Dust grains in protoplanetary disks are the building blocks of planets.Investigating the dust composition and size,and their variation over time,is crucial for understanding the planet formation process.The PDS 70 dis...Dust grains in protoplanetary disks are the building blocks of planets.Investigating the dust composition and size,and their variation over time,is crucial for understanding the planet formation process.The PDS 70 disk is so far the only protoplanetary disk with concrete evidence for the presence of young planets.Mid-infrared spectra were obtained for PDS 70 by the Infrared Spectrograph(IRS)on the Spitzer Space Telescope(SST)and the Mid-Infrared Instrument(MIRI)on the James Webb Space Telescope(JWST)in 2007 and 2022,respectively.In this work,we investigate the dust mineralogy through a detailed decomposition of the observed mid-infrared spectra.The results show that both the dust size and crystallinity increased by a factor of about two during the two epochs of observation,indicating evident dust processing in the terrestrial planet-forming region of the PDS 70 disk.The dust size(~0.8μm)and crystallinity(~6%)in the PDS 70 disk are similar to those of other disks,which implies that the two nascent planets,PDS 70b and PDS 70c located at radial distances of~22 AU and~34 AU,do not have a significant impact on the dust processing in the inner disk.The flux densities atλ16μm measured by JWST/MIRI are only 60%of those obtained by Spitzer/IRS.Based on self-consistent radiative transfer modeling,we found that such a strong variability in mid-infrared fluxes can be produced by adjustments to the dust density distribution and structure of the inner disk probably induced by planet-disk interaction.展开更多
基金financial supports by the National Natural Science Foundation of China(Grant No.11973090)the International Partnership Program of Chinese Academy of Sciences(Grant No.019GJHZ2023016FN)+5 种基金the Natural Science Foundation of Sichuan Province of China(Grant No.2025ZNSFSC0060)the financial support by the National Natural Science Foundation of China(Grant No.11973091)financial supports by the National Natural Science Foundation of China(Grant No.12041305)the National Key R&D Program of China(Grant No.2023YFA1608000)support from the Carlsberg Foundation(Grant No.CF23-0481)the Max Planck Society。
文摘Dust grains in protoplanetary disks are the building blocks of planets.Investigating the dust composition and size,and their variation over time,is crucial for understanding the planet formation process.The PDS 70 disk is so far the only protoplanetary disk with concrete evidence for the presence of young planets.Mid-infrared spectra were obtained for PDS 70 by the Infrared Spectrograph(IRS)on the Spitzer Space Telescope(SST)and the Mid-Infrared Instrument(MIRI)on the James Webb Space Telescope(JWST)in 2007 and 2022,respectively.In this work,we investigate the dust mineralogy through a detailed decomposition of the observed mid-infrared spectra.The results show that both the dust size and crystallinity increased by a factor of about two during the two epochs of observation,indicating evident dust processing in the terrestrial planet-forming region of the PDS 70 disk.The dust size(~0.8μm)and crystallinity(~6%)in the PDS 70 disk are similar to those of other disks,which implies that the two nascent planets,PDS 70b and PDS 70c located at radial distances of~22 AU and~34 AU,do not have a significant impact on the dust processing in the inner disk.The flux densities atλ16μm measured by JWST/MIRI are only 60%of those obtained by Spitzer/IRS.Based on self-consistent radiative transfer modeling,we found that such a strong variability in mid-infrared fluxes can be produced by adjustments to the dust density distribution and structure of the inner disk probably induced by planet-disk interaction.
