Using open clusters as tracers of the galactic disk history

2017 ◽  
Vol 13 (S334) ◽  
pp. 312-313
Author(s):  
Orlando J. Katime Santrich ◽  
Silvia Rossi ◽  
Yuri Abuchaim ◽  
Geraldo Gonçalves
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Spectroscopic Analysis ◽  
Galactic Disk ◽  
Dynamical Behavior ◽  
Open Clusters ◽  
Atmospheric Parameters ◽  
Giant Stars ◽  
Stellar Formation ◽  
Formation And Evolution

AbstractOpen clusters are important objects to study the galactic structure and its dynamical behavior as well as the stellar formation and evolution. We carried out a spectroscopic analysis to derive atmospheric parameters and chemical composition for 52 giant stars within 9 galactic open clusters. We have used the high-resolution spectra from FEROS, HARPS and UVES in the ESO archive. The methodology used is based on LTE-hypothesis. Abundances of C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Ni, YII, LaII, CeII, and NdII were calculated. Although most of these clusters present spectroscopic analysis in the literature, some CNO and s-process abundances were not previously estimated or were calculated with high uncertainties. Several lines of such elements were identified and used to calculate new abundances and improve some previous one.

scholarly journals High-resolution spectroscopy of giant stars in the open clusters IC 4651 and IC 4725

2017 ◽  
Vol 95 (9) ◽  
pp. 862-868 ◽  
Author(s):  
Orlando J. Katime Santrich ◽  
Silvia Rossi
Keyword(s):  
High Resolution ◽  
Solar Spectrum ◽  
Open Clusters ◽  
High Resolution Spectroscopy ◽  
Local Thermal Equilibrium ◽  
Atmospheric Parameters ◽  
Chemical Abundances ◽  
Abundance Pattern ◽  
Giant Stars ◽  
Disk Structure

Open clusters are important astrophysical laboratories to study the stellar formation and evolution and to verify the disk structure of the Milky Way. We present calculations of stellar atmospheric parameters and s-process abundances for nine giant stars in the galactic open clusters IC 4651 and IC 4725. These objects have their memberships confirmed from dynamic studies and chemical analysis. The high-resolution spectra are available in the FEROS ESO archive. We have applied a line by line analysis relative to Juno solar spectrum to determine the stellar atmospheric parameters and chemical abundances of Y II, Zr I, La II, Ce II, and Nd II under the local thermal equilibrium hypothesis. The obtained results were compared to the literature values. The derived s-process abundance pattern agrees with the most recent behaviors reported for giant stars in galactic open clusters.

scholarly journals Abundances of seven red giants in the open cluster NGC 3114

2009 ◽  
Vol 5 (S266) ◽  
pp. 495-498
Author(s):  
C. B. Pereira ◽  
C. Quireza
Keyword(s):  
Chemical Composition ◽  
Chemical Analysis ◽  
Galactic Disk ◽  
Open Cluster ◽  
Open Clusters ◽  
Red Giants ◽  
The Sun ◽  
Atmospheric Parameters ◽  
Red Giant ◽  
Good Agreement

AbstractWe present a chemical analysis of seven red giants in the open cluster NGC 3114. Our main goal is to investigate the chemical composition of this cluster, which is not yet available in the literature. We employed the FEROS spectrograph on the ESO 2.2m telescope. Atmospheric parameters and metallicity were derived from the measured equivalent widths of several iron lines using the spectral code moog and Kurucz model atmospheres. We obtained the abundances of O, Al, Ca, Mg, Si, Ti, Ni, Cr, Sc, Y, Zr, La, Ce and Nd by measuring the equivalent widths of the absorption lines of these elements. A mean metallicity of [Fe/H] = 0.05 ± 0.13 relative to the Sun was determined from the data of the red-giant members. This result is in good agreement with the Galactic-disk radial distribution of iron traced by open clusters. We did not find any intrinsic star-to-star scatter in the [element/Fe] ratios for the stars in this cluster. We compare our results with investigations of other open clusters. An age of 8.2 Gyr is derived from isochrone fits.

LITHIUM IN THE STELLAR OPEN CLUSTER M67

2007 ◽  
Vol 16 (02n03) ◽  
pp. 391-396 ◽  
Author(s):  
B. L. CANTO MARTINS ◽  
J. D. DO NASCIMENTO ◽  
J. R. DE MEDEIROS ◽  
A. LÈBRE ◽  
O. RICHARD ◽  
...  
Keyword(s):  
High Resolution ◽  
Spectroscopic Analysis ◽  
Open Cluster ◽  
Atmospheric Parameters ◽  
Large Sample ◽  
Giant Stars ◽  
Evolved Stars ◽  
Synthetic Spectra

In this work we present atmospheric parameters and Li abundances, obtained from a detailed spectroscopic analysis, for a large sample of stars with different evolutionary stages (turn-off, subgiant and giant stars) in the open cluster M67. The observations were carried out with high resolution (R ~ 47,000) and high S/N using the UVES+FLAMES at VLT/UT2. From available photometry and computed synthetic spectra for the region around the lithium line at 6707.75 Å, we derive atmospheric parameters (T eff , log g, [ Fe/H ], v sin i) and Li abundances for each star, in order to better understand the level of mixing and convective dilution of evolved stars in M67.

