English
Related papers

Related papers: Improved AGN light curve analysis with the z-trans…

200 papers

We present new measurements of the evolution of the X-ray luminosity functions (XLFs) of unabsorbed and absorbed Active Galactic Nuclei (AGNs) out to z~5. We construct samples containing 2957 sources detected at hard (2-7 keV) X-ray…

High Energy Astrophysical Phenomena · Physics 2015-05-11 James Aird , Alison L. Coil , Antonis Georgakakis , Kirpal Nandra , Guillermo Barro , Pablo G. Perez-Gonzalez

In this article we derive the average and the variance of the cross-correlation of a noise wavefield. The noise cross-correlation function (NCF) is widely used to passively estimate the Green's function between two probes and is…

Disordered Systems and Neural Networks · Physics 2015-06-17 Julien de Rosny , Matthieu Davy

Modern astronomical surveys, such as the Zwicky Transient Facility (ZTF), are capable of detecting thousands of transient events per year, necessitating the use of automated and scalable data analysis techniques. Recent advances in machine…

Instrumentation and Methods for Astrophysics · Physics 2025-04-17 Betty X. Hu , Avi Loeb

Image subtraction in astronomy is a tool for transient object discovery and characterization, particularly useful in wide fields, and is well suited for moving or photometrically varying objects such as asteroids, extra-solar planets and…

Instrumentation and Methods for Astrophysics · Physics 2013-01-09 Steven Hartung

Domain adaptive image retrieval includes single-domain retrieval and cross-domain retrieval. Most of the existing image retrieval methods only focus on single-domain retrieval, which assumes that the distributions of retrieval databases and…

Computer Vision and Pattern Recognition · Computer Science 2020-03-09 Fuxiang Huang , Lei Zhang , Yang Yang , Xichuan Zhou

Literature on optical and infrared microvariability in Active Galactic Nuclei (AGNs) reflects a diversity of statistical tests and strategies to detect tiny variations in the lightcurves of these sources. Comparison between the results…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Jose A. de Diego

We used the mark weighted correlation functions (MCFs), $W(s)$, to study the large scale structure of the Universe. We studied five types of MCFs with the weighting scheme $\rho^\alpha$, where $\rho$ is the local density, and $\alpha$ is…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-02 Yizhao Yang , Haitao Miao , Qinglin Ma , Miaoxin Liu , Cristiano G. Sabiu , Jaime Forero-Romero , Yuanzhu Huang , Limin Lai , Qiyue Qian , Yi Zheng , Xiao-Dong Li

Constrained density functional theory (CDFT) is used to evaluate the energy level alignment of a benzene molecule as it approaches a graphene sheet. Within CDFT the problem is conveniently mapped onto evaluating total energy differences…

Mesoscale and Nanoscale Physics · Physics 2016-01-27 Subhayan Roychoudhury , Carlo Motta , Stefano Sanvito

In large-scale traffic optimization, models based on Macroscopic Fundamental Diagram (MFD) are recognized for their efficiency in broad network analyses. However, they fail to reflect variations in the individual traffic status of each road…

Machine Learning · Computer Science 2025-05-20 Zhixiong Jin , Dimitrios Tsitsokas , Nikolas Geroliminis , Ludovic Leclercq

Flexible modelling of the autocovariance function (ACF) is central to time-series, spatial, and spatio-temporal analysis. Modern applications often demand flexibility beyond classical parametric models, motivating non-parametric…

Methodology · Statistics 2025-06-30 Lachlan Astfalck

The orientation-based unification model of active galactic nuclei (AGNs) posits that the principle difference between obscured (Type 2) and unobscured (Type 1) AGNs is the line-of-sight into the central engine. If this model is correct than…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 D. R. Ballantyne

We present a generalised estimator for the autocorrelation function, S-ACF, which is an extended version of the standard estimator of the autocorrelation function (ACF). S-ACF is a versatile definition that can robustly and efficiently…

Instrumentation and Methods for Astrophysics · Physics 2023-05-16 Lars T. Kreutzer , Edward Gillen , Joshua T. Briegal , Didier Queloz

Timing systems based on Analog-to-Digital Converters are widely used in the design of previous high energy physics detectors. In this paper, we propose a new method based on deep learning to extract the time information from a finite set of…

Data Analysis, Statistics and Probability · Physics 2019-04-02 Pengcheng Ai , Dong Wang , Guangming Huang , Ni Fang , Deli Xu , Fan Zhang

We derive an analytic expression for the height correlation function of a rough surface based on the inverse wave scattering method of Kirchhoff theory. The expression directly relates the height correlation function to diffuse scattered…

Optics · Physics 2016-11-02 M. Zamani , F. Shafiei , S. M. Fazeli , M. C. Downer , G. R. Jafari

Stellar activity is one of the primary limitations to the detection of low-mass exoplanets using the radial-velocity (RV) technique. We propose to estimate the variations in shape of the CCF by fitting a Skew Normal (SN) density which,…

Earth and Planetary Astrophysics · Physics 2019-02-13 Umberto Simola , Xavier Dumusque , Jessi Cisewski-Kehe

Force distance curves (FCs) are among the most direct measurements performed in atomic force microscopy (AFM), yet their information content is often reduced by filtering and quasi-static interpretation. Here, enabled by a new…

Mesoscale and Nanoscale Physics · Physics 2026-01-09 Roger Proksch

This is the fifth paper in a series of investigations of the clustering properties of luminous, broad-emission-line active galactic nuclei (AGN) identified in the ROSAT All-Sky Survey (RASS) and Sloan Digital Sky Survey (SDSS). In this work…

Optical imaging quality can be severely degraded by system and sample induced aberrations. Existing adaptive optics systems typically rely on iterative search algorithm to correct for aberrations and improve images. This study demonstrates…

In the area of bearing fault diagnosis, deep learning (DL) methods have been widely used recently. However, due to the high cost or privacy concerns, high-quality labeled data are scarce in real world scenarios. While few-shot learning has…

Machine Learning · Computer Science 2025-09-16 Shengke Sun , Shuzhen Han , Ziqian Luan , Xinghao Qin , Jiao Yin , Zhanshan Zhao , Jinli Cao , Hua Wang

The angular correlation function is a powerful tool for deriving the clustering properties of AGN and hence the mass of the corresponding dark matter halos in which they reside. However, studies based on the application of the angular…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-04 L. Koutoulidis , M. Plionis , I. Georgantopoulos , A. Georgakakis , A. Akylas , S. Basilakos , G. Mountrichas
‹ Prev 1 3 4 5 6 7 10 Next ›