Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-29T09:34:00.888Z Has data issue: false hasContentIssue false

Protoplanetary disks around Herbig Ae/Be stars: Indications from ISO spectroscopy

Published online by Cambridge University Press:  26 May 2016

M.E. van den Ancker*
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

An analysis of solid-state features in infrared spectra of 46 Herbig Ae/Be stars is presented. The presence of solid-state emission bands is compared to other indicators of circumstellar material, such as Hα emission, optical variability and sub-mm continuum fluxes. The correlation between these different indicators is weak, if present at all, in our sample. However, a strong dependence on spectral type of the central star seems to be present: stars with spectral type earlier than B9 show either amorphous silicate in absorption or infrared spectra dominated by PAH emission, whereas more than 70% of the stars of later spectral type show silicate emission. We conclude that the infrared spectrum of Herbig Be stars is in general dominated by emission from the circumstellar envelope, whereas the lower-mass Herbig Ae stars show a spectrum that is dominated by a disk that is passively heated by the central star.

Type
Part IV: Protoplanetary and β Pic disks
Copyright
Copyright © Astronomical Society of the Pacific 2004 

References

Bernasconi, P.A. 1996, A&AS, 120, 57.Google Scholar
Hillenbrand, L.A., Strom, S.E., Vrba, F.J., & Keene, J. 1992, ApJ, 397, 613.Google Scholar
Kessler, M.F., Steinz, J.A., Anderegg, M.E. et al., 1996, A&A, 315, L27.Google Scholar
Malfait, K., Waelkens, C., Waters, L.B.F.M., Vandenbussche, B., Huygen, E., & de Graauw, M.S. 1998, A&A, 332, L25.Google Scholar
Malfait, K., Waelkens, C., Bouwman, J., de Koter, A., & Waters, L.B.F.M. 1999, A&A, 345, 181.Google Scholar
van den Ancker, M.E., de Winter, D., & Tjin A Djie, H.R.E. 1998, A&A, 330, 145.Google Scholar
van den Ancker, M.E., Bouwman, J., Wesselius, PR., Waters, L.B.F.M., Dougherty, S.M., & van Dishoeck, E.F. 1999, A&A, 357, 325.Google Scholar