Dust continuum imaging of the HH 24 region in L1630

We have mapped the 1300 and 350 mu m continuum emission in the region surro unding the Herbig-Haro objects HH 22-HH 26 in L1630, which is part of the O rion B molecular cloud complex, using the MPIR bolometer at the IRAM 30 m t elescope and the SHARC bolometer camera at the Caltech Submillimeter Observ atory (CSO). Our observations reveal the presence of a cluster of at least nine protostellar condensations at various evolutionary stages in the regio n around HH 24-HH 26. In addition to two previously identified class 0 prot ostars, two additional sources with a low 350/1300 mu m flux ratio are dete cted. Although the lack of far-infrared fluxes precludes a definitive deter mination of their nature, their low 350/1300 mu m flux ratio along with the absence of embedded infrared and radio continuum sources suggests that the y are likely to be in a very early evolutionary stage. In particular, one o f these two sources appears quite compact in the 1300 mu m image and may be in the short-lived phase of isothermal collapse. In addition, we have dete cted three millimeter continuum sources in the vicinity of the HH 22-HH 23 objects, including a compact source at the origin of the HH 23 optical jet. The bolometric luminosity, submillimeter-to-bolometric luminosity ratio, t emperature, and mass of this source are all consistent with those of a clas s 0 protostar. However, the compactness of the source suggests that the con tinuum emission may be dominated by an unresolved disk, as would be expecte d for a more evolved protostellar source. No evidence is found for the pres ence of a molecular outflow associated with this source in our CO, (CO)-C-1 3, and HCO+ data obtained with the CSO.