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Related papers: Metallicity measurements in AGNs

200 papers

Metallicity is one of the crucial factors that determine stellar evolution. To characterize the properties of stellar populations one needs to know the fraction of stars forming at different metallicities. Knowing how this fraction evolves…

Astrophysics of Galaxies · Physics 2019-07-29 Martyna Chruslinska , Gijs Nelemans

We determine in a homogeneous way the metallicity and individual abundances of a large sample of evolved stars, with and without known planetary companions. Our methodology is based on the analysis of high-resolution echelle spectra. The…

Earth and Planetary Astrophysics · Physics 2015-06-15 J. Maldonado , E. Villaver , C. Eiroa

We use XMM-Newton data of the merging cluster Abell 3667 to analyze its metallicity distribution. A detailed abundance map of the central 1.1x1.1 Mpc region indicates that metals are inhomogeneously distributed in the cluster showing a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 L. Lovisari , W. Kapferer , S. Schindler , C. Ferrari

Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions, in particular to better constrain the solar abundance problem [S. Basu and H.M. Antia, Physics Reports 457, 217 (2008)].…

Solar and Stellar Astrophysics · Physics 2014-05-19 T. Nagayama , J. E. Bailey , G. Loisel , S. B. Hansen , G. A. Rochau , R. C. Mancini , J. J. MacFarlane , I. Golovkin

We have obtained spectroscopic observations from 3600 Angstrom to 9200 Angstrom with FORS at the Very Large Telescope for approximately 70 H II regions located in the spiral galaxies NGC 1232, NGC 1365, NGC 2903, NGC 2997 and NGC 5236.…

Astrophysics · Physics 2009-11-11 Fabio Bresolin , Daniel Schaerer , Rosa Gonzalez Delgado , Grazyna Stasinska

We present a new determination of the metallicity gradient in M33, based on Keck/LRIS measurements of oxygen abundances using the temperature-sensitive emission line [OIII] 4363 A in 61 HII regions. These data approximately triple the…

Astrophysics · Physics 2009-11-13 Erik Rosolowsky , Joshua D. Simon

We present an analysis of $UBVRI$ data from the Selected Area SA 141. By applying recalibrated methods of measuring ultraviolet excess (UVX), we approximate abundances and absolute magnitudes for 368 stars over 1.3 square degrees out to…

Astrophysics of Galaxies · Physics 2009-11-13 Michael H. Siegel , Yuksel Karatas , I. Neill Reid

(Abridged)The X-ray measurements of the ICM metallicity are becoming more frequent due to the availability of powerful X-ray telescope with excellent spatial and spectral resolutions. The information which can be extracted from the…

Astrophysics · Physics 2009-11-13 E. Rasia , P. Mazzotta , H. Bourdin , S. Borgani , L. Tornatore , S. Ettori , K. Dolag , L. Moscardini

The internal distribution of heavy elements, in particular the radial metallicity gradient, offers insight into the merging history of galaxies. Using our cosmological, chemodynamical simulations that include both detailed chemical…

Astrophysics of Galaxies · Physics 2017-08-30 Philip Taylor , Chiaki Kobayashi

The combination of gas-phase oxygen abundances and stellar metallicities can provide us with unique insights into the metal enrichment histories of galaxies. In this work, we compare the stellar and gas-phase metallicities measured within a…

The research focuses on determining the metallicity ([Fe/H]) predicted in the solar twin stars by using various regression modeling techniques which are, Random Forest, Linear Regression, Decision Tree, Support Vector, and Gradient…

Solar and Stellar Astrophysics · Physics 2024-10-10 Sathwik Narkedimilli , Satvik Raghav , Sujith Makam , Prasanth Ayitapu , Aswath Babu H

The chemical composition of high-redshift galaxies is an important property that gives clues to their past history and future evolution. Measuring abundances in distant galaxies with current techniques is often a challenge, and the…

Astrophysics · Physics 2009-11-11 Claus Leitherer

We explore a scenario where metal-poor globular clusters (GCs) are enriched by the first supernovae in the Universe. If the first stars in a 10^7 Msun dark halo were very massive (>180 Msun), then a pair instability supernova from a single…

We investigate electron temperature (Te) and gas-phase oxygen abundance (Z_Te) measurements for galaxies in the local Universe (z < 0.25). Our sample comprises spectra from a total of 264 emission-line systems, ranging from individual HII…

Astrophysics of Galaxies · Physics 2020-02-19 Robert M. Yates , Patricia Schady , Ting-Wan Chen , Tassilo Schweyer , Philip Wiseman

This paper explores the gas metallicity gradients in a sample of 25 nearby galaxies using new Integral Field Spectroscopy observations from the Metal-THINGS survey. We derive and study the resolved diffuse ionised gas content, Baldwin,…

Based on high resolution and high signal-to-noise ratio (S/N) spectra analysis of 90 solar type stars, we have established several new metallicity calibrations in Teff range [5600, 6500] K based on red spectra with the wavelength range of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 J. K. Zhao , G. Zhao , Y. Q. Chen , A. L. Luo

We present a stellar mass-metallicity relation at z~1.4 with an unprecedentedly large sample of ~340 star-forming galaxies obtained with FMOS on the Subaru Telescope. We observed K-band selected galaxies at 1.2 < z_{ph} < 1.6 in the…

The gas-phase metallicity of galaxies is regulated by multiple astrophysical processes, which makes it a crucial diagnostic of galaxy formation and evolution. Beyond the fundamental mass-metallicity relation, a debate about the secondary…

Astrophysics of Galaxies · Physics 2024-08-09 Chengyu Ma , Kai Wang , Enci Wang , Yingjie Peng , Haochen Jiang , Haoran Yu , Cheng Jia , Zeyu Chen , Haixin Li , Xu Kong

We report the first high spectral resolution study of 17 M giants kinematically confirmed to lie within a few parsecs of the Galactic Center, using R=24,000 spectroscopy from Keck/NIRSPEC and a new linelist for the infrared K band. We…

Astrophysics of Galaxies · Physics 2017-11-29 R. M. Rich , N. Ryde , B. Thorsbro , T. K. Fritz , M. Schultheis , L. Origlia , H. Jönsson

The comparison of chemical abundances in the neutral gas of galaxies to photospheric abundances of old and young stars, ionized gas abundances, and abundances in galactic halos can trace the chemical enrichment of the universe through…