On the milliarcsecond scale structural properties of lowand high
نویسنده
چکیده
We analyse VLBI data of a sample of radio quasars in order to study the milliarcsecond scale structural properties of quasars in the widest available redshift range of 0:2 < z < 4:5. The statistical study is based on a combination of the 5 GHz Caltech-Jodrell VLBI survey and our data for a set of extremely high redshift sources. We show that the apparently less prominent milliarcsecond scale structures found in z > 3 quasars do not contradict the assumption of intrinsic similarity of radio sources at diierent redshifts and may be explained by a diierence in spectral properties of cores and extended components (jets).
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