Rapid compact jet quenching in the Galactic black hole candidate X-ray binary MAXI J1535−571

Abstract

We present results from six epochs of quasi-simultaneous radio, (sub-)millimetre, infrared, optical, and X-ray observations of the black hole X-ray binary MAXI J1535−571. These observations show that as the source transitioned through the hard-intermediate X-ray state towards the soft intermediate X-ray state, the jet underwent dramatic and rapid changes. We observed the frequency of the jet spectral break, which corresponds to the most compact region in the jet where particle acceleration begins (higher frequencies indicate closer to the black hole), evolve from the IR band into the radio band (decreasing by ≈3 orders of magnitude) in less than a day. During one observational epoch, we found evidence of the jet spectral break evolving in frequency through the radio band. Estimating the magnetic field and size of the particle acceleration region shows that the rapid fading of the high-energy jet emission was not consistent with radiative cooling; instead the particle acceleration region seems to be moving away from the black hole on approximately dynamical timescales. This result suggests that the compact jet quenching is not caused by local changes to the particle acceleration, rather we are observing the acceleration region of the jet travelling away from the black hole with the jet flow. Spectral analysis of the X-ray emission show a gradual softening in the few days before the dramatic jet changes, followed by a more rapid softening ∼1–2 days after the onset of the jet quenching.

Disk, Corona, Jet Connection in the Intermediate State of MAXI J1820+070 Revealed by NICER Spectral-timing Analysis

“…If the blob is launched when the corona is most compact (MJD ∼58,298) and travels at ∼0.9 c (Bright et al 2020), then a delay of ∼5 days until a radio flare would suggest that the radio-emitting blob is at 10 9 R g . Unfortunately, there have been no published radio measurements of the synchrotron break to independently estimate the radius and distance of the jet ejecta, but this distance is reasonable, when compared to the BHB MAXI J1535-571 where the emission height above the black hole is ∼ 10 8 R g (Russell et al 2020). We also note that recent Chandra imaging showed a transient X-ray jet ejecta at the time of the radio flare, inferring that the ejecta was a cone of 1.5 × 10 4 au by 7.7 × 10 3 au (Espinasse et al 2020).…”

The black hole transient MAXI J1348–630: evolution of the compact and transient jets during its 2019/2020 outburst

“…In the hard state, collimated and continuously replenished compact jets are typically observed in the radio band (Corbel et al 2000;Fender 2001), emitting self-absorbed synchrotron radiation. This results in a flat or slightly inverted radio spectrum (α 0, where the radio flux density follows S ν ∼ ν α ) up to a break frequency ν break located in the infrared (IR) (Markoff, Falcke & Fender 2001;Russell et al 2013bRussell et al , 2014Russell et al , 2020a, after which the jet becomes optically thin. Synchrotron radiation from compact jets can also contribute to the hard X-ray emission (e.g.…”

Fast infrared variability from the black hole candidate MAXI J1535−571 and tight constraints on the modelling

“…Contribution from the hot-inflow at these wavelengths seems also be unlikely when considering the preliminary parameters obtained in the previous section. The same authors, instead, conclude that in the near-IR band there may be potential contribution from both jet and accretion disc (Baglio et al 2018;Russell et al 2020). We therefore discuss our results regarding the mid/near-IR connection according to these two possible scenarios:…”

“…Simulations from the internal shocks model have shown that the peak of the near-IR emission region (R) can span, depending on the jet physical conditions, a range of values from ≈ 5 × 10 3 g to ≈ 5 × 10 5 g (Malzac 2014;Malzac et al 2018). Given also the limits to the jet first acceleration zone imposed by Russell et al (2020), we set a conservative value for R of 5 × 10 3 g , which leads to a required jet Lorentz factor of Γ 1.7 and a jet inclination 40 • . It is interesting to notice that this is in good agreement with radio observations of MAXI J1535−571 performed close to our campaign, which revealed a relativistic ejection with a reported inclination ≤ 45…”

“…Black hole low mass X-ray binaries (BH LMXB) have been historically studied mainly in X-rays, where, depending on the accretion regime, great part of the dissipated gravitational energy is radiated away by either a geometrically-thin, optically-thick accretion disc (Shakura & Sunyaev 1973) or a geometrically-thick, optically-thin inflow (Esin et al 1997;Poutanen et al 1997). However, multiwavelength studies have shown that bright (non-thermal) emission is also present at lower (from optical-UV down to radio) frequencies (see e.g.…”