [Kulsrud et al 1972]. Some such dam 3 / 2 ) ) = 10 4 2 emits c − e ω ω / m 3 γ (B A complete description of the detailed functioning of the je All this said, the reader will still find a short review of abov Apart from their inability to blow jets, Black Holes ought no (i) In order to blow a relativistic twin jet of power L, one nee At the same time, we have learned from that a rotating 5 , which we conceive of as a rotating magnetosphere rubbing (s . 9 4 L / (2 10 to occur via scattering on thedistribution ambient of photon the bath, escaping whose charges, mai as isare known routinely from cooled labor via scatteringpresently high on enough laser feeding, light. or low enough On inverse-Compt the ot measure-zero subset of the class ofif all at gravitational all colla – would be Naked Singularities; which are, however, tial astrophysical sources, ever since Pankaj Joshi [2009, ties, and various morphologies, would takeit in more the space quoted than literature. i Sufficebeen it to recently mention assessed that by pair Dal fo have Pino been et al first [2010], reported thatquasars by pair and Kaiser ann quasars & are described Hannikainen insimilar [2002], Körding kinds et that of al the [2006, 200 jet[1996]. phenomenon Finally, were if given the by CEsray Phil of outbursts reported Morris the by AGN Komossa are mayperturbed BDs orbits have rather colliding to than with be BHs, the re-interpre heavy innermost disk of inner-galactic diskal coronas [Kundt& 1979, Krishna 1990, 1980, 1996, 2004]. 200 acceleration by They their share LFWs, thequite and magnetic similar-functioning self-blown reconnection twin jets. deLaval nozzles the next section At thechannel-wall same material of time, non-negligible this density, review impacte will generalis 2. My (improved) Semi-Analytical Jet Model A Uniform Description of All the Astrophysical Jets ing Disks (BDs), which act analogously to heavy, magnetised of a surrounding gaseous ,matter, but cf. the precise [Kundt mod 1996, 2001,may 2002]. rather In be the due case to ofthe reconnections our escaping of prese solar excess wind, magnetic but flux only dra at a low rate which post-accelerates charges of either sign to an asympto 10 velocity for a typical coronal field of strength B measured in kG, with B PoS(FRAPWS2014)025 – 4 idal (2.2) 10 verse- . , where- e uniform γ , whereby in a Wolfgang Kundt 2 /B (delta) flow [Kundt B x E = ulk Lorentz factor turns out to be small, of order β relativistic Maxwellian cal dressed-beam section, showing s consistent with monoenergetic F waves, and the more isotropic ϕ β const s o heavy thermal deLaval nozzles – mono-energetic y funneled by buoyancy, and strongly / e energy distribution of the escaping = ) radial electric Hall fields imply unique z ollisional losses on the photon bath of R B / -drifters, s s been that also dressed beams are electrically , B towards a π s ( x / ) E cos R ) / 4 s R π / ( C } = {charge density, current density, radial electric, toro π sin ψ C = ( ,B s = c / ϕ z }, smoothly distributed throughout the (naked) beam, whose j ). In this way, their propagation is loss-free, apart from in B j , j, E 4 ρ , = = , z}, with R = cylinder radius; 10 ρ s ϕ ρ ≈ E -drifting rearranges the speeds of the charges until they ar γ B x s / R) of { E ∼ Cross section through (the stable ground mode of) a cylindri Taken together, the newly created pair plasma is antipodall (ii) Beyond a deLaval nozzle, the relativistic charges – of b in cylindrical coordinates {s, lowest-order Fourier components read: Compton losses on the background radiations. the radial dependences ( & Krishna 2004]. Its across the beam. (Remember thatsynchrotron the radiation, with radio spectrum of Sgr A* i Figure 1: the BLR [Jiang et al 2007]. boosted by the outgoing low-frequencyHigh-Frequency (LF) (HF) background waves. radiation tend Both torelativistic the narrow L th (of the radio-loud subpopulation) A Uniform Description of All the Astrophysical Jets are radio quiet, or even radio silent, through exactly such c magnetic field}, R := beam radius.neutral, An and essential current-free. assumption ha upon their subsequent feeding intohas two been antipodal shown jets to – by further tw narrow the distribution towards a cylindical section of a naked beam, thecharge- toroidal and B-fields and current-densities { rearrange their velocities in an orderly manner as PoS(FRAPWS2014)025 + ted E (2.4) (2.3) (2.5) bient )( e )˙= (e/m Wolfgang Kundt γβ of those of the neutral yr old) of , 3 , one of the nearest radio . 