MEASURING THE CORE SHIFT EFFECT IN AGN JETS WITH THE EXTENDED KOREAN VLBI NETWORK

作者：Jung Taehyun^*; Dodson Richard; Han Seog Tae; Rioja Maria J; Byun Do Young; Honma Mareki; Stevens Jamie; de Vicente Pablo; Sohn Bong Won

来源：Journal of the Korean Astronomical Society, 2015, 48(5): 277-284.

DOI：10.5303/JKAS.2015.48.5.277

• techniques: interferometeric
• astrometry
• high angular resolution
• radio continuum: active galactic nuclei

We present our efforts for extending the simultaneous multi-frequency receiver system of the Korean Very Long Baseline Interferometry (VLBI) Network (KVN) to global baselines in order to measure the frequency-dependent position shifts in Active Galactic Nuclei (AGN) jets, the so called core shift effect, with an unprecedented accuracy (a few micro-arcseconds). Millimeter VLBI observations with simultaneous multi-frequency receiver systems, like those of the KVN, enable us to explore the innermost regions of AGN and high precision astrometry. Such a system is capable of locating the frequency dependent opacity changes accurately. We have conducted the feasibility test-observations with the interested partners by implementing the KVN-compatible systems. Here we describe the science case for measuring the core shift effect in the AGN jet and report progress and future plans on extending the simultaneous multi-frequency system to global baselines.

• 出版日期2015-10-31
• 单位CSIRO, Australia; 中国科学院国家天文台