Results 131 to 140 of about 4,406,721 (399)

The High-Redshift Gas-Phase Mass–Metallicity Relation in FIRE-2

The Astrophysical Journal Letters
The unprecedented infrared spectroscopic capabilities of JWST have provided high-quality interstellar medium metallicity measurements and enabled characterization of the gas-phase mass–metallicity relation (MZR) for galaxies at z ≳ 5 for the first time ...
Andrew Marszewski, Guochao Sun, Claude-André Faucher-Giguère, Christopher C. Hayward, Robert Feldmann   +4 more
doaj   +1 more source

Discovery of Super-enriched Gas ∼1 Gyr after the Big Bang

The Astrophysical Journal Letters, 2023
Abundances of chemical elements in the interstellar and circumgalactic media of high-redshift galaxies offer important constraints on the nucleosynthesis by early generations of stars.
Jianghao Huyan, Varsha P. Kulkarni, Suraj Poudel, Nicolas Tejos, Celine Péroux, Sebastian Lopez   +5 more
doaj   +1 more source

Planetary nebulae: abundances and abundance gradients [PDF]

, 1999
In this work, a review is given of some recent results and problems involved in the determination of chemical abundances of galactic planetary nebulae, particularly regarding disk and bulge objects.
arxiv   +1 more source

New and updated stellar parameters for 90 transit hosts. The effect of the surface gravity

, 2013
Context. Precise stellar parameters are crucial in exoplanet research for correctly determining of the planetary parameters. For stars hosting a transiting planet, determining of the planetary mass and radius depends on the stellar mass and radius, which
Adibekyan, V. Zh., Fernandes, J. M., Israelian, G., Mena, E. Delgado, Montalto, M., Mortier, A., Santos, N. C., Sousa, S. G.   +7 more
core   +1 more source

CHEMICAL ABUNDANCES AND PROPERTIES OF THE IONIZED GAS IN NGC 1705 [PDF]

, 2015
We obtained [O iii] narrow-band imaging and multi-slit MXU spectroscopy of the blue compact dwarf (BCD) galaxy NGC 1705 with FORS2@VLT to derive chemical abundances of planetary nebulae and H ii regions and, more in general, to characterize the ...
F. Annibali, M. Tosi, A. Pasquali, A. Aloisi, M. Mignoli, D. Romano   +5 more
semanticscholar   +1 more source

Unlocking the potential of tumor‐derived DNA in urine for cancer detection: methodological challenges and opportunities

Molecular Oncology, EarlyView.
Urine is a rich source of biomarkers for cancer detection. Tumor‐derived material is released into the bloodstream and transported to the urine. Urine can easily be collected from individuals, allowing non‐invasive cancer detection. This review discusses the rationale behind urine‐based cancer detection and its potential for cancer diagnostics ...
Birgit M. M. Wever, Renske D. M. Steenbergen   +1 more
wiley   +1 more source

Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11

The Astrophysical Journal Letters
We interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 ( z = 10.6) using our state-of-the-art chemical evolution models.
Chiaki Kobayashi, Andrea Ferrara
doaj   +1 more source

Could the Ultra Metal-poor Stars be Chemically Peculiar and Not Related to the First Stars? [PDF]

, 2008
Chemically peculiar stars define a class of stars that show unusual elemental abundances due to stellar photospheric effects and not due to natal variations. In this paper, we compare the elemental abundance patterns of the ultra metal-poor stars with metallicities [Fe/H] $\sim -5 $ to those of a subclass of chemically peculiar stars.
arxiv   +1 more source

On the Influence of Uncertainties in Chemical Reaction Rates on Results of the Astrochemical Modelling

, 2003
With the chemical reaction rate database UMIST95 (Millar et al. 1997) we analyze how uncertainties in rate constants of gas-phase chemical reactions influence the modelling of molecular abundances in the interstellar medium.
A. I. Vasyunin, A. M. Sobolev, B. E. Turner, D. A. Semenov, D. P. Ruffle, D. S. Wiebe, E. Dishoeck van, G. Pineau Forêts des, H.-H. Lee, M. Matsumoto, R. Terzieva, S. W. Stahler, T. J. Millar, Y. H. Teuff Le, Y. Hirahara, Yu. Aikawa, Z.-Y. Li   +16 more
core   +1 more source

Chemical Abundances in Globular Clusters [PDF]

Proceedings of XII International Symposium on Nuclei in the Cosmos — PoS(NIC XII), 2013
The Milky Way globular clusters are ideal laboratories for testing the predictions of nuclear astrophysics. Driven by Hubble Space Telescope photometry and high-resolution multi-object spectrographs on 8m-class telescopes, the study of chemical abundances in globular clusters is a vibrant area of astronomical research.
openaire   +2 more sources