4 10 5 ) − z π + 1/3 of its original energy uV. 4 Cen A / 1 2 ( rful container of relativistic pair asma’s energy: The pressure p of , see Fig.2. And Pakull et al [2010] 6 B t such beams have vanishing net eam particles into the (expanding) γ 2 with more than ten times its radio / / ≈ e ultimate power-law distribution of me time, a large fraction of the co- 44 1 elope (of expanded cocoon matter), its switch-on phase, like water being No stochastic (in situ) acceleration is f order 10 m transfer, of course, implies a small h-off phase of rapid relaxation, does ch mediate the transfer of its impact ed by the power L of a beam and its L iny subvolume, the relativistic gas has rized beam plasma will induce mirror π asma, converting its delta-type energy der that ed jet sources. by an extended, heavy conductor? Such 8 filling-factor filaments. Such explosive Mpc -up and heated circumsource matter. Al- eV / given by = u/3. Consequently, in order to compress 5 ) . 2 = 19 B deg γ 10 + stalled 3K 2 u = E 5 T ( 2 σ / 1 4 ≈ inverse Compton collisions on the 2.73 K background ) gamma-ray galaxy’, / c 2 / c Ac L e / erg/s, from the optical emission of its radio lobes, whereby π 7 L m ( . e 3 40 ≈ distribution, and energizing it such that it squeezes the am . Note that these field strengths correspond to (huge) convec ≈ 2 e = c ′ n φ e γ e / m γ γ -drifting leptons described by equns. (2.2) and by c( e = n in the Sculptor galaxy NGC 7793 was a (10 : B x deg l E S 26 given by Φ broad power-law ) have their dominating losses through Note also that the Blowing the cocoon consumes one third of the stalled beam-pl (iii) What happens when a pair-plasma beam is B , unrelated to observed spiral patterns, see Fig.1. Note tha 1 x − (excessive mechanical) power L = 10 , has been recently mappedpower; at Teddy Cheung MeV [2010] has energies, called glowing it a ‘ have concluded that charges and currents, and that their charge amplitudes are o β A Uniform Description of All the Astrophysical Jets γ radiation, with a (large) degradation e-folding length l which guarantee electron energies up intothe the charges, once PeV they range have in been th required stalled anywhere by in a the heavy obstacle. beams. for a pair-plasma number density pre-existing plasma near the distal end of the cocoon into a t a relativistic gas equals one third of its energy density u, p to perform work given byThis p means times that its the volume cocoonplasma, V, of storing which a two amounts thirds bipolar of to flow its (BF) energy at is injection. still No a won powe (thermal) circumsource plasma into high-pressure,compression is small- known to be Rayleigh-Taylorblown unstable apart during by pressurized air.the lobe Only develop later, a during smooth,observed the as Rayleigh-Taylor switc its stable bounding, outer shocked outer env layer. which puts only marginal restrictions on the longest observ conductive obstacles form naturally, as (part of the) swept ready before any mechanical contact, the approaching, pola charges, and mirror currents inmomentum to the the obstructing ‘head plasma, material’, and‘lobe’, whi more or or ‘cocoon’, less which reflect is the therebyenergy b inflated. transfer This to momentu the (compressed)moving head electromagnetic energy material. is At transferreddistribution to the into the a sa pair pl flows. Fields and chargescross are section in A equipartition, via: and determin electric potentials PoS(FRAPWS2014)025 (2.6) erg/s 7 . 37 among the Wolfgang Kundt a jet, a comparison PeV sources -ray galaxy Cen A, at distance γ ctrostatically repelled from it, , i.e. to jets propagating through celeration: When the huge con- , , or even Mpc scale. e signs of their excess charges as t reports of TeV sources among the e in the real world, caused by the 4 , during jet formation? For the sake radio frequencies in orange, and MeV y, rather / . 