Giant Radio Sources in View of the Dynamical Evolution of FRII-Type Population. II. The Evolutionary Tracks on the P-D and u_c - E_tot Planes

• Autorzy: Machalski J. , Chyży K. T. , Jamrozy M.
• Języki publikacji: EN

Abstrakty

EN

The time evolution of "fiducial" radio sources derived from fitting the dynamical model of Kaiser et al. (1997) is compared with the observational data for the "clan" sources found in the sample of giant and normal-size FRII-type sources published in Paper I (Machalski et al. 2004). Each "clan" comprises 3, 4 or 5 sample sources having similar values of the two basic physical parameters: the jet power Q₀ and central density of the galaxy nucleus ρ₀ (determined in Paper I) but different ages, radio luminosities and axial ratios. These sources are considered as the "same" source observed at different epochs of its lifetime and used to fit the evolutionary luminosity-size (P-D) and energy density-total energy (u_c-E_tot) tracks derived from the model for a "fiducial" source with Q₀ and ρ₀ equal to the averages of relevant values obtained for the "clan" members, as well as to constrain the evolutionary model of the source dynamics used. In the result we find that (i) the best fit is achieved when the Kaiser et al.'s model is modified by allowing an evolution of the sources' cocoon axial ratio with time as suggested by Blundell et al. (1999), (ii) a slow acceleration of the average expansion speed of the cocoon along the jet axis is suggested by the "clan" sources. We argue that this acceleration, although minor, may be real and some supporting arguments come from the well known hydrodynamical considerations.

Słowa kluczowe

EN

galaxies: active; galaxies: evolution; galaxies: kinematics; galaxies: dynamics

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2004
• Tom: Vol. 54, No. 4
• Strony: 391--403
• Opis fizyczny: Bibliogr. 17 poz., tab., wykr.

Twórcy

autor

Machalski J.

• Astronomical Observatory, Jagellonian University, ul. Orla 171, 30-244 Cracow, Poland

autor

Chyży K. T.

• Astronomical Observatory, Jagellonian University, ul. Orla 171, 30-244 Cracow, Poland

autor

Jamrozy M.

• Astronomical Observatory, Jagellonian University, ul. Orla 171, 30-244 Cracow, Poland

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