New constraints on the multiplicity of massive young stars in Upper Scorpius

Context: Observations and simulations have clearly established that most stars form in multiple systems. Characterizing their properties is thus important for our understanding of the star formation process. Aims: To provide statistics about the number of companions per star over the full range of a...

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Bibliographic Details
Main Authors: Grellmann, Rebekka (Author) , Ratzka, Th. (Author) , Köhler, Rainer (Author) , Preibisch, Th. (Author) , Mucciarelli, P. (Author)
Format: Article (Journal)
Language:English
Published: 10 June 2015
In: Astronomy and astrophysics
Year: 2015, Volume: 578
ISSN:1432-0746
DOI:10.1051/0004-6361/201219577
Online Access:Verlag, Volltext: https://doi.org/10.1051/0004-6361/201219577
Verlag, Volltext: https://www.aanda.org/articles/aa/abs/2015/06/aa19577-12/aa19577-12.html
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Author Notes:R. Grellmann, Th. Ratzka, R. Köhler, Th. Preibisch, and P. Mucciarelli
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Summary:Context: Observations and simulations have clearly established that most stars form in multiple systems. Characterizing their properties is thus important for our understanding of the star formation process. Aims: To provide statistics about the number of companions per star over the full range of angular distances, infrared long-baseline interferometric studies can be employed to fill the gap between spectroscopic and adaptive optics searches. The Upper Scorpius OB association is a good target for such observations, because its stellar content is very well known from both spectroscopic and adaptive optics searches. Methods: We used the ESO Very Large Telescope Interferometer to perform long-baseline interferometric observations of a sample of seven B stars. Furthermore, we used ROSAT X-ray data to search for indications of low-mass companions. Results: With the interferometric observations, we find previously known companions around <i>σ<i/> Sco and HR 6027. For the other targets we determine the parameter space in which the presence of companions can be excluded from our data. For two of the B stars in our sample, <i>π<i/> Sco and HR 6026, the detection of X-ray emission provides indirect evidence of previously unknown low-mass companions. Conclusions: In total we find two previously unknown companions. We can exclude the presence of other unknown companions within the separation range of ~2 to ~100 mas and for a brightness ratio ≥0.1.
Item Description:Gesehen am 09.11.2020
Physical Description:Online Resource
ISSN:1432-0746
DOI:10.1051/0004-6361/201219577