| Abstract: |
Recent multi-band observations have found that galaxies with suppressed star formation activity exist even in the high redshift universe. The state-of-art spectrograph has now confirmed them up to z~4. On the other hand, it is not well understood why they get quenched at such a high redshift, even though the cold streams are expected to supply gas. One of the preferable causes is the feedback from active galactic nuclei (AGNs). To explore the connection between quenching and AGN activity, it is beneficial to constrain the properties of quiescent galaxies in the multi-wavelength. I will introduce our recent work of stacking X-ray and radio images for massive quiescent galaxies up to z~5, which uses the latest COSMOS2020 catalog and the deep Chandra and VLA survey. |
