Mid-infrared observations of the circumstellar disks around PDS 66 and CRBR 2422.8-3423

Aims: We present mid-infrared observations and photometry of the circumstellar disks around PDS 66 and CRBR 2422.8-3423, obtained with VISIR/VLT in the N band and for the latter also in the Q band. Our aim is to resolve the inner regions of these protoplanetary disks, which carry potential signatures of intermediate or later stages of disk evolution and ongoing planet formation.
Methods: We determined the radial brightness profiles of our target objects and the corresponding PSF reference that were observed before and after our target objects. Background standard deviations, the standard errors, and the seeing variations during the observations were considered. Adopting a simple radiative transfer model based on parameters taken from previous studies, we derived constraints on the inner-disk hole radius of the dust disk.
Results: Neither of the circumstellar disks around our science targets are spatially resolved in our observations. However, we are able to constrain the inner-disk hole radius to <15.0_-0.5^+0.5 AU and <10.5_-1.0^+0.5 AU for PDS 66 and CRBR 2422.8-3423, respectively. The photometry we performed yields N-band flux densities of 599 ± 8 mJy for PDS 66 and 130 ± 14 mJy for CRBR 2422.8-3423, as well as a Q-band flux density of 858 ± 109 mJy for CRBR 2422.8-3423.