Black Hole`` Systems.` - Tata Institute of Fundamental Research
Transcription
Black Hole`` Systems.` - Tata Institute of Fundamental Research
Exploring Magnetospheric Origin of Jets For Both Neutron Star and ``Black Hole'' Systems. Abhas Mitra, akmitra@hbni.ac.in Homi Bhabha National Institute, Mumbai https://barc-in.academia.edu/AbhasMitra WORKSHOP ON ``JET TRIGGERING MECHANISM’’ in Black Hole SOURCES (Jan. 20 -23, 2016) TATA INSTITUTE OF FUNDAMENTAL RESEARCH, Mumbai, India This Talk on Jan 20, 2016 http://www.tifr.res.in/~tifrjet/home.html Ubiquity of Jets in Astrophysics: Protostars to Neutron Stars, Microquasars to AGNs Twisted Helical Magnetic Fields May Always Be Necessary But though the importance of Magnetic Field for harnessing Jet Power For BH Systems is always emphasized, the role Magnetic Field is not invoked with same intensity for BH astrophysics: Such as for State Transitions or Jet Formation, because BBH =0 Most of the jets from stars or even Neutron Stars are usually Non-ultra-relativistic And Relativistic Jets Are Often Found From ``Black Hole Systems’’, be it X-Ray Binaries or AGNs. This gave rise to the notion that somehow EVENT HORIZON IS NECESSARY For The ORIGIN of ULTRA-RELATIVISTIC JETS In Contrast, Tangible SOLID Physics For Accretion onto Magnetized Compact Objects: Disk Gets Arrested At The Alfven Radius Inner Edge of the Disk is at ALFVEN RADIUS RA : Magnetic Pressure = Ram Pressure MAGNETICALLY ARRESTED DISK: Mag Field DYNAMICALLY Important CO-ROTATING RADIUS: Kepler Vel of Accretion= Rotation Speed of Magnetosphere Ω: PROPELLER MECHANISM & EJECTION OF ACCRETING PLASMA: NATURAL MECHANISM FOR STATE TRANSITIONs • If RA < RCO : Plasma Is Forced into Co-rotation By Mag Field • Steady Accretion • But If RA > RCO: Mag Field Cannot Properly Guide: No Steady Accretion PROPELLER REGIME • Plasma Likely To Accumulate At Boundary Layer & Ejected Out by Along OPEN FIELD LINES b Magneto-Centrifugal Repulsion: Outflow Has 2 COMPONENTS: Episodic Conical Wind (Low Velocity) + High Velocity Magnetically Dominated Axial Jet: Lovelace, Romanova (Cornell) Computational Astrophysics & Cosmology, 1, 3 (2014) In 2004, EVIDENCE Came THAT EVENT HORIZON NOT NECESSARY FOR RELATIVISTIC JETS: Case For NS+BH Unified Jet Model? • ``An ultra-relativistic outflow from a neutron star (Circinus X-1) accreting gas from a companion’’: Fender… Nature 427, 222(2004) Bulk Lorentz Factor Γ> 15! • ``We conclude that the generation of highly relativistic outflows does not require properties that are unique to black holes, such as an event horizon’’ • Cir X-1 is the youngest XRB (4600 Yr!) & the NS May Be Spinning Very Fast • May be, the Accretion Disk should be close by & Yet Propeller Mechanism should operate due to fast spin of the compact object. • • • • EVIDENCES FOR UNEXPECTED STRONG MAGNETIC FIELD AROUND BLACK HOLE CANDIDATES Strong B~ 10**8 G near inner disk of Cyg X-1; astro-ph/0304158, Gnedin et al. As if Cyg X-1 Compact Object has µ ~ 10**30 G cm^3; Karitskaya + Gnedin+ .. arXiv:0908.2719 (Submitted to Nature …): BBH ~10**(8-9) G (STELLAR MASS): BBH ~ 10**4 G (Supermassive) Piotrovich et al; arXiv:1002.4948 ``A strong magnetic field around the supermassive black hole at the centre of the Galaxy’’ (Sgr A*): Eatough et al. Nature 501, 391 (2013) • ``Surprisingly Strong Magnetic Fields Challenge Black Holes’ Pull’’: Zamaninasab et al., Nature 510, 126–128 (2014) “Here we report that jet magnetic field and accretion disk luminosity are tightly correlated over seven orders of magnitude for a sample of 76 radio-loud active galaxies..” DYNAMICALLY IMPORTANT MAGNETIC FIELD • Resolved Magnetic Field Structure …Sgr A*: Science, 350 (2015): (Event Horz Teles) ``Alternatively, accumulation of sufficiently