Astronomy and Astrophysics – Astrophysics
Scientific paper
Jun 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009a%26a...500.1065d&link_type=abstract
Astronomy and Astrophysics, Volume 500, Issue 3, 2009, pp.1065-1076
Astronomy and Astrophysics
Astrophysics
6
Stars: Individual: Ab Aur, Stars: Circumstellar Matter, Stars: Pre-Main Sequence, Methods: Observational, Techniques: Interferometric
Scientific paper
Aims: We aim at using the long baselines of the VLT Interferometer and the mid-IR combiner MIDI (8-13 μm) to derive the morphology of the protoplanetary disk surrounding the Herbig Ae star AB Aurigae Methods: We present the first N-band analysis of AB Aur performed with a maximum angular resolution of 17 mas (2.5 AU at the Taurus-Auriga distance). We used the radiative transfer code MC3D and a silicate-dominated dust grain mixture to fit the spectral energy distribution (SED), together with the N-band dispersed visibilities (λ / δλ ~ 30) and to constrain the inner-disk spatial structure. Results: The silicate band is prominent in the ~ 300 mas FOV of the MIDI instrument, the emission reaches 70 to 90% of the total flux measured by ISO. The circumstellar emission (CSE) is resolved even at the shortest baselines. The spectrally dispersed visibilities show a steep drop between 8 and 9.5 μm, followed by a plateau between 10 and 13 μm. Our modelling shows that the observed SED and visibilities can be reproduced with a simple passive disk model. For such a weakly inclined disk (i ~ 30 deg), the mid-IR visibilities can directly determine the flaring index, while the scale height can be subsequently and unambiguously derived from the combination of the spectral and interferometric constraints. The modelling yields typical values for the scale height of about 8 AU at a radial distance of 100 AU and a flaring index in the range 1.25-1.30 for the explored range of model input parameters. Conclusions: The radial structure of the circumstellar inner disk around AB Aur is directly determined by MIDI. The radiative transfer modelling demonstrates the powerful synergy of interferometry and spectro-photometry to alleviate the degeneracy, which may hamper determining the disk morphology. Our analysis supports the classification of AB Aur among the flared disks of the first group in the Meeus classification.
Based on observations collected at ESO (Paranal Observatory) with the VLT Interferometer - Prog ID: 074.C-552 & 076.C-252.
Chesneau Olivier
di Folco Emmanuel
Dutrey Anne
Leinert Ch.
Lopez Belen
No associations
LandOfFree
The flared inner disk of the Herbig Ae star AB Aurigae revealed by VLTI/MIDI in the N-band does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The flared inner disk of the Herbig Ae star AB Aurigae revealed by VLTI/MIDI in the N-band, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The flared inner disk of the Herbig Ae star AB Aurigae revealed by VLTI/MIDI in the N-band will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-775301