Results 1 to 10 of about 158,470 (140)

Chemical Abundances from the Continuum [PDF]

Physica Scripta, 2008
The calculation of solar absolute fluxes in the near-UV is revisited, discussing in some detail recent updates in theoretical calculations of bound-free opacity from metals.
Allende Prieto C, Allende Prieto C, Allende Prieto C, Asplund M, Bautista M A, C Allende Prieto, Cunto W, Hubeny I Lanz T, Koesterke L, Nahar S N, Sbordone L   +10 more
core   +2 more sources

Chemical Abundances of Planetary Nebulae in M33 [PDF]

Astronomy & Astrophysics, 2004
Using spectroscopic data presented in Magrini et al. (2003), we have analyzed with the photoionization code CLOUDY 94.00 (Ferland et al. 1998) 11 Planetary Nebulae belonging to the spiral galaxy M 33. Central star temperatures and nebular parameters have
A. Mampaso, Ambartsumian, Armsdorfer, Che, Corradi, Costa, Dufour, Exter, Ferland, Gurzadyan, Henry, Howard, Iben, Jacoby, Jacoby, Jacoby, Kingsburgh, L. Magrini, Leisy, M. Perinotto, Magrini, Mampaso, Maran, Morisset, Peimbert, Perinotto, Phillips, R. L. M. Corradi, Rauch, Richer, Stasinska, Vílchez, Walsh, Walsh   +33 more
core   +2 more sources

Chemical abundances in Seyfert galaxies – VIII. Argon abundance estimates [PDF]

Monthly Notices of the Royal Astronomical Society, 2021
ABSTRACT For the first time, the argon abundance relative to hydrogen abundance (Ar/H) in the narrow line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow emission line intensities of a sample of 64 local Seyfert 2 nuclei (z < 0.25) taken from Sloan Digital Sky Survey DR7 and measured by the
A F Monteiro, O L Dors
  +12 more sources

Chemical abundances in active galaxies [PDF]

Monthly Notices of the Royal Astronomical Society, 2020
ABSTRACT The Sloan Digital Sky Survey (SDSS) has proved to be a powerful resource for understanding the physical properties and chemical composition of star-forming galaxies in the local Universe. The SDSS population of active galactic nuclei (AGNs) remains as of yet less explored in this capacity.
Flury, Sophia R., Moran, Edward C.
openaire   +2 more sources

Chemical Analysis of the Brightest Star of the Cetus II Ultrafaint Dwarf Galaxy Candidate

The Astrophysical Journal, 2023
We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra.
K. B. Webber, T. T. Hansen, J. L. Marshall, J. D. Simon, A. B. Pace, B. Mutlu-Pakdil, A. Drlica-Wagner, C. E. Martínez-Vázquez, M. Aguena, S. S. Allam, O. Alves, E. Bertin, D. Brooks, A. Carnero Rosell, J. Carretero, L. N. da Costa, J. De Vicente, P. Doel, I. Ferrero, D. Friedel, J. Frieman, J. García-Bellido, G. Giannini, D. Gruen, R. A. Gruendl, S. R. Hinton, D. L. Hollowood, K. Honscheid, K. Kuehn, J. Mena-Fernández, F. Menanteau, R. Miquel, R. L. C. Ogando, M. E. S. Pereira, A. Pieres, A. A. Plazas Malagón, E. Sanchez, B. Santiago, J. Allyn Smith, M. Smith, E. Suchyta, G. Tarle, C. To, N. Weaverdyck, B. Yanny   +44 more
doaj   +1 more source

Understanding the Chemical Evolution of Blue Edge-on Low Surface Brightness Galaxies

The Astrophysical Journal, 2023
We present a sample of 330 blue edge-on low surface brightness galaxies (ELSBGs). To understand the chemical evolution of ELSBGs, we derived the gas-phase abundance and the [ α /Fe] ratio.
Tian-wen Cao, Hong Wu, Gaspar Galaz, Venu M. Kalari, Cheng Cheng, Zi-Jian Li, Jun-feng Wang   +6 more
doaj   +1 more source

Direct D-atom Incorporation in Radicals: An Overlooked Pathway for Deuterium Fractionation

The Astrophysical Journal, 2023
Direct D-H exchange in radicals is investigated in a quasi-uniform flow employing chirped-pulse millimeter-wave spectroscopy. Inspired by the H-atom catalyzed isomerization of C _3 H _2 reported in our previous study, D-atom reactions with the propargyl (
Nureshan Dias, Ranil M. Gurusinghe, Bernadette M. Broderick, Tom J Millar, Arthur G. Suits   +4 more
doaj   +1 more source

On the Hunt for the Origins of the Orphan–Chenab Stream: Detailed Element Abundances with APOGEE and Gaia

The Astrophysical Journal, 2023
Stellar streams in the Galactic halo are useful probes of the assembly of galaxies like the Milky Way. Many tidal stellar streams that have been found in recent years are accompanied by a known progenitor globular cluster or dwarf galaxy.
Keith Hawkins, Adrian M. Price-Whelan, Allyson A. Sheffield, Aidan Z. Subrahimovic, Rachael L. Beaton, Vasily Belokurov, Denis Erkal, Sergey E. Koposov, Richard R. Lane, Chervin F. P. Laporte, Christian Nitschelm   +10 more
doaj   +1 more source

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, M Valerdi, R A Riffel, R Riffel, M V Cardaci, G F Hägele, Mark Armah, M Revalski, S R Flury, P Freitas-Lemes, E B Amôres, A C Krabbe, L Binette, A Feltre, T Storchi-Bergmann   +14 more
openaire   +3 more sources

Origin of cosmic chemical abundances [PDF]

Monthly Notices of the Royal Astronomical Society, 2015
Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the ...
Maio, Umberto, Tescari, Edoardo
openaire   +2 more sources