Results 41 to 50 of about 205,088 (284)
Relations between abundance characteristics and rotation velocity for star-forming MaNGA galaxies [PDF]
A&A 623, A122 (2019), 2019 We derive rotation curves, surface brightness profiles, and oxygen abundance distributions for 147 late-type galaxies using the publicly available spectroscopy obtained by the MaNGA survey. Changes of the central oxygen abundance (O/H)_0, the abundance at the optical radius (O/H)_R25, and the abundance gradient with rotation velocity V_rot are examined
arxiv +1 more source
Interstellar Extinction and Elemental Abundances [PDF]
, 2020 Elements in the interstellar medium (ISM) exist in the form of gas or dust. The interstellar extinction and elemental abundances provide crucial constraints on the composition, size and quantity of interstellar dust. Most of the extinction modeling efforts have assumed the total abundances (both in gas and in dust) of the dust-forming elements---known ...
arxiv +1 more source
Chemical abundances in the dwarf galaxy NGC 4163 based on the nebular and auroral emission lines [PDF]
, 2022 We constructed an oxygen abundance map and N/O ratio map of the unusually low excitation dwarf irregular galaxy NGC 4163 based on publicly available spectroscopy obtained by the MaNGA survey. We detected auroral emission line [OII]$\lambda\lambda$7320,7330 which allows us to measure chemical abundance by direct T$_e$ method.
arxiv +1 more source
ON THE SURVIVAL AND ABUNDANCE OF DISK-DOMINATED GALAXIES [PDF]
The Astrophysical Journal, 2009 We study the formation of disk-dominated galaxies in a Lambda CDM universe. Their existence is considered to be a challenge for the Lambda CDM cosmology, because galaxy mergers isotropize stellar disks and trigger angular momentum transport in gas disks, thus fostering the formation of central stellar spheroids. Here, we postulate that the formation of
Koda, Jun +2 more
openaire +7 more sources
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
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
Dust Formation in a Galaxy with Primitive Abundances [PDF]
Science, 2009 Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial.
Sloan, G C +8 more
openaire +5 more sources
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
Complete element abundances of nine stars in the r-process galaxy Reticulum II [PDF]
, 2016 We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II.
Chiti, Anirudh +3 more
core +2 more sources
Abundance Gradients in the Galaxy
The Astrophysical Journal Supplement Series, 2006 Six H II regions at galactocentric distances of R = 10-15 kpc have been observed in the far-IR emission lines of [O III] (52 μm, 88 μm), [N III] (57 μm), and [S III] (19 μm) using the Kuiper Airborne Observatory. These observations have been combined with Very Large Array radio continuum observations of these sources to determine the abundances of O++,
Gwendolyn R. Bell +7 more
openaire +2 more sources