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

• Verfasst von: Grellmann, Rebekka [VerfasserIn]
• Verfasst von: Ratzka, Th. [VerfasserIn]
• Verfasst von: Köhler, Rainer [VerfasserIn]
• Verfasst von: Preibisch, Th. [VerfasserIn]
• Verfasst von: Mucciarelli, P. [VerfasserIn]
• Titel: New constraints on the multiplicity of massive young stars in Upper Scorpius
• Verf.angabe: R. Grellmann, Th. Ratzka, R. Köhler, Th. Preibisch, and P. Mucciarelli
• E-Jahr: 2015
• Jahr: 10 June 2015
• Umfang: 11 S.
• Fussnoten: Gesehen am 09.11.2020
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 2015
• Band/Heft Quelle: 578(2015) Artikel Nummer: A84, 11 Seiten
• ISSN Quelle: 1432-0746
• DOI: doi:10.1051/0004-6361/201219577
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1738242285

Abstract

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.