Black hole accretion and jet ejection James MillerJones

Black hole accretion and jet ejection James Miller-Jones Collaborators: Greg Sivakoff, the JACPOT XRB collaboration, Tom Russell, Peter Jonker, Dave Russell Email: james. miller-jones@curtin. edu. au

Overview • Disc-jet coupling in X-ray binaries • Hard states: – Compact jets – Radio/X-ray correlation • Hard-to-soft transitions: – Compact jets quenched – Launching of discrete ejecta Image credit: R Hynes • Soft state quenching – Role of a disc wind? • Soft-to-hard transitions – Compact jets re-established Image credit: R Hynes

The multiwavelength view of an XRB • Jets: IR, radio • Donor: IR, optical • Disc: optical, UV, X-rays • Corona: X-rays • Corona/jet base: g-rays? Markoff (2007)

Why study XRBs in the radio band? • Band in which emission is dominated by the jets • Probe of high-energy processes • High-resolution imaging – Resolve jet morphology evolving in real time – Jet collimation, propagation, energetics – Probe accretion-ejection coupling • Astrometry – Faint, persistent emission in hard/quiescent state – Model-independent parallax distances – Proper motions (formation mechanisms, birthplaces)

Jet-disk coupling in accreting black holes Disc-dominated Power-law dominated Bright Dhawan et al. (2000) Faint Fender, Belloni & Gallo (2004) Mirabel & Rodriguez (1994), Fender et al. (1999)

Compact jets in the hard state Disc-dominated Bright Faint Fender, Belloni & Gallo (2004) Power-law dominated

Compact jets: spectra • Flat or slightly inverted spectra from radio through IR • Overlapping SSA spectra, we see emission from optical depth 1 at each frequency • Spectral break (typically mid-IR) provides radiative luminosity of jet Fender et al. (2000) MAXI J 1836 -194

Compact jets: morphology • Jets directly resolved in 3 sources Rushton et al. (2012) • Inferred to exist in all hard-state systems • Flat/inverted radio spectra • Radio/X-ray correlation MAXI J 1836 -194 GRS 1915+105 Dhawan et al. (2000) Cygnus X-1

Compact jets: radio polarization • Polarized emission probes B-field ordering and orientation • Few percent polarization detected in 3 sources • EVPA, B-field aligned with jet axis MAXI J 1836 -194 Corbel et al. (2000) GX 339 -4 Cyg X-1

The radio/X-ray correlation • Non-linear correlation over 8 decades in Lx Corbel et al. (2003) Gallo et al. (2006)

The radio/X-ray correlation • Lr a Lx 0. 7 Corbel et al. (2003) Gallo et al. (2006)

Universality? • Radio-quiet outliers falling well below correlation Jonker et al. (2012)

Two tracks • Clustering analysis shows evidence for two distinct clusters • Bayesian regression of the two clusters shows different slopes Gallo et al. (2012)

Efficient vs inefficient accretion? • Transition between radio-quiet and radio-loud branches Coriat et al. (2011)

Efficient vs inefficient accretion? • Transition between radio-quiet and radio-loud branches Ratti et al. (2012)

A mix of physical processes? • Steep slope: has to be radiatively efficient? Lr a Lx 2. 1

Transition period Disc-dominated Bright Faint Fender, Belloni & Gallo (2004) Power-law dominated

H 1743 -322 Transition • X-ray emission rises • X-ray hardness, fractional variability decrease • Appearance of QPOs • Compact jet quenching • Major radio flare • Launching of discrete ejecta Miller-Jones et al. (2012)

The accretion-ejection connection

Spectral signatures of ejection • Use VLBA proper motions to determine ejection date • Does the “Unified Model’ hold? – As far as we can tell – Additional radio quench phase Miller-Jones et al. (2012)

Timing signatures of ejection • What happens in the accretion disc to cause the switch? – X-ray spectral state transition – Type C QPOs disappear from power spectrum – Fractional rms variability drops Miller-Jones et al. (2012)

The transient ejecta • Note delay between derived ejection date and when transient jets appear – Ejection precedes radio quenching – Time for ejecta to become optically thin at radio frequencies? – Time for internal shocks to form within the jet? Miller-Jones et al. (2012)

Comparison of different outbursts • Does the ejection always happen at the same hardness? – No; different in two outbursts of the same source Miller-Jones et al. (2012)

Comparison of different outbursts • Jet ejecta have different speeds in the two outbursts – Proper motions 3. 7 ± 0. 7, 3. 3 ± 0. 8 mas/d in 2009 – Corresponds to 0. 19<b<0. 28 – Compare with 21. 2 ± 1. 4, 13. 3 ± 0. 6 mas/d in 2003 (after deceleration) • Black hole spin unlikely to have changed between outbursts: more likely to be mass accretion rate • 2003 outburst significantly brighter – Is jet speed correlated with outburst luminosity?

Quenched jets in the soft state Disc-dominated Bright Faint Fender, Belloni & Gallo (2004) Power-law dominated

Compact jet quenching • Compact jets quenched in soft states • Quenching factor >700 (Coriat et al. 2011) • Quenching factor >330810 (Russell et al. 2011) • Possible difference with AGN (less quenching) • Role played by disc winds? (see Neilsen talk) Russell et al. (2011)

Jet reactivation Disc-dominated Bright Faint Fender, Belloni & Gallo (2004) Power-law dominated

Jet re-activation • When do compact jets re-ignite in the radio band? – On moving from HSS to HIMS • No VLBA detection after main outburst; emission location unconfirmed • OIR jets known to switch on only after return to LHS • Gradual evolution of jet power? • Remnant optically thin emission? Miller-Jones et al. (2012)

Summary • Compact jets ubiquitous in hard states of BH XRBs • Magnetic fields oriented along jet axis • Correlation between radio, X-ray emission • Separate branches, with transition between them • Different spectral slopes • Jet ejection events correlate with X-ray spectral and timing changes • Causal sequence not yet established • Different outbursts have different jet speeds • Quenching of radio emission in soft states (factor 102 -103) • Compact radio jets re-ignite on moving from HSS to HIMS