A census of dense cores in the Aquila cloud complex: SPIRE/PACS
  observations from the Herschel Gould Belt survey
  We present and discuss the results of the Herschel Gould Belt survey
observations in a ~11 deg^2 area of the Aquila molecular cloud complex at d~260
pc, imaged with the SPIRE/PACS cameras from 70 to 500 micron. We identify a
complete sample of starless dense cores and embedded protostars in this region,
and analyze their global properties and spatial distributions. We find a total
of 651 starless cores, ~60% 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 prestellar
cores is very similar in shape to the stellar initial mass function (IMF),
supporting the earlier view that there is a close physical link between the IMF
and the CMF. The global shift in mass scale observed between the CMF and the
IMF is consistent with a typical star formation efficiency of ~40%. By
comparing the numbers of starless cores to the number of young stellar objects,
we estimate that the lifetime of prestellar cores is ~1 Myr. We find a strong
correlation between the spatial distribution of prestellar cores and the
densest filaments. About 90% of the Herschel-identified prestellar cores are
located above a background column density corresponding to A_V~7, and ~75% of
them lie within filamentary structures with supercritical masses per unit
length >~16 M_sun/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 ~5+-2 x 10^-8 yr^-1 for the star formation process in
dense gas.
