Frequency-Dependent Core Shifts in Ultracompact Quasars
- Authors: Voitsik P.A.1, Pushkarev A.B.1,2, Kovalev Y.Y.1,3,4, Plavin A.V.1,3, Lobanov A.P.4,5, Ipatov A.V.6
- 
							Affiliations: 
							- Astro Space Center, Lebedev Physical Institute
- Crimean Astrophysical Observatory
- Moscow Physical Technical Institute
- Max Planck Institut for Radio Astronomy
- Institute for Experimental Physics
- Institute of Applied Astronomy
 
- Issue: Vol 62, No 11 (2018)
- Pages: 787-813
- Section: Article
- URL: https://journals.rcsi.science/1063-7729/article/view/191922
- DOI: https://doi.org/10.1134/S1063772918110094
- ID: 191922
Cite item
Abstract
Results of a pilot project with the participation of the “Kvazar-KVO” radio interferometry array in observations carried out with the European VLBI Network are presented. The aim of the project was to conduct and analyze multi-frequency (1.7, 2.3, 5.0, 8.4 GHz) observations of the parsec-scale jets of 24 active galactic nuclei. Three observing sessions were successfully carried out in October 2008. Maps of the radio intensity distributions have been constructed in all four frequencies using phase referencing. A method for measuring the frequency-dependent shift of the position of the VLBI core by applying relative astrometry to observations of close triplets of radio sources has been developed. The fundamental possibility of detecting core shifts in ultra-compact sources for which traditional methods based on the achromatic positions of optically thin regions of the jet are not suitable is demonstrated. The conditions for successful measurement of this shift are discussed; these are determined by the closeness of the calibrator used, the effective resolution of the system, the quality of the filling of the uv plane, the relative orientations of the jets in the triplets, and the brightnesses of the sources.
About the authors
P. A. Voitsik
Astro Space Center, Lebedev Physical Institute
							Author for correspondence.
							Email: voitsik@asc.rssi.ru
				                					                																			                												                	Russian Federation, 							ul. Profsoyuznaya 84/32, Moscow, 117997						
A. B. Pushkarev
Astro Space Center, Lebedev Physical Institute; Crimean Astrophysical Observatory
														Email: voitsik@asc.rssi.ru
				                					                																			                												                	Russian Federation, 							ul. Profsoyuznaya 84/32, Moscow, 117997; Nauchnyi, Crimea, 298409						
Yu. Yu. Kovalev
Astro Space Center, Lebedev Physical Institute; Moscow Physical Technical Institute; Max Planck Institut for Radio Astronomy
														Email: voitsik@asc.rssi.ru
				                					                																			                												                	Russian Federation, 							ul. Profsoyuznaya 84/32, Moscow, 117997; Institutskii proezd 9, Dolgoprudnyi, Moscow oblast, 141700; 69 Auf dem Hügel, Bonn (Endenich), D-53121						
A. V. Plavin
Astro Space Center, Lebedev Physical Institute; Moscow Physical Technical Institute
														Email: voitsik@asc.rssi.ru
				                					                																			                												                	Russian Federation, 							ul. Profsoyuznaya 84/32, Moscow, 117997; Institutskii proezd 9, Dolgoprudnyi, Moscow oblast, 141700						
A. P. Lobanov
Max Planck Institut for Radio Astronomy; Institute for Experimental Physics
														Email: voitsik@asc.rssi.ru
				                					                																			                												                	Germany, 							69 Auf dem Hügel, Bonn (Endenich), D-53121; Luruper Chaussee 149, Hamburg, D-22761						
A. V. Ipatov
Institute of Applied Astronomy
														Email: voitsik@asc.rssi.ru
				                					                																			                												                	Russian Federation, 							Kutuzovskaya nab. 10, St. Petersburg, 191187						
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