Cold dust around Herbig–Haro energy sources: morphology and new protostellar candidates

We present 1300μmmaps of regions centered on the energy sources of 20 HH objects in order to study the distribution of circumstellar matter around these young stellar objects. The data show that the emission generally originates from a rather compact region which is embedded in a more diffuse environment. The relative contribution of the compact component to the total emission varies from 15 to 100%. About half of the compact components appear spherically symmetric while the other half displays an elongated structure. There is, however, no correlation between the optical jet axis and the flattened dust structures, indicating that collimation occurs on smaller scales. Close to the energy source of HH114 we discovered a so far unknown mm–source with Lbol/Lsmm < 100 suggesting that it is still in its early protostellar evolutionary stage. In three other regions we detected similar unknown mm–sources without IRAS counterparts, indicating that they are also likely new protostellar candidates.