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The recent introduction of high resolution/large spectral range spectrographs provided the opportunity to investigate in detail the chemical composition of classical Cepheids. This paper is focussed on new abundance determinations for iron…

Astrophysics · Physics 2009-11-13 B. Lemasle , P. Francois , G. Bono , M. Mottini , F. Primas , M. Romaniello

Observations of infrared fine-structure lines provide direct information on the metallicity and ionization structure of HII regions and indirectly on the hardness of the radiation field ionizing these nebulae. We have analyzed a sample of…

We review the theory of electron-conduction opacity, a fundamental ingredient in the computation of low-mass stellar models; shortcomings and limitations of the existing calculations used in stellar evolution are discussed. We then present…

Astrophysics · Physics 2008-11-26 S. Cassisi , A. Y. Potekhin , A. Pietrinferni , M. Catelan , M. Salaris

Spectral measures arise in numerous applications such as quantum mechanics, signal processing, resonances, and fluid stability. Similarly, spectral decompositions (pure point, absolutely continuous and singular continuous) often…

Spectral Theory · Mathematics 2021-03-02 Matthew John Colbrook

In recent years, arrays of radio antennas operating in the MHz regime have shown great potential as detectors in astroparticle physics. In particular, they fulfill an important role in the indirect detection of ultra-high energy cosmic…

Instrumentation and Methods for Astrophysics · Physics 2023-08-17 Max Büsken , Tomáš Fodran , Tim Huege

We report on a far above saturation absorption imaging technique to investigate the characteristics of dense packets of ultracold atoms. The transparency of the cloud is controlled by the incident light intensity as a result of the…

Optics · Physics 2009-11-13 G. Reinaudi , T. Lahaye , Z. Wang , D. Guery-Odelin

A radio interferometer indirectly measures the intensity distribution of the sky over the celestial sphere. Since measurements are made over an irregularly sampled Fourier plane, synthesising an intensity image from interferometric…

Instrumentation and Methods for Astrophysics · Physics 2014-03-18 Daniel Muscat

We discuss the potential of high sensitivity mid-IR and far-IR spectroscopy to proof the physical properties of active nuclei and starburst regions of local and distant galaxies. For local galaxies, it will be possible to map the discs and…

Astrophysics · Physics 2007-05-23 Luigi Spinoglio , Anna Maria Di Giorgio , Paolo Saraceno

Frequency domain spectroscopy allows an experimenter to establish optical properties of solids in a wide frequency band including the technically challenging 10 THz region, and in other bands enables metrological comparison between…

Optics · Physics 2018-09-21 Steven Chick , Ben Murdin , Guy Matmon , Mira Naftaly

Laser spectroscopy of hot atomic vapours has been studied extensively. Theoretical models that predict the absolute value of the electric susceptibility are crucial for optimising the design of photonic devices that use hot vapours, and for…

Ultraviolet absorption line spectroscopy is a sensitive diagnostic for the properties of interstellar and circumgalactic gas. Down-the-barrel observations, where the absorption is measured against the galaxy itself, are commonly used to…

The detailed shapes of spectral line profiles provide valuable information about the emitting plasma, especially when the plasma contains an unresolved mixture of velocities, temperatures, and densities. As a result of finite spectral…

Solar and Stellar Astrophysics · Physics 2015-07-17 James A. Klimchuk , Spiros Patsourakos , Durgesh Tripathi

We perform three dimensional radiation hydrodynamic simulations of the structure and dynamics of radiation dominated envelopes of massive stars at the location of the iron opacity peak. One dimensional hydrostatic calculations predict an…

Solar and Stellar Astrophysics · Physics 2015-11-04 Yan-Fei Jiang , Matteo Cantiello , Lars Bildsten , Eliot Quataert , Omer Blaes

We applied machine learning to the entire data history of ESO's High Accuracy Radial Velocity Planet Searcher (HARPS) instrument. Our primary goal was to recover the physical properties of the observed objects, with a secondary emphasis on…

Solar and Stellar Astrophysics · Physics 2024-12-13 Vojtěch Cvrček , Martino Romaniello , Radim Šára , Wolfram Freudling , Pascal Ballester

Models of stellar spectra are necessary for interpreting light from individual stars, planets, integrated stellar populations, nebulae, and the interstellar medium. We provide a comprehensive and homogeneous collection of synthetic spectra…

Solar and Stellar Astrophysics · Physics 2018-10-10 Carlos Allende Prieto , Lars Koesterke , Ivan Hubeny , Manuel A. Bautista , Paul S. Barklem , Sultana N. Nahar

High-spectral resolution observations of clusters of galaxies are a powerful tool to understand the physical processes taking place in these massive objects. Their hot multi-million-degree X-ray emitting cluster atmospheres, containing most…

High Energy Astrophysical Phenomena · Physics 2025-02-27 Jeremy S. Sanders

The technique of Penning trap mass spectrometry is briefly reviewed particularly in view of precision experiments on unstable nuclei, performed at different facilities worldwide. Selected examples of recent results emphasize the importance…

Nuclear Experiment · Physics 2009-09-24 K. Blaum , Sz. Nagy , G. Werth

This paper presents a detailed spectral pixel (spaxel) analysis of the ten Luminous Infrared Galaxies (LIRGs) previously observed with the Wide Field Spectrograph (WiFeS), an integral field spectrograph mounted on the ANU 2.3m telescope,…

Resolving fine details of astronomical objects provides critical insights into their underlying physical processes. This drives in part the desire to construct ever-larger telescopes and interferometer arrays and to observe at shorter…

The IRON Project, initiated in 1991, aims at two main objectives, i) study the characteristics of and calculate large-scale high accuracy data for atomic radiative and collisional processes, and ii) application in solving astrophysical…

Atomic Physics · Physics 2018-01-17 Sultana N. Nahar