A new solution to the plasma starved event horizon magnetosphere

Abstract

Very Long Baseline Interferometry observations at 86 GHz reveal an almost hollow jet in M87 with a forked morphology. The detailed analysis presented here indicates that the spectral luminosity of the central spine of the jet in M87 is a few percent of that of the surrounding hollow jet 200-400 µ as from the central black hole. Furthermore, recent jet models indicate that a hollow "tubular" jet can explain a wide range of plausible broadband spectra originating from jetted plasma located within ∼30 µ as of the central black hole, including the 230 GHz correlated flux detected by the Event Horizon Telescope. Most importantly, these hollow jets from the inner accretion flow have an intrinsic power capable of energizing the global jet out to kiloparsec scales. Thus motivated, this paper considers new models of the event horizon magnetosphere (EHM) in low luminosity accretion systems. Contrary to some models, the spine is not an invisible powerful jet. It is an intrinsically weak jet. In the new EHM solution, the accreted poloidal magnetic flux is weak and the background photon field is weak. It is shown how this accretion scenario naturally results in the dissipation of the accreted poloidal magnetic flux in the EHM not the accumulation of poloidal flux required for a powerful jet. The new solution indicates less large scale poloidal magnetic flux (and jet power) in the EHM than in the surrounding accretion flow and cannot support significant EHM driven jets.

The Details of Limb Brightening Reveal the Structure of the Base of the Jet in M87 for the First Time

“…The results are only suggestive taken as a whole and certainly not very reliable taken individually. The relevant crosscuts of the superresolved image from z = 0.3, 0.4, and 0.5 mas were previously published (Punsly et al 2018). The main advantage of a high resolution image is the possibility of achieving a stronger connection between the FWHM of the deconvolved Gaussian fits of the peaks, FWHM deconvolved , and the intrinsic width of the jet walls.…”

“…It is worth noting that one can also consider the crosscuts of the superresolved version of the 86 GHz image in the bottom left frame of Figure 1 that was previously published (Hada et al 2016;Punsly et al 2018). The image was restored with a circular beam of 0.11 mas instead of the 0.116 mas × 0.307 mas, PA = −9°restoring beam of Figure 1.…”

Constraints on Black Hole Jet Models Used As Diagnostic Tools of Event Horizon Telescope Observations of M87

“…This is possible due to the fact that the luminosity distribution is restricted to a very thin boundary layer in both M87 and the model. At 0.2 mas from the source, it was shown in Figure 5 of Punsly et al (2018) that the intrinsic surface brightness associated with the 86 GHz VLBI observation of Hada et al (2016) is approximately a double δ-function, S int (ρ, z = 0.2mas) ≈ S Hada [0.48δ(ρ + 0.15mas) + δ(ρ − 0.15mas)], where S Hada = 19 mJy/beam is a normalization constant. The observed S(ρ, z = 0.2mas) restored with the full beam is highly blurred, but still edge dominated (Hada et al 2016).…”

“…In spite of this, the comparison is not trivial because the jet morphology is different between the models and the observations within 0.4 mas. The flux from the M87 jet is dominated by the edges on these small scales (see Figure 5 of Punsly et al (2018)), but the images produced by the simulation have jets in which the flux is concentrated along the axis of the jet. One might say that the M87 jet is extremely edge brightened for z < 0.4 mas and the H10 and R17 simulations are edge darkened for z < 0.4 mas.…”