English
Related papers

Related papers: The ILIUM forward modelling algorithm for multivar…

200 papers

Context. An increasing number of high-resolution stellar spectra is available today thanks to many past and ongoing extensive spectroscopic surveys. Consequently, the scientific community needs automatic procedures to derive atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2014-10-01 S. Blanco-Cuaresma , C. Soubiran , U. Heiter , P. Jofré

We present a novel method for both forecasting and recasting upper limits (ULs) on dark matter (DM) annihilation cross sections, $\left< \sigma v \right>^{UL}$, or decay lifetime $\tau^{LL}$ . The forecasting method relies solely on the…

High Energy Astrophysical Phenomena · Physics 2025-11-04 Giacomo D'Amico , Michele Doro , Michela De Caria

Context. Kinematical data such as the mean velocities and velocity dispersions of stellar samples are useful tools to study galactic structure and evolution. However, observational data are often incomplete (e.g., lacking the radial…

Instrumentation and Methods for Astrophysics · Physics 2013-02-19 Toktam Aghajani , Lennart Lindegren

We study Bayesian methods for large-scale linear inverse problems, focusing on the challenging task of hyperparameter estimation. Typical hierarchical Bayesian formulations that follow a Markov Chain Monte Carlo approach are possible for…

Numerical Analysis · Mathematics 2024-01-05 Khalil A Hall-Hooper , Arvind K Saibaba , Julianne Chung , Scot M Miller

Aims. This paper introduces LRPayne, a novel algorithm designed for the efficient determination of stellar parameters and chemical abundances from low-resolution optical spectra, with a primary focus on data from large-scale galactic…

Solar and Stellar Astrophysics · Physics 2026-02-18 Nagaraj Vernekar , Lorenzo Spina , Sara Lucatello , Carmelo Arcidiacono , Luca Cortese , Matteo Simioni , Andrea Balestra

Rapid parameter estimation is critical when dealing with short lived signals such as kilonovae. We present a parameter estimation algorithm that combines likelihood-free inference with a pre-trained embedding network, optimized to…

Instrumentation and Methods for Astrophysics · Physics 2025-06-27 Malina Desai , Deep Chatterjee , Sahil Jhawar , Philip Harris , Erik Katsavounidis , Michael Coughlin

We introduce NEIDSpecMatch, a tool developed to extract stellar parameters from spectra obtained with the NEID spectrograph. NEIDSpecMatch is based on SpecMatch-Emp and HPFSpecMatch, which estimate stellar parameters by comparing the…

In the case of ground-based telescopes equipped with adaptive optics systems, the point spread function (PSF) is only poorly known or completely unknown. Moreover, an accurate modeling of the PSF is in general not available. Therefore in…

Numerical Analysis · Mathematics 2015-06-09 M. Prato , A. La Camera , S. Bonettini , S. Rebegoldi , M. Bertero , P. Boccacci

We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in…

Solar and Stellar Astrophysics · Physics 2020-09-02 Phillip A. Cargile , Charlie Conroy , Benjamin D. Johnson , Yuan-Sen Ting , Ana Bonaca , Aaron Dotter , Joshua S. Speagle

The advent of space-based observatories such as CoRoT and Kepler has enabled the testing of our understanding of stellar evolution on thousands of stars. Evolutionary models typically require five input parameters, the mass, initial Helium…

Solar and Stellar Astrophysics · Physics 2016-09-07 Kuldeep Verma , Shravan Hanasoge , Jishnu Bhattacharya , H M Antia , Ganapathy Krishnamurthi

Mega-pixel charge-integrating detectors are common in near-IR imaging applications. Optimal signal-to-noise ratio estimates of the photocurrents, which are particularly important in the low-signal regime, are produced by fitting linear…

Instrumentation and Methods for Astrophysics · Physics 2016-06-16 Michael Zemcov , Brendan Crill , Matthew Ryan , Zak Staniszewski

A flood of reliable seismic data will soon arrive. The migration to larger telescopes on the ground may free up 4-m class instruments for multi-site campaigns, and several forthcoming satellite missions promise to yield nearly uninterrupted…

Astrophysics · Physics 2007-05-23 Travis S. Metcalfe

The majority of research on efficient and scalable algorithms in computational science and engineering has focused on the forward problem: given parameter inputs, solve the governing equations to determine output quantities of interest. In…

Optimization and Control · Mathematics 2015-11-05 Tobin Isaac , Noemi Petra , Georg Stadler , Omar Ghattas

We extend the Bayesian model fitting shape measurement method presented in Miller et al. (2007) and use the method to estimate the shear from the Shear TEsting Programme simulations (STEP). The method uses a fast model fitting algorithm…

Astrophysics · Physics 2009-11-13 T. D. Kitching , L. Miller , C. E. Heymans , L. van Waerbeke , A. F. Heavens

New generation large-aperture telescopes, multi-object spectrographs, and large format detectors are making it possible to acquire very large samples of stellar spectra rapidly. In this context, traditional star-by-star spectroscopic…

Stellar distances constitute a foundational pillar of astrophysics. The publication of 1.47 billion stellar parallaxes from Gaia is a major contribution to this. Yet despite Gaia's precision, the majority of these stars are so distant or…

Solar and Stellar Astrophysics · Physics 2021-02-26 C. A. L. Bailer-Jones , J. Rybizki , M. Fouesneau , M. Demleitner , R. Andrae

We implemented non-solar-scaled opacities in a simultaneous derivation of fundamental parameters and abundances. We carried out a high-precision stellar parameters and abundance determination by applying non-solar-scaled opacities and model…

Solar and Stellar Astrophysics · Physics 2018-12-05 C. Saffe , M. Flores , P. Miquelarena , F. M. Lopez , M. Jaque Arancibia , A. Collado , E. Jofre , R. Petrucci

The performance of data fusion and tracking algorithms often depends on parameters that not only describe the sensor system, but can also be task-specific. While for the sensor system tuning these variables is time-consuming and mostly…

Machine Learning · Computer Science 2024-01-29 André Brandenburger , Folker Hoffmann , Alexander Charlish

In this paper we study the computation of the nonparametric maximum likelihood estimator (NPMLE) in multivariate mixture models. Our first approach discretizes this infinite dimensional convex optimization problem by fixing the support…

Methodology · Statistics 2024-02-20 Yangjing Zhang , Ying Cui , Bodhisattva Sen , Kim-Chuan Toh

The complexity of constraining the stellar initial mass function (IMF) in early-type galaxies cannot be overstated, given the necessity of both very high signal-to-noise (S/N) data and the difficulty of breaking the strong degeneracies that…

Astrophysics of Galaxies · Physics 2021-10-27 Ilaria Lonoce , Anja Feldmeier-Krause , Wendy L. Freedman