A5071677132- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Academic Publishing and Open Access
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Gaussian Processes and Bayesian Inference
Institute of High Energy Physics
2023-2024
Chinese Academy of Sciences
2023-2024
University of Chinese Academy of Sciences
2023-2024
China Spallation Neutron Source
2023
Abstract Changing-look active galactic nuclei (CL-AGNs), characterized by the emergence or disappearance of broad lines accompanied extreme continuum flux variability, have drawn much attention for their potential to reveal physical processes underlying AGN evolution. We perform seven-season spectroscopic monitoring on Mrk1018, one earliest identified CL-AGN. Around 2020, we detect a full-cycle changing-look transition Mrk 1018 within year, associated with nucleus outburst, which likely...
We report the results of long-term reverberation mapping (RM) campaigns nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022, based on archived observations FAST Spectrograph Publicly Archived Programs and our new with 2.3m telescope at Wyoming Infrared Observatory. reduce calibrate all spectra in a consistent way, derive light curves broad H$\beta$ line 5100\,{\AA} continuum. Continuum are also constructed using public archival photometric data increase sampling...
ABSTRACT We conduct a systematic search for quasars with periodic variations from the archival photometric data of Zwicky Transient Facility by cross-matching quasar catalogues Sloan Digital Sky Survey and Véron-Cetty Véron. first select out 184 primitive candidates using generalized Lomb–Scargle periodogram autocorrelation function then estimate their statistical significance periodicity based on two red-noise models, i.e. damped random walk (DRW) single power-law (SPL) models. As such, we...
Abstract We report first-time reverberation-mapping results for 14 active galactic nuclei (AGNs) from the ongoing Monitoring AGNs with H β Asymmetry campaign (MAHA). These utilize optical spectra obtained Long Slit Spectrograph on Wyoming Infrared 2.3 m Telescope between 2017 November and 2023 May. MAHA combines long-duration monitoring high cadence. multiple observing seasons nine of objects. include time lags, supermassive black hole masses, velocity-resolved lags. The lags allow us to...
Abstract Strong iron lines are a common feature of the optical spectra active galactic nuclei (AGNs) and quasars from z ∼ 6−7 to local universe, [Fe/Mg] ratios do not show cosmic evolution. During episodes, accretion disks surrounding supermassive black holes (SMBHs) inevitably form stars in self-gravitating part, these accrete with high rates. In this paper, we investigate population evolution accretion-modified (AMSs) produce magnesium AGNs. The AMSs, as new type star, allowed have any...
ABSTRACT We compile optical and mid-infrared light curves from the time-domain surveys (i.e. CRTS, PTF, ZTF, ASAS-SN) Wide-field Infrared Survey Explorer (WISE) archive for a selected sample of active galactic nuclei (AGNs) with Hβ reverberation mapping (RM) measurements. measure time lags (and thus torus sizes) W1 (∼3.4 $\mu$ m) W2 (∼4.6 band relative to one using MICA method. Through RM, has well-measured AGN properties, therefore allowing us reliably constrain relations between sizes...
Abstract Over the past three decades, multiple reverberation mapping (RM) campaigns conducted for quasar PG 2130+099 have exhibited inconsistent findings with time delays ranging from ∼10 to ∼200 days. To achieve a comprehensive understanding of geometry and dynamics broad-line region (BLR) in 2130+099, we continued an ongoing high-cadence RM monitoring campaign using Calar Alto Observatory 2.2 m optical telescope extra four years 2019 2022. We measured lags several broad emission lines...
Abstract We present a noteworthy transient AT 2021aeuk exhibiting three distinct optical flares between 2018 and 2023. It is hosted in radio-loud narrow-line Seyfert 1 galaxy, with an image showing minor tidal morphology red mid-infrared color ( W − 2 = 1.1). Flares II III exhibit rapid rises, long-term decays (≳1000 days) recurring after-peak bumps. The g r after subtracting the reference magnitude exhibited drop recovery during Flare II, followed by evolution blue colors. applied canonical...
In our previous study, we identified a shift in the synchrotron peak frequency of blazar B2 1308$+$326 from 10$^{12.9}$ Hz to 10$^{14.8}$ during flare, suggesting it could be changing-look (CLB). this work, investigate CL behaviour 1308+326 by analysing newly acquired optical spectrum and comparing with an archival spectrum. We find that between two epochs, continuum flux increased factor $\sim$4.4, while Mg II emission line decreased 1.4$\pm$0.2. Additionally, equivalent width reduced $\sim...
Abstract In our previous study, we identified a shift in the synchrotron peak frequency of blazar B2 1308+326 from 10 12.9 to 14.8 Hz during flare, suggesting it could be changing-look (CLB). this work, investigate behaviour by analysing newly acquired optical spectrum and comparing with an archival spectrum. We find that between two epochs, continuum flux increased factor ~4.4, while Mg ii emission line decreased 1.4 ± 0.2. Additionally, equivalent width reduced ~20 ~3 Å, indicating...