HUBBLE SPACE TELESCOPE OBSERVATIONS OF SUB-DAMPED Lyα ABSORBERS AT z < 0.5, AND IMPLICATIONS FOR GALAXY CHEMICAL EVOLUTION [PDF]
, 2015 We report observations of four sub-damped Lyα (sub-DLA) quasar absorbers at z < 0.5 ?> obtained with the Hubble Space Telescope Cosmic Origins Spectrograph. We measure the available neutrals or ions of C, N, O, Si, P, S, Ar, Mn, Fe, and/or Ni.
D. Som +7 more
semanticscholar +1 more source
Chemical evolution of ultra-faint dwarf galaxies in the self-consistently calculated integrated galactic IMF theory [PDF]
Astronomy & Astrophysics, 2020 The galaxy-wide stellar initial mass function (gwIMF) of a galaxy in dependence on its metallicity and star formation rate can be calculated by the integrated galactic IMF (IGIMF) theory.
Zhiqiang Yan, T. Jeřábková, P. Kroupa
semanticscholar +1 more source
A SPECTROSCOPIC STUDY OF BLUE SUPERGIANT STARS IN THE SCULPTOR GALAXY NGC 55: CHEMICAL EVOLUTION AND DISTANCE [PDF]
, 2016 Low-resolution (4.5–5 Å) spectra of 58 blue supergiant stars distributed over the disk of the Magellanic spiral galaxy NGC 55 in the Sculptor group are analyzed by means of non-LTE techniques to determine stellar temperatures, gravities, and ...
R. Kudritzki +7 more
semanticscholar +1 more source
CONTRIBUTION OF NEUTRON STAR MERGERS TO THE r-PROCESS CHEMICAL EVOLUTION IN THE HIERARCHICAL GALAXY FORMATION [PDF]
, 2016 The main astronomical source of r-process elements has not yet been identified. One plausible site is neutron star mergers (NSMs), but from the perspective of the Galactic chemical evolution, it has been pointed out that NSMs cannot reproduce the ...
Y. Komiya, T. Shigeyama
semanticscholar +1 more source
CHEMICAL EVOLUTION LIBRARY FOR GALAXY FORMATION SIMULATION [PDF]
, 2016 We have developed a software library for chemical evolution simulations of galaxy formation under the simple stellar population (SSP) approximation. In this library, all of the necessary components concerning chemical evolution, such as initial mass ...
T. Saitoh
semanticscholar +1 more source
JWST/NIRSpec Measurements of Extremely Low Metallicities in High Equivalent Width Lyα Emitters
The Astrophysical Journal, 2023 Deep Very Large Telescope/MUSE optical integral field spectroscopy has recently revealed an abundant population of ultra-faint galaxies ( M _UV ≈ −15; 0.01 L _⋆ ) at z = 2.9−6.7 due to their strong Ly α emission with no detectable continuum.
Michael V. Maseda +21 more
doaj +1 more source
THE CHEMICAL EVOLUTION OF THE BOÖTES I ULTRA-FAINT DWARF GALAXY [PDF]
, 2016 We present chemical abundance measurements of two metal-poor red giant stars in the ultra-faint dwarf galaxy Boötes I, based on Magellan/MIKE high-resolution spectra.
A. Frebel +3 more
semanticscholar +1 more source
Evolution of the Mass–Metallicity Relation from Redshift z ≈ 8 to the Local Universe
The Astrophysical Journal, 2023 A tight positive correlation between the stellar mass and the gas-phase metallicity of galaxies has been observed at low redshifts. The redshift evolution of this correlation can strongly constrain theories of galaxy evolution.
Danial Langeroodi +19 more
doaj +1 more source
Chemie Ingenieur Technik, EarlyView., 2023 Let us consider an alternative perspective on climate change: The sum of solar radiation and heat generated by human activity result in a net energy input of 1.96 times that of the Sun on the Earth's surface. The expanding global population is expected to exacerbate this issue. Potential solutions are proposed, including replacement and heat recycling.
Martin Bertau, Gerald Steiner
wiley +1 more source
THE NEW MODEL OF CHEMICAL EVOLUTION OF r-PROCESS ELEMENTS BASED ON THE HIERARCHICAL GALAXY FORMATION. I. Ba AND Eu [PDF]
, 2014 We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree.
Y. Komiya +3 more
semanticscholar +1 more source