On November 19th, 2019, at the invitation of Astrophysics Group, School of Physical Science and Technology, Nanjing Normal University, Zhenfeng Sheng from University of Science and Technology of China gave an academic report entitled “The changing-Look AGN” at Room K2-436. Teachers and graduate students in related fields took part in the academic report.
Zhenfeng Sheng, graduated from the Department of Astronomy of USTC in 2019. He has been working as a postdoctoral fellow at USTC since 2019. His research interest is the active galactic nuclei.
At the beginning of the report, Dr. Sheng introduced the background of the active galactic nuclei (AGN) and the changing-look AGN. For this peculiar type of AGN, Dr. Sheng gave three usual explanations for these changing-look AGNs: obscured by dust, the sudden increase of black hole accretion rate and tidal disruption event(TDE) respectively.
Next, Dr. Sheng introduced his three recent research works. The first work searched the changing-look AGNs in literature and investigated the mid-infrared properties and mechanism of the changing-look AGNs. The second work was the measurement of the dust torus scale through the reverberation mapping method. The third work, Dr. Sheng, introduced a method to search the changing-look AGNs and selected about 400 candidates. After he observed 7 sources from these candidates, 6 of 7 were identified as changing-look AGNs.
In the report, the response from teachers and students was very enthusiastic. This kind of changeable and mysterious object stimulated everyone interest. This report provides a very good learning opportunity for everyone to understand this field.