Results 51 to 60 of about 1,023,166 (254)
Mid-Ultraviolet Determination of Elliptical Galaxy Abundances and Ages
, 2000 We investigate the effects of abundance and age on the mid-UV spectra and Mg2 strengths of stellar populations using simple population synthesis models. These models are used to constrain the star formation history of four nearby elliptical galaxies and ...
J. Lotz, H. Ferguson, R. Bohlin
semanticscholar +1 more source
The Evolution of the Elemental Abundances in the Gas and Dust Phases of the Galaxy [PDF]
, 1997 We present models for the evolution of the elemental abundances in the gas and dust phases of the interstellar medium (ISM) of our Galaxy by generalizing standard models for its dynamical and chemical evolution.
E. Dwek
semanticscholar +1 more source
R-process enrichment from a single event in an ancient dwarf galaxy [PDF]
Nature, 2015 Elements heavier than zinc are synthesized through the rapid (r) and slow (s) neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years.
A. Ji, A. Frebel, A. Chiti, J. Simon
semanticscholar +1 more source
On the maximum value of the cosmic abundance of oxygen and the oxygen yield [PDF]
Mon.Not.Roy.Astron.Soc.376:353-360,2007, 2007 We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies.
arxiv +1 more source
The Astrophysical Journal, 2023 The Milky Way (MW) stellar disk has both a thin and a thick component. The thin disk is composed mostly of younger stars (≲8 Gyr) with a lower abundance of α -elements, while the thick disk contains predominantly older stars (≳8–12 Gyr) with a higher α ...
Bethany R. Garver +4 more
doaj +1 more source
EXTRAGALACTIC CHEMICAL ABUNDANCES: DO H ii REGIONS AND YOUNG STARS TELL THE SAME STORY? THE CASE OF THE SPIRAL GALAXY NGC 300 [PDF]
, 2009 We have obtained new spectrophotometric data for 28 H ii regions in the spiral galaxy NGC 300, a member of the nearby Sculptor Group. The detection of several auroral lines, including [O iii] λ4363, [S iii] λ6312, and [N ii] λ5755, has allowed us to ...
F. Bresolin +5 more
semanticscholar +1 more source
Spectroscopic study of blue compact galaxies V. oxygen abundance and the metallicity-luminosity relation [PDF]
Astron.Astrophys.437:849,2005, 2005 This is the fifth paper in a series studying the stellar components, star formation histories, star formation rates and metallicities of a blue compact galaxy (BCG) sample. Based on our high-quality ground-based spectroscopic observations, we have determined the electron temperatures, electron densities, nitrogen abundances and oxygen abundances for 72
arxiv +1 more source
Chemical behavior of the dwarf irregular galaxy NGC6822. Its PN and HII region abundances [PDF]
, 2009 Aims. We aim to derive the chemical behavior of a significant sample of PNe and HII regions in the irregular galaxy NGC 6822. The selected objects are distributed in different zones of the galaxy.
L. Hernández-Martínez +3 more
semanticscholar +1 more source
Subsystems of the Galactic halo, their structures and compositions
Odessa Astronomical Publications, 2017 It is shown that general populations of globular clusters and metal-poor field stars are components at least of three subsystems occupying different volumes in the Galaxy.
V. A. Marsakov, T. V. Borkova
doaj +1 more source
Oxygen abundance maps of CALIFA galaxies [PDF]
, 2016 We construct maps of the oxygen abundance distribution across the disks of 88 galaxies using CALIFA data release 2 (DR2) spectra. The position of the center of a galaxy (coordinates on the plate) were also taken from the CALIFA DR2. The galaxy inclination, the position angle of the major axis, and the optical radius were determined from the analysis of
arxiv +1 more source