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[ABRIDGED] AIMS. MONOS is collecting information and studying O-type spectroscopic binaries with delta > -20 deg. In this 1st paper we describe the sample and provide spectral classifications and additional information for objects with…

Many analyses and parameter estimations undertaken in astronomy require a large set (> 10^5) of non-analytical, theoretical spectra, each of these defined by multiple parameters. We describe the construction of an N-dimensional grid which…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Ching-Wa Yip

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…

Over the last decades, evolutionary population synthesis models have powered an unmatched leap forward in our understanding of galaxies. From dating the age of the first galaxies in the Universe to detailed measurements of the chemical…

Astrophysics of Galaxies · Physics 2024-11-13 I. Martín-Navarro , A. Vazdekis

Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an orbiting planet. However, as abundance measurement…

Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. Contrast-enhanced spectral imaging has been thoroughly investigated,…

Medical Physics · Physics 2021-01-26 Erik Fredenberg , Magnus Aslund , Bjorn Cederstrom , Mats Lundqvist , Mats Danielsson

Theoretical stellar spectra rely on model stellar atmospheres computed based on our understanding of the physical laws at play in the stellar interiors. These models, coupled with atomic and molecular line databases, are used to generate…

Solar and Stellar Astrophysics · Physics 2020-07-01 Kaushal Sharma , Harinder P. Singh , Ranjan Gupta , Ajit Kembhavi , Kaustubh Vaghmare , Jianrong Shi , Yongheng Zhao , Jiannan Zhang , Yue Wu

Chemical tagging of stars based on their similar compositions can offer new insights about the star formation and dynamical history of the Milky Way. We investigate the feasibility of identifying groups of stars in chemical space by…

Astrophysics of Galaxies · Physics 2018-02-20 Natalie Price-Jones , Jo Bovy

Stellar spectra are often modeled and fit by interpolating within a rectilinear grid of synthetic spectra to derive the stars' labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a…

Solar and Stellar Astrophysics · Physics 2016-07-26 Yuan-Sen Ting , Charlie Conroy , Hans-Walter Rix

Stellar population synthesis (SPS) models have long struggled to reproduce observed optical through near-IR (NIR) spectral energy distributions (SED) of massive quiescent galaxies. We revisit this issue using a novel approach that combines…

Astrophysics of Galaxies · Physics 2019-02-27 Jieun Choi , Charlie Conroy , Benjamin D. Johnson

The integrated spectra of stellar systems contain a wealth of information, and its analysis can reveal fundamental parameters such as metallicity, age and star formation history. Widely used methods to analyze these spectra are based on…

Solar and Stellar Astrophysics · Physics 2019-02-04 Lucimara P. Martins , Círia Lima-Dias , Paula R. T. Coelho , Tatiana F. Laganá

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

Instrumentation and Methods for Astrophysics · Physics 2022-08-12 E. Gallego-Cano , R. Schödel , A. T. Gallego-Calvente , A. M. Ghez

In this technical note, we deal with a spectrum approximation problem arising in THREE-like multivariate spectral estimation approaches. The solution to the problem minimizes a suitable divergence index with respect to an a priori spectral…

Optimization and Control · Mathematics 2014-06-27 Mattia Zorzi

Parameter estimation in astrophysics often requires the use of complex physical models. In this paper we study the problem of estimating the parameters that describe star formation history (SFH) in galaxies. Here, high-dimensional spectral…

Applications · Statistics 2012-03-21 Joseph W. Richards , Ann B. Lee , Chad M. Schafer , Peter E. Freeman

Line-by-line calculations are becoming the standard procedure for carrying spectral simulations. However, it is important to insure the accuracy of such spectral simulations through the choice of adapted models for the simulation of key…

Optics · Physics 2007-05-23 M. Lino da Silva

Orbital solutions for binary or multiple stellar systems that combine astrometry (e.g., position angles and angular separations) with spectroscopy (radial velocities) have important advantages over astrometric-only or spectroscopic-only…

Astrophysics · Physics 2007-05-23 Guillermo Torres

Since the early 1970s, stellar population modelling has been one of the basic tools for understanding the physics of unresolved systems from observation of their integrated light. Models allow us to relate the integrated spectra (or…

Instrumentation and Methods for Astrophysics · Physics 2013-12-03 Miguel Cerviño

Forthcoming space-based observations will require high-quality point-spread function (PSF) models for weak gravitational lensing measurements. One approach to generating these models is using a wavefront model based on the known telescope…

Instrumentation and Methods for Astrophysics · Physics 2020-06-29 Bryan R. Gillis , Tim Schrabback , Ole Marggraf , Rachel Mandelbaum , Richard Massey , Jason Rhodes , Andy Taylor

Stellar abundance analysis relies on flexible, high-performance spectral synthesis. To meet these needs, we present PySME v1.0, an updated Python implementation of Spectroscopy Made Easy (SME) designed for precise and survey-scale modelling…

Instrumentation and Methods for Astrophysics · Physics 2026-05-12 Mingjie Jian , Nikolai Piskunov , Jeff Valenti , Ella Xi Wang , Brian Thorsbro , Henrik Jönsson , Ansgar Wehrhahn

CONTEXT: Spectral-line asymmetries and wavelength shifts are signatures of hydrodynamics in solar and stellar atmospheres. Theory may precisely predict idealized lines, but observed spectra are limited by blends, too few suitable lines,…

Astrophysics · Physics 2009-11-13 Dainis Dravins