ydrodynamics of Small ale Jets: Observation aspects Esko Valtaoja Tuorla Observatory, University of Turku, Finland Metsähovi Radio Observatory, Helsinki University of Technology A-METSÄHOVI AGN GROUP : Talvikki Hovatta, Elina ors, Anne Lähteenmäki, Elina Nieppola, Pia-Maria Salo s Savolainen, Ilona Torniainen, Merja Tornikoski, Kaj
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Hydrodynamics of Small- Scale Jets: Observational aspects
Hydrodynamics of Small- Scale Jets: Observational aspects. Esko Valtaoja Tuorla Observatory, University of Turku, Finland Metsähovi Radio Observatory, Helsinki University of Technology. TUORLA-METSÄHOVI AGN GROUP : Talvikki Hovatta, Elina - PowerPoint PPT Presentation
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Hydrodynamics of Small-Scale Jets: Observational
aspectsEsko Valtaoja
Tuorla Observatory, University of Turku, FinlandMetsähovi Radio Observatory, Helsinki University of Technology
TUORLA-METSÄHOVI AGN GROUP: Talvikki Hovatta, ElinaLindfors, Anne Lähteenmäki, Elina Nieppola, Pia-Maria Saloranta,Tuomas Savolainen, Ilona Torniainen, Merja Tornikoski, Kaj Wiik
Meg Urry 2007: ”Luckily, nobody remembers what wesaid 25 years ago, and the old acetates have decayed.”
NEED: basic GLOBAL and LOCALparameters from observations asinputs to theory / simulations...... which, in turn, should givepredictions which observers can test
GLOBAL: e.g., BH mass vs. jet speed?LOCAL: e.g., magnetic field strength along the jet?
Aloy et al. 2003 Gómez et al. 2001
Qualitativeagreement-but need alsoquantitative:global andlocal parametersvs. simulatedparameters
VLBA with all frequencies and polarization...(Savolainen et al., 2006, 2007)
LOCALdata!
...gives us local information along and transverse to the jet(which you cannot get from single and/or low frequency VLBI)
magnetic fieldvs. distance
electron energy densityvs. distance
+ jet/mf structures,instabilities, nonrelativisticplasma, speeds, IC fluxes...
SAVE VLBA BY USING ITS FULL POWER!
Mar
sch
er &
Gea
r sh
ock
-in
-jet
mod
el (
1985
)
(picturecourtesy ofMarc Türler)
Ten years of 3C 279 cm-to-optical variations modelled as”M & G” shocks in a jet (Lindfors et al., 2006, originalcode developed by Marc Türler)
LOCALdata!
Lindfors et al. 2005, 2006: shock and jet component spectra(+ SSC spectra) from mf continuum monitoring and 3-D fitsimultaneously to all data
VLBI: Savolainen et al. 2007
Exponential, sharp flares (Valtaoja et al. 1999)
Theory and simulations: quite different flare shapes(Gomez et al. 1997) ... are we missing something crucial?
- VLBI components correspond to TFD flares = shocks in the jet- strong gamma flares from the same shocks far from BH/BLR- T0(mm) < T0(VLBI)- T0(mm), T0(VLBI) < T0(gamma)
need more accurate timings foreach: physics of the radio core!
Savolainen et al 2002
Jorstad et al.2001
Lähteenmäki & Valtaoja 2003
radiogamma
Average delay from TFD/VLBI zero epoch to strong gammaflares ~ 2 months = parsecs, so External Compton fails...
...but the only alternative,synchrotron-self-Comptonalso fails (Lindfors et al.2005, 2006)
(Heh.)
EC photonsare here!
radiocore
Blazar sequence?(Ghisellini et al. 1998)
One-parameter(total power) family:
Most powerful sourceshave lowest synchrotronpeak frequencies
...but fuller samples destroy the sequence!
Nieppola et al. 2006:381 Northern Veron-Cetty&Veron BL Lacs,a ”complete” sample
(also Giommi et al. 2005; Padovani 2007 + others)
Doppler boosting vs. peak frequency(PMS + Nieppola, QSOs and BLOs)