Flaring and self-shadowed disks around Herbig Ae stars: simulations for 10 μm interferometers

¹ Sterrenkundig Instituut “Anton Pannekoek”, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands e-mail: vboekel@science.uva.nl
² European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching, Germany
³ Max-Planck-Institut für Astronomie Heidelberg, Königstuhl 17, Heidelberg, Germany

Received: 26 October 2004
Accepted: 27 June 2005

Abstract

We present simulations of the interferometric visibilities of Herbig Ae star disks. We investigate whether interferometric measurements in the 10 μm atmospheric window are sensitive to the presence of an increased scale height at the inner disk edge, predicted by recent models. Furthermore, we investigate whether such measurements can discriminate between disks with a “flaring” geometry and disks with a “flat” geometry. We show that both these questions can be addressed, using measurements at a small number of appropriately chosen baselines. The classification of Herbig Ae stars in two groups, based on the appearance of the spectral energy distribution (SED), has been attributed to a difference in disk geometry. Sources with a group I SED would have a flaring outer disk geometry, whereas the disk of group II sources is proposed to be flat (or “self-shadowed”). We show that this hypothesis can be tested using long-baseline interferometric measurements in the 10 μm atmospheric window.