NIRCAm photometric properties of ONC disks

From this information we construct a typology for ONC disks: Type I sources show an IF and DF nearly merged at the disk surface; Type II sources have their DFs at the disk surface and IFs at a distance of several 10s of astronomical units from the disk; and Type III sources also have their DF at the disk surface, but show no IF. For all types of disks, we find that PAH emission traces the PDR. We establish that the SEDs of candidate Jupiter Mass Binary Objects (JuMBOs) observed as part of the PDRs4All program are similar to the SEDs of Type III ONC disks except for one of them, JuMBO24, which is of Type I or II.

A detailed look at this SED shows it is compatible with a young low mass binary star with an unresolved ionized disk : a microproplyd binary. We observe that the disk radius of ONC disks r_mdisk_ increases with increasing projected distance to the ionizing source d_mproj_ , following a power law r_mdisk_{prop.to} d_mproj_^0.30^, which is interpreted as evidence of the truncation of the disks by the photoevaporation (as reported in previous studies).

The disk radii measured at infrared wavelengths appear larger than the disk radii measured at millimeter wavelengths, interpreted as evidence of the dust radial segregation within the disks. In agreement with theoretical models and observations of PDRs in the interstellar medium, the thermal pressure within the PDRs of ONC disk increases with the intensity of the FUV radiation field G_0_, but with a flatter slope.