English
Related papers

Related papers: Modeling the Echelle Spectra Continuum with Alpha …

200 papers

Time domain astronomy and the increasing number of exoplanet candidates call for reliable, robust, and automatic wavelength calibration. We present an algorithm for wavelength calibrating \'echelle spectrographs that uses order-by-order…

Instrumentation and Methods for Astrophysics · Physics 2020-06-24 G. M. Brandt , T. D. Brandt , C. McCully

Optimal extraction is a key step in processing the raw images of spectra as registered by two-dimensional detector arrays to a one-dimensional format. Previously reported algorithms reconstruct models for a mean one-dimensional spatial…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 M. Zechmeister , G. Anglada-Escudé , A. Reiners

A new method for the analysis of the scattering rates from angle-resolved photoelectron spectroscopy (ARPES) is presented and described in details. It takes into account experimental instrumental resolution and finite temperature effects.…

Strongly Correlated Electrons · Physics 2022-02-04 R. Kurleto , J. Fink

In this paper, we apply the Feature Space Decomposition (FSD) method developed in [LS24, GLS25, LSSW26, ALSS26] to obtain, under fairly general conditions, matching upper and lower bounds for the population excess risk of spectral methods…

Statistics Theory · Mathematics 2026-05-18 Guillaume Lecué , Zhifan Li , Zong Shang

We focus on an alignment-free method to estimate the underlying signal from a large number of noisy randomly shifted observations. Specifically, we estimate the mean, power spectrum, and bispectrum of the signal from the observations. Since…

Signal Processing · Electrical Eng. & Systems 2018-07-04 Hua Chen , Mona Zehni , Zhizhen Zhao

Finite mixture modelling is a popular method in the field of clustering and is beneficial largely due to its soft cluster membership probabilities. A common method for fitting finite mixture models is to employ spectral clustering, which…

Machine Learning · Statistics 2024-03-22 Liam Welsh , Phillip Shreeves

Unsupervised feature selection (UFS) is an important task in data engineering. However, most UFS methods construct models from a single perspective and often fail to simultaneously evaluate feature importance and preserve their inherent…

Machine Learning · Computer Science 2025-05-28 Jingjing Liu , Xiansen Ju , Xianchao Xiu , Wanquan Liu

Fitting the continuum component of a quasar spectrum in UV/optical band is challenging due to contamination of numerous emission lines. Traditional fitting algorithms such as the least-square fitting and the Levenberg-Marquardt algorithm…

Instrumentation and Methods for Astrophysics · Physics 2013-12-31 Jian Wu , Daniel E. Vanden Berk

Precise continuum normalisation of merged \'{e}chelle spectra is a demanding task necessary for various detailed spectroscopic analyses. Automatic methods have limited effectiveness due to the variety of features present in the spectra of…

Instrumentation and Methods for Astrophysics · Physics 2022-03-30 Tomasz Różański , Ewa Niemczura , Jakub Lemiesz , Natalia Posiłek , Paweł Różański

This paper proposes a novel calibration-free wavelength modulated spectroscopy (WMS) spectral fitting technique based on the firefly algorithm. The technique by simulating the information interaction behavior between fireflies to achieve…

Instrumentation and Detectors · Physics 2022-11-01 Tingting Zhang , Yongjie Sun , Pengpeng Wang , Yufeng Qiu , Chenxi Wang , Xiaohui Du , Shaokai Li , Haixu Liu , Tongwei Chu , Cunguang Zhu

The calculation of the transmission power spectrum of QSO's Lyman alpha absorption requires two parameters for the normalization: the continuum Fc and mean transmission, i.e. average of e^{-tau}. Traditionally, the continuum is obtained by…

Astrophysics · Physics 2009-11-06 Priya Jamkhedkar , Hongguang Bi , Li-Zhi Fang

We present a modelling scheme that predicts the centroids of spectral line features for a high resolution Echelle spectrograph to a high accuracy. Towards this, a computing scheme is used, whereby any astronomical spectrograph can be…

Instrumentation and Methods for Astrophysics · Physics 2015-05-05 Anantha Chanumolu , Damien Jones , Sivarani Thirupathi

We present a novel spectral learning algorithm for simultaneous localization and mapping (SLAM) from range data with known correspondences. This algorithm is an instance of a general spectral system identification framework, from which it…

Machine Learning · Computer Science 2012-07-12 Byron Boots , Geoffrey J. Gordon

Graph matching, typically formulated as a Quadratic Assignment Problem (QAP), seeks to establish node correspondences between two graphs. To address the NP-hardness of QAP, some existing methods adopt projection-based relaxations that embed…

Machine Learning · Computer Science 2025-08-05 Binrui Shen , Yuan Liang , Shengxin Zhu

We have studied the Residual Blaze Functions (RBF) resulting from division of individual echelle orders by extracted flat-field in spectra obtained by slit-fed OES spectrograph of 2m telescope of Ond\v{r}ejov observatory, Czech Republic. We…

Instrumentation and Methods for Astrophysics · Physics 2011-12-20 Petr Škoda , Brankica Šurlan , Sanja Tomić

This paper introduces a fast algorithm, applicable throughout the electromagnetic spectrum, for the numerical solution of problems of scattering by periodic surfaces in two-dimensional space. The proposed algorithm remains highly accurate…

Computational Physics · Physics 2018-05-25 Oscar Bruno , Martín Maas

Spectra observed with the Ultraviolet and Visual Echelle Spectrograph (UVES) on the European Southern Observatory's VLT exhibit long-range wavelength distortions. These distortions impose a systematic error on high-precision measurements of…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-06 Vincent Dumont , John K. Webb

Reconstructing gamma-ray spectra from detector measurements is an ill-posed inverse problem. Standard methods, such as Folding Iteration with Compton Subtraction (FICS), provide point estimates but lack calibrated uncertainties and may bias…

Instrumentation and Detectors · Physics 2025-11-24 E. Lima , L. L. Braseth , A. H. Mjøs , M. Hjorth-Jensen , A. Kvellestad , A. C. Larsen

The rigorous convergence analysis of adaptive finite element methods for regularized variational models of quasi-static brittle fracture in strain-limiting elastic solids is presented. This work introduces two novel adaptive mesh refinement…

Numerical Analysis · Mathematics 2025-11-19 Ram Manohar , S. M. Mallikarjunaiah

Analytic continuation aims to reconstruct real-time spectral functions from imaginary-time Green's functions; however, this process is notoriously ill-posed and challenging to solve. We propose a novel neural network architecture, named the…

Strongly Correlated Electrons · Physics 2024-11-28 Zhe Zhao , Jingping Xu , Ce Wang , Yaping Yang
‹ Prev 1 2 3 10 Next ›