中文
相关论文

相关论文: On possible proxies of AGN light curves cadence se…

200 篇论文

We have developed two metrics related to AGN variability observables (time-lags, periodicity, and Structure Function (SF)) to evaluate LSST OpSim FBS 1.5, 1.6, 1.7 performance in AGN time-domain analysis. For this purpose, we generate an…

Machine learning is a promising tool to reconstruct time-series phenomena, such as variability of active galactic nuclei (AGN), from sparsely-sampled data. Here we use three Continuous Auto-Regressive Moving Average (CARMA) representations…

高能天体物理现象 · 物理学 2022-04-21 Xinyue Sheng , Nicholas Ross , Matt Nicholl

Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable across the entire electromagnetic spectrum. Upcoming optical…

AGN variability offers a direct probe of accretion physics, disk structure, and black hole growth, but progress has been limited by sample size, cadence heterogeneity, and photometric systematics. The Vera C. Rubin Observatory Legacy Survey…

The Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) will monitor tens of millions of active galactic nuclei (AGNs) for a period of 10 years with an average cadence of 3 days in six broad photometric bands. This…

The survey of the COSMOS field by the VLT Survey Telescope is an appealing testing ground for variability studies of active galactic nuclei (AGN). With 54 r-band visits over 3.3 yr and a single-visit depth of 24.6 r-band mag, the dataset is…

星系天体物理 · 物理学 2021-01-27 D. De Cicco , F. E. Bauer , M. Paolillo , S. Cavuoti , P. Sánchez-Sáez , W. N. Brandt , G. Pignata , M. Vaccari , M. Radovich

In a previous paper, we studied two statistical methods used to analyse the variability of active galactic nuclei (AGNs): the C and F statistics. Applying them to observed differential light-curves of 39 AGNs, we found that, even though the…

星系天体物理 · 物理学 2020-09-02 L. Zibecchi , I. Andruchow , S. A. Cellone , D. D. Carpintero

We present the multi-wavelength and environmental properties of 37 variability-selected active galactic nuclei (AGNs), including 30 low luminosity AGNs (LLAGNs), using a high cadence time-domain survey (ASAS-SN) from a spectroscopic sample…

星系天体物理 · 物理学 2025-01-30 Heechan Yuk , Xinyu Dai , Marko Mićić

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time…

天体物理学 · 物理学 2009-11-13 T. Hovatta , M. Tornikoski , M. Lainela , H. J. Lehto , E. Valtaoja , I. Torniainen , M. F. Aller , H. D. Aller

The Vera C. Rubin Observatory LSST is expected to discover tens of millions of new Active Galactic Nuclei (AGNs). The survey's exceptional cadence and sensitivity will enable UV/optical/NIR monitoring of a significant fraction of these…

The advent of new time domain surveys and the imminent increase in astronomical data expose the shortcomings in traditional time series analysis (such as power spectra analysis) in characterising the abundantly varied, complex and…

星系天体物理 · 物理学 2020-07-22 R. A. Phillipson , P. T. Boyd , A. P. Smale , M. S. Vogeley

Optical variability is a key observational probe for studying the accretion dynamics and central engine physics of Active Galactic Nuclei (AGNs). The quality and completeness of light curves have a direct impact on variability studies,…

星系天体物理 · 物理学 2025-10-31 Jiaqi Lin , Zhen-Ya Zheng , Bin Ma , Lin Long , Yangfan Xie , Pu Lin , Ruqiu Lin , Xiang Ji

A simple, model-independent method to quantify the stochastic variability of active galactic nuclei (AGNs) is the structure function (SF) analysis. If the SF for the timescales shorter than the decorrelation timescale $\tau$ is a single…

星系天体物理 · 物理学 2017-02-08 Szymon Kozłowski

The Active Galactic Nuclei (AGN) glossary is vast and complex. Depending on selection method, observing wavelength, and brightness, AGNs are assigned distinct labels, yet the relationship between different selection methods and the…

Context. Variability is a ubiquitous feature of active galactic nuclei (AGNs), and the characterisation of the variability is crucial to constrain its physical mechanism and proper applications in AGN studies. The advent of all-sky and…

高能天体物理现象 · 物理学 2025-06-04 Heechan Yuk , Xinyu Dai

Over the last years, a number of broadband reverberation mapping campaigns have been conducted to explore the short-term UV and optical variability of nearby AGN. Despite the extensive data collected, the origin of the observed variability…

The study of X-ray time-lag spectra in active galactic nuclei (AGN) is currently an active research area, since it has the potential to illuminate the physics and geometry of the innermost region (i.e. close to the putative super-massive…

天体物理仪器与方法 · 物理学 2016-06-29 A. Epitropakis , I. E. Papadakis

We present the first short time-scale ($\sim$hours to days) optical variability study of a large sample of Active Galactic Nuclei (AGN) observed with the Kepler/K2 mission. The sample contains 252 AGN observed over four campaigns with $\sim…

高能天体物理现象 · 物理学 2018-03-14 E. Aranzana , E. Kording , P. Uttley , S. Scaringi , S. Bloemen

In this study, we demonstrate some of the caveats in common statistical methods used for analysing astronomical variability timescales. We consider these issues specifically in the context of active galactic nuclei (AGNs) and use a more…

星系天体物理 · 物理学 2024-12-12 Sofia Kankkunen , Merja Tornikoski , Talvikki Hovatta

We present a numerical framework for the variability of active galactic nuclei (AGN), which links the variability of AGN over a broad range of timescales and luminosities to the observed properties of the AGN population as a whole, and…

星系天体物理 · 物理学 2019-10-09 Lia F. Sartori , Benny Trakhtenbrot , Kevin Schawinski , Neven Caplar , Ezequiel Treister , Ce Zhang
‹ 上一页 1 2 3 10 下一页 ›