Results 61 to 70 of about 948,048 (332)
Emission-line Diagnostics of Low Metallicity AGN [PDF]
, 2006 Current emission-line based estimates of the metallicity of active galactic nuclei (AGN) at both high and low redshifts indicate that AGN have predominantly solar to supersolar metallicities. This leads to the question: do low metallicity AGN exist?
Groves, Brent +2 more
core +3 more sources
Chemical abundances in Seyfert galaxies – X. Sulphur abundance estimates
Monthly Notices of the Royal Astronomical Society, 2023 ABSTRACT For the first time, the sulphur abundance relative to hydrogen (S/H) in the narrow-line regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission-line intensities from the Sloan Digital Sky Survey (SDSS) Data Release 17 (DR17) [in the wavelength range 3000
Oli L Dors +14 more
openaire +3 more sources
Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III [PDF]
Astrophysical Journal, 2019 We present the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we determined the abundances of nine stars in Car II ...
A. Ji +17 more
semanticscholar +1 more source
Molecular tracers of PDR-dominated galaxies [PDF]
, 2009 Photon-dominated regions (PDRs) are powerful molecular line emitters in external galaxies. They are expected in galaxies with high rates of massive star formation due to either starburst (SB) events or starburst coupled with active galactic nuclei (AGN ...
Bayet +37 more
core +2 more sources
Element Abundances In Nearby Galaxies [PDF]
, 2004 In these lectures I present a highly opinionated review of the observed patterns of metallicity and element abundance ratios in nearby spiral, irregular, and dwarf elliptical galaxies, with connection to a number of astrophysical issues associated with chemical evolution.
openaire +2 more sources
OXYGEN ABUNDANCE MEASUREMENTS OF SHIELD GALAXIES [PDF]
The Astrophysical Journal, 2015 We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey.
Haurberg, Nathalie C. +3 more
openaire +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++,
Alexander L. Rudolph +6 more
openaire +1 more source
CUMULATIVE OXYGEN ABUNDANCES OF SPIRAL GALAXIES [PDF]
The Astrophysical Journal, 2012 14 pages, 7 figures, 5 ...
Dack, Stuart, McCall, Marshall L.
openaire +2 more sources
Baryon-CDM isocurvature galaxy bias with IllustrisTNG [PDF]
Journal of Cosmology and Astroparticle Physics, 2019 We study the impact that baryon-CDM relative density perturbations δbc have on galaxy formation using cosmological simulations with the IllustrisTNG model.
A. Barreira +3 more
semanticscholar +1 more source
Validity of abundances derived from spaxel spectra of the MaNGA survey [PDF]
, 2017 We measured the emission lines in the spaxel spectra of MaNGA galaxies in order to determine the abundance distributions therein. It has been suggested that the strength of the low-ionization lines, R_2, N_2, and S_2 may be increased (relative to Balmer ...
Berczik, P. P. +6 more
core +2 more sources