A Washington photometric survey of the Large Magellanic Cloud field star population

We present photometry for an unprecedented database of some 5.5 million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6deg 2, obtained from Washington CT 1 T 2 CTIO 4m MOSAIC data. Extensive artificial star tests over the whole mosaic im...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Piatti, A.E., Geisler, D., Mateluna, R.
Formato: JOUR
Materias:
galaxies: individual (LMC)
galaxies: star clusters: general
Magellanic Clouds
techniques: photometric
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00046256_v144_n4_p_Piatti
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00046256_v144_n4_p_Piatti
record_format dspace
spelling todo:paper_00046256_v144_n4_p_Piatti2023-10-03T13:59:42Z A Washington photometric survey of the Large Magellanic Cloud field star population Piatti, A.E. Geisler, D. Mateluna, R. galaxies: individual (LMC) galaxies: star clusters: general Magellanic Clouds techniques: photometric We present photometry for an unprecedented database of some 5.5 million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6deg 2, obtained from Washington CT 1 T 2 CTIO 4m MOSAIC data. Extensive artificial star tests over the whole mosaic image data set and the observed behavior of the photometric errors with magnitude demonstrate the accuracy of the morphology and clearly delineate the position of the main features in the color-magnitude diagrams (CMDs). The representative T 1(MS TO) mags are on average ∼0.5mag brighter than the T 1 mags for the 100% completeness level of the respective field, allowing us to derive an accurate age estimate. We have analyzed the CMD Hess diagrams and used the peaks in star counts at the main sequence turnoff and red clump (RC) locations to age date the most dominant sub-population (or "representative" population) in the stellar population mix. The metallicity of this representative population is estimated from the locus of the most populous red giant branch track. We use these results to derive age and metallicity estimates for all of our fields. The analyzed fields span age and metallicity ranges covering most of the galaxy's lifetime and chemical enrichment, i.e., ages and metallicities between ∼1 and 13Gyr and ∼-0.2 and -1.2dex, respectively. We show that the dispersions associated with the mean ages and metallicities represent in general a satisfactory estimate of the age/metallicity spread (∼1-3Gyr/0.2-0.3dex), although a few subfields have a slightly larger age/metallicity spread. Finally, we revisit the study of the vertical structure (VS) phenomenon, a striking feature composed of stars that extend from the bottom, bluest end of the RC to ∼0.45mag fainter. We confirm that the VS phenomenon is not clearly seen in most of the studied fields and suggest that its occurrence is linked to some other condition(s) in addition to the appropriate age, metallicity, and the necessary red giant star density. © 2012. The American Astronomical Society. All rights reserved. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00046256_v144_n4_p_Piatti
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic galaxies: individual (LMC)
galaxies: star clusters: general
Magellanic Clouds
techniques: photometric
spellingShingle galaxies: individual (LMC)
galaxies: star clusters: general
Magellanic Clouds
techniques: photometric
Piatti, A.E.
Geisler, D.
Mateluna, R.
A Washington photometric survey of the Large Magellanic Cloud field star population
topic_facet galaxies: individual (LMC)
galaxies: star clusters: general
Magellanic Clouds
techniques: photometric
description We present photometry for an unprecedented database of some 5.5 million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6deg 2, obtained from Washington CT 1 T 2 CTIO 4m MOSAIC data. Extensive artificial star tests over the whole mosaic image data set and the observed behavior of the photometric errors with magnitude demonstrate the accuracy of the morphology and clearly delineate the position of the main features in the color-magnitude diagrams (CMDs). The representative T 1(MS TO) mags are on average ∼0.5mag brighter than the T 1 mags for the 100% completeness level of the respective field, allowing us to derive an accurate age estimate. We have analyzed the CMD Hess diagrams and used the peaks in star counts at the main sequence turnoff and red clump (RC) locations to age date the most dominant sub-population (or "representative" population) in the stellar population mix. The metallicity of this representative population is estimated from the locus of the most populous red giant branch track. We use these results to derive age and metallicity estimates for all of our fields. The analyzed fields span age and metallicity ranges covering most of the galaxy's lifetime and chemical enrichment, i.e., ages and metallicities between ∼1 and 13Gyr and ∼-0.2 and -1.2dex, respectively. We show that the dispersions associated with the mean ages and metallicities represent in general a satisfactory estimate of the age/metallicity spread (∼1-3Gyr/0.2-0.3dex), although a few subfields have a slightly larger age/metallicity spread. Finally, we revisit the study of the vertical structure (VS) phenomenon, a striking feature composed of stars that extend from the bottom, bluest end of the RC to ∼0.45mag fainter. We confirm that the VS phenomenon is not clearly seen in most of the studied fields and suggest that its occurrence is linked to some other condition(s) in addition to the appropriate age, metallicity, and the necessary red giant star density. © 2012. The American Astronomical Society. All rights reserved.
format JOUR
author Piatti, A.E.
Geisler, D.
Mateluna, R.
author_facet Piatti, A.E.
Geisler, D.
Mateluna, R.
author_sort Piatti, A.E.
title A Washington photometric survey of the Large Magellanic Cloud field star population
title_short A Washington photometric survey of the Large Magellanic Cloud field star population
title_full A Washington photometric survey of the Large Magellanic Cloud field star population
title_fullStr A Washington photometric survey of the Large Magellanic Cloud field star population
title_full_unstemmed A Washington photometric survey of the Large Magellanic Cloud field star population
title_sort washington photometric survey of the large magellanic cloud field star population
url http://hdl.handle.net/20.500.12110/paper_00046256_v144_n4_p_Piatti
work_keys_str_mv AT piattiae awashingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
AT geislerd awashingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
AT matelunar awashingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
AT piattiae washingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
AT geislerd washingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
AT matelunar washingtonphotometricsurveyofthelargemagellaniccloudfieldstarpopulation
_version_ 1807316746649993216

Ejemplares similares