Results 11 to 20 of about 52,001 (350)
Fluorine Abundances of Galactic Low-Metallicity Giants [PDF]
The Astrophysical Journal, 2013 With abundances and 2{\sigma} upper limits of fluorine (F) in seven metal-poor field giants, nucleosynthesis of stellar F at low metallicity is discussed.
Caffau, E. +4 more
core +4 more sources
Reionization and the Abundance of Galactic Satellites [PDF]
The Astrophysical Journal, 2000 One of the main challenges facing standard hierarchical structure formation models is that the predicted abundance of galactic subhalos with circular velocities of 10-30 km/s is an order of magnitude higher than the number of satellites actually observed within the Local Group.
James S. Bullock +2 more
openalex +3 more sources
Fluorine Abundances in the Galactic Disk [PDF]
The Astrophysical Journal, 2019 Abstract The chemical evolution of fluorine is investigated in a sample of Milky Way red giant stars that span a significant range in metallicity from [Fe/H] ∼ −1.3 to 0.0 dex. Fluorine abundances are derived from vibration-rotation lines of HF in high-resolution infrared spectra near 2.335 μm.
Rafael Guerço +7 more
openalex +4 more sources
PNe Abundances: Galactic Bulge versus the Disc [PDF]
Astrophysics and Space Science, 2001 We compare the abundances of He, N, O, Ar, S, and Ne, determined in a similar way, for a sample of Galactic bulge and disc planetary nebulae (PNe). We find that in all aspects — average abundances and dispersion, distribution functions, abundance relationships, and the ratio of N/O — the bulge and disc PNe are indistinguishable.
Exter, K +3 more
openaire +2 more sources
Oxygen abundance distribution in the Galactic disc [PDF]
Monthly Notices of the Royal Astronomical Society, 2014 We have performed a NLTE analysis of the infrared oxygen triplet for a large number of cepheid spectra obtained with the Hobby-Eberly telescope. These data were combined with our previous NLTE results for the stars observed with Max Planck Gesellschaft telescope with the aim to investigate oxygen abundance distribution in Galactic thin disc.
Korotin, S. +5 more
openaire +4 more sources
ABUNDANCES OF GALACTIC ANTICENTER PLANETARY NEBULAE AND THE OXYGEN ABUNDANCE GRADIENT IN THE GALACTIC DISK [PDF]
The Astrophysical Journal, 2010 Accepted for publication in the Astrophysical Journal; 42 pages including 5 ...
Henry, R. B. C. +5 more
openaire +2 more sources
Chemical Abundances in Galactic Bulge Pn [PDF]
Symposium - International Astronomical Union, 1993 We present abundance determinations, in particular of carbon, and C/O ratios, for 11 Galactic bulge planetary nebulae (PN) based on our low resolution UV data from IUE observations and optical spectrophotometry from the Anglo-Australian Telescope. We compare the observed abundances with those predicted by dredge-up theory for the high metallicity ...
N. A. Walton +2 more
openaire +1 more source
Sulphur abundance in Galactic stars [PDF]
Astronomy & Astrophysics, 2005 accepted by A& ...
Caffau, Elisabetta +5 more
openaire +4 more sources
The Galactic Oxygen Abundance Gradient [PDF]
The Astrophysical Journal, 1997 We have previously published medium- to high-resolution spectroscopic observations of early B-type main-sequence objects, lying in 18 young, stellar clusters and associations or the general disk population, over galactocentric distances 6 Rg 18 kpc. Using a homogeneous subset of stars with similar atmospheric parameters, we have reanalyzed the O II ...
Smartt, Stephen J. +1 more
openaire +1 more source
Manganese abundances in Galactic bulge red giants [PDF]
Astronomy & Astrophysics, 2013 Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut beween the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy.
Barbuy, B. +8 more
openaire +9 more sources