AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved

Details AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved

Nov 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007a%26a...474l..45d&link_type=abstract

Astronomy and Astrophysics, Volume 474, Issue 3, November II 2007, pp.L45-L48

Astronomy and Astrophysics

Astrophysics

25

Techniques: Interferometric, Stars: Agb And Post-Agb, Stars: Circumstellar Matter, Stars: Individual: Iras 08544-4431

Scientific paper

Context: For a large group of post-AGB binaries, the presence of a stable reservoir of dust is postulated. Although this reservoir will influence the final evolution stages of these objects significantly, its actual geometry and structure remains largely unknown. Aims: We aim at determining the dust morphology of a member of this group, IRAS 08544-4431. Methods: We use the interferometric capabilities of the AMBER and MIDI instruments, operating in the K and N-band respectively. The high spatial resolution measurements are used in conjunction with the broad band spectral characteristics to determine the dust geometry, based on self consistent 2D radiative transfer models. Results: We resolve the object in both K and N. Moreover, using the closure phase capabilities of AMBER, we measure in the K-band a large asymmetry of the dusty environment. The interferometric data are clearly incompatible with a spherical outflow. We model the dusty environment with a passive irradiated dusty disc model. Although this model is constrained mainly on the basis of the spectral energy distribution, it reproduces simultaneously the amplitude and closure phase of the visibilities, in both wavelength bands. Conclusions: Our model of a passive, irradiated disc in equilibrium gives an excellent fit to both the K and N-band visibilities and closure phase. The dust around this evolved binary star is indeed locked in a circumbinary disc with a significant scale height. Grain growth, settling, radial mixing and crystallization are efficient in such an environment. We conclude that the circumbinary disc of this evolved object, is governed by the same physical processes that govern the proto-planetary discs around young stellar objects.
Based on observations collected at the European
Southern Observatory, Chile: ESO.076.D-0274, ESO.078.D-0113.

Affiliated with

Also associated with

No associations

Rating

AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved 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 AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and AMBER and MIDI interferometric observations of the post-AGB binary IRAS 08544-4431: the circumbinary disc resolved will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1695602