Chemical Composition of a Young Star HD 377

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
Tõnu Kipper
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Main Sequence ◽  
Young Star ◽  
Main Sequence Star ◽  
High Resolution Spectrum ◽  
Atmospheric Parameters

AbstractA high resolution spectrum of a pre-main sequence star HD 377 is analyzed. The atmospheric parameters are found to be: T

The Nature of the Triangulum-Andromeda Stellar Structures

2018 ◽  
Vol 14 (S344) ◽  
pp. 122-124
Author(s):  
J. V. Sales Silva ◽  
H. Perottoni ◽  
K. Cunha ◽  
H. J. Rocha-Pinto ◽  
D. Souto ◽  
...  
Keyword(s):  
High Resolution ◽  
Kinematic Analysis ◽  
Dwarf Galaxies ◽  
Galactic Disk ◽  
Thin Disk ◽  
Atmospheric Parameters ◽  
Chemical Abundances ◽  
The Galaxy ◽  
Stellar Halo ◽  
Debris Cloud

AbstractThe outer stellar halo is home to a number of substructures that are remnants of former interactions of the Galaxy with its dwarf satellites. Triangulum-Andromeda (TriAnd) is one of these halo substructures, found as a debris cloud by Rocha-Pinto et al., (2004) using 2MASS M giants. Would be these structures related to dwarf galaxies or to the galactic disk? To uncover the nature of these stars we performed a high-resolution spectroscopic study (R = 40,000) along with a kinematic analysis using Gaia data. We determined the atmospheric parameters and chemical abundances of Ca and Mg for the 13 TriAnd candidate stars along with their respective orbits. Our results indicate that the TriAnd stars analyzed have a galactic nature but that these stars are not from the local thin disk.

scholarly journals Chemically tagging the Galactic disk: abundance patterns of old open clusters

2008 ◽  
Vol 4 (S254) ◽  
pp. 133-138
Author(s):  
G. M. De Silva ◽  
K. C. Freeman ◽  
J. Bland-Hawthorn
Keyword(s):  
Large Scale ◽  
Galactic Disk ◽  
Chemical Properties ◽  
Open Clusters ◽  
Star Forming ◽  
Abundance Patterns ◽  
Chemical Tagging ◽  
Formation And Evolution ◽  
Moving Groups

AbstractThe long term goal of large-scale chemical tagging is to use stellar elemental abundances as a tracer of dispersed substructures of the Galactic disk. The identification of such lost stellar aggregates and exploring their chemical properties will be key in understanding the formation and evolution of the disk. Present day stellar structures such as open clusters and moving groups are the ideal testing grounds for the viability of chemical tagging, as they are believed to be the remnants of the original larger star-forming aggregates. We examine recent high resolution abundance studies of open clusters to explore the various abundance trends and reassess the prospects of large-scale chemical tagging.

scholarly journals Metallicities for 13 nearby open clusters from high-resolution spectroscopy of dwarf and giant stars

2008 ◽  
Vol 493 (1) ◽  
pp. 309-316 ◽  
Author(s):  
N. C. Santos ◽  
C. Lovis ◽  
G. Pace ◽  
J. Melendez ◽  
D. Naef
Keyword(s):  
High Resolution ◽  
Open Clusters ◽  
High Resolution Spectroscopy ◽  
Giant Stars

scholarly journals Investigation of ancient substructures in the Milky Way: chemical composition study

2009 ◽  
Vol 5 (S265) ◽  
pp. 376-377
Author(s):  
Edita Stonkutė ◽  
Birgitta Nordström ◽  
Gražina Tautvaišienė
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Milky Way ◽  
Galactic Disk ◽  
Optical Telescope ◽  
La Palma ◽  
Dynamical Properties ◽  
Composition Study

AbstractFrom high resolution spectra taken with the spectrograph FIES on the Nordic Optical Telescope, La Palma, we measure abundances of oxygen and α-elements in order to characterize stars which from their dynamical properties are suspected to have originated in disrupted satellites. We find that the chemical composition of investigated stars is homogeneous and distinct from Galactic disk dwarfs, which is providing further evidence of their extragalactic origin.

scholarly journals On The Physical Existence of The Zeta Reticuli Moving Group: A Chemical Composition Analysis

2009 ◽  
Vol 5 (S265) ◽  
pp. 360-361
Author(s):  
Letícia D. Ferreira ◽  
Gustavo F. Porto de Mello ◽  
Licio da Silva
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Spectroscopic Analysis ◽  
Composition Analysis ◽  
Abundance Pattern ◽  
Group A ◽  
Chemical Composition Analysis ◽  
Effective Temperatures ◽  
Ionization Equilibria ◽  
First Time

AbstractWe report the spectroscopic analysis of six kinematical members of the Zeta Reticuli Moving Group, one of them for the first time. We confirm the existence of the Group by establishing a common abundance pattern for four kinematical members. High resolution spectra yielded abundances of Si, Ca, Fe, Ni and Ba, and others. Effective temperatures were derived from the excitation & ionization equilibria of Fe lines of four stars. For these, and the remaining two members, temperatures were derived from colors and the fitting of theoretical spectra to the Hα line, and ages and masses were estimated from theoretical HR diagrams. We suggest that the Group is physical being metal-poor and ~6 Gyr old.

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