Speaker
Dr
Alla Miroshnichenko
(Institute of Radio Astronomy, NAS of Ukraine)
Description
We consider four samples of steep-spectrum radio sources from our catalogue UTR-2 at the decameter band. These contain galaxies and quasars of both spectral types - with linear steep spectrum and break steep spectrum. To obtain the relation of low-frequency luminosity, at the frequency 25 MHz, L_25 and linear size R of sample objects we determine one at the different redshift ranges at the frame of LambdaCDM Universe model. The derived relatios show positive power trend (L_25 ~ R^n, n = 0.5....2.0) for galaxies and quasars. Since the object's luminosity ratio for monochromatic luminosities at different frequency ranges is independent from the Universe model, one is examined on the luminosity ratio-linear size relation. For the purpose of estimate on the linear size's cosmological evolution, we determine linear size-redshift relations at the narrow luminosity bins (R ~ (1+z)^k, k = 0.7....1.87) in our samples. It is very interesting, that obtained luminosity ratio-linear size relations at higher frequency ranges (infrared, X-ray) display two branches of evolution of steep-spectrum radio sources.
Author
Dr
Alla Miroshnichenko
(Institute of Radio Astronomy, NAS of Ukraine)