1 pairs from the unperturbed flow – at upper-end (of the power law) Lorentz ) al of their charges, for which electrons ons – such that they end up co-moving urposes, these two subsets of solution ed mechanical power f L = 10 r source smoothly joins the class (c) of r plasma of their jet engines. ± 44 bare jets imited discharge, borrowed from the (as- L ( 2 . (largest) 7 TeV sources 10 of the radiating lobe material, corresponding to 3 6 ≈ − 2 / 1 ) Φ γ 8 ( ≈ ∞ γ found in Eq. (2.4) is discharged, at the termination shock of Φ Multifrequency map of our nearest elliptical (radio) galax of order: ∞ γ (iv) All our above formulae referred to naked jets, or And what about occasional recent reports of Figure 2: A Uniform Description of All the Astrophysical Jets d = 3 Mpc,energies in plotted purple. by Its NASA. feeding jets It are maps not resolved visible on this colours naturally, [Kundt & Krishna 2004], large enoughBFs as to inverse-Compton explain radiation all from the the recen relativistic pai (extreme) vacuum. They are symmetrical w.r.t.and a sign revers exchange their positions.look indistinguishable. For all Or practicalasymmetry is p of one protons and of electrons theof in two their dressing surrounding subsets such BLR unstabl jetsin (with Fig.1 ambient above. matter),and let Impacting at ions us the from choose same their th time CSM dragged will along then by be the ele relativistic e they omitted a likely filling factor f of order 10 sumed) polar-cap discharges of pulsars, yields an expected with Michel’s relativistic Child’s Law for a space-charge l factor an f-times lower radiating mass, and an f-times lower inferr members of the jetvected family? potential No need for stochastic (in situ) ac roughly comparable particle momenta for sufficiently slow i of the microquasar. With such aBFs filling from factor binary included, neutron thei stars, as an older brother of SS 433. PoS(FRAPWS2014)025 }. 0 , 60 0 -drifting B x = {0 E Θ Wolfgang Kundt he form of thin, o to Ole Marggraf, electric neutrality of jets and rsonically into their surround- R) boundary layer indicated in lows: No jets, or bipolar flows, 3 arfs. − necessary post-acceleration of the N [Kundt, 1997]. As concerns the c to supersonic propagation, inside ergies; but also most of the High- ver the beams get tapped by obsta- 10 ) = {1/8, 1/4} for i - naturally forming deLaval nozzles, e classes differ strongly. Jean Eilek pply the necessary (relativistic) pair IVCs) of the ’s halo may e satisfactory – they mutually differ & Θ hout jets). Supersonic tion is the neutron-star binary SS 433, on the ambient photon bath must not ritical speed, and expand only subson- eir heads, the jets blow the lobes, which ources. nses, and (the quality of) correlations – of the escaping power through their self- r density of positrons, almost neutralised rmal inclusions of small filling factor, and hin ( emplified by the Galactic X-ray binary SS -ray emitters, with Lorentz factors reaching -ray regime. γ γ 7 = 1 / 8 cos(i - respectively, in slight (though important) revision of β type B with β and type A 1/8. & β My cordial thanks for the manuscript, and for its contents, g . And embedding gas and/or plasma is dragged along by them in t 6 10 . γ This dressed-beam model has been based on the assumptions of But already during their formation, in passing from subsoni (v) The heads of young jets move fast enough to penetrate supe In short, the key properties of my updated jet model are as fol Fig.1, whose constituents are (intruded) ions plus a simila by (again) a comparable density of (ambient) electrons. of a vanishing net current alongwith them. Its its best fast-moving known applica ions atVelocity Clouds both (HVCs) X-ray and and Intermediate-Velocity optical Cloudsowe their ( photon existence en to a moreSS powerful 433 past system, of note our that Galactic nonein AG of model, its distance, published mass, evaluations ar power,and orientations, arrive at rotation different se speeds v = c A Uniform Description of All the Astrophysical Jets alongside at subrelativistic speeds with the bare jet, in a t marginally subrelativistc channel-wall bandages, best ex Acknowledgments 433. Weakest among all jet sources are those blown by brown dw up to their deLaval nozzles, the forming jets are strong and also to Hans Baumann. We presently prefer ings, whilst those of olderically. copies tend As to is fall well short known,[2002] the of has morphologies this termed of c them these of two sourc the earlier Fanaroff & Riley classification of double radio s 3. Summary of the Model without a rotating magnet, whoseplasma, magnetic and reconnections whose su outgoing low-frequencyleptonic waves charges. provide the In thisbe process, excessive, otherwise inverse-Compton we losses deal with radio-silent QSOs (wit with spectra which extend up in energy to the VHE jets emerge at two oppositewhereby equipartition outlets electromagnetic of fields the convect half (central)rammed BLR, jet via channels. They servecles, as most notably comoving at batteries their downstream where shocks (heads).are observed At as th low-density relativistic balloons with the PoS(FRAPWS2014)025 th , eds. -302. , eds. H. in Buenos , 2-7, pp. , Springer, W. 46 ; 275 Wolfgang Kundt 471 518 , 335-345. -Tirado, J. Greiner & and 62 Frontier Objects in Astrophys. & Space Sci. , Vulcano Workshop 2010, eds. F. , 109-134. , 636-639. Life Cycles of Radio Galaxies 103 Cambridge Univ. Press, pp. 92-93. 