Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies

Context. An OB association is a gravitationally unbound group of stars. The identification of the members of the association is an important aspect of its study. There are few astrometric membership studies for OB associations, but the combination of these studies with astrophysical techniques becom...

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Detalles Bibliográficos
Autores principales: Corti, Mariela Alejandra, Orellana, Rosa Beatriz
Formato: Articulo
Lenguaje:Inglés
Publicado: 2013
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85526
Aporte de:
id I19-R120-10915-85526
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Open clusters and associations: individual: Centaurus OB1
Open clusters and associations: individual: NGC 4755
Proper motions
Stars: early-type
spellingShingle Ciencias Astronómicas
Open clusters and associations: individual: Centaurus OB1
Open clusters and associations: individual: NGC 4755
Proper motions
Stars: early-type
Corti, Mariela Alejandra
Orellana, Rosa Beatriz
Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
topic_facet Ciencias Astronómicas
Open clusters and associations: individual: Centaurus OB1
Open clusters and associations: individual: NGC 4755
Proper motions
Stars: early-type
description Context. An OB association is a gravitationally unbound group of stars. The identification of the members of the association is an important aspect of its study. There are few astrometric membership studies for OB associations, but the combination of these studies with astrophysical techniques becomes a very powerful tool for this type of research. Aims. We perform new spectroscopic and astrometric studies of the members of the association Centaurus OB1 (Cen OB1) and the open cluster NGC 4755. Methods. To carry out this study we used new spectroscopic optical observations obtained at CASLEO, and proper motion and photometric data from the Tycho-2 Catalogue and other databases available via the Internet. Results. With this investigation we found 52 members of Cen OB1 (l = 303º.7, b = 0º.4) and four members of NGC 4755 (l = 303º.2, b = 2º.5), an open cluster integrated into the Cen OB1 stellar association. The distance, heliocentric radial velocity, proper motion, and age of Cen OB1 are 2.6 ± 0.5 kpc, ~-20 km s<SUP>-1</SUP>, μ<SUB>α</SUB>cosδ = -4.78 ± 0.10 mas yr<SUP>-1</SUP>, μ<SUB>δ</SUB> = -0.93 ± 0.10 mas yr<SUP>-1</SUP>, and ~20 × 10<SUP>6</SUP> years old, respectively. The same parameters found for NGC 4755 are 1.9 ± 0.5 kpc, -18 ± 2 km s<SUP>-1</SUP>, μ<SUB>α</SUB>cosδ = -4.14 ± 0.19 mas yr<SUP>-1</SUP>, μ<SUB>δ</SUB> = -1.09 ± 0.12 mas yr<SUP>-1</SUP>, and ~15 × 10<SUP>6</SUP> years old. The pulsars PSR J1253-5820 and PSR J1254-6150 could have been born as the result of supernovae explosions that occurred in the past by massive members of Cen OB1. We have seen Infrared Astronomical Satellite (IRAS) sources near Cen OB1, that show that star formation is still occurring. The age gradient observed between the different members of Cen OB1 makes it likely that the stellar association and IRAS sources represent different stages of a sequential formation process.
format Articulo
Articulo
author Corti, Mariela Alejandra
Orellana, Rosa Beatriz
author_facet Corti, Mariela Alejandra
Orellana, Rosa Beatriz
author_sort Corti, Mariela Alejandra
title Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
title_short Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
title_full Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
title_fullStr Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
title_full_unstemmed Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
title_sort members of centaurus ob1 and ngc 4755: new spectroscopic and astrometric studies
publishDate 2013
url http://sedici.unlp.edu.ar/handle/10915/85526
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AT orellanarosabeatriz membersofcentaurusob1andngc4755newspectroscopicandastrometricstudies
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