Optimizing HST High-Contrast Imaging Observations of a Planet-Forming Disk

Recent developments in direct imaging of young stellar objects have unveiled actively forming planets and various complex structures in protoplanetary disks, which could be advance indicators of ongoing planet formation. However, due to factors such as imperfect PSF subtraction and retention of disk flux, it has proven difficult to quantize the confidence of direct imaging detections. We present Hubble Space Telescope direct imaging data of RX J1604.3-2130 and demonstrate a set of image processing techniques that allow us to robustly identify the disk's features. We have performed both Angular and Reference Differential Imaging (ADI, RDI) on these data in order to remove the stellar flux and probe the faint disk and potential protoplanet candidates. After thorough exploration of relevant parameters that can affect subtraction results, we developed a robust criterion to optimize the signal-to-noise ratio of potential planetary signals, and now present a tool that can replicate these results for general use. Through the injection and recovery of physically-motivated models of accreting protoplanets, we show that it is likely that a Jupiter-mass protoplanet accreting at 10^-8 Jupiter masses per year is detectable. These images also reveal interesting geometric structures that could trace the formation of planets.