Introduction to Oxygen Abundances

What is/are Oxygen Abundances?

Oxygen Abundances - We report a saturation of Oxygen abundances for the nuclear regions of SFG. ^[1] However, simultaneous, bounded constraints on both carbon and oxygen abundances, which are key for understanding giant planet formation (Oeberg et al. ^[2] 5) star-forming galaxies (SFGs) with respect to oxygen abundances, stellar masses M?, far-UV absolute magnitudes MFUV, star-formation rates SFR and specific star-formation rates sSFR, Lyman-continuum photon production efficiencies (ξion), UV continuum slopes β, [O III] λ5007/[O II] λ3727 and [Ne III] λ3868/[O II] λ3727 ratios, and emission-line equivalent widths EW([O II] λ3727), EW([O III] λ5007), and EW(Hα). ^[3] Using the extremely high O32 in J2229+2725, we have improved the strong-line calibration for the determination of oxygen abundances in the most metal-deficient galaxies, in the range 12 + logO/H $\lesssim$ 7. ^[4] We rederive the oxygen abundances of all CHAOS galaxies using this new temperature prioritization method, and we find that the gradients are consistent with the results of a recent study of Berg et al. ^[5] Oxygen abundances, derived using different lines, were taken from previous papers in this series and updated with the new stellar parameters. ^[6] The relative intensities of emission lines were used to derive the ionic and total neon and oxygen abundances through electron temperature estimations (Te-method). ^[7] Moreover, dayside atomic oxygen abundances also vary periodically as the Kelvin wave momentarily decreases horizontal wind speeds and enhances atomic oxygen abundances, explaining the observations of EUV oxygen dayglow. ^[8] 49, selected from the Sloan Digital Sky Survey (SDSS) to be local analogues of high-redshift galaxies, was used to analyze their most prominent emission lines and to derive total oxygen abundances and nitrogen-to-oxygen ratios following the direct method in the ranges 7. ^[9] We extract spectra from emission line regions identified within dendrograms, combine emission line ratios and line widths to distinguish between ${\rm H\, \small {II}}$ regions, planetary nebulae, and supernova remnants, and compute their ionised gas properties, gas-phase oxygen abundances, and feedback-related pressure terms. ^[10] The oxygen abundances for the bulk of compact galaxies are distributed in the range 7. ^[11] Deriving oxygen abundances using optical spectra often relies on empirical strong-line calibrations calibrated to the direct method. ^[12] Increases in WC carbon and oxygen abundances turn out to slightly reduce the predicted mass-loss rates. ^[13] We have determined the gas phase oxygen abundances for 7,138 HII regions across the disks of eight nearby galaxies using VLT/MUSE optical integral field spectroscopy as part of the PHANGS-MUSE survey. ^[14] The three sequences of low-mass stars in NGC 6752 are consistent with stellar populations with different oxygen abundances. ^[15] The motivation for such a study is clearly explained in the Introduction which provides a comprehensive description of the historic use of these spectra in remote sensing of the mesopause temperature and the retrieval of atomic oxygen abundances. ^[16] Non-LTE analysis of the oxygen abundances for 51 Galactic A-, F- and G-type supergiants and bright giants is performed. ^[17] Oxygen abundances were then derived via strong emission lines using a Bayesian approach. ^[18] First, I briefly summarise the global spectroscopic properties of these galaxies, discussing the main ionization processes, and the global relations described between the star-formation rates, oxygen abundances, and average properties of their stellar populations (age and metallicity) with the stellar mass. ^[19] In the first paper of the series we describe the project and present a sample of 18 void galaxies with oxygen abundances that fall below the reference `metallicity-luminosity' relation, or with possible signs of recent external accretion in their optical morphology. ^[20] For the first time, we take into account three-dimensional (3D) hydrodynamic effects together with departures from local thermodynamic equilibrium (LTE) when determining both the stellar parameters and the elemental abundances, by deriving effective temperatures from 3D non-LTE H$\beta$ profiles, surface gravities from Gaia parallaxes, iron abundances from 3D LTE Feii equivalent widths, and carbon and oxygen abundances from 3D non-LTE Ci and Oi equivalent widths. ^[21] We characterise the HII regions in terms of their sizes, morphologies, ionisation structure, luminosity and kinematics, and derive oxygen abundances via emission line ratios. ^[22] Stellar parameters (effective temperature, surface gravity, projected rotational velocity, microturbulence, and macroturbulence) and silicon and oxygen abundances are presented for 28 stars located beyond 9 kpc from the Galactic centre plus three stars in the solar neighborhood. ^[23] We also derived the oxygen abundances of all the six regions adopting indirect method calibrations. ^[24] Star-forming regions on this galaxy display oxygen abundances that are consistent with solar metallicities. ^[25] The calculated data are important for modelling stellar spectra, leading to accurate oxygen abundances. ^[26] We measured oxygen abundances for ten cluster galaxies with detected [NII] lines in the individual galaxy spectra and compared the MZR of the galaxies inside half R200 with the infalling galaxies and a field sample at similar redshifts. ^[27] A giant planet forming in the inner disk would be accreting gas with low carbon and oxygen abundances as well as very little icy dust, potentially leading to a planet atmosphere with strongly substellar C/H and O/H ratios. ^[28] This paper presents a new dataset of nighttime atomic oxygen density [O], derived from OH(8–4) ro-vibrational band emissions, using a non-local thermal equilibrium model, with the aim of offering new insight into the atomic oxygen abundances in the mesopause region. ^[29] This paper presents a new dataset of nighttime atomic oxygen density [O], derived from OH(8–4) ro-vibrational band emissions, using a non-local thermal equilibrium model, with the aim of offering new insight into the atomic oxygen abundances in the mesopause region. ^[30] Using literature and MUSE emission line fluxes, we derived gas-phase metallicities (oxygen abundances) for over 10 000 individual regions and determine characteristic metallicities for each galaxy. ^[31]

Atomic Oxygen Abundances

Moreover, dayside atomic oxygen abundances also vary periodically as the Kelvin wave momentarily decreases horizontal wind speeds and enhances atomic oxygen abundances, explaining the observations of EUV oxygen dayglow. ^[1] The motivation for such a study is clearly explained in the Introduction which provides a comprehensive description of the historic use of these spectra in remote sensing of the mesopause temperature and the retrieval of atomic oxygen abundances. ^[2] This paper presents a new dataset of nighttime atomic oxygen density [O], derived from OH(8–4) ro-vibrational band emissions, using a non-local thermal equilibrium model, with the aim of offering new insight into the atomic oxygen abundances in the mesopause region. ^[3] This paper presents a new dataset of nighttime atomic oxygen density [O], derived from OH(8–4) ro-vibrational band emissions, using a non-local thermal equilibrium model, with the aim of offering new insight into the atomic oxygen abundances in the mesopause region. ^[4]

Phase Oxygen Abundances

We extract spectra from emission line regions identified within dendrograms, combine emission line ratios and line widths to distinguish between ${\rm H\, \small {II}}$ regions, planetary nebulae, and supernova remnants, and compute their ionised gas properties, gas-phase oxygen abundances, and feedback-related pressure terms. ^[1] We have determined the gas phase oxygen abundances for 7,138 HII regions across the disks of eight nearby galaxies using VLT/MUSE optical integral field spectroscopy as part of the PHANGS-MUSE survey. ^[2]