Year: 2026
Type: article
Abstract: Debris disks are dusty structures around mature stars, primarily identified by infrared excesses in the stellar spectra. A subset, known as extreme debris disks (EDDs), exhibits stochastic infrared variability, believed to result from large-scale violent collisions that contribute to the formation or destruction of rocky planetary bodies. We analyze JWST and Spitzer mid-infrared spectra for 21 EDDs to investigate the connection between impact-produced dust mineralogy and the age and dynamical state of these systems during various stages of planet formation and evolution. Our findings indicate that EDDs contain significantly more optically thin, small dust grains compared to those typically seen in protoplanetary and debris disks. Predominantly submicron in size, these grains are thermally altered, as shown by their high levels of silica and crystalline silicate composition. Along with stochastic infrared variability, these features define EDDs as a subclass of debris systems where dust is generated from large collisions between Moon- and Mars-sized bodies. Our results not only provide diagnostic information about the physical conditions of violent events during terrestrial planet formation, aiding in differentiating the complex outcomes of these impacts, but also offer a potential marker for identifying planetary systems experiencing dynamical instability.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Aeronautics and Space Administration, California Institute of Technology, University of Arizona, Towson University, Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, Directorate for Biological Sciences, Goddard Space Flight Center, Jess and Mildred Fisher College of Science and Mathematics, Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, National Research, Development and Innovation Office
Awards: G1632446036, G4927423465, G5566414014, G6155711494, 1. SCIENCE INVESTIGATION: SUMMARY IN MY ORIGINAL PROPOSAL WRITTEN PRIOR TO THE LAUNCH OF SPITZER I PLANNED A JWST PROGRAM ON ACTIVE GALACTIC NUCLEI (AGN) AND THEIR HOST GALAXIES BUILDING ON THEN-FUTURE SPITZER OBSERVATIONS. TOWARD THE END OF THE SPITZER COLD MISSION AS THE PI FOR THE MIPS INSTRUMENT I HAD LED SUBSTANTIAL PROGRAMS ON BOTH EXTRAGALACTIC OBSERVATIONS AND DEBRIS DISKS SO I PROPOSED TO EXPAND MY JWST EFFORT TO INCLUDE BOTH AN EXPANSION THAT WAS APPROVED BY ED WEILER ON OCTOBER 16 2009. THE FOLLOWING PROGRAM THEREFORE INCLUDES BOTH OF THESE THEMES. SINCE BOTH PROPOSALS WERE WRITTEN MAJOR NEW CAPABILITIES HAVE ANSWERED SOME OF THE PREVIOUS SCIENTIFIC QUESTIONS AND POSED NEW ONES. IN THE EXTRAGALACTIC ARENA THESE INCLUDE SPITZER ITSELF HERSCHEL THE EXPANDED CAPABILITIES OF THE JVLA AND ALMA. FOR DEBRIS DISKS THE MOST IMPORTANT ARE HERSCHEL ALMA AND HIGH PERFORMANCE ADAPTIVE OPTICS. THEREFORE THE MATERIAL IN THIS PROPOSAL IS RE-THOUGHT TO PROVIDE A PROGRAM AT THE CUTTING EDGE OF THE CURRENT PROBLEMS IN THESE AREAS. EACH OF THE INDIVIDUAL INVESTIGATIONS DESCRIBED BELOW IS DESCRIBED IN A DETAILED INTERNAL REPORT AND IS READY FOR DETAILED OBSERVATION PLANNING. THIS PROPOSAL GIVES A SUMMARY OF THE HIGH LEVEL GOALS AND REQUIRED OBSERVATIONS ONLY. IT INTENTIONALLY SOMEWHAT OVERSUBSCRIBES MY TIME ALLOTMENT TO ALLOW FOR COLLABORATIONS AND SHARED TIME AS WELL AS FURTHER OPTIMIZATION. ALTHOUGH THERE ARE A NUMBER OF INVESTIGATIONS MY RESEARCH GROUP HAS BEEN ACTIVE IN ALL OF THEM; I HAVE BOLD-FACED CITATIONS OF OUR RELEVANT WORK IN THE BIBLIOGRAPHY (ATTACHED AS APPENDIX A). IN ADDITION I WAS ASSIGNED AN ADDITIONAL 60 HOURS OF GTO TIME TO BE DISTRIBUTED AMONG (MOSTLY) YOUNG SCIENTISTS IN THE UNITED STATES WHO HAD MADE MAJOR COMMITMENTS IN SUPPORT OF MIRI (ROUGHLY PARALLEL TO THE GTO TIME FOR MIRI SUPPORT BY THE EUROPEAN CONSORTIUM (EC)). APPENDIX C INCLUDES SHORT STATUS REPORTS ON THEIR PLANS., G6686480456, G7339330145
OpenAlex ID: W7167847953