We present and discuss the results of the Herschel Gould Belt survey ( HGBS ) observations in a \sim 11 deg ^ { 2 } area of the Aquila molecular cloud complex at d \sim 260 pc , imaged with the SPIRE and PACS photometric cameras in parallel mode from 70 \mu m to 500 \mu m. Using the multi-scale , multi-wavelength source extraction method getsources , we identify a complete sample of starless dense cores and embedded ( Class 0-I ) protostars in this region , and analyze their global properties and spatial distributions .
We find a total of 651 starless cores , \sim 60 \% \pm 10 \% of which are gravitationally bound prestellar cores , and they will likely form stars in the future .
We also detect 58 protostellar cores .
The core mass function ( CMF ) derived for the large population of prestellar cores is very similar in shape to the stellar initial mass function ( IMF ) , confirming earlier findings on a much stronger statistical basis and supporting the view that there is a close physical link between the stellar IMF and the prestellar CMF .
The global shift in mass scale observed between the CMF and the IMF is consistent with a typical star formation efficiency of \sim 40 % at the level of an individual core .
By comparing the numbers of starless cores in various density bins to the number of young stellar objects ( YSOs ) , we estimate that the lifetime of prestellar cores is \sim 1 Myr , which is typically \sim 4 times longer than the core free-fall time , and that it decreases with average core density .
We find a strong correlation between the spatial distribution of prestellar cores and the densest filaments observed in the Aquila complex .
About 90 % of the Herschel -identified prestellar cores are located above a background column density corresponding to A _ { V } \sim 7 , and \sim 75 \% of them lie within filamentary structures with supercritical masses per unit length \buildrel > \over { \sim } 16 M _ { \odot } /pc .
These findings support a picture wherein the cores making up the peak of the CMF ( and probably responsible for the base of the IMF ) result primarily from the gravitational fragmentation of marginally supercritical filaments .
Given that filaments appear to dominate the mass budget of dense gas at A _ { V } > 7 , our findings also suggest that the physics of prestellar core formation within filaments is responsible for a characteristic “ efficiency ” { SFR } / M _ { dense } \sim 5 ^ { +2 } _ { -2 } \times 10 ^ { -8 } { yr } ^ { -1 } for the star formation process in dense gas .