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The OGLE database is revisited to investigate in more detail the properties of the Fourier parameters. Methodological improvements led us to identify a clear separation among High-Amplitude Delta Scuti (HADS), RRc and RRab stars. The…

Astrophysics · Physics 2009-11-06 Ennio Poretti

High-dispersion IUE data encode significant information about aggregate line absorptions that cannot be conveniently extracted from individual spectra. We apply a new technique in which fluxes from each echelle order of a short wavelength…

Astrophysics · Physics 2009-11-06 Myron A. Smith

We study the mean properties of a large representative sample of 217 galaxies showing CIII] emission at $2<z<4$, selected from a parent sample of $\sim$750 main-sequence star-forming galaxies in the VANDELS survey. These CIII] emitters have…

Quasar spectra reveal a rich array of important astrophysical information about galaxies which intersect the quasar line of sight. They also enable tests of the variability of fundamental constants over cosmological time and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Michael T. Murphy , Julian C. Berengut

Red giants show a large number of absorption lines in both optical and near-infrared wavelengths. Still, the characteristics of the lines in different wave passbands are not necessarily the same. We searched for lines of Mg I, Si I, Ca I,…

Synthetic stellar spectra are extensively used for many different applications in astronomy, from stellar studies (such as in the determination of atmospheric parameters of observed stellar spectra), to extragalactic studies (e.g. as one of…

Solar and Stellar Astrophysics · Physics 2017-04-05 Jessica R. Kitamura , Lucimara P. Martins , Paula Coelho

We apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the…

Materials Science · Physics 2021-04-12 Lars Banko , Phillip M. Maffettone , Dennis Naujoks , Daniel Olds , Alfred Ludwig

The spectrum of the Fe I atom is critical to many areas of astrophysics and beyond. Measurements of the energies of its high-lying levels remain woefully incomplete, however, despite extensive analysis of ultraviolet laboratory iron…

Solar and Stellar Astrophysics · Physics 2015-06-19 Ruth C. Peterson , Robert L. Kurucz

Version 11 of the CHIANTI database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si and S), and represent a significant improvement…

Solar and Stellar Astrophysics · Physics 2024-03-26 R. P. Dufresne , G. Del Zanna , P. R. Young , K. P. Dere , E. Deliporanidou , W. T. Barnes , E. Landi

Parameters associated with the collisional perturbation of spectral lines are essential for modeling the absorption of electromagnetic radiation in gas media. The HITRAN molecular spectroscopic database provides these parameters, although…

We present a new database of stellar evolution models for a large range of masses and chemical compositions, based on an up-to-date theoretical framework. We briefly discuss the physical inputs and the assumptions adopted in computing the…

Astrophysics · Physics 2010-12-09 S. Cassisi , A. Pietrinferni , M. Salaris , F. Castelli , D. Cordier , M. Castellani

In this review we discuss possible systematic errors inherent in classical 1D LTE abundance analyses of late-type stars for the light elements (here: H, He, Li, Be and B). The advent of realistic 3D hydrodynamical model atmospheres and the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Martin Asplund , Karin Lind

We present an updated release of the BaSTI (a Bag of Stellar Tracks and Isochrones) stellar model and isochrone library for a solar scaled heavy element distribution. The main input physics changed from the previous BaSTI release include…

Astrophysics of Galaxies · Physics 2018-04-11 S. L. Hidalgo , A. Pietrinferni , S. Cassisi , M. Salaris , A. Mucciarelli , A. Savino , A. Aparicio , V. Silva Aguirre , K. Verma

UV, optical, and near-IR spectra of Vega have been combined to test our understanding of stellar atmospheric opacities, and to examine the possibility of constraining chemical abundances from low-resolution UV fluxes. We have carried out a…

MOL-D database is a collection of cross-sections and rate coefficients for specific collisional processes and a web service within the Serbian Virtual Observatory (SerVO) and the Virtual Atomic and Molecular Data Center (VAMDC). This…

Instrumentation and Methods for Astrophysics · Physics 2016-03-29 V. Vujčić , D. Jevremović , A. A. Mihajlov , Lj. M. Ignjatović , V. A. Srećković , M. S. Dimitrijević , M. Malović

Aims: We generate theoretical ultraviolet and extreme-ultraviolet emission line ratios for O IV and show their strong versatility as electron temperature and density diagnostics for astrophysical plasmas. Methods: Recent fully relativistic…

Solar and Stellar Astrophysics · Physics 2009-11-13 F P Keenan , P J Crockett , K M Aggarwal , D B Jess , M Mathioudakis

Very Large Area gamma-ray Space Telescope (VLAST) is the next-generation flagship space observatory for high-energy gamma-ray detection proposed by China. The observation energy range covers from MeV to TeV and beyond, with acceptance of 10…

For an ensemble of data points in a multi-parameter space, we present a visual analytics technique to select a representative distribution of parameter values, and analyse how representative this distribution is in all ensemble members. A…

Human-Computer Interaction · Computer Science 2020-07-31 Alexander Kumpf , Josef Stumpfegger , Patrick Fabian Härtl , Rüdiger Westermann

The latest version of the HITRAN molecular spectroscopic database, HITRAN2020, has recently been released featuring many updates, including line-by-line broadening parameters (and their temperature dependence) appropriate for the dominant…

Earth and Planetary Astrophysics · Physics 2022-06-22 Frances M. Skinner , Robert J. Hargreaves , Iouli E. Gordon

HII regions play a crucial role in the measurement of the chemical composition of the interstellar medium and provide fundamental data about element abundances that constrain models of galactic chemical evolution. Discrepancies that still…

Solar and Stellar Astrophysics · Physics 2015-11-04 J. A. Weber , A. W. A. Pauldrach , T. L. Hoffmann
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