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Context: Studies of extremely metal-poor stars indicate that chemical abundance ratios [X/Fe] have an rms scatter as low as 0.05 dex (12 \%). It remains unclear whether this reflects observational uncertainties or intrinsic astrophysical…

Solar and Stellar Astrophysics · Physics 2016-03-09 Henrique Reggiani , Jorge Meléndez , David Yong , Ivan Ramírez , Martin Asplund

Accurate wavelength calibration is critical for qualitative and quantitative spectroscopic measurements. Many spectrometers for planetary exploration are equipped with onboard calibration sources. However, such calibration sources are not…

Aims: We aim to extend our current observational understanding of the integrated planet Earth spectropolarimetry from the optical to the near-infrared wavelengths. Major biomarkers like O$_{\rm 2}$ and water vapor are strong flux absorbents…

Earth and Planetary Astrophysics · Physics 2015-06-18 P. A. Miles-Páez , E. Pallé , M. R. Zapatero Osorio

The luminosity of embedded protostars is commonly measured via observations of the dust continuum spectral energy distribution from millimetre to infrared wavelengths. However, this method cannot be applied to embedded protostars in binary…

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

Compact objects undergoing mass transfer exhibit significant (and double-peaked) $H_{\alpha}$ emission lines. Recently, new methods have been developed to identify black hole X-ray binaries (BHXBs) and calculate their systematic parameters…

High Energy Astrophysical Phenomena · Physics 2025-03-18 Xinlin Zhao , Song Wang , Jifeng Liu

We present a method for detection of weak continuous signals from sources in binary systems via the incoherent combination of many "short" coherently-analyzed segments. The main focus of the work is on the construction of a metric on the…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Chris Messenger

A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set…

Luminous BA-SGs allow topics ranging from NLTE physics and the evolution of massive stars to the chemical evolution of galaxies and cosmology to be addressed. A hybrid NLTE technique for the quantitative spectroscopy of BA-SGs is discussed.…

Astrophysics · Physics 2009-11-11 N. Przybilla , K. Butler , S. R. Becker , R. P. Kudritzki

We develop a data-driven spectral model for identifying and characterizing spatially unresolved multiple-star systems and apply it to APOGEE DR13 spectra of main-sequence stars. Binaries and triples are identified as targets whose spectra…

This paper proposes a novel and rapid calibration-free wavelength modulation spectroscopy algorithm based on even-order harmonics. The proposed algorithm, analytically deduced from Voigt line-shape function, only involves simple algebraic…

Optics · Physics 2021-09-01 Yihong Wang , Bin Zhou , Chang Liu

We present abundances of globular clusters in the Milky Way and Fornax from integrated light spectra. Our goal is to evaluate the consistency of the integrated light analysis relative to standard abundance analysis for individual stars in…

Astrophysics of Galaxies · Physics 2017-01-11 J. E. Colucci , R. A. Bernstein , A. McWilliam

Rydberg atomic quantum receivers have been seen as novel radio frequency measurements and the high sensitivity to a large range of frequencies makes it attractive for communications reception. However, their unique physical characteristics…

Signal Processing · Electrical Eng. & Systems 2025-09-24 Hao Wu , Xinyuan Yao , Rui Ni , Chen Gong , Kaibin Huang

The achievable level of precision on photospheric abundances of stars is a major limiting factor on investigations of exoplanet host star characteristics, the chemical histories of star clusters, and the evolution of the Milky Way and other…

Solar and Stellar Astrophysics · Physics 2015-06-22 M. Bedell , J. Melendez , J. Bean , I. Ramirez , P. Leite , M. Asplund

We present a grism extraction package (LINEAR) designed to reconstruct one-dimensional spectra from a collection of slitless spectroscopic images, ideally taken at a variety of orientations, dispersion directions, and/or dither positions.…

Instrumentation and Methods for Astrophysics · Physics 2018-02-21 R. E. Ryan , S. Casertano , N. Pirzkal

We present model spectra of stellar populations with variable chemical composition. We derived the [alpha/Fe] abundance ratio of the stars of the most important libraries (ELODIE, CFLIB and MILES) using full spectrum fitting and we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Philippe Prugniel , Mina Koleva

We present new or improved methods for calculating NLTE, line-blanketed model atmospheres for hot stars with winds (spectral types A to O), with particular emphasis on a fast performance. These methods have been implemented into a previous,…

Astrophysics · Physics 2009-11-10 J. Puls , M. A. Urbaneja , R. Venero , T. Repolust , U. Springmann , A. Jokuthy , M. R. Mokiem

We use a combination of the XMM-Newton serendipitous X-ray survey with the optical SDSS, and the infrared WISE all-sky survey in order to check the efficiency of the low X-ray to infrared luminosity selection method in finding heavily…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 E. Rovilos , I. Georgantopoulos , A. Akylas , J. Aird , D. M. Alexander , A. Comastri , A. Del Moro , P. Gandhi , A. Georgakakis , C. M. Harrison , J. R. Mullaney

This paper studies the performance of the spectral method in the estimation and uncertainty quantification of the unobserved preference scores of compared entities in a general and more realistic setup. Specifically, the comparison graph…

Methodology · Statistics 2024-03-04 Jianqing Fan , Zhipeng Lou , Weichen Wang , Mengxin Yu

Photospheric C, N, and O abundances of 118 solar-analog stars were determined by applying the synthetic-fitting analysis to their spectra in the blue or near-UV region comprising lines of CH, NH, and OH molecules, with an aim of clarifying…

Solar and Stellar Astrophysics · Physics 2023-02-01 Yoichi Takeda
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