Results 61 to 70 of about 59,640 (247)

Inside-out versus Upside-down: The Origin and Evolution of Metallicity Radial Gradients in FIRE Simulations of Milky Way-mass Galaxies and the Essential Role of Gas Mixing

open access: yesThe Astrophysical Journal
Within the Milky Way (MW), younger stellar populations exhibit steeper (more negative) metallicity radial gradients; the origin of this trend remains debated. The FIRE-2 cosmological simulations of MW-mass galaxies show the same trend as the MW, which in
Russell L. Graf   +3 more
doaj   +1 more source

The building up of the disk galaxy M33 and the evolution of the metallicity gradient

open access: yes, 2007
The evolution of radial gradients of metallicity in disk galaxies and its relation with the disk formation are not well understood. Theoretical models of galactic chemical evolution make contrasting predictions about the time evolution of metallicity ...
Aller   +104 more
core   +1 more source

The Chemical Evolution of Galaxies [PDF]

open access: yesProceedings of Frank N. Bash Symposium 2015 — PoS(BASH2015), 2016
The gas-phase oxygen abundance, i.e. metallicity, of a galaxy is set by the interplay between star formation and gas flows. Metals are dispersed into the interstellar medium by stellar winds and supernovae. Metals accumulate in the interstellar medium of star-forming galaxies and provide a record of star-formation.
openaire   +1 more source

Planetary nebulae in the inner Milky Way: new abundances [PDF]

open access: yes, 2009
The study of planetary nebulae in the inner-disk and bulge gives important information on the chemical abundances of elements such as He, N, O, Ar, Ne, and on the evolution of these abundances, which is associated with the evolution of intermediate-mass ...
Cavichia, O.   +2 more
core   +2 more sources

An autonomous and economical benthic incubation chamber for measuring dissolved oxygen fluxes in shallow, low‐flow environments

open access: yesLimnology and Oceanography: Methods, EarlyView.
Abstract Benthic incubation chambers enclose a known volume of water overlying a known area to measure water chemistry changes and are typically used to quantify the metabolic activity of benthic organisms or communities. Here we present an economical benthic incubation chamber for shallow, low‐flow environments, built using off‐the‐shelf components ...
Luke D. Groff   +2 more
wiley   +1 more source

Exploring the Relationship between Stellar Mass, Metallicity, and Star Formation Rate at z ∼ 2.3 in KBSS-MOSFIRE

open access: yesThe Astrophysical Journal
The metal enrichment of a galaxy is determined by the cycle of baryons in outflows, inflows, and star formation. The relative contribution and timescale of each process sets the relationship between stellar mass, metallicity, and the star formation rate (
Nathalie A. Korhonen Cuestas   +6 more
doaj   +1 more source

The mass-metallicity relation of tidal dwarf galaxies

open access: yes, 2015
Dwarf galaxies generally follow a mass-metallicity (MZ) relation, where more massive objects retain a larger fraction of heavy elements. Young tidal dwarf galaxies (TDGs), born in the tidal tails produced by interacting gas-rich galaxies, have been ...
Kroupa, P., Ploeckinger, S., Recchi, S.
core   +1 more source

Germanium‐Based Mid‐Infrared Integrated Photonics

open access: yesLaser &Photonics Reviews, EarlyView.
The mid‐infrared (mid‐IR) spectral range is a part of the electromagnetic spectrum in which most of the molecules have vibrational and rotational resonances. Photonics integration in this wavelength range have thus seen a burst of interest in the recent years, mainly driven by applications related with the detection of chemical and biological ...
Delphine Marris‐Morini   +6 more
wiley   +1 more source

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

open access: yesThe 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   +6 more
doaj   +1 more source

Chemical Evolution of Galaxies

open access: yes, 2001
Chemical abundances provide important clues to the evolution of galaxies. Ionized nebulae are one of the main sources of chemical abundance measurements, especially in external galaxies. Studies of H II regions have shown that the overall metallicity of galaxies increases with galactic luminosity, and that spiral galaxies characteristically have radial
openaire   +2 more sources

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