EPoS Contribution

Evolution of Protostellar Disks Cheng-Han Hsieh Yale, New Haven, US
The high angular resolution observations by ALMA have revealed for the first time substructures in disks with unprecedented details. However, these surveys focused on more evolved Class II disks or the brightest, largest disks. We present the CAMPOS Legacy survey, an ALMA survey of embedded Class0/I and Flat protostellar disks in the star-forming clouds of Chamaeleon, Ophiuchus, Aquila, Corona Australis, and Serpens. We probed over 90 disks down to 15 au resolution and conducted the first statistical search for disk substructures around Class 0/I protostars. Our findings reveal compelling evidence suggesting a lack of substructures in young Class 0 and early Class I disks. Intriguingly, disk substructures begin to emerge only in sources with a bolometric temperature exceeding 110 K, indicating the rapid evolution of disk substructures during the Class I phase. Our CAMPOS survey has for the first time discovered how early disk substructures form and, as a corollary, when giant planet formation begins. In addition, we found that the size distribution of the 53 Class 0 disks in 7 nearby clouds is in high tension with the hydrodynamical models, which implies protostellar disk formation is magnetically regulated. Furthermore,the Class 0 disk size distribution from our CAMPOS survey contradicts the prediction by the ambipolar diffusion and Hall effect models,indicating that protostellar disk formation remains an unsolved question.

Caption: The evolutionary sequence of protostellar disks with substructures, from the ALMA CAMPOS survey.
Collaborators: H. Arce, YaleU, US A. Arun, ChileU, CL J. Pineda, MPA, DE D. Segura-Cox, UT AusCn, US M. Jos𝑒́, MPA, DE M. Dunham, UFredonia, US D. Mardones, ChileU, CL	Key publication Relevant topic(s): Low-Mass SF Turbulence
Relevant Big Question: How early protostellar disk substructure form?