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dc.contributor.authorKraus, Stefan
dc.contributor.authorCalvet, Nuria
dc.contributor.authorHartmann, Lee
dc.contributor.authorHofmann, Karl-Heinz
dc.contributor.authorKreplin, Alexander
dc.contributor.authorMonnier, John D.
dc.contributor.authorWeigelt, Gerd
dc.date.accessioned2015-01-09T10:45:32Z
dc.date.issued2012
dc.description.abstractV921 Scorpii is a close binary system (separation 0farcs025) showing the B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which might have been shaped by episodic mass-loss events, possibly triggered by dynamical interactions between the companion and the circumprimary disk. In this paper, we investigate the spatial structure and kinematics of the circumprimary disk, with the aim to obtain new insights into the still strongly debated evolutionary stage. For this purpose, we combine, for the first time, infrared spectro-interferometry (VLTI/AMBER, λ/Δλ = 12, 000) and spectro-astrometry (VLT/CRIRES, λ/Δλ = 100, 000), which allows us to study the AU-scale distribution of circumstellar gas and dust with an unprecedented velocity resolution of 3 km s–1. Using a model-independent photocenter analysis technique, we find that the Brγ-line-emitting gas rotates in the same plane as the dust disk. We can reproduce the wavelength-differential visibilities and phases and the double-peaked line profile using a Keplerian-rotating disk model. The derived mass of the central star is 5.4 ± 0.4 M ☉ ▪ (d/1150 pc), which is considerably lower than expected from the spectral classification, suggesting that V921 Sco might be more distant (d ~ 2 kpc) than commonly assumed. Using the geometric information provided by our Brγ spectro-interferometric data and Paschen, Brackett, and Pfund line decrement measurements in 61 hydrogen recombination line transitions, we derive the density of the line-emitting gas (Ne = (2-6) × 1019 m–3). Given that our measurements can be reproduced with a Keplerian velocity field without an outflowing velocity component and the non-detection of age-indicating spectroscopic diagnostics, our study provides new evidence for the pre-main-sequence nature of V921 Sco.en_GB
dc.description.sponsorshipNASA, through the Sagan Fellowship Programen_GB
dc.identifier.citationVol. 752, article 11en_GB
dc.identifier.doi10.1088/0004-637X/752/1/11
dc.identifier.urihttp://hdl.handle.net/10871/16133
dc.language.isoenen_GB
dc.publisherIOP Publishing for American Astronomical Societyen_GB
dc.relation.urlhttp://dx.doi.org/10.1088/0004-637X/752/1/11en_GB
dc.subjectaccretion, accretion disksen_GB
dc.subjectbinaries: closeen_GB
dc.subjectprotoplanetary disksen_GB
dc.subjectstars: emission-line, Been_GB
dc.subjectstars: individual (V921 Scorpii)en_GB
dc.subjectstars: pre-main sequenceen_GB
dc.subjecttechniques: interferometricen_GB
dc.titleOn the Nature of the Herbig B[e] Star Binary System V921 Scorpii: Geometry and Kinematics of the Circumprimary Disk on Sub-AU Scalesen_GB
dc.typeArticleen_GB
dc.date.available2015-01-09T10:45:32Z
dc.identifier.issn0004-637X
dc.descriptionCopyright © 2012 IOP Publishing / American Astronomical Societyen_GB
dc.identifier.eissn1538-4357
dc.identifier.journalAstrophysical Journalen_GB


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