Title: X-ray Insights into the Variability and Emission Characteristics of Changing-State AGN NGC 7314
Speaker: Debjit Chatterjee (NTHU)
Date: September 13 at 14:30
Location: R521, General Building II
Abstract:
Active galactic nuclei (AGNs) are deļ¬ned galaxies containing an accreting supermassive black hole. AGNs are classified as type-1 or type-2, depending on the presence or absence of broad optical emission lines. However, the simplest version of this classification scheme has been challenged in recent years, due to the discovery of two classes of highly variable AGN known as changing-obscuration and changing-state AGNs; often lumped together as changing-look AGNs. I will present a detailed analysis of the X-ray properties of NGC 7314, based on observations from XMM-Newton, NuSTAR, and RXTE. We explore the timing variability across different energy bands and discuss the distinct origins of soft and hard X-ray photons. Spectral analysis reveals key features such as a soft energy excess, Fe Kα line emission, and a strong reflection component. Long-term monitoring of the photon index and flux unveils evolving emission properties, potentially indicating NGC 7314 as a changing-state active galactic nucleus.
