The supermassive black hole (SMBH) binary systems are important for testing the models of SMBH formation, comparing the physics of SMBH merging to gravitational wave (GW) detection, and determining the stochastic GW background at low frequencies, just to name a few.
We present an overview of current efforts on combining information from complementary techniques to detect close binary...
Supermassive black hole binaries lurk, often unseen, in the centers of post-merger galaxies, and numerous electromagnetic surveys are seeking evidence of these dynamic duos’ effects on their host galaxies. In this talk I’ll discuss our recent paper, which analyzed the capabilities of promising methods to search for electromagnetic signatures of supermassive black hole binaries in current and...
Quasar variability is often modeled simplistically as originating from a point-like lamp post geometry with a damped random walk time dependence. We create more realistic simulations of variability propagation through quasar structure using a flexible and physically motivated quasar model that incorporates lensing by the SMBH, disk and broad-line reprocessing, and extended geometry of the...
Active galactic nuclei (AGN) are thought to be powered by the accretion of matter around supermassive black holes at the centers of galaxies. The time-dependent variability of an AGN's brightness can provide valuable insights into the physical characteristics of its underlying black hole. The variability can be well modeled by a damped random walk process described by a stochastic differential...
We present a new tool FANTASY (Fully Automated pythoN Tool for Agn Spectral analYsis) for multicomponent fitting of active galactic nuclei (AGN) spectra in the optical and near infrared wavelength band. Spectra are modeled by simultaneously fitting the underlying broken power-law continuum, predefined emission line (narrow, broad, coronal, etc.) lists, and an Fe II model, which is here...
The emerging all-sky multi-epoch surveys (e.g., ZTF, Rubin LSST) have started a new era of time-domain astronomy. The variable nature of AGN across all wavelengths presents us with unique opportunities to probe AGN physics via time-domain analysis. I will start this talk by reviewing the time-domain analysis techniques, traditional and machine-learning based, currently employed in AGN...
Brightness variations of active galactic nuclei (AGNs) provide an alternative way to identify AGN candidates that could be missed by more traditional selection techniques. In this talk, I will first present a new variability and color-based classifier, designed to identify multiple classes of transients, persistently variable, and non-variable sources, from the Zwicky Transient Facility (ZTF)...
Quasi-periodic eruptions (QPEs) are a novel phenomenon in high-energy astrophysics, and to date have only been confirmed to be observed in a small number of AGN. Characterised by high amplitude variability over relatively short timescales, QPEs have the potential to provide insights into the strong gravity regimes in the innermost regions of the accretion disks around AGN. To provide robust...
Active galactic nuclei (AGN) exhibit small amplitude, short timescale variability in their optical luminosities, of roughly a few tenths of a magnitude over periods of hours to years. But extreme variability of AGN - large luminosity changes that are a significant departure from the baseline variability - are known as AGN flares. These events are rare and their timescales poorly constrained,...
