ADS: "Identifying gaps in flaring Herbig Ae/Be disks using spatially resolved mid-infrared imaging. Are all group I disks transitional?"
Maaskant, K. M.; Honda, M.; Waters, L. B. F. M.; Tielens, A. G. G. M.; Dominik, C.; Min, M.; Verhoeff, A.; Meeus, G.; van den Ancker, M. E.
The evolution of protoplanetary disks towards mature planetary systems is expected to include the formation of 'gaps' in the disk possibly due to planet formation. We studied the disks of four key intermediate mass (Herbig Ae/Be) stars in order to understand the influence of gaps to their observational appearance. We investigate mid-infrared images and perform radiative transfer modeling to examine the radial distribution of dust and PAHs. Our solutions constrain the sizes of the gaps. For one particular object, HD 97048, this is the first detection of a disk gap. The large gaps deplete the entire population of silicate particles with temperatures suitable for prominent mid-infrared feature emission, while small carbonaceous grains and PAHs can still show prominent emission at mid-infrared wavelengths. Our results suggest that many, if not all Herbig disks with weak or no silicate features in the spectrum are disks with large gaps and can be characterized as (pre-)transitional. (2013-05)
ADS: "Mid-IR imaging of the transitional disk of HD169142: Measuring the size of the gap"
Honda, M.; Maaskant, Koen; Okamoto, Y. K.; Kataza, H.; Fukagawa, M.; Waters, L. B. F. M.; Dominik, C.; Tielens, A. G. G. M.; Mulders, G. D.; Min, M.; Yamashita, T.; Fujiyoshi, T.; Miyata, T.; Sako, S.; Sakon, I.; Fujiwara, H.; Onaka, T.
This research studies the geometrical structure of the protoplanetary disk of HD 169142. We proof that there is a large gap in the disk possibly caused by planets. The observed sizes as well as the steep rise of the SED near 20 micron require a disk model with an inner hole the size of 23 AU, making HD 169142 a transitional disk. HD 169142 is one of a growing number of Herbig Ae disks that are classified as group I source and that also require the presence of a large inner gap. It appears that many if not all group I sources may be strong candidates for classification as transitional disks. (2012-04)
ADS: "Sequential star formation in IRAS 06084-0611 (GGD 12-15). From intermediate-mass to high-mass stars"
K. M. Maaskant1,2, A. Bik3, L.B.F.M. Waters4,1, L. Kaper1, Th. Henning3, E. Puga5,6, M. Horrobin7, and J. Kainulainen3
This research studies the complex environment of the high mass star forming region IRAS 06084-0611. We show that the formation history of this cluster can be understood by sequential star formation along the line of sight. (2011-06)
