Presentation on theme: "1 IAU symp. 238 (Aug. 2006) Synchrotron Outbursts in Galactic and Extra-galactic Jets, Any Difference ? Marc Türler INTEGRAL Science Data Centre Geneva."— Presentation transcript:
1 IAU symp. 238 (Aug. 2006) Synchrotron Outbursts in Galactic and Extra-galactic Jets, Any Difference ? Marc Türler INTEGRAL Science Data Centre Geneva Observatory Elina Lindfors Tuorla Observatory, Finland
2 Model & Methodology ● Aim. Derive the properties of synchrotron outbursts in astrophysical jets ● Method. Fit a series of model outbursts to the lightcurves at different frequencies ● Outburst model. Generalization of the shock-in-jet model of Marscher & Gear (1985) with modifications of Björnsson & Aslaksen (2000)
3 From Spectra to Lightcurves Evolution of the spectrum from high to low frequencies Longer outbursts at lower frequencies
4 Simulated jet images ● Outbursts differ from each other by their: ● onset time ● normalization of the electron energy spectrum ● magnetic field strength ● Doppler factor of the shock ● Jet images can be simulated from model outbursts assuming a constant apparent speed
7 Cyg X-3 (Feb-Mar 1994) Ref.: Lindfors et al. (in prep.)
8 GRS 1915+105 (15 May 1997) Ref.: Türler et al. (2004)
9 Derived jet properties ● Similarities among all sources ● Infrared outbursts are higher and last longer than expected by the standard adiabatic shock model of Marscher & Gear (1985) [except for 3C 273 ?]. ● True outbursts have also a slower rise and a faster decay than expected. These differences are reduced by the modifications to the Compton stage by Björnsson & Aslaksen (2000) and the choice of a shock viewed sideways for the 2 quasars. ● Differences between galactic & extra-galactic jets ● The electron energy index s tends to be smaller for the microquasars (1.7-1.8) than for the quasars 2.1 (3C 279) and 2.5 (3C 273). NB: Giant outbursts in GRS 1915+105 have s = 2.2 (spectral index = 0.6) ● The jet of the galactic sources are apparently widening with distance (like a trumpet), while quasars tend to have rather conical jets.
10Conclusion ● We showed that infrared-to-radio variability of quasars and microquasars can be well reproduced by a shock-in-jet model, suggesting that: ● the basic physics of relativistic jets are independent of the mass of the black hole over height orders of magnitude ● outbursts in the lightcurves are associated to moving structures in the inner jet (e.g. the unresolved AU- scale “baby” jet of GRS 1915+105) ● these moving stuctures are likely propagating shock waves rather than ejected plasma clouds ● Future studies shall further constrain the physical properties of the jets by modelling also the associated Compton (SSC) emission in the X-rays
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