2024年11月20日 · The UV/optical light curves observed in active galactic nuclei (AGNs) are well-characterized by damped random walk (DRW) process, with the damping time τd exhibiting correlations with both the black hole mass (MBH) and the photon wavelength (λ).

2023年10月24日 · Measuring the optical variation properties of AGNs, such as variation timescale and amplitude, and then correlating them with their fundamental physical parameters, have long served as a critical way of exploring the origin of AGN variability and the associated physics of the accretion process in AGNs.

2025年3月13日 · In this manuscript, an oversimplified model is proposed to test the effects of intrinsic AGN variability on expected optical quasi-periodic oscillations (QPOs) related to sub-pc binary black hole systems (BBHs) in broad line AGN.

2017年9月21日 · Variability studies of active galactic nuclei (AGNs) typically use either power spectral density (PSD) and structure function (SF) analyses or direct modeling of light curves with the damped random walk (DRW) and the continuous autoregressive moving …

2025年3月20日 · The galaxy does not contain a bright central AGN point source at optical wavelengths, and lacks obvious signs of mergers or interaction with any massive neighbouring galaxy (Bagchi et al. 2014).

2025年2月28日 · Being a ubiquitous characteristic among active galactic nuclei (AGNs), variability is an important aspect of AGNs. For this study, we used different methods to characterize optical AGN variability for various analyses. We first used structure function to characterize the optical variability of galaxies and find which ones are AGN-like.

2023年3月1日 · The optical/UV radiation from the accretion disk is absorbed in the torus and re-emit in the near to mid-IR wavelengths in most of the AGNs. All the primary structures pertaining to BLR, NLR and dusty torus are primarily affected by the X-ray radiation produced in the inner region of the accretion disk.

2020年3月23日 · Optical/near-infrared spectroscopic follow-up of 786 AGN candidates selected using a slightly modified Lacy wedge, together with a requirement for a 24-μm detection, resulted in 527 AGN ...

5 天之前 · The wide-area component of the LOFAR Two-Metre Sky Survey (LoTSS) is currently the largest radio survey ever carried out, and a large fraction of the 4.5 million radio sources it contains have been optically identified with galaxies or quasars with spectroscopic or photometric redshifts. Identification of radio-luminous AGN from this LoTSS source catalogue is not only important from the point ...

AGN/QSO Value-Added Catalog for DESI DR1 Overview This value-added catalog (VAC) includes DESI DR1 galaxies and quasars from all targets (MWS, BGS, LRG, ELG, QSO as well as secondary targets; Myers et al. 2023). The DESI Redrock pipeline (Bailey et al., in prep.) assigns a spectral type (SPECTYPE='STAR', 'GALAXY' or 'QSO') and a redshift (Z) to all spectra. Then the machine-learning algorithm ...