1. Lecture 7:
Jets on all scales
Superluminal apparent motions

2. Stellar Jets: visible in protostar phases, pc-scale, non-relativistic, but supersonic (T-Tauri or Herbig-Haro objects)

3. Galactic sources: micro-quasars
they are powered by stellar black holes, the kinematics is mildly relativistic: ~ 2-3

4. Extragalactic Jets: radiogalaxies and blazars Lorentz factors ~ 10-20
Virgo A (M87)
Cen A

5. Isotropic irradiated –ray energy vs redshift
Gamma-Ray Bursts: jets have been never resolved, but their presence is implied by the energetics.
Lorentz factors: ~
Isotropic irradiated –ray energy vs redshift
Long GRB
Short GRB
“hybrids”

6. What is the observational evidence that blazars and GRBs are highly relativistic sources with strong special relativity aberration effects?
Large luminosities
Non-thermal spectra
superluminal motions (blazars, but also micro-QSO)
Gamma-ray transparency

7. Blazar 3C279 (z = 0.54)
The gamma-ray luminosity exceeds the Eddington limit
For a 10^8 solar masses BH

8. Multiwavelength
Spectrum of blazar
Spectrum of GRB

9. VLBI monitoring of radio structures and blobs
Radio-blobs emitted at
different epochs may
have different apparent
velocities, vapp = appc
~5c
~20c
43 GHz; Jorstad et al. 2005
BL Lac
GHz; Mutel et al. 1990

10. VLBA observations at 7 mm (43 GHz) of BL Lac
Marscher et al. 2008, Nature, 452, 966

11. Superluminal motion  = 0.999 ( = 22)  = 0.99995 ( = 100)
 = ( = 7)
 = ( = 70)
 = 0.95
 = 0.9
 = 0.7
 = 0.5

12. In micro-QSO one also observes the counterjet, so that
both  and viewing angle can be determined

13. C.M. Urry & P. Padovani 1995
Unified Schemes for Radio-Loud Active Galactic Nuclei
PASP, 107, 803
G.B. Rybicki & A.P. Lightman 1979
Radiative Processes in Astrophysics
I.F. Mirabel & L.F. Rodriguez 1999
Sources of Relativisiic Jets in the Galaxy
Annual Review of Astronomy & Astrophysics 37, 409
L. Maraschi, G. Ghisellini, & A. Celotti 1992
A jet model for the gamma-ray emitting blazar 3C279
ApJ, 397, L5