Results 61 to 70 of about 226,407 (198)

Chemical Cartography with APOGEE: Two-process Parameters and Residual Abundances for 288,789 Stars from Data Release 17

The Astrophysical Journal
Stellar abundance measurements are subject to systematic errors that induce extra scatter and artificial correlations in elemental abundance patterns. We derive empirical calibration offsets to remove systematic trends with surface gravity $\mathrm{log ...
Tawny Sit, David H. Weinberg, Adam Wheeler, Christian R. Hayes, Sten Hasselquist, Thomas Masseron, Jennifer Sobeck   +6 more
doaj   +1 more source

Core to Cosmic Edge: SIMBA-C’s New Take on Abundance Profiles in the Intragroup Medium at z = 0

Universe
We employ the simba-c cosmological simulation to study the impact of its upgraded chemical enrichment model (Chem5) on the distribution of metals in the intragroup medium (IGrM).
Aviv Padawer-Blatt, Zhiwei Shao, Renier T. Hough, Douglas Rennehan, Ruxin Barré, Vida Saeedzadeh, Arif Babul, Romeel Davé, Chiaki Kobayashi, Weiguang Cui, François Mernier, Ghassem Gozaliasl   +11 more
doaj   +1 more source

Chemical abundances of stars with brown-dwarf companions

, 2014
It is well-known that stars with giant planets are on average more metal-rich than stars without giant planets, whereas stars with detected low-mass planets do not need to be metal-rich.
Hernández, J. I. González, Israelian, G., Sahlmann, J., Santos, N. C., Sánchez, D. Mata, Udry, S.   +5 more
core   +1 more source

Two-process Model and Residual Abundance Analysis of the Milky Way Massive Satellites

The Astrophysical Journal
The “two-process model” is a promising technique for interpreting stellar chemical abundance data from large-scale surveys (e.g., the Sloan Digital Sky Survey IV/V and the Galactic Archeology with HERMES survey), enabling more quantitative empirical ...
Sten Hasselquist, Christian R. Hayes, Emily J. Griffith, David Weinberg, Tawny Sit, Rachael L. Beaton, Danny Horta   +6 more
doaj   +1 more source

Abundances in Damped Ly-alpha Galaxies

, 2005
Damped Ly_alpha galaxies provide a sample of young galaxies where chemical abundances can be derived throughout the whole universe with an accuracy comparable to that for the local universe.
A. Chie, G. Israelian, J. Prochaska, P. Molaro   +3 more
core   +1 more source

Chemical sensitivity to the ratio of the cosmic-ray ionization rates of He and H2 in dense clouds [PDF]

, 2006
Aim: To determine whether or not gas-phase chemical models with homogeneous and time-independent physical conditions explain the many observed molecular abundances in astrophysical sources, it is crucial to estimate the uncertainties in the calculated ...
Baldwin, Bergin, Boger, Charnley, Dalgarno, E. Herbst, F. Selsis, G. Massacrier, Glassgold, Graedel, Herbst, Le Bourlot, Le Bourlot, Le Teuff, Lee, Pagani, Pineau des Forets, Shalabiea, Smith, Snell, Terzieva, V. Wakelam, Wakelam, Wakelam, Wakelam   +24 more
core   +3 more sources

Metallicities from High-resolution TRES Spectra with uberMS: Performance Benchmarks and Literature Comparison

The Astrophysical Journal Supplement Series
As the field of exoplanetary astronomy has matured, demand has grown for precise stellar abundances to probe subtle correlations between stellar compositions and planetary demographics.
Emily K. Pass, Phillip A. Cargile, Victoria DiTomasso, Romy Rodríguez Martínez, David Charbonneau, David W. Latham, Andrew Vanderburg, Allyson Bieryla, Samuel N. Quinn, Lars A. Buchhave   +9 more
doaj   +1 more source

Chemical Abundances of the Leo II Dwarf Galaxy

, 2008
We use previously-published moderate-resolution spectra in combination with stellar atmosphere models to derive the first measured chemical abundance ratios in the Leo II dSph galaxy.
Azzopardi, Chou, Cohen, Coleman, David O. Cook, Demers, Dolphin, Dotter, Fulbright, Fulbright, Gratton, Helmi, Hinkle, Ivans, Koch, Koch, Koch, Lee, Majewski, Majewski, Marin-Franch, Matthew D. Shetrone, Michael H. Siegel, Milone, Palma, Piotto, Pritzl, Ramírez, Ramírez, Shetrone, Shetrone, Shetrone, Siegel, Siegel, Siegel, Simon, Sneden, Sohn, Sollima, Swope, Tammy Bosler, Thévenin, Tolstoy, Venn, Walker   +44 more
core   +1 more source

Analysis of chemical abundances in planetary nebulae with [WC] central stars [PDF]

Astronomy & Astrophysics, 2013
Accepted for publication in A&A. 15 Tables and 18 Figures.
García Rojas, Jorge, Peña, Miriam, Morisset, Christophe, Delgado Inglada, Gloria, Mesa Delgado, Adal, Ruiz, María Teresa   +5 more
openaire   +3 more sources

Modelling the chemical evolution

, 2010
Advanced observational facilities allow to trace back the chemical evolution of the Universe, on the one hand, from local objects of different ages and, secondly, by direct observations of redshifted objects.
Argast, Cescutti, Chiappini, Colavitti, Gerhard Hensler, Harfst, Hensler, Hensler, Hensler, Hensler, Hirschi, Ikuta, Koch, Koeppen, Koeppen, Kroeger, Maciel, Maeder, Matteucci, Meynet, Meynet, Meynet, Momany, Nordstroem, Pagel, Pagel, Portinari, Portinari, Prantzos, Prantzos, Recchi, Recchi, Recchi, Recchi, Revaz, Samland, Schaller, Simone Recchi, Spitoni, Theis, Tinsley   +40 more
core   +1 more source