Periodic Reporting for period 1 - SPICES (Statistics-driven Planet Imaging in Circumstellar Environments)
Berichtszeitraum: 2023-06-01 bis 2025-05-31
Nearly 6000 exoplanets have been detected to date, showing a great diversity in planetary system architectures that is substantially advancing our knowledge of planet formation and evolution. However, the majority of these discoveries come from systems that have their birth environments dissipated, precluding the exploration of the early stages of planetary systems. In contrast, direct imaging of protoplanets – the most effective means to probe these formation stages – remains extremely rare, with less than 5 such planets imaged so far. Meanwhile, the images of over 100 circumstellar disks in the past decade hint the existence of such elusive protoplanets. The SPICES project is designed to bridge the gap between high quality direct imaging datasets and the current limitation of data analysis methods. By refining and advancing applied mathematical methods for astronomical imaging, SPICES remarks an interdisciplinary exploration on the earliest stages of planet formation.
To push the boundaries of planet formation through direct imaging, the SPICES project is built around two synergistic objectives that drive our quest to understand the genesis of planetary systems:
1. SAFFRON (Spiral Arm Formation From mOtion aNalysis) Survey: Illuminating Hidden Worlds
By re-imaging spiral features in protoplanetary disks, the SAFFRON survey is dedicated to unearthing the subtle signatures of hidden planets residing within circumstellar environments. With a temporal separation of nearly 5 years, we can extract spiral motion signals that suggest the presence of nascent planetary bodies. The results then guide targeted direct imaging follow-up, facilitating the imaging of the next protoplanets.
2. Spectroscopic Characterization of Circumstellar Disks: Decoding the Building Blocks' Mineralogy
The imaging of circumstellar disks at multiple wavelengths, i.e. spectroscopy, informs their mineralogical composition. With current high-contrast imaging data reduction facing inherent computational compromises, advanced data imputation techniques can provide authentic disk images. This can enable a precise characterization of dust properties and opens the possibility to detect water ice tracers—key indicators of water reservoirs that might foster Earth analogs. With a systematic extraction of spectroscopy for circumstellar disks, we can explore the compositional trends for the building blocks of planetary formation sites. This not only informs the bulk composition of potential planets, but also facilitates a full exploration of the integral field spectrograph instruments in current and future high-contrast imagers.
To push the boundaries of planet formation through direct imaging, the SPICES project is built around two synergistic objectives that drive our quest to understand the genesis of planetary systems:
1. SAFFRON (Spiral Arm Formation From mOtion aNalysis) Survey: Illuminating Hidden Worlds
By re-imaging spiral features in protoplanetary disks, the SAFFRON survey is dedicated to unearthing the subtle signatures of hidden planets residing within circumstellar environments. With a temporal separation of nearly 5 years, we can extract spiral motion signals that suggest the presence of nascent planetary bodies. The results then guide targeted direct imaging follow-up, facilitating the imaging of the next protoplanets.
2. Spectroscopic Characterization of Circumstellar Disks: Decoding the Building Blocks' Mineralogy
The imaging of circumstellar disks at multiple wavelengths, i.e. spectroscopy, informs their mineralogical composition. With current high-contrast imaging data reduction facing inherent computational compromises, advanced data imputation techniques can provide authentic disk images. This can enable a precise characterization of dust properties and opens the possibility to detect water ice tracers—key indicators of water reservoirs that might foster Earth analogs. With a systematic extraction of spectroscopy for circumstellar disks, we can explore the compositional trends for the building blocks of planetary formation sites. This not only informs the bulk composition of potential planets, but also facilitates a full exploration of the integral field spectrograph instruments in current and future high-contrast imagers.
Method development: we have developed the Karhunen-Loève Data Imputation (DIKL) method, which analytically imputes missing data for imaging datasets to authentically recover disk images. DIKL is 5 orders of magnitude faster than existing iterative methods.
Scientific exploration: we have obtained high quality protoplanetary disk images in total intensity light, offering polarization fraction maps and phase functions systematically for the first time.
Instrumentation demonstration: we have pioneered the usage of Hubble Space Telescope's STIS coronagraph in obtaining the host galaxy image of the prototypical quasar 3C 273.
Scientific exploration: we have obtained high quality protoplanetary disk images in total intensity light, offering polarization fraction maps and phase functions systematically for the first time.
Instrumentation demonstration: we have pioneered the usage of Hubble Space Telescope's STIS coronagraph in obtaining the host galaxy image of the prototypical quasar 3C 273.
Analytical imputation method: we developed the Karhunen-Loève Data Imputation (DIKL) method, which analytically imputes missing data for imaging datasets. Being an analytical approach, DIKL is 5 orders of magnitude faster than existing iterative methods. DIKL enables large scale data analysis not just for datasets from high-contrast imaging of planetary systems, but also for more general data analysis scenarios.
Quasar coronagraphic imaging: using Hubble Space Telescope's STIS instrument, we applied coronagraphic imaging, an approach originally developed for exoplanet studies, to the field of quasar imaging. Being the first of its kind, STIS was able to image the host galaxy for 3C 273 the first quasar to a region that is 8 times closer than before. The results have been extensively highlighted by NASA news to reach millions of audience around the world.
Quasar coronagraphic imaging: using Hubble Space Telescope's STIS instrument, we applied coronagraphic imaging, an approach originally developed for exoplanet studies, to the field of quasar imaging. Being the first of its kind, STIS was able to image the host galaxy for 3C 273 the first quasar to a region that is 8 times closer than before. The results have been extensively highlighted by NASA news to reach millions of audience around the world.