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Related papers: Gd Transition Probabilities and Abundances

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We present an analysis of the correlation between the mid-UV Mg II h and k emission lines and measured rotational periods of G-type stars. Based on IUE and HST high resolution spectra of a sample of 36 stars, we derive an exponential…

Solar and Stellar Astrophysics · Physics 2015-06-17 Manuel Olmedo , Miguel Chávez , Emanuele Bertone , Víctor De la Luz

To study the structure of spatially unresolved features of the solar photosphere, we calculated the Stokes profiles of seven photospheric iron lines using two-dimensional nonstationary MHD models of solar granulation for various amounts of…

Solar and Stellar Astrophysics · Physics 2012-11-13 I. N. Atroshchenko , V. A. Sheminova

Observations and modeling suggest that the dust abundance (gas-to-dust ratio, G/D) depends on (surface) density. The variations of the G/D provide constraints on the timescales for the different processes involved in the lifecycle of metals…

Astrophysics of Galaxies · Physics 2017-05-31 Julia Roman-Duval , Caroline Bot , Jeremy Chastenet , Karl Gordon

Employing two state-of-the-art methods, multiconfiguration Dirac--Hartree--Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the $2s^2 2p^4$, $2s 2p^5$, $2p^6$, $2s^2…

Atomic Physics · Physics 2017-04-19 K. Wang , P. Jönsson , J. Ekman , G. Gaigalas , M. R. Godefroid , R. Si , Z. B. Chen , S. Li , C. Y. Chen , J. Yan

We present the abundance analyses for the neutron-capture elements, and discuss the observed abundance distributions in very metal-poor stars with excesses of r-process elements. As has been found by previous abundance studies, the…

Astrophysics · Physics 2009-11-10 S. Honda , W. Aoki , T. Kajino , H. Ando , T. C. Beers , H. Izumiura , K. Sadakane , M. Takada-Hidai

The heavy element content ("metallicity") of the Universe is a record of the total star formation history. Gas-phase metallicity in galaxies, as well as its evolution with time, is of particular interest as a tracer of accretion and outflow…

In recent years a number of poorly studied chemical elements, such as phosphorus, sulphur, and strontium, have received special attention as important tracers of the Galactic chemical evolution. By exploiting the capabilities of the…

Solar and Stellar Astrophysics · Physics 2015-12-16 E. Caffau , S. Andrievsky , S. Korotin , L. Origlia , E. Oliva , N. Sanna , H. -G. Ludwig , P. Bonifacio

We have carried out model calculations of the photoionized intergalactic medium (IGM) to determine the effects on the predicted ionic column densities due to uncertainties in the published dielectronic recombination (DR) rate coefficients.…

Astrophysics · Physics 2016-09-07 Daniel Wolf Savin

We report precision measurements of the excited state lifetime of the $5p$ $^2P_{1/2}$ and $5p$ $^2P_{3/2}$ levels of a single trapped Cd$^+$ ion. The ion is excited with picosecond laser pulses from a mode-locked laser and the distribution…

The Galactic Center and inner disk of the Milky Way contain complex stellar populations obscured by heavy dust extinction. To study their chemical composition, high-resolution near-infrared (near-IR) spectroscopy is necessary. Expanding the…

Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding its…

Solar and Stellar Astrophysics · Physics 2020-02-26 Ana Rita Costa Silva , Elisa Delgado Mena , Maria Tsantaki

Mg is the alpha element of choice for Galactic population and chemical evolution studies as it is easily detectable in all late-type stars. Such studies require precise elemental abundances, and thus departures from LTE need to be accounted…

Solar and Stellar Astrophysics · Physics 2016-02-10 Yeisson Osorio , Paul S. Barklem

We present a comprehensive analysis of the detailed chemical abundances for a sample of 11 metal-poor, very metal-poor and extremely metal-poor stars ([Fe/H] = -1.65 to [Fe/H] = -3.0) as part of the HESP-GOMPA (Galactic survey Of Metal Poor…

With a sample of 22 metal-poor stars, we demonstrate that the heavy element abundance pattern (Z > 55) is the same as the r-process contributions to the solar nebula. This bolsters the results of previous studies that there is a universal…

Astrophysics · Physics 2009-11-06 Jennifer A. Johnson , Michael Bolte

The abundance of {\alpha}-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical abundances are crucial to improving our…

Calculations of energy levels, radiative rates and lifetimes are reported for 17 F-like ions with 37 $\le$ Z $\le$ 53. For brevity, results are only presented among the lowest 113 levels of the 2s$^2$2p$^5$, 2s2p$^6$, 2s$^2$2p$^4$3$\ell$,…

Atomic Physics · Physics 2015-12-02 K M Aggarwal , F P Keenan

The study of the elemental composition of stars and galaxies is a key topic for understanding their origin and evolution. In this study, we present the results of the calculation of solar abundances of the isotopes $^{1}$H, $^{4}$He,…

Solar and Stellar Astrophysics · Physics 2018-06-13 M. H. Talafha , M. A. Al-Wardat , N. M. Ershidat

We present interstellar elemental abundance measurements derived from Space Telescope Imaging Spectrograph echelle observations of 47 sight lines extending up to 6.5 kpc through the Galactic disk. These paths probe a variety of interstellar…

Astrophysics · Physics 2009-11-13 Stefan I. B. Cartledge , J. T. Lauroesch , David M. Meyer , Ulysses J. Sofia

We report lifetimes, branching fractions, and the resulting oscillator strengths for transitions within the P II multiplet (3s23p2 3P - 3s3p3 3Po) at 1308 {\AA}. These comprehensive beam-foil measurements, which are the most precise set…

The second Gaia data release (DR2) delivers accurate and homogeneous photometry data of the whole sky to an exquisite quality, reaching down to the unprecedented milli-magnitude (mmag) level for the G, GRP, and GBP passbands. However, the…

Solar and Stellar Astrophysics · Physics 2021-03-10 Zexi Niu , Haibo Yuan , Jifeng Liu