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(Abridged) Galactic archaeology aims to determine the evolution of the Galaxy from the chemical and kinematical properties of its stars. The analysis of current large spectroscopic surveys (thousands of stars) and future ones (millions of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 G. Kordopatis , A. Recio-Blanco , P. de Laverny , A. Bijaoui , V. Hill , G. Gilmore , R. F. G. Wyse , C. Ordenovic

We describe a scheme to extract linearly supporting (LSU) features from stellar spectra to automatically estimate the atmospheric parameters $T_{eff}$, log$~g$, and [Fe/H]. "Linearly supporting" means that the atmospheric parameters can be…

Solar and Stellar Astrophysics · Physics 2019-03-20 Xiangru Li , Yu Lu , Georges Comte , Ali Luo , Yongheng Zhao , Yongjun Wang

In the past years we have made great efforts to reduce the statistical and systematic uncertainties in stellar parameter and chemical abundance determinations of early B-type stars. Both the construction of robust model atoms for non-LTE…

Solar and Stellar Astrophysics · Physics 2009-02-18 Maria-Fernanda Nieva , Norbert Przybilla

We introduce Bayesian Estimation Applied to Multiple Species (BEAMS), an algorithm designed to deal with parameter estimation when using contaminated data. We present the algorithm and demonstrate how it works with the help of a Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2016-12-07 Martin Kunz , Renée Hlozek , Bruce A. Bassett , Mathew Smith , James Newling , Melvin Varughese

We describe a technique for deriving effective temperatures, surface gravities, rotation velocities, and radial velocities from high resolution near-IR spectra. The technique matches the observed near-IR spectra to spectra synthesized from…

Astrophysics · Physics 2009-11-10 G. W. Doppmann , D. T. Jaffe

We propose an adaptive iteratively linearized finite element method (AILFEM) in the context of strongly monotone nonlinear operators in Hilbert spaces. The approach combines adaptive mesh-refinement with an energy-contractive linearization…

Numerical Analysis · Mathematics 2025-03-18 Ani Miraçi , Dirk Praetorius , Julian Streitberger

We describe methods designed to determine the astrophysical parameters of quasars based on spectra coming from the red and blue spectrophotometers of the Gaia satellite. These methods principally rely on two already published algorithms…

Astrophysics of Galaxies · Physics 2017-09-28 L. Delchambre

In this paper we describe Kea a new spectroscopic fitting method to derive stellar parameters from moderate to low signal/noise, high-resolution spectra. We developed this new tool to analyze the massive data set of the Kepler mission…

Solar and Stellar Astrophysics · Physics 2016-06-29 Michael Endl , William D. Cochran

We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um & ~1mJy at 6.7um. We separate the stellar contribution from the…

Estimating parameters from data is a fundamental problem, customarily done by minimizing a loss function between a model and observed statistics. In scattering-based analysis, researchers often employ their domain expertise to select a…

Computational Physics · Physics 2024-09-05 Mengyang Gu , Yue He , Xubo Liu , Yimin Luo

We present precise photometric estimates of stellar parameters, including effective temperature, metallicity, luminosity classification, distance, and stellar age, for nearly 26 million stars using the methodology developed in the first…

We study the problem of periodicity detection in massive data sets of photometric or radial velocity time series, as presented by ESA's Gaia mission. Periodicity detection hinges on the estimation of the false alarm probability (FAP) of the…

The scarcity of high-fidelity extinction measurements remains a bottleneck in deriving accurate stellar properties from Gaia parallaxes. In this work, we aim to derive precision extinction estimates for APOGEE DR19 stars, establishing a new…

The recovery of an exoplanet's atmospheric parameters from its spectrum requires accurate knowledge of the spectral errors and covariances. Unfortunately, the complex image processing used in high-contrast integral-field spectrograph (IFS)…

Earth and Planetary Astrophysics · Physics 2016-12-14 Johnny P. Greco , Timothy D. Brandt

We introduce ADAM, the All-Data Asteroid Modelling algorithm. ADAM is simple and universal since it handles all disk-resolved data types (adaptive optics or other images, interferometry, and range-Doppler radar data) in a uniform manner via…

Earth and Planetary Astrophysics · Physics 2015-03-18 Matti Viikinkoski , Mikko Kaasalainen , Josef Durech

Along the life of the IUE project, a large archive with spectral data has been generated, requiring automated classification methods to be analyzed in an objective form. Previous automated classification methods used with IUE spectra were…

Astrophysics · Physics 2019-08-15 E. F. Vieira , J. D. Ponz

Adsorption breakthrough modeling often requires complex software environments and scripting, limiting accessibility for many practitioners. We present AIM, a MATLAB-based graphical user interface (GUI) application that streamlines fixed-bed…

This paper reports on the application of the supervised machine-learning algorithm to the stellar effective temperature regression for the second $Gaia$ data release, based on the combination of the stars in four spectroscopic surveys:…

Solar and Stellar Astrophysics · Physics 2019-08-14 Yu Bai , JiFeng Liu , ZhongRui Bai , Song Wang , DongWei Fan

Estimating stellar masses and radii is a challenge for most of the stars but their knowledge is critical for many different astrophysical fields. One of the most extended techniques for estimating these variables are the so-called empirical…

Solar and Stellar Astrophysics · Physics 2022-07-27 Andy Moya , Roberto J. López-Sastre

We report the application of implicit likelihood inference to the prediction of the macro-parameters of strong lensing systems with neural networks. This allows us to perform deep learning analysis of lensing systems within a well-defined…

Instrumentation and Methods for Astrophysics · Physics 2023-01-25 Ronan Legin , Yashar Hezaveh , Laurence Perreault-Levasseur , Benjamin Wandelt