1 / 44

Jets from Black Holes: Observations and Theory

This study delves into various systems producing highly collimated jets, from stellar objects to AGNs, analyzing mechanisms of jet acceleration and collimation. Insights into jet origins, ongoing research on accretion disks, and implications for angular momentum removal are discussed. The text presents observations and theories on jet production, focusing on key ingredients and necessary conditions for jet acceleration, addressing questions on jet-disk interactions and the role of outflows in removing angular momentum from accretion disks.

mikejoseph
Download Presentation

Jets from Black Holes: Observations and Theory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Jets from Black Holes:Observations and Theory Mario LivioSpace Telescope Science Institute

  2. Which Systems Have Highly Collimated Jets? Stellar Extragalactic

  3. Jets in Young Stellar Objects

  4. HH 901 Carina Nebula

  5. Jet in M87: From 60 kpc to 0.06 pc

  6. Superluminal Motion in M87 HST-1 Do FR I radio galaxies have relativistic jets like BL Lacs?

  7. “Superluminal” sources • GRS 1915+105V ~ 0.9c • Some extragalactic jets showV > 0.995c

  8. Gamma Ray Burst Hosts

  9. Symbiotic Systems Southern Crab NebulaHe2-104 STScI-PRC99-32

  10. NGC 6543 Jets in Planetary Nebulae? NGC 5307 NGC 3918 NGC 7009 NGC 6826

  11. High mass x-ray binaries SS 433

  12. Supersoft X-Ray Sources RXJ 0513-69

  13. Pulsar Jets Vela Pulsar Crab Pulsar Chandra Chandra

  14. Do jet-producing systems have accretion disks? What are the absolutely necessary ingredients for the mechanism of jet acceleration and collimation?

  15. [O I] l6300 Profiles for T Tauri Stars Redshifted component not seen because of disk.

  16. X-Ray Spectroscopy of Accretion Disks in AGNs • MCG-6-30-15 • Gravitational redshift plus Doppler shift

  17. Do Jets Require an Accretion Disk? Qualified Yes “Interacting winds”, “ion torus”, Pulsars, GRBs, need more work

  18. Do Accretion Disks Require Jets or Outflows? • Are outflows/jets the main mechanism for transport/removal of angular momentum? • Angular momentum carried by wind

  19. Do Accretion Disks Require Jets or Outflows? Angular momentum that needs to be removed from disk For rA ~ 10r, only 1% of the accreted mass needs to be lost in wind.

  20. Behavior of Disk Radius During Dwarf Nova Outburst • At outburst, matter diffuses inward. Angular momentum of that matter is transferred to outer parts of the disk. • Radius expandsObservationally: • Disks in U Gem, OY Car, HT Cas and Z Cha larger in outburst. U Gem

  21. Behavior of Disk Radius During Dwarf Nova Outburst Theory: disk instability

  22. Do accretion disks require jets or outflows for angular momentum removal? Probably not. • More observations of rotation in jets and bipolar outflows are needed (velocity gradients).

  23. Other Clues on Jets Jet Origin

  24. Other Clues on Jets • Jets originate from the center of the accretion disk! • Models which work at all radii are probably not the “correct” ones, (e.g. self similar).

  25. Black Hole Jets – x-ray transients • Two states: • dissipation and disk luminosity, • bulk flow and jet.

  26. New Timescale Timescale for jettj ~ td2R/H 1/f power spectrum below a break frequency.

  27. Main Question: Which ingredients play a major role in the acceleration and collimation?

  28. Ingredients which may notbe absolutely necessary

  29. What Does Work? A reasonably ordered large-scale magnetic field threading the disk!

  30. Magneto-Centrifugal Jet Acceleration and Collimation • Acceleration like a bead on a wire up to the Alfven surface. • Acceleration optimal around inclination of 60°.

  31. Collimation Outside Alfven Surface Collimation by hoop stress? BUT Kink Instability

  32. Poloidal Collimation Necessary Conditions • Rdisk/Robject = Significant number of decades • Bz largest at inner disk but largest at outer disk e.g. Bz ~ (r/Rin)-1 Good collimation obtained forRAlfven ~ Rdisk Consequences Minimum opening angle of jetΘmin ~ (Rin/Rout)1/2

  33. M87 VLBA at 43 GHz

  34. M87

  35. Long GRB: Collapse of Massive Star

  36. Short GRB: Collision of Two Neutron Stars

  37. Are There Additional Ingredients? • Why are there radio-loud and radio-quiet AGN? • Why do CVs appear not to produce jets while SSS do? • How can pulsars produce jets?

  38. Conjecture • The production of powerful jets requires an additional heat/wind source. • Solutions to transsonic flow in disk corona: for strong B a potential difference exists even for i > 30 (Δφ ~ B4).

  39. Radio Loud vs. Radio Quiet AGN Central engineparameters:

  40. Recent simulations: Magnetic “Tower”

  41. Simulation results for spinning black hole • Outgoing velocity ~0.4 - 0.6 c in funnel wall jet • Poynting flux dominates within funnel • Both pressure and Lorentz forces important for acceleration • Existence of funnel jet depends on establishing radial funnel field • Jet luminosity increases with hole spin – Poynting flux jet is powered by the black hole

  42. Simulations: dependence on black hole spin

  43. Spins of Black Holes? • RISCO, a*, determined on the basis of x-ray continuum data (even beyond thermal-dominant state). • Study of plunging orbits important. Spin estimates based on stress-free inner boundary condition give upper limit on a*?

  44. Critical Observations • Determinations of the collimation scale in all classes of objects. • Detection and measurement of rotation and of toroidal magnetic fields in jets and bipolar outflows. • Searches for jets in other SSS, in PNe, in other XRTs (during flares, e.g. A0620-00, GS2023+338, GS 1124-683, Cen X-4, AQL X-1), and other symbiotic systems, in CVs! • Determination of black hole masses in AGN. • Determination of black hole spins. • Observations of collimated jets in pulsars. • Afterglow light curves and breaks in GRBs. • Differences between short and long burst in GRBs.

More Related