The Eagle Nebula's fingers - pointers to the earliest stages of star formation?

Molecular line, millimetre/submillimetre continuum, and mid-IR observations are reported of the opaque fingers which cross the Eagle Nebula. The finge rs are surprisingly warm when viewed in the CO J= 3-2 lines, with kinetic t emperatures approaching 60 K, although the lines are relatively narrow. Mos t of the mass in the fingers is concentrated in cores which lie at the tips of the fingers, and contain from similar to 10 to 60 M., representing 55-8 0% of the mass of the individual fingers. The integrated mass contained in the three fingers and the nearby extended material is similar to 200 M.. Th e velocity fields of the gas are complex and the material is very clumpy. T he best evidence for coherent velocity structure is seen running along the central finger, which has a velocity gradient similar to 1.7 km s(-1) pc(-1 ). The fingers contain several embedded submm continuum cores, with the mos t intense located at the tips of the fingers. The continuum spectra of thes e cores shows that they are much cooler, T-dust similar to 20 K, than T-gas similar to 60 K of their respective fingers. A simple thermal and chemical model of a finger was developed to study the physical environment, which t akes into account the external UV illumination (similar to 1700 G(0)), and the chemical and thermal structure of a finger. The model predictions are consistent with all of the available observations . The fingers appear to have been formed after primordial dense clumps in t he original cloud were irradiated by the light of its OB stars. These clump s then shielded material lying behind from the photoevaporative dispersal o f the cloud, and facilitated the formation of the finger structures. The co res in the tips of the fingers appear to be at a very early stage of pre-pr otostellar development: there are no embedded infrared sources or molecular outflows present. The pressure inside the cores is just less than that of the surrounding gas, allowing them to be compressed by the external pressur e. The cores are probably just starting the final stages of collapse, which will lead to the formation of a condensed, warm object. It is well known t hat such characteristics are expected from the earliest stages of objects p opularly known as 'protostars'. The cores in the tips of the Eagle Nebula's fingers have characteristics similar to those expected to occur in the ear liest stages of protostellar formation.