172 28 Astron. Astrophys. , IAU Symposium No. The Physics of Galactic Halos e Verlag, 255-259. New Reviews a, eds. Mario Novello & Santiago s, in: tellar Objects?, n of Quasars and Microquasars, in , February, 22-33; literally reprinted in May 010, -Hole , in , in: s of deliberation, in , 1366-1378. , 277-288. , Lecture Notes in Physics XIIIth Brazilian School of Cosmology & r, D.P., Strauss, M.A., Kelly, B.C.: 2007, COSMOLOGY and XIV GRAVITATION), , 225-231. ( 372 383 Astrophys. & Space Science , Springer, Chapter 11. 330 Phys. Rev. Lett. 8 Jets at All Scales , ESO Symposia, Springer, 159-163. MNRAS MNRAS MNRAS Astrophys. & Space Sci. Scientific American , M. Novello & S.E.P. Bergliaffa (eds.), Melville, N.Y., 288 , Conference Proceedings Vol. 1132 Growing Black Holes Jets from Stars and Galactic Nuclei , Proceedings of the Third Miroquasar Workshop, A.J. Castro Astrophysics, A New Approach , 680-690. , Nr. 9, 1967-1980. 656 41 , AIP Conf. Proc. , 343-361. Gravitation Aires, eds. Gustav Romero, Rashid Sunyaev & Tomaso Belloni, Astrophysics and Particle Physics Giovannelli & G. Mannocchi, Bologna, pp.389-404. Astrophys. J. MICROQUASARS Lesch, R.-J. Dettmar, U. Mebold, & R. Schlickeiser, Akademi Gravitation 2013. J.M. Paredes (eds.), Kluwer, 273-277. Kundt (ed.), 140-144. 257-261. arXiv:1005.3067v1. Brazilian School of Cosmology and Gravitation,Bergliaffa, Mangaratib Cambridge Scientific Publishers, pp. 109-118. 148 J.A. Biretta, A.M. Koekemoer, E.S. Perlman, & C.O. O’Dea, [9] Kulsrud, R.M., Ostriker, J.P., Gunn, J.E.: 1972, [4] Joshi, P.S.: 2009, Naked Singularities, [5] Kaiser, C.R., Hannikainen, D.C.: 2002, [6] Körding, E.G., Jester, S., Fender, R.: 2006, [7] Körding, E.G., Jester, S., Fender, R.: 2008, [8] Komossa, S.: 2005, in [3] Jiang, L., Fan, X., Ivecic, Z., Richards, G.T., Schneide [1] Blome, H.-J., Kundt, W.: 1988, Leptonic Jets from Young S [2] Dal Pino, E.M. de G., Piovezan, P.P., Kadowaki, L.H.S.: 2 [11] Kundt, W.: 1990, The Galactic Centre, [18] Kundt, W.: 2009b, Jürgen Ehlers and the fate of the Black [19] Kundt, W.: 2011a, The Astrophysical Jets, in [10] Kundt, W.: 1979, A Model for Galactic Centers, [20] Kundt, W.: 2011b, The Astrophysical Jets – after 30 year [14] Kundt, W.: 2001, Jet Formation and Dynamics: Compariso [21] Kundt, W.: 2011c, Black Holes cannot blow Jets, in [17] Kundt, W.: 2009a, Critical Thoughts on Cosmology, in [12] Kundt, W.: 1996, in [15] Kundt, W.: 2002: Radio Galaxies powered by Burning Disk [13] Kundt, W.: 1997, Structure of the and Disk [16] Kundt, W.: 2005, A Uniform Description of All the Astrophysical Jets References PoS(FRAPWS2014)025 from the , too short 471 , 115-127. Wolfgang Kundt 25 pc length in the upper 2 , Springer, Ch. 7. n those curved outflows be injet, which has been traced at J. Astrophys. Astr. atter and anti-matter). . It looks rather modest and straight, , Lecture Notes in Physics 1 pc out to 10 h existed in our cosmic neighbourhood produced by just a burning disk around . r (rotating) Galactic disk. In my [2011c] orro, during IAU Symposium 97 at B-drifting Jets, × 9 , 149-150. 288 Nature Physikalische Mythen auf dem Prüfstand Jets from Stars and Galactic Nuclei Thanks, Pieter, for asking this relevant question. Time was From your diagram it looks like there is a curved outflow (jet) Albuquerque. (on Extragalactic Radio Sources formed from m Springer, W. Kundt (ed.), 35-40. A Uniform Description of All the Astrophysical Jets [22] Kundt, W., Gopal-Krishna: 1980, [23] Kundt, W., Krishna, G.: 2004, The Physics of E [24] Kundt, W., Marggraf, O.: 2014, [25] Morrison, P.: 1981, unpublished evening lecture at Soc [26] Scheuer, P.A.G.: 1996, in for me to show thelow complete radio evidence frequencies, we IR have frequencies, of and our at Galactic X-rays from tw central regions of theinterpreted Milky as a Way precessing galaxy jet perhaps (botha and BH if up so, ? and can that down) be . Ca WOLFGANG KUNDT: DISCUSSION PIETER MEINTJES: galactic hemisphere, and out to 30just pc like in an old, the low-power lower jet hemisphere fromlecture the at (stable) center Mangaratibo, of I ou argue that black– holes cannot – possibly even blow if jets. suc