Survey of Orion Disks with ALMA (SODA)
Sierk van Terwisga, A. Hacar
Abstract
Context. External far-ultraviolet (FUV) irradiation of protoplanetary disks has an important impact on their evolution and ability to form planets. However, nearby (< 300 pc) star-forming regions lack sufficiently massive young stars, while the Trapezium cluster and NGC 2024 have complicated star-formation histories and their O-type stars’ intense radiation fields (> 10 4 G 0 ) destroy disks too quickly to study this process in detail. Aims. We study disk mass loss driven by intermediate (10 − 1000 G 0 ) FUV radiation fields in L1641 and L1647, where it is driven by more common A0- and B-type stars. Methods. Using the large ( N = 873) sample size offered by the Survey of Orion Disks with ALMA (SODA), we searched for trends in the median disk dust mass with FUV field strength across the region as a whole and in two separate regions containing a large number of irradiated disks. Results. For radiation fields between 1 − 100 G 0 , the median disk mass in the most irradiated disks drops by a factor ∼2 over the lifetime of the region, while the 95th percentile of disk masses drops by a factor 4 over this range. This effect is present in multiple populations of stars, and localized in space, to within 2 pc of ionizing stars. We fitted an empirical irradiation – disk mass relation for the first time: M dust,median = −1.3 −0.13 +0.14 log 10 ( F FUV / G 0 ) + 5.2 −0.19 +0.18 . Conclusions. This work demonstrates that even intermediate FUV radiation fields have a significant impact on the evolution of protoplanetary disks.