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Accurate redshift calibration is required to obtain unbiased cosmological information from large-scale galaxy surveys. In a forward modelling approach, the redshift distribution n(z) of a galaxy sample is measured using a parametric galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Beatrice Moser , Tomasz Kacprzak , Silvan Fischbacher , Alexandre Refregier , Dominic Grimm , Luca Tortorelli

Approximate Bayesian computation (ABC) refers to a family of inference methods used in the Bayesian analysis of complex models where evaluation of the likelihood is difficult. Conventional ABC methods often suffer from the curse of…

Computation · Statistics 2016-07-08 Jingjing Li , David J. Nott , Yanan Fan , Scott A. Sisson

In this study, we present a modelling of the X-ray emission from the simulated SMBHs within the cosmological hydrodynamical Magneticum Pathfinder Simulation, in order to study the statistical properties of the resulting X-ray Active…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-26 V. Biffi , K. Dolag , A. Merloni

We introduce an ordinal classification algorithm for photometric redshift estimation, which significantly improves the reconstruction of photometric redshift probability density functions (PDFs) for individual galaxies and galaxy samples.…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-20 Markus Michael Rau , Stella Seitz , Fabrice Brimioulle , Eibe Frank , Oliver Friedrich , Daniel Gruen , Ben Hoyle

The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 D. Emmanoulopoulos , I. M. McHardy , I. E. Papadakis

We present a novel, general-purpose method for deconvolving and denoising images from gridded radio interferometric visibilities using Bayesian inference based on a Gaussian process model. The method automatically takes into account…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 P. M. Sutter , Benjamin D. Wandelt , Jason D. McEwen , Emory F. Bunn , Ata Karakci , Andrei Korotkov , Peter Timbie , Gregory S. Tucker , Le Zhang

The Poisson distribution arises naturally when dealing with data involving counts, and it has found many applications in inverse problems and imaging. In this work, we develop an approximate Bayesian inference technique based on expectation…

Numerical Analysis · Mathematics 2019-09-04 Chen Zhang , Simon Arridge , Bangti Jin

We present a large sample of infrared-luminous candidate active galactic nuclei (AGNs) that lack X-ray detections in Chandra, XMM-Newton, and NuSTAR fields. We selected all optically detected SDSS sources with redshift measurements,…

This paper introduces a Bayesian framework for image inversion by deriving a probabilistic counterpart to the regularization-by-denoising (RED) paradigm. It additionally implements a Monte Carlo algorithm specifically tailored for sampling…

Machine Learning · Statistics 2024-02-20 Elhadji C. Faye , Mame Diarra Fall , Nicolas Dobigeon

Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spectral power from x-ray sources, but uniquely extracting spectral content from a finite set of broad, spectrally overlapping channel spectral…

Computational Physics · Physics 2020-08-03 G. E. Kemp , M. S. Rubery , C. D. Harris , M. J. May , K. Widmann , R. F. Heeter , S. B. Libby , M. B. Schneider , B. E. Blue

We model the evolution of active galactic nuclei by constructing their radio luminosity functions. We use a set of surveys of varying area and depth, namely the deep COSMOS survey of $1,916$ AGN sources, the wide shallow 3CRR, 7C and 6CE…

Astrophysics of Galaxies · Physics 2023-12-25 B. Šlaus , V. Smolcic , Ž. Ivezic , S. Fotopoulou , C. J. Willott , P. Pendo , C. Vignali , L. Chiappetti , M. Pierre

We report on the spectral properties of a sample of 90 hard X-ray selected serendipitous sources detected in 12 XMM observations with 1<F(2-10)<80 10^(-14) erg/cm2/s. Approximately 40% of the sources are optically identified with 0.1<z<2…

Astrophysics · Physics 2009-11-10 E. Piconcelli , M. Cappi , L. Bassani , G. Di Cocco , M. Dadina

We present a multi-fidelity method for uncertainty quantification of parameter estimates in complex systems, leveraging generative models trained to sample the target conditional distribution. In the Bayesian inference setting, traditional…

Machine Learning · Computer Science 2025-04-03 Caroline Tatsuoka , Minglei Yang , Dongbin Xiu , Guannan Zhang

We have incorporated the description of the X-ray properties of Active Galactic Nuclei (AGNs) into a semi-analytic model of galaxy formation, adopting physically motivated scaling laws for accretion triggered by galaxy encounters. Our model…

Astrophysics · Physics 2009-11-10 N. Menci , F. Fiore , G. C. Perola , A. Cavaliere

X-ray reflectivity (XRR) is widely used for thin-film structure analysis, and XRR data analysis involves minimizing the difference between an XRR curve calculated from model parameters describing the thin-film structure. This analysis takes…

Disordered Systems and Neural Networks · Physics 2022-03-31 Kook Tae Kim , Dong Ryeol Lee

This paper presents a research study focused on uncovering the hidden population distribution from the viewpoint of a variational non-Bayesian approach. It asserts that if the hidden probability density function (PDF) has continuous partial…

Statistics Theory · Mathematics 2023-11-02 U Jin Choi , Kyung Soo Rim

A robust uncertainty estimate in global analyses of Parton Distribution Functions (PDFs) is essential at the Large Hadron Collider (LHC), especially in view of the high-precision data anticipated by experimentalists in the High-Luminosity…

High Energy Physics - Phenomenology · Physics 2026-04-14 Mark N. Costantini , Luca Mantani , James M. Moore , Maria Ubiali

In the context of the upcoming SRG/eROSITA survey, we present an N-body simulation-based mock catalogue for X-ray selected AGN samples. The model reproduces the observed hard X-ray AGN luminosity function (XLF) and the soft X-ray logN-logS…

The aim of this paper is to study the stellar population of galaxies hosting an active galactic nucleus (AGN). We studied a sub-sample of hard X-ray emitting AGNs from the INTEGRAL and Swift catalogs which were previously identified and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 L. Morelli , V. Calvi , N. Masetti , P. Parisi , R. Landi , E. Maiorano , D. Minniti , G. Galaz

We investigate the nature of the faint X-ray source population through X-ray spectroscopy and variability analyses of 136 AGN detected in the 2 Ms Chandra Deep Field-North survey with > 200 background-subtracted 0.5-8.0 keV counts…