A study of the B and Be star population in the field of the LMC open cluster NGC2004 with VLT-FLAMES
- Others:
- Galaxies, Etoiles, Physique, Instrumentation (GEPI) ; Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris ; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
- Observatorio Astronomico de la Universidad de Valencia ; Universitat de València (UV)
- Royal Observatory of Belgium [Brussels] (ROB)
- Instituut voor Sterrenkunde [Leuven] ; Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven)
- Observatoire de la Côte d'Azur (OCA) ; Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Institut d'Astrophysique de Paris (IAP) ; Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Description
Observations of hot stars belonging to the young cluster LMC-NGC2004 and its surrounding region have been obtained with the VLT-GIRAFFE facilities in MEDUSA mode. 25 Be stars were discovered; the proportion of Be stars compared to B-type stars is found to be of the same order in the LMC and in the Galaxy fields. 23 hot stars were discovered as spectroscopic binaries (SB1 and SB2), 5 of these are found to be eclipsing systems from the MACHO database, with periods of a few days. About 75% of the spectra in our sample are polluted by hydrogen (Halpha and Hgamma), [SII] and [NII] nebular lines. These lines are typical of HII regions. They could be associated with patchy nebulosities with a bi-modal distribution in radial velocity, with higher values (+335 kms^{-1}) preferentially seen inside the southern part of the known bubble LMC4 observed in HI at 21 cm.
Abstract
12 pages, 17 figures, accepted to A&A
Additional details
- URL
- https://hal.archives-ouvertes.fr/hal-00008693
- URN
- urn:oai:HAL:hal-00008693v1
- Origin repository
- UNICA