magnetic field near the event horizon may have led to a stable, magnetically dominated inner region, • *** This is a DIRECT EVIDENCE OF ORDERED MAGNETIC FIELD Around Astrophysical BHs But How Can There Be Strong Magnetic Field Close To A BH? HYPOTHEIS: Magnetically Arrested Disk (Mad Idea for a BH!): Narayan et al. PASJ 2003 • • ``Figure 1a shows the basic idea. We assume that a significant amount of poloidal magnetic flux has collected in the vicinity of the BH as a result of the cumulative action of the accretion flow, and that the magnetic field is dynamically dominant. The field is prevented from escaping by the continued inward pressure of accretion. At the same time, the field lines do not fall into the BH because the BH only “wants” the plasma but “does not want” the field’’ (Wishful thinking without real justification). • Because Embedded Magnetic Field Cannot Be Segregated From The Plasma. There is just no such physical mechanism. • Also Everything, whether Magnetic Field or Light Has MASS-ENERGY and Gets Pulled by Gravity Note, magnetic field embedded in the disk or accretion flow is expected to be chaotic, Even if it would be assumed to be organized on relatively larger scale, large scale STEADY Dipole Type Field is Impossible. SO THE PICTURE THAT IS REQUIRED: SPINNING NSs & BHs MAY HAVE A SOMEWHAT SIMILAR ORDERED MAGNETIC STRUCTURE In fact, having inferred µ~10**30 cgs; Karitskaya + Gnedin, arXiv:0908.2719 , Concluded that it looks as if the ``BH’’ in Cyg X-1 is a ``Magnetospheric Eternally Collapsing Object’’ MECO= An ultra-compact & ultra-magnetized ball of Plasma held in quasi-static –state by RADIATION PRESSURE + MAGNETIC STRESSES Conceived by Mitra, Robertson (South Okalohoma), Leiter (West Virginia, deceased), Schild (Harvard) MECO Paradigm is supported by 26 Peer Reviewed Papers, 2 Invited Book Chapters, 1 Essay in Gravity Foundation Context, Several Published Plenary Talks + Preprints NEXT FEW SLIDES SHOW PAPERS WHICH HAVE PUT NS+BH SYSTEMS IN An UNIFIED SELF CONSISTENT PLATFORM BY CONSIDERING: BH Candidates = MECO A rotating intrinsic magnetic field (shown in pale yellow) anchored to the MECO generates a magnetic propeller, sweeping out a large region (shown in black) of the inner accretion disk. The magnetic propeller also creates radial outflows of atomic nuclei (shown in indigo blue) and relativistic jets of electrons (shown in red) along the rotation axis. A bright blue-white ring forms where the MECO's rotating magnetic field sweeps the inner edge of the accretion disk, creating a hot, thin boundary layer that pushes matter outward against the intense inward pull of gravity. Outer gas clouds (shown in grey-green) gather together and flow into the accretion disk, heading for the highly redshifted, rotating MECO at the quasar's core. Many Conceptual Problems With The Notion of ``Black Holes’’ Even within General Relativity even after 100 Years ``The Schwarzschild solution: Some conceptual difficulties’’, Narlikar & Padmanabhan (IUCAA): Foundations of Physics, 18, 659 (1988): • ``It is shown that inconsistencies arise when we look upon the Schwarzschild solution as the space-time arising from a localized point singularity…the discussion of physical behavior of black holes, classical or quantum, is only of academic interest. It is suggested that problems related to the source could be avoided if the event horizon did not form and that the universe only contained quasiblack holes.’’ Most Natural & Generic Form of Such Quasi Black Holes = MECO Masses of Galaxy, Star, Planet… Arise From an INTEGRATION CONSTANT whose value Must Be Different In Different Cases GalaxyStarPlanet BlackHole And I showed that Rs = 0 For the Point Mass Which means MBH =0 So anything with finite mass cannot be True BH Thus, observed BHs Must Be Quasi-BHs. Ref: Mitra, J. Math. Phys., 50(4) 042502 (2009) Bel, J. Math. Phys., 10, 1501 (1969): Mitra, Ad. Sp. Res., 38, 2917 (2006) . Whenever A Star Contracts, It Radiates & Yet Becomes Hotter & Hotter! And a stage is reached when immediately before BH Formation: OUTWARD RADIATION FORCE ↑ = INWARD PULL OF GRAVITY ↓ (Eddington Luminosity) The Star Now Becomes Almost But Not Exact BH Star Material Ultra-Hot Fire/Plasma. It nonetheless keep on contracting Eternally Towards A TRUE BH State– A Point Having M=0 Eternally Collapsing Object (ECO) ECOs Expected To Be UltraMagnetized (MECO) SUN= MAGNETIZED BALL OF FIRE Refs: Mitra, PRD (2006), MNRAS Lett. (2006) MNRAS (2006), New Astron. (2006) Mitra & Glendenning, MNRAS Lett. (2010) Nov. 2015: NuStar Reported That A Flare Appears To Have Been Triggered By Eruption of Corona From Very Close To A So-Called BH (Mrk335). Could Be Something Like Eruption From Sun & Best Explained BY MECO Paradigm All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident. — Arthur Schopenhauer SEARCHING FOR MECO PARADIGM IN LITERATURE 1. A.P. Lobanov: (MPI Radioastronomie), Mem. A. It., 79, 1062 (2008) ``It still remains an open issue whether the central supermassive bodies in AGN indeed harbour black holes or other more exotic objects such as boson stars or Magnetospheric Eternally Collapsing Objects (MECO) (Robertson & Leiter 2003). The major difference between these alternatives is the absence of the event horizon in BS and MECO. 2. Sera Markoff (Anton Pannekoek) in Jet Paradigm, ed. T. Belloni, Springer (2010) ``One of the radical proposals comes from Robertson & Leiter (2002) who suggested that any jet producing object, driven by magnetic field, could be interpreted in terms of Magnetospheric Eternally Collapsing Objects (MECOs)… The idea is a new application of propeller theory where the inner disk is coupled to the Interior magnetosphere…. Hope, in future, Astrophysicists Will Explore This Paradigm to rule it out or confirm.. (David vs Goliath) Physics Today October 2013 Individualism: The legacy of great physicists Ricardo Heras ``New scientific ideas never spring from a communal body, however organized, but rather from the head of an individually inspired researcher who struggles with his problems in lonely thought and unites all his thought on one single point which is his whole world for the moment’’. PEER REVIEWED PAPERS IN SUPPORT OF THE MECO PARADIGM: 1. Non-occurrence of trapped surfaces and Black Holes in spherical gravitational collapse: An abridged version: A. Mitra, Found. Phys. Lett., 13(6), 543 (2000). 2. On the Final State of Spherical Gravitational Collapse: A. Mitra, Found. Phys. Lett., 15(5), 439 (2002). 3. Evidence for Intrinsic Magnetic Moments in Black Hole Candidates: S.L. Robertson, D.J. Leiter, Astrophysical J. 565, 447 (2002). 4. Does the Principle of Equivalence Prohibit Trapped Surfaces from Forming in the General Relativistic Collapse Process?: D.J. Leiter, S. Robertson, 16(2), 143 (2003) 5. On Intrinsic Magnetic Moments in Black Hole Candidates, S.L. Robertson, D.J. Leiter, Astrophysical J. 596, L203-L206 (2003) 6. On the origin of the universal radio-X-ray luminosity correlation in black hole candidates, S.L. Robertson, D.J. Leiter, Monthly Notices of the Royal Astronomical Society, 350, 1391 (2004). 7. Why Gravitational Collapse Must be Accompanied by Emission of Radiation Both in Newtonian and Einstein Gravity?: A. Mitra, Physical Review D. 74(2), 024010 (2006) 8. A Generic Relationship Between Baryonic and Radiative Energy Densities of Stars: A. Mitra, Monthly Notices of the Royal Astronomical Society (Lett.), 367, L66 (2006). 