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Related papers: Atomic transitions for adaptive optics

200 papers

LTE abundances of light elements in extremely metal-poor (EMP) stars have been previously derived from high quality spectra. New derivations, free from the NLTE effects, will better constrain the models of the Galactic chemical evolution…

Astrophysics of Galaxies · Physics 2015-05-14 S. M. Andrievsky , Monique Spite , S. A. Korotin , F. Spite , P. Bonifacio , R. Cayrel , P. François , V. Hill

Alternative materials are required to enhance the efficacy of plasmonic devices. We discuss the optical properties of a number of alloys, doped metals, intermetallics, silicides, metallic glasses and high pressure materials. We conclude…

Optics · Physics 2015-05-18 Martin G Blaber , Matthew D Arnold , Michael J Ford

The 2008 optical transient in NGC 300 is one of a growing class of intermediate-luminosity transients that brighten several orders of magnitude from a previously optically obscured state. The origin of their eruptions is not understood. Our…

We discuss possible search for optical transitions in Sm13+ and Sm14+ using ab initio calculations of differential dynamic polarizability. We calculate dynamic polarizability for M1 transition between first and second excited states of…

Atomic Physics · Physics 2015-06-17 A. Kozlov , V. A. Dzuba , V. Flambaum

The development of optical nanofibers (ONF) and the study and control of their optical properties when coupling atoms to their electromagnetic modes has opened new possibilities for their use in quantum optics and quantum information…

We present accurate methods of abundance determination based on the non-local thermodynamic equilibrium (NLTE) line formation for carbon, oxygen, calcium, titanium, and iron in the atmospheres of BAF-type stars. For C I-II, O I, Ca I-II,…

Solar and Stellar Astrophysics · Physics 2018-08-22 Tatyana Sitnova , Tatyana Ryabchikova , Sofya Alexeeva , Lyudmila Mashonkina

We investigate the chemical evolution of odd-numbered elements such as sodium (Na) and aluminum (Al) during the early epochs of the Galactic halo with the use of a model that reproduces the observed box-shaped distribution of extremely…

Astrophysics · Physics 2009-11-07 Takuji Tsujimoto , Toshikazu Shigeyama , Yuzuru Yoshii

Highly charged ions (HCIs) are insensitive to external perturbations and are attractive for the development of ultrastable clocks. However, only a few HCI candidates are known to provide optical clock transitions. In this Letter, we show…

Atomic Physics · Physics 2025-01-07 Chunhai Lyu , Christoph H. Keitel , Zoltán Harman

Optical transitions of highly charged ions can be very sensitive to hypothetical beyond-the-Standard-Model phenomena. Those near the $5s-4f$ level crossing, where the $5s$ and $4f$ are degenerate are especially promising. We present…

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai…

The individual characteristics of C, N, O, Na, Mg, Al, Si, and Fe on isochrones have been investigated in this study. Stellar models have been constructed for various mixtures in which the content of each element is changed up to the…

Solar and Stellar Astrophysics · Physics 2016-08-19 Minje Beom , Chongsam Na , Jason W. Ferguson , Y. -C. Kim

Parameters and abundances for 1002 stars of spectral types F, G, and K of luminosity class IV and V have been derived. After culling the sample for rotational velocity and effective temperature, 867 stars remain for discussion. Twenty-eight…

Solar and Stellar Astrophysics · Physics 2016-12-28 R. Earle Luck

High-resolution (R ~ 90,000) spectra of 34 nearby, young Sun-like stars were analyzed using stellar atmosphere models to estimate effective photosphere temperatures, surface gravities, and the abundance of certain heavy elements (C, Na, Mg,…

Astrophysics · Physics 2009-11-07 E. J. Gaidos , G. Gonzalez

We present detailed spectroscopic analysis of nitrogen abundances in 31 unevolved metal-poor stars analysed by spectral synthesis of the near-UV NH band at 3360 A observed at high resolution with various telescopes. We found that [N/Fe]…

Astrophysics · Physics 2009-11-10 G. Israelian , A. Ecuvillon , R. Rebolo , R. Garcia Lopez , P. Bonifacio , P. Molaro

Bimetallic nanoparticles are often superior candidates for a wide range of technological and biomedical applications, thanks to their enhanced catalytic, optical, and magnetic properties, which are often better than their monometallic…

The transition from galactic to extragalactic cosmic rays is discussed. One of critical indications for transition is given by the Standard Model of Galactic cosmic rays, according to which the maximum energy of acceleration for iron nuclei…

Astrophysics · Physics 2007-10-20 V. Berezinsky

Molecular overtone transitions provide optical frequency transitions sensitive to variation in the proton-to-electron mass ratio ($\mu\equiv m_p/m_e$). However, robust molecular state preparation presents a challenge critical for achieving…

The hyperfine (hf) transition rates for muonic atoms have been re-measured for select light nuclei, using neutron detectors to evaluate the time dependence of muon capture. For $^{19}$F $\Lambda$$_{h}$ = 5.6 (2) $\mu$s$^{-1}$ for the hf…

Nuclear Experiment · Physics 2009-11-07 T. J. Stocki , D. F. Measday , E. Gete , M. A. Saliba , J. Lange , T. P. Gorringe

We present homogeneous abundances for Fe and some of the elements involved in the proton-capture reactions (O, Na, Mg, Al, and Si) for 202 red giants in 17 Galactic globular clusters (GCs) from the analysis of high resolution UVES spectra…

Astrophysics of Galaxies · Physics 2015-05-14 Eugenio Carretta , Angela Bragaglia , Raffaele Gratton , Sara Lucatello

Ground-based high-resolution spectroscopy has identified various chemical species in the atmospheres of ultra-hot Jupiters, including neutral and ionized metals, providing key insights into planet formation through refractory element…

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