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 +24 more
core +3 more sources
Recent Development of the Atomic Line List
Galaxies, 2018 The Atomic Line List is an online database of wavelengths and transition probabilities of atomic lines. It is primarily set up as a tool to help identify unknown spectral features.
Peter A. M. van Hoof
doaj +1 more source
Chemical Abundances in the Leading Arm of the Magellanic Stream [PDF]
, 2018 The Leading Arm (LA) of the Magellanic Stream is a vast debris field of H i clouds connecting the Milky Way and the Magellanic Clouds. It represents an example of active gas accretion onto the Galaxy.
A. Fox +11 more
semanticscholar +1 more source
TOPoS. IV. Chemical abundances from high-resolution observations of seven extremely metal-poor stars [PDF]
, 2018 Context. Extremely metal-poor (EMP) stars provide us with indirect information on the first generations of massive stars. The TOPoS survey has been designed to increase the census of these stars and to provide a chemical inventory that is as detailed as ...
P. Bonifacio +22 more
semanticscholar +1 more source
Evidence for Ubiquitous Carbon Grain Destruction in Hot Protostellar Envelopes
The Astrophysical Journal Letters, 2023 Earth is deficient in carbon and nitrogen by up to ∼4 orders of magnitude compared with the Sun. Destruction of (carbon- and nitrogen-rich) refractory organics in the high-temperature planet-forming regions could explain this deficiency.
Pooneh Nazari +4 more
doaj +1 more source
Chemical Abundances from the Continuum
, 2008 The calculation of solar absolute fluxes in the near-UV is revisited, discussing in some detail recent updates in theoretical calculations of bound-free opacity from metals.
Allende Prieto C +10 more
core +1 more source
On the Galactic chemical evolution of sulphur. Sulphur abundances from the [S i] 1082 nm line in giants [PDF]
, 2013 Context. The Galactic chemical evolution of sulphur is still under debate. At low metallicities some studies find no correlation between [S/Fe] and [Fe/H], others find [S/Fe] increasing towards lower metallicities, and still others find a combination of ...
Dupree, A. K., Matrozis, E., Ryde, N.
core +1 more source
JINAbase—A Database for Chemical Abundances of Metal-poor Stars [PDF]
Astrophysical Journal Supplement Series, 2017 Reconstructing the chemical evolution of the Milky Way is crucial for understanding the formation of stars, planets, and galaxies throughout cosmic time.
Abdu Abohalima, A. Frebel
semanticscholar +1 more source
DETAILED CHEMICAL ABUNDANCES IN THE r-PROCESS-RICH ULTRA-FAINT DWARF GALAXY RETICULUM 2 [PDF]
, 2016 The ultra-faint dwarf (UFD) galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey. We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber System.
I. Roederer +12 more
semanticscholar +1 more source
ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE [PDF]
, 2015 The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R ≈ 22,500) spectroscopic map of the stars across the Milky Way, and including dust-obscured areas.
A. G. García Pérez +29 more
semanticscholar +1 more source