9. Radiation Pressure Supported Stars in Einstein Gravity : Eternally Collapsing Objects: A. Mitra, Monthly Notices of the Royal Astronomical Society, 369, 492, (2006). 10. Sources of Stellar Energy, Einstein -Eddington Timescale of Gravitational Contraction and Eternally Collapsing Objects: A. Mitra, New Astronomy, 12(2), 146 (2006); (One of the Highlight Publications of Max Planck Society, Germany, 2006) *11. Observations Supporting the Existence of an Intrinsic Magnetic Moment inside the Central Compact Object within the Quasar Q0957+561: Astronomical Journal, 132, 420 (2006). (CFA PRESS RELEASE) 12. On the non-occurrence of Type I X-ray bursts from the black hole candidates: A. Mitra, Advances in Space Research, 38(12), 2917 (2006) 13. Direct Microlensing-Reverberation Observations of the Intrinsic Magnetic Structure of Active Galactic Nuclei in Different Spectral States: A Tale of Two Quasars: R. Schild, D.J. Leiter, Darryl, S.L. Robertson: Astrophysical Journal, 135, 947 (2008). 14. Comments on ``The Euclidean gravitational action as black hole entropy, singularities, and space-time voids [J. Math. Phys. 49, 042501 (2008)'': A. Mitra, J. Math. Phys., 50(4) 042502 (2009) 15. Quantum Information Paradox: Real or Fictitious? : A. Mitra, Pramana, 73(3), 615, (2009). 16. Black Hole or Meco: Decided by a thin Luminous Ring Structure Deep Within Quasar Q0957+561: Journal of Cosmology, 6, 1400 (2010). 17. Does Sgr A* Have an Event Horizon or a Magnetic Moment?: S.L. Robertson, D.J. Leiter, Journal of Cosmology, 6, 1438 (2010). 18. Does Pressure Increase or Decrease Active Gravitational Mass? A. Mitra, Physics Letters B., 685(1), 8 (2010). 19. Likely formation of general relativistic radiation pressure supported stars or eternally collapsing objects'': A. Mitra and N.K. Glendenning, Mon. Not. Roy. Astron. Soc. Lett., 404, L50-L54 (2010). 20. Why No Energy Can Be Extracted From Rotating Kerr Black Holes: A. Mitra, K.D. Krori, Journal of Cosmology, 17, 7064 (2011). 21. General Relativistic Radiation Pressure Supported Stars as Quasar Central Engines in an Universe Which is Recycling Matter: A. Mitra, Journal of Cosmology, 17, 7376 (2011). 22. The fallacy of Oppenheimer Snyder collapse: no general relativistic collapse at all, no black hole, no physical singularity: A. Mitra, Astrophysics Space Science (Letter) , 332, 43, (2011). 23. Kruskal Dynamics for Radial Geodesics": A. Mitra, Int. J. Astron. & Astrophys, 2, 174, (2012) 24. Kruskal Coordinates and Mass of the Schwarzschild Black Hole: No Finite Mass Black Hole: A. Mitra, Int. J. Astron. & Astrophys. 2, 236 (2012). 25. Farewell to Black Hole Horizons and Singularities: C. Corda, D. Leiter, H. Mosquera Cuesta, S. Robertson, R. Schild, Journal of Cosmology, 17, 7412 (2011); (This was an essay in Gravity Foundation Competition, and may not have been peer reviewed). 26. Discovery of universal outflow structures above and below the accretion disc plane in radio-quiet quasars: J. Lovegrove, R.E. Schild, D. Leiter, Monthly Notices of the Royal Astronomical Society, 412, 2631 (2011). 27. The Mass of the Oppenheimer Snyder Black Hole: Only Finite Mass Quasi-Black Holes: A. Mitra, K.K. Singh, International J. Modern Physics (D) 22, 1350054 (2013). 28. Does Pressure Accentuate General Relativistic Gravitational Collapse Formation of Trapped Surfaces?: A. Mitra, International Journal of Modern Physics (D), 22(5), 1350021, (2013). 29. Schwarzschild Singularity: Luis Bel, Journal of Mathematical Physics, 10, 1501 (1969). The Abstract of this paper is just a one liner: ``A new point of view is presented for which the Schwarzschild singularity becomes a real point singularity on which the sources of Schwarzschild's exterior solution are localized.’’ Hans Alfven – Plasma Physics JAMES MAXWELL: Electromagnetism Accepted 10 Years After His Death, Lord Kelvin Opposed, Ignored For 25 Yr Svante Arrhenius – Ion Chemistry J. L. Baird – Television Robert Bakker – Warm-blooded dinosaurs Subrahmanyan Chandrasekhar – White Dwarf Upper Mass Limit Ernst Chladni – meteorites in 1800 Doppler – optical Doppler effect Galileo – Heliocentric view Evariste Galois – Group Theory Luigi Galvani – bioelectricity Karl F. Gauss – non Euclidean geometry Binning/Roher/Gimzewski – scanning-tunneling microscope Robert Goddard – rocket-powered space ships Thomas Gold – deep non-biological petroleum deposits; deep mine bacteria William Harvey – circulation of blood, 1628 Nikola Tesla – Earth electrical resonance, “Schumann” resonance Although, existence of an extended HOT Corona around DISK may be understandable, there is no explanation for Compact Corona Around a True BH which is vacuum & From Which Nothing can Escape. But a MECO Can Have Compact Corona The Way Sun Has Its Corona. Artist’s Impression Is Fine: But No Solid Explanation For StateTransitions & Jet In BH Paradigm In The Absence of Any Intrinsic Magnetosphere SCHWARZSCHILD SOLUTION: MASSES OF Galaxies, Stars & Black Holes Arise From an INTEGRATION PARAMETER Which Can Be, +ve, -ve, 0 A BH Soln. is Obtained From a Single POINT MASS ( . ), & BH Paradigm is Based On The Assumption That M0 >0. Schwarzschild Singularity: Luis Bel, Journal of Mathematical Physics, 10, 1501 (1969): ``A new point of view is presented for which the Schwarzschild singularity becomes a real point singularity on which the sources of Schwarzschild's exterior solution are localized.’’; IMPLICATIONS: Rg =0→ M(point mass) =0 → Anything having M>0 is NOT a TRUE BH! • Mitra, Advances in Space Research, 38(12), 2917 (2006) • Mitra, J. Math. Phys., 50(4) 042502 (2009): CONFIRMED: M( True BH) =0. • So BH Candidates CANNOT BE TRUE BHS! Why This Result Is Inevitable? • Ricci Scalar: R =R(pressure, density) • So For a Point Singularity, One expects: R (physical)~ M0 δ(0) (1) • Ref: (i) Petrov & Narlikar, Foundations of Physics, 26, 1201 (1996) • (ii) Tangherlini, Frank R., Physical Review Letters, 6 (3), 147 (1961) By directly using the BH Metric, one May Also Obtain R (BH=Point Mass) to find R (Math BH)=0 Now Equate (1) & (2) : R (physical) =R(Math) M0 δ(0) =0 which cannot be satisfied unless : M0 (True Math BH)=0 (2) A TRUE M=0 BH FORMATION WOULD REQUIRE INFINITE (Comoving) Proper Time: τ=∞ Thus Grav. Collapse Should Result in Either Static Objects (WD, NS) or Continue Indefinitely/Asymtotically (Eternally) Through Quasi-Static Sts As a star undergoes gravitational contraction, it must radiate and yet become hotter Resulting in increase of radiation pressure. Further, once it contracts below its PHOTON SPHERE, R= 1.5 Rg (3M), trapped RADIATION PRESSURE INCREASES DRAMATICALLY: As Gravitational Redshift, z>>>1, sooner or later, a stage is reached when ECO IS FORMED: OUTWARD FORCE OF TRAPPED RADIATION = INWARD PULL OF GRAVITY: EDDINGTON LUMIN 1. Why Gravitational Collapse Must be Accompanied by Emission of Radiation Both in Newtonian and Einstein Gravity?: Mitra, Physical Review D. 74(2), 024010 (2006) 2. A Generic Relationship Between Baryonic and Radiative Energy Densities of Stars: A. Mitra, MNRAS (Lett.), 367, L66 (2006). 3. Radiation Pressure Supported Stars in Einstein Gravity : Eternally Collapsing Objects: A. Mitra, MNRAS 369, 492, (2006). 4. Sources of Stellar Energy, Einstein -Eddington Timescale of Gravitational Contraction and Eternally Collapsing Objects: A. Mitra, New Astronomy, 12(2), 146 (2006) 5. Likely formation of general relativistic radiation pressure supported stars or Eternally Collapsing Objects: Mitra & Glendenning, MNRAS Lett., 404, L50-L54 (2010).