dc.contributor.author | Weigelt, G | |
dc.contributor.author | Grinin, VP | |
dc.contributor.author | Groh, JH | |
dc.contributor.author | Hofmann, K-H | |
dc.contributor.author | Kraus, S | |
dc.contributor.author | Miroshnichenko, AS | |
dc.contributor.author | Schertl, D | |
dc.contributor.author | Tambovtseva, LV | |
dc.contributor.author | Benisty, M | |
dc.contributor.author | Driebe, T | |
dc.contributor.author | Lagarde, S | |
dc.contributor.author | Malbet, F | |
dc.contributor.author | Meilland, A | |
dc.contributor.author | Petrov, R | |
dc.contributor.author | Tatulli, E | |
dc.date.accessioned | 2018-01-15T10:08:13Z | |
dc.date.issued | 2011-03 | |
dc.description.abstract | Context. Circumstellar disks and outflows play a fundamental role in star formation. Infrared spectro-interferometry allows the inner accretion-ejection region to be resolved.
Aims. We study the disk and Brγ-emitting region of MWC 297 with high spatial and spectral resolution and compare our observations with disk-wind models.
Methods. We measured interferometric visibilities, wavelength-differential phases, and closure phases of MWC 297 with a spectral resolution of 12 000. To interpret our MWC 297 observations, we employed disk-wind models.
Results. The measured continuum visibilities confirm previous results that the continuum-emitting region of MWC 297 is remarkably compact. We derive a continuum ring-fit radius of ~2.2 mas (~0.56 AU at a distance of 250 pc), which is ~5.4 times smaller than the 3 AU dust sublimation radius expected for silicate grains (in the absence of radiation-shielding material). The strongly wavelength-dependent and asymmetric Brγ-emitting region is more extended (~2.7 times) than the continuum-emitting region. At the center of the Brγ line, we derive a Gaussian fit radius of ~6.3 mas HWHM (~1.6 AU). To interpret the observations, we employ a magneto-centrifugally driven disk-wind model consisting of an accretion disk, which emits the observed continuum radiation, and a disk wind, which emits the Brγ line. The calculated wavelength-dependent model intensity distributions and Brγ line profiles are compared with the observations (i.e., K-band spectrum, visibilities, differential phases, and closure phases). The closest fitting model predicts a continuum-emitting disk with an inner radius of ~0.3 AU and a disk wind ejection region with an inner radius of ~ 0.5 AU (~17.5 stellar radii). We obtain a disk-wind half-opening angle (the angle between the rotation axis and the innermost streamline of the disk wind) of ~80°, which is larger than in T Tau models, and a disk inclination angle of ~20° (i.e., almost pole-on).
Conclusions. Our observations with a spectral resolution of 12 000 allow us to study the AU-scale environment of MWC 297 in ~10 different spectral channels across the Brγ emission line. We show that the K-band flux, visibilities, and remarkably strong phases can be explained by the employed magneto-centrifugally driven disk wind model. | en_GB |
dc.identifier.citation | Astronomy and Astrophysics, 2011, Vol. 527, article number A103 | en_GB |
dc.identifier.doi | 10.1051/0004-6361/201015676 | |
dc.identifier.uri | http://hdl.handle.net/10871/30970 | |
dc.language.iso | en | en_GB |
dc.publisher | EDP Sciences | en_GB |
dc.rights | © ESO 2011 | en_GB |
dc.subject | stars | en_GB |
dc.subject | individual | en_GB |
dc.subject | MWC 297 / stars | en_GB |
dc.subject | pre-main sequence / stars | en_GB |
dc.subject | winds, outflows / circumstellar matter / techniques | en_GB |
dc.subject | interferometric / techniques | en_GB |
dc.subject | spectroscopic | en_GB |
dc.title | VLTI/AMBER spectro-interferometry of the Herbig Be star MWC 297 with spectral resolution 12 000 | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2018-01-15T10:08:13Z | |
dc.identifier.issn | 0004-6361 | |
dc.description | This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record. | en_GB |
dc.identifier.journal | Astronomy and Astrophysics | en_GB |