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Related papers: Spectral Classification; Old and Contemporary

200 papers

We investigate the use of dimensionality reduction techniques for the classification of stellar spectra selected from the SDSS. Using local linear embedding (LLE), a technique that preserves the local (and possibly non-linear) structure…

Solar and Stellar Astrophysics · Physics 2011-11-16 Scott F. Daniel , Andrew J. Connolly , Jeff Schneider , Jake Vanderplas , Liang Xiong

We proposed a machine learning approach to identify and distinguish dusty stellar sources employing supervised and unsupervised methods and categorizing point sources, mainly evolved stars, using photometric and spectroscopic data collected…

Spectral analysis in conjunction with discrete data in one and more dimensions can become a challenging task, because the methods are sometimes difficult to understand. This paper intends to provide an overview about the usage of the…

Methodology · Statistics 2017-08-01 Martin Seilmayer , Matthias Ratajczak

The study of stellar populations is a discipline that is highly dependent on both imaging and spectroscopy. I discuss techniques in different regimes of resolving power: broadband imaging (R~4), intermediate band imaging (R~16, 64),…

Astrophysics · Physics 2009-11-13 Joss Bland-Hawthorn

The growth of sky surveys and the large amount of stellar spectra in the current databases, has generated the necessity of developing new methods to estimate atmospheric parameters, a fundamental task on stellar research. In this work we…

Instrumentation and Methods for Astrophysics · Physics 2022-06-27 Miguel Flores R. , Luis J. Corral , Celia R. Fierro-Santillán

Expanded lecture notes. Preliminary version, comments are welcome.

Combinatorics · Mathematics 2018-05-31 Bogdan Nica

The current need for atomic data to model stellar spectra obtained in various wavelength ranges is described. The level of completeness and accuracy of these data is discussed.

Instrumentation and Methods for Astrophysics · Physics 2015-10-01 R. Monier

Over the last half-century quantitative stellar spectroscopy has made great progress. However, most stellar abundance analyses today still employ rather simplified models, which can introduce severe systematic errors swamping the…

Astrophysics · Physics 2007-05-23 Martin Asplund

Linear (spectro) polarimetry is usually performed using separate photon flux measurements after spatial or temporal polarization modulation. Such classical polarimeters are limited in sensitivity and accuracy by systematic effects and…

Optics · Physics 2010-05-28 Frans Snik , Theodora Karalidi , Christoph U. Keller

Spectral evolution models are a widely used tool for determining the stellar content of galaxies. I provide a review of the latest developments in stellar atmosphere and evolution models, with an emphasis on massive stars. In contrast to…

Solar and Stellar Astrophysics · Physics 2015-05-14 Claus Leitherer

In this paper, we present a deep learning system approach to estimating luminosity, effective temperature, and surface gravity of O-type stars using the optical region of the stellar spectra. In previous work, we compare a set of machine…

Instrumentation and Methods for Astrophysics · Physics 2022-10-31 Miguel Flores R. , Luis J. Corral , Celia R. Fierro-Santillán , Silvana G. Navarro

We give a summary on spectral techniques for finite dimensional algebras and study its link to singularity theory. In particular, we offer a contribution to the categorification of the Milnor lattice of two-dimensional singularities through…

Representation Theory · Mathematics 2008-05-08 Helmut Lenzing , Jose Antonio de la Pena

The use of a method of spectra disentangling for telluric lines is explained in detail, with a particular emphasis on high-precision radial-velocity measurements for the search for extrasolar planets. New improvements to the method are…

Astrophysics · Physics 2009-11-11 Petr Hadrava

While Spectral Methods have long been used for Principal Component Analysis, this survey focusses on work over the last 15 years with three salient features: (i) Spectral methods are useful not only for numerical problems, but also discrete…

Data Structures and Algorithms · Computer Science 2010-04-09 Ravindran Kannan

Discussion of the designation of multiple-star components leads to a conclusion that, apart from components, we need to designate systems and centers-of-mass. The hierarchy is coded then by simple links to parent. This system is adopted in…

Astrophysics · Physics 2007-05-23 A. Tokovinin

The well-known age-metallicity-attenuation degeneracy does not permit unique and good estimates of basic parameters of stars and stellar populations. The effects of dust can be avoided using spectral line indices, but current methods have…

Instrumentation and Methods for Astrophysics · Physics 2020-02-03 Lino H. Rodriguez-Merino , Y. D. Mayya , Paula R. T. Coelho , Gustavo Bruzual , Stephane Charlot , Esperanza Carrasco , Armando Gil de Paz

We define and study a numerical-range analogue of the notion of spectral set. Among the results obtained are a positivity criterion and a dilation theorem, analogous to those already known for spectral sets. An important difference from the…

Functional Analysis · Mathematics 2017-01-23 Hubert Klaja , Javad Mashreghi , Thomas Ransford

An algorithm is presented which generates pairs of oscillatory random time series which have identical periodograms but differ in the number of oscillations. This result indicate the intrinsic limitations of spectral methods when it comes…

Data Analysis, Statistics and Probability · Physics 2007-05-23 A. G. Rossberg

The spectral energy distribution (SED) of observed stars in wide-field images is crucial for chromatic point spread function (PSF) modelling methods, which use unresolved stars as integrated spectral samples of the PSF across the field of…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 Ezequiel Centofanti , Samuel Farrens , Jean-Luc Starck , Tobias Liaudat , Alex Szapiro , Jennifer Pollack

Spectral-spatial processing has been increasingly explored in remote sensing hyperspectral image classification. While extensive studies have focused on developing methods to improve the classification accuracy, experimental setting and…

Computer Vision and Pattern Recognition · Computer Science 2017-03-08 Jie Liang , Jun Zhou , Yuntao Qian , Lian Wen , Xiao Bai , Yongsheng Gao