An Evolving Compact Jet in the Black Hole X-Ray Binary Maxi J1836–194

Abstract

We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836-194 over state transitions during its discovery outburst in 2011. A fading of the opticalinfrared (IR) flux occurred as the source entered the hard-intermediate state, followed by a brightening as it returned to the hard state. The optical-IR spectrum was consistent with a power law from optically thin synchrotron emission, except when the X-ray spectrum was softest. By fitting the radio to optical spectra with a broken power law, we constrain the frequency and flux of the optically thick/thin break in the jet synchrotron spectrum. The break gradually shifted to higher frequencies as the source hardened at X-ray energies, from ∼ 10 11 to ∼ 4 × 10 13 Hz. The radiative jet luminosity integrated over the spectrum appeared to be greatest when the source entered the hard state during the outburst decay (although this is dependent on the high energy cooling break, which is not seen directly), even though the radio flux was fading at the time. The physical process responsible for suppressing and reactivating the jet (neither of which are instantaneous but occur on timescales of weeks) is uncertain, but could arise from the varying inner accretion disk radius regulating the fraction of accreting matter that is channeled into the jet. This provides an unprecedented insight into the connection between inflow and outflow, and has implications for the conditions required for jets to be produced, and hence their launching process.A Based on observations collected at the European Southern Observatory, Chile, under ESO Programme IDs 087.D-0914 and 089.D-0970.

Combining timing characteristics with physical broad-band spectral modelling of black hole X-ray binary GX 339–4

“…Understanding the interplay between these spectral components, determining which is the dominant mechanism at play, and explaining the connection between the accretion disc, corona and jet, is a key focus of recent targeted multiwavelength observing campaigns on BHBs (e.g. Corbel et al 2000Corbel et al , 2003Gandhi et al 2008Gandhi et al , 2010Miller-Jones et al 2012;Russell et al 2013;Corbel et al 2013;Russell et al 2014). X-ray variability studies show state classifications can also be made in the time domain, with low-rms/high-rms variability observed in soft/hard states respectively (see, e.g., Remillard & McClintock 2006b for a review).…”

Tracking the variable jets of V404 Cygni during its 2015 outburst

“…In quiescence and the hard accretion state, there exists a steady, compact synchrotron-emitting jet, which primarily emits at radio, sub-mm, and optical/infrared (OIR) frequencies (Fender 2001;Chaty et al 2011;Russell et al 2006;Tetarenko et al 2015a;Gallo et al 2005;Russell et al 2013b;Plotkin et al 2013Plotkin et al , 2015Plotkin et al , 2016. This compact jet displays a characteristic flat to slightly-inverted broad-band spectrum (α ≥ 0, f ν ∝ ν α ; Blandford & Königl 1979;Falcke & Biermann 1995;Fender 2001) extending up to OIR frequencies Casella et al 2010;Chaty et al 2011), where it breaks to an optically thin spectrum (α ∼ −0.7; Russell et al 2013a).…”

The First Low-Mass Black Hole X-Ray Binary Identified in Quiescence Outside of a Globular Cluster

“…Accreting BHs are known to (i) emit compact radio jets in both the hard and quiescent spectral states (e.g., Gallo et al 2004;see Done et al 2007 for a description of X-ray spectral states) that produce spectrum ranging from flat to slightly inverted (α ∼ 0.0-0.7, where F ν ∝ ν α ; Blandford & Konigl 1979;Fender et al 2004a;Fender 2009;Russell et al 2013aRussell et al , 2013b, (ii) be more radio bright (i.e., have much higher radio luminosities at a given X-ray luminosity) than neutron stars (Fender & Hendry 2000;Migliari & Fender 2006), and (iii) exhibit a strong correlation between X-ray and radio emission in the hard and quiescent spectral states (e.g., Hannikainen et al 1998;Corbel et al 2000Corbel et al , 2003. As such, it is possible to distinguish between an accreting BH and an analogous neutron star or white dwarf system using a combination of X-ray and radio observations of a source.…”