26-30 June 2023
Centro Congressi Federico II
Europe/Rome timezone

Studying Changing-Look AGNs using variability and light curves

Not scheduled
Aula Magna (Centro Congressi Federico II)

Aula Magna

Centro Congressi Federico II

Via Partenope, 36, Napoli, Italy
Poster Poster


Shu Wang (Seoul National University)


The discovery of ~100 changing-look AGNs, i.e., changing their optical spectral types between type-I and II, challenges the AGNs unified model that uses the orientation to explain the difference between these two AGN subclasses. Recent works demonstrate that the large difference in the optical variability between type-I and type-II AGNs can be used to distinguish these two spectral types. We took MDM and Gemini spectra of a dozen of AGNs currently showing light curves inconsistent with their known types in the literatures, classified by light curve classifier ${\it qsofit}$ using ZTF light curves from our independent analysis. We successfully obtain a sample of new H beta changing-look AGNs, many of which still have weak broad H$\alpha$ line in their faint states, indicating that they are weak type-I AGNs. Our results favour the large change in the accretion rates to be responsible for the appearance/disappearance of the H$\beta$ profiles of these objects. We will briefly discuss the typical timescale and Eddington ratios of changing-look AGNs using our sample.

Primary authors

Shu Wang (Seoul National University) Prof. Jong-Hak Woo (Seoul National University) Hengxiao Guo

Presentation Materials

There are no materials yet.
Your browser is out of date!

Update your browser to view this website correctly. Update my browser now