Isolating the jet in broadband spectra of XBs Dave Russell niversity of Amsterdam In collaboration with: Fraser Lewis, Dipankar Maitra, Robert Dunn, Sera Markoff, James Miller-Jones, Kieran O’Brien, Piergiorgio Casella, Peter Jonker, Jeroen Homan, Manuel Linares, Rob Fender, Elena Gallo, Valeriu Tudose 12 th October 2010

Radio emission:  is synchrotron in nature  unambiguously originates in collimated outflows (2 types of jet) RadioX-ray? The spectrum of a steady, hard state jet (to zeroth order): Turnover  log Optically thickOptically thin X-ray Binary Jets The jets are radiatively inefficient, and the power carried in the jets is uncertain and highly dependent on the position of the turnover/break(s) Does the turnover change with luminosity; how does the jet spectrum evolve during transitions? Black hole XB: GRO J Tingay et al Neutron star XB: Sco X-1 Fomalont et al The turnover also helps constrain the synchrotron contribution to X-ray

 Optical outburst light curves and spectra similar to dwarf novae  disc Can we see the jet at higher energies?  Actually, the X-ray heated disc tends to dominate over the viscous disc (reprocessing) Kuulkers 1998 Hynes et al (XTE J ) Courtesy of Kieran O'Brien Well…

In the last decade evidence shows that:  the jet is sometimes visible in optical and NIR But wait… Mirabel et al. (1998) showed NIR flares from GRS (found by Fender et al. 1997) originate in the jets

In the last decade evidence shows that:  the jet is sometimes visible in optical and NIR  the turnover in the jet spectrum probably lies somewhere in the IR But wait… Homan et al. (2005) showed NIR emission from GX has negative spectral index in the hard state, and is quenched in the soft state Corbel & Fender 2002 Data from Homan et al. 2005, Jain et al. 2001, Buxton & Bailyn 2004 > 90%  of flux is from the jet in the brightest hard state

Multi-wavelength monitoring of GX F. Lewis et al. in prep, F. Lewis PhD thesis

Time resolution typically ~100 sec Multi-wavelength monitoring of GX High amplitude variability on short timescales: monitoring the flickering See also P. Casella’s talk, next! Infrared SEDs from the VLT: We can infer the average SED by taking lots of data over long timescales “its like taking a simultaneous 2-month long exposure”

So where is the jet break? Not clear in GX SEDs Hynes et al had simultaneous NIR J,H,K observations of XTE J They found the NIR to be consistent with optically thin synchrotron

So where is the jet break? Not clear in GX SEDs Hynes et al had simultaneous NIR J,H,K observations of XTE J They found the NIR to be consistent with optically thin synchrotron Jet break must reside in the mid-IR Very few mid-IR data of LMXBs in outburst exist in the literature See also Migliari et al. 2006, 2007, 2010: Spitzer 4 – 24 micron detections of the BH GRO J and the NS 4U Our team have approved time on the VLT with VISIR – the first data came in this summer 8 – 12 micron imaging 10-micron detections van Paradijs et al  50 mJy! Probably jet?

The jet is not there  Russell et al. in prep. Data of GX during a state transition, type B QPO seen (P. Casella) – soft intermediate state Some of the first mid-IR data of outbursting LMXBs

VLT VISIR Data of XTE J during the hard state decline of its 2009 – 2010 outburst (EVLA radio data courtesy of J. Miller-Jones, P. Jonker, ATel #2278, NIR also from ATel #2268) Some of the first mid-IR data of outbursting LMXBs

What about neutron stars? Migliari et al identify the jet break in 4U : In the mid-IR: between 8 and 24 microns

What about neutron stars? Optical, NIR, UV and X-ray monitoring of the 2008 double-peaked outburst of IGR J Lewis, Russell, Jonker, Linares, et al. 2010, A&A, 517, A72

What about neutron stars? Optical, NIR, UV and X-ray monitoring of the 2008 double-peaked outburst of IGR J Lewis, Russell, Jonker, Linares, et al. 2010, A&A, 517, A72 Jet break around the H-band? (1.6 microns)

Optical & infrared data published in Jain et al. 2001; radio in Corbel et al X-ray analysis as in Dunn et al Introducing the 2000 outburst of XTE J Well monitored in X-ray, optical and near-infrared (NIR) We can separate disc and jet emission Assumes continuation of the exponential decay of disc flux Jet has optically thin spectrum

Russell, Maccarone, Körding & Homan 2007 Could it be a synchrotron jet dominating X-ray? NIR jet flux is proportional to X-ray flux Variability info: Kalemci et al. 2001, Kalemci’s talk at IAU Symposium, Buenos Aires 2010 Russell, Maitra, Dunn & Markoff 2010, MNRAS, 405, 1759 α (NIR  optical) ~ -0.7 α (optical  X-ray) = -0.7 α (X-ray power law) = -0.7 (photon index = 1.7) α (X-ray power law before) = -0.6 A single power law decreasing in flux by a factor of ten Markoff, Falcke & Fender 2001 XTE J

Fender, Gallo & Jonker 2003: Energetics are jet dominated at low luminosities in the hard state A possible revised picture for BH outbursts Jet could dominate X-ray flux in the hard state between Dunn et al. 2010: 60% of BH outbursts show this softening on the hard state decay Is the jet the reason for the softening?

Multi-wavelength monitoring of GX Extinction plays a massive role in optical-UV SEDs F. Lewis et al. in prep, F. Lewis PhD thesis