1. L. Rudnick - Krakow - June 2006 Particle distributions in large scale radio jets Lawrence Rudnick University of Minnesota

2. L. Rudnick - Krakow - June 2006 conclusion FRI (low luminosity, non-classical double source) jets have a narrow distribution of low frequency spectral (energy) indices around -0.55 ( -2.1), not the test particle strong shock limit of -0.50 ( -2.0). CONCLUSIONS

3. L. Rudnick - Krakow - June 2006 Particle acceleration in kpc jets Why look in the radio? How do you look in the radio? What do we find about particle distributions?

4. L. Rudnick - Krakow - June 2006 WHY look in the radio? Low frequencies – can see injection power law – averages over long timescales

5. L. Rudnick - Krakow - June 2006 HOW do you measure low frequency (injection) slope? 1. Need clear indication of low frequency power law 2. Must measure homogeneous population - resolve spatial variations in spectra - separate out background (lobe) confusion

6. L. Rudnick - Krakow - June 2006 Has the low frequency power law been seen? Are spectral variations adequately resolved? Has jet/lobe emission been separated?

7. L. Rudnick - Krakow - June 2006 Multi- resolution filtering 3C438

8. L. Rudnick - Krakow - June 2006 Spectral Tomography Make series of images, S t by varying  t S t = S( 2 ) – ( 2 / 1 )  * S( 1 ) t

9. L. Rudnick - Krakow - June 2006 Jet spectra from tomography

10. L. Rudnick - Krakow - June 2006 x = original map = filtered = tomography

11. L. Rudnick - Krakow - June 2006 Has the low frequency power law been seen? Are spectral variations adequately resolved? Has jet/lobe emission been separated?

12. L. Rudnick - Krakow - June 2006 Determining the low frequency index 1.Asymptotic behavior  nucleus 2.Color-color diagrams

13. L. Rudnick - Krakow - June 2006 Evolving electron population – spectral changes Log Intensity Log Frequency

14. L. Rudnick - Krakow - June 2006

15. Tomography separation – Original spectrum Jet (& sheath)

16. L. Rudnick - Krakow - June 2006 COLOR-COLOR Diagrams reconstructing full spectral shapes from three frequency observations

17. L. Rudnick - Krakow - June 2006 Log Intensity Log Frequency Evolving electron population – mapping spectral shape

18. L. Rudnick - Krakow - June 2006

19. Color-color – problem diagnosis

20. L. Rudnick - Krakow - June 2006 North South 3C449

21. L. Rudnick - Krakow - June 2006  = -0.55

22. L. Rudnick - Krakow - June 2006 Summary of spectra  = -0.55

23. L. Rudnick - Krakow - June 2006 Summary of spectra  = -0.55

24. L. Rudnick - Krakow - June 2006 Regulating ~ -0.55 -- where? Initial acceleration at nucleus? [ – e.g.,Hydra A pc scale, optically thin regions -0.7, kpc scale, ~ -0.59 ] Flaring region? – jet flaring/ brightening regions post “gap” NGC315 3C449 Multifrequency. Spectra needed 1553+24

25. L. Rudnick - Krakow - June 2006 Regulating ~ -0.55 – how? First-order regulation? Other regulation? 2 nd order, shock-drift in turbulence/shear at flare? Ultra-relavistic (but  -2.25?) Shock modification – self-regulation?

26. L. Rudnick - Krakow - June 2006 Short digression…

27. L. Rudnick - Krakow - June 2006 Crab Nebula  = -0.3 pileup from high energy losses

28. L. Rudnick - Krakow - June 2006 caveat - NGC315 Multifrequency observations of the jets in the radio galaxy NGC315, 2006MNRAS.368...48L Laing, R. A.; Canvin, J. R.; Cotton, W. D.; Bridle, A. H.

29. L. Rudnick - Krakow - June 2006 conclusion FRI (low luminosity, non-classical double source) jets have a narrow distribution of low frequency spectral (energy) indices around -0.55 ( -2.1), not the test particle strong shock limit of -0.50 ( -2.0).  We need a characteristic acceleration mechanism;  And, it’s not the whole acceleration story.

30. L. Rudnick - Krakow - June 2006