By probing nuclear regions and the overall properties of AGN hosts as a function of their environments, we aim to observationally examine how AGN activities are related to their surroundings. We have selected a representative sample of AGN hosts in the Virgo cluster. The selected galaxies are located in a range of density regions showing various morphologies in 1.4 GHz continuum emission. High-resolution obser- vations with the Korean VLBI Network (KVN) allow us to access the inner region of the AGN without suffering from dust extinction and synchrotron self-absorption. Since a number of our targets are too weak to be detected at K-band (22 GHz) within their coherence time, we applied phase referencing to calibrate fast atmospheric phase uctuations.

ABSTRACT
1. INTRODUCTION
2. SAMPLE SELECTION AND DATA
3. PHASE REFERENCING
4. SUMMARY & DISCUSSION
REFERENCES

• Evangelia Tremou(Department of Astronomy and Yonsei University Observatory, Yonsei University)
• Taehyun Jung(Korea Astronomy and Space Science Institute)
• Aeree Chung(Department of Astronomy and Yonsei University Observatory, Yonsei University)
• Bong Won Sohn(Korea Astronomy and Space Science Institute)