The Nearest Herbig Ae Star Transitional Disks
First Author:
Carol Grady
Email: Carol.A.Grady AT nasa.gov
Eureka Scientific & GSFC
Code 667, NASA's GSFC
Greenbelt, MD 20771 USA
Coauthors:
Wisniewski, John, U. Washington
Sitko, Michael L., U. Cincinnati & SSI
Woodgate, Bruce, NASA's GSFC
Kuchner, Marc, NASA's GSFC
Williger, Gerard M., U. Louisville
Collins, Karen A., U. Louisville
Abstract
The shape of this IR spectral energy distribution (SED) has been used to infer the degree of dust grain growth and settling in protoplanetary disks and to distinguish between disks which are geometrically flat, those with constant opening angle, and flared disks. Flared disks are expected to be gas-rich, and concentrated among the younger systems lacking evidence of grain growth and settling, and in those with higher current accretion rates. However, transitional disks with dust deficits in the inner disk have similar SEDs to flared disks. By combining SED data, disk outer radius measures, and the radial surface brightness of the disk in scattered light, we test the hypothesis that the majority of Herbig Ae star disks detected in scattered light have flared disks. Instead, we find that the majority of these disks are flatter structures. Low current accretion rates sampled by FUSE FUV spectra further suggest that these disks are the nearest intermediate-mass transitional disks.
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