English
Related papers

Related papers: Reconstructing AGN X-ray spectral parameter distri…

200 papers

We present here RadioSED, a Bayesian inference framework tailored to modelling and classifying broadband radio spectral energy distributions (SEDs) using only data from publicly-released, large-area surveys. We outline the functionality of…

Astrophysics of Galaxies · Physics 2024-12-10 Emily F. Kerrison , James R. Allison , Vanessa A. Moss , Elaine M. Sadler , Glen A. Rees

Approximate Bayesian Computation (ABC) methods are commonly used to approximate posterior distributions in models with unknown or computationally intractable likelihoods. Classical ABC methods are based on nearest neighbor type algorithms…

Methodology · Statistics 2025-06-24 Meili Baragatti , Casenave Céline , Bertrand Cloez , David Métivier , Isabelle Sanchez

When modeling a probability distribution with a Bayesian network, we are faced with the problem of how to handle continuous variables. Most previous work has either solved the problem by discretizing, or assumed that the data are generated…

Machine Learning · Computer Science 2013-02-21 George H. John , Pat Langley

Combining multiple events into population analyses is a cornerstone of gravitational-wave astronomy. A critical component of such studies is the assumed population model, which can range from astrophysically motivated functional forms to…

High Energy Astrophysical Phenomena · Physics 2025-05-21 Cecilia Maria Fabbri , Davide Gerosa , Alessandro Santini , Matthew Mould , Alexandre Toubiana , Jonathan Gair

Monte Carlo methods are often necessary for the implementation of optimal Bayesian estimators. A fundamental technique that can be used to generate samples from virtually any target probability distribution is the so-called rejection…

Computation · Statistics 2011-11-22 Luca Martino , Joaquín Míguez

The "Cosmic Evolution Survey" (COSMOS) enables the study of the Spectral Energy Distributions (SEDs) of Active Galactic Nuclei (AGN) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present a SED…

We present a new Bayesian algorithm making use of Markov Chain Monte Carlo sampling that allows us to simultaneously estimate the unknown continuum level of each quasar in an ensemble of high-resolution spectra, as well as their common…

Astrophysics of Galaxies · Physics 2017-08-09 Anna-Christina Eilers , Joseph F. Hennawi , Khee-Gan Lee

In image reconstruction, an accurate quantification of uncertainty is of great importance for informed decision making. Here, the Bayesian approach to inverse problems can be used: the image is represented through a random function that…

Numerical Analysis · Mathematics 2025-04-24 Jonas Latz , Aretha L. Teckentrup , Simon Urbainczyk

We present a novel Bayesian method for the joint reconstruction of cosmological matter density fields, peculiar velocities and power-spectra in the quasi-nonlinear regime. We study its applicability to the Ly-alpha forest based on multiple…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Francisco-Shu Kitaura , Simona Gallerani , Andrea Ferrara

Background: Continuous traits evolution of a group of taxa that are correlated through a phylogenetic tree is commonly modelled using parametric stochastic differential equations to represent deterministic change of trait through time,…

Populations and Evolution · Quantitative Biology 2026-04-03 Bayu Brahmantio , Krzysztof Bartoszek , Etka Yapar

We compiled a sample of 95 AGNs serendipitously detected in the 3-20 keV band at Galactic latitude |b|>10 during the RXTE slew survey (XSS, Revnivtsev et al.), and utilize it to study the statistical properties of the local population of…

Astrophysics · Physics 2009-11-10 S. Sazonov , M. Revnivtsev

This paper investigates what constraints can be placed on the fraction of Compton-thick (CT) AGN in the Universe from the modeling of the spectrum of the diffuse X-ray background (XRB). We present a model for the synthesis of the XRB that…

High Energy Astrophysical Phenomena · Physics 2015-06-11 A. Akylas , A. Georgakakis , I. Georgantopoulos , M. Brightman , K. Nandra

Bayesian methods are a popular choice for statistical inference in small-data regimes due to the regularization effect induced by the prior. In the context of density estimation, the standard nonparametric Bayesian approach is to target the…

Machine Learning · Statistics 2023-02-21 Sahra Ghalebikesabi , Chris Holmes , Edwin Fong , Brieuc Lehmann

Changes in population size influence genetic diversity of the population and, as a result, leave a signature of these changes in individual genomes in the population. We are interested in the inverse problem of reconstructing past…

Methodology · Statistics 2015-03-19 Julia A. Palacios , Vladimir N. Minin

The Two Micron All Sky Survey (2MASS) is finding previously unidentified, luminous red active galactic nuclei (AGN). This new sample has a space density similar to, or greater than, previously known AGN, suggesting that a large fraction of…

We study the comoving space density of X-ray-selected luminous active galactic nuclei (AGNs) and the obscured AGN fraction at high redshifts ($3 < z < 5$) in the Subaru/{\it XMM-Newton} Deep Survey (SXDS) field. From an X-ray source catalog…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Kazuo Hiroi , Yoshihiro Ueda , Masayuki Akiyama , Mike G. Watson

The assembly and co-evolution of supermassive black holes (SMBH) and their host galaxy stellar population is a key open questions in galaxy evolution. Stellar mass ($M_\star$) and star formation rate (SFR), are inferred by modeling the…

We present a compression algorithm for parton densities using synthetic replicas generated from the training of a Generative Adversarial Network (GAN). The generated replicas are used to further enhance the statistics of a given Monte Carlo…

High Energy Physics - Phenomenology · Physics 2021-07-07 Stefano Carrazza , Juan M. Cruz-Martinez , Tanjona R. Rabemananjara

To infer the parameters of mechanistic models with intractable likelihoods, techniques such as approximate Bayesian computation (ABC) are increasingly being adopted. One of the main disadvantages of ABC in practical situations, however, is…

Computation · Statistics 2018-08-03 Jonathan U Harrison , Ruth E Baker

Active galactic nuclei (AGN) are typically identified through their distinctive X-ray or radio emissions, mid-infrared (MIR) colors, or emission lines. However, each method captures different subsets of AGN due to signal-to-noise (SNR)…

‹ Prev 1 8 9 10 Next ›