A silicate disk in the heart of the Ant
- Author(s)
- O. Chesneau, F. Lykou, B. Balick, E. Lagadec, M. Matsuura, Nathan Smith, Alain Spang, Sebastian Wolf, A. A. Zijlstra
- Abstract
We aim at getting high spatial resolution information on the dusty core of bipolar planetary nebulae to directly constrain the shaping process. Methods: We present observations of the dusty core of the extreme bipolar planetary nebula Menzel 3 (Mz 3, Hen 2-154, the Ant) taken with the mid-infrared interferometer MIDI/VLTI and the adaptive optics NACO/VLT. The core of Mz 3 is clearly resolved with MIDI in the interferometric mode, whereas it is unresolved from the Ks to the N bands with single dish 8.2 m observations on a scale ranging from 60 to 250 mas. A striking dependence of the dust core size with the PA angle of the baselines is observed, that is highly suggestive of an edge-on disk whose major axis is perpendicular to the axis of the bipolar lobes. The MIDI spectrum and the visibilities of Mz 3 exhibit a clear signature of amorphous silicate, in contrast to the signatures of crystalline silicates detected in binary post-AGB systems, suggesting that the disk might be relatively young. We used radiative-transfer Monte Carlo simulations of a passive disk to constrain its geometrical and physical parameters. Its inclination (74 degrees $\pm$ 3 degrees) and position angle (5 degrees $\pm$ 5 degrees) are in accordance with the values derived from the study of the lobes. The inner radius is 9$\pm$ 1 AU and the disk is relatively flat. The dust mass stored in the disk, estimated as 1 x 10-5Msun, represents only a small fraction of the dust mass found in the lobes and might be a kind of relic of an essentially polar ejection process.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Washington, University of Manchester, National Astronomical Observatory of Japan, University of California, Berkeley, Max-Planck-Institut für Astronomie, Université Côte d'Azur
- Journal
- Astronomy & Astrophysics
- Volume
- 473
- Pages
- L29-L32
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361:20078268
- Publication date
- 10-2007
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/ae7e1a7b-3e75-40e1-9f6d-e2114e9bac66