dc.contributor.author | Chen, L. | |
dc.contributor.author | Kreplin, Alexander | |
dc.contributor.author | Wang, Y. | |
dc.contributor.author | Weigelt, Gerd | |
dc.contributor.author | Hofmann, Karl-Heinz | |
dc.contributor.author | Kraus, Stefan | |
dc.contributor.author | Schertl, D. | |
dc.contributor.author | Lagarde, S. | |
dc.contributor.author | Natta, A. | |
dc.contributor.author | Petrov, R. | |
dc.contributor.author | Robbe-Dubois, S. | |
dc.contributor.author | Tatulli, E. | |
dc.date.accessioned | 2015-01-08T14:53:17Z | |
dc.date.issued | 2012-05-10 | |
dc.description.abstract | Aims. We study the sub-AU-scale circumstellar environment of the Herbig Ae star HD 144432 with near-infrared VLTI/AMBER observations to investigate the structure of its inner dust disk.
Methods. The interferometric observations were carried out with the AMBER instrument in the H and K band. We interpret the measured H- and K-band visibilities, the near- and mid-infrared visibilities from the literature, and the spectral energy distribution (SED) of HD 144432 by using geometric ring models and ring-shaped temperature-gradient disk models with power-law temperature distributions.
Results. We derive a K-band ring-fit radius of 0.17 ± 0.01 AU and an H-band radius of 0.18 ± 0.01 AU (for a distance of 145 pc). This measured K-band radius of ~0.17 AU lies in the range between the dust sublimation radius of ~0.13 AU (predicted for a dust sublimation temperature of 1500 K and gray dust) and the prediction of models including backwarming (~0.27 AU). We find that an additional extended halo component is required in both the geometric and temperature-gradient modeling. In the best-fit temperature-gradient model, the disk consists of two components. The inner part of the disk is a thin ring with an inner radius of ~0.21 AU, a temperature of ~1600 K, and a ring thickness ~0.02 AU. The outer part extends from ~1 AU to ~10 AU with an inner temperature of ~400 K. We find that the disk is nearly face-on with an inclination angle of <.
Conclusions. Our temperature-gradient modeling suggests that the near-infrared excess is dominated by emission from a narrow, bright rim located at the dust sublimation radius, while an extended halo component contributes ~6% to the total flux at 2 μm. The mid-infrared model emission has a two-component structure with ~20% of the flux originating from the inner ring and the rest from the outer parts. This two-component structure is indicative of a disk gap, which is possibly caused by the shadow of a puffed-up inner rim. | en_GB |
dc.identifier.citation | Vol. 541, article A104 | en_GB |
dc.identifier.doi | 10.1051/0004-6361/201218818 | |
dc.identifier.uri | http://hdl.handle.net/10871/16132 | |
dc.language.iso | en | en_GB |
dc.publisher | EDP Sciences for European Southern Observatory (ESO) | en_GB |
dc.subject | accretion, accretion disks | en_GB |
dc.subject | techniques: interferometric | en_GB |
dc.subject | protoplanetary disks | en_GB |
dc.subject | circumstellar matter | en_GB |
dc.subject | stars: pre-main sequence | en_GB |
dc.subject | stars: individual: HD 144432 | en_GB |
dc.title | Near-infrared interferometric observation of the Herbig Ae star HD 144432 with VLTI/AMBER | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2015-01-08T14:53:17Z | |
dc.identifier.issn | 0004-6361 | |
dc.description | Copyright © ESO, 2012 | en_GB |
dc.identifier.eissn | 1432-0746 | |
dc.identifier.journal | Astronomy and Astrophysics | en_GB |