SPIRE 500 m ( top), 350 m ( middle), and 250 m ( bottom) images of the Aquila SDP field. See details about data reduction and map making in Sect. 2. The corresponding PACS 160 m and 70 m images are shown in Bontemps et al. (2010).

Mass versus size diagram comparing the locations of the 452 starless cores identified with Herschel in the Aquila main subfield to both models of critical isothermal Bonnor-Ebert spheres at T = 7 K and T = 20 K (black solid lines) and observed prestellar cores from the ground-based (sub)-mm continuum studies of Ophiuchi and NGC 2068/2071 by e.g., Motte et al. (1998). The masses of the Herschel cores were derived as explained in the text and their sizes measured at 250 m. The 314 candidate prestellar cores of the main subfield are shown as filled triangles, while the other starless cores are shown as open triangles. The mass-size correlation observed for diffuse CO clumps is also displayed (shaded yellow band - Elmegreen & Falgarone 1996). The typical (5) detection threshold of current ground-based (sub)mm (e.g., MAMBO, SCUBA) surveys at d = 150 pc is shown by the dashed curve. The estimated detection threshold of our SPIRE 250 m observations is shown by the blue curve. The lower and upper red diagonal lines correspond to constant 10²¹ cm^-2 and 10²² cm^-2 mean column densities, respectively. The arrow indicates the global shift of the sources if a distance of 400 pc were adopted instead of 260 pc for the Aquila rift complex (see also Appendix A of André et al. 2010).

a) Close-up column density image (selected from Fig. 1a) showing a close view of several starless cores identified with getsources. The black ellipses mark the major and minor FWHM sizes determined by getsources for these cores at m. Two protostars are also shown by red stars. b) Intensity profiles returned by getsources for the starless core marked by the arrow in Fig. 5a, at the five Herschel wavelengths.

a) Column density map of the Aquila entire field derived from Herschel data. The effective FWHM resolution is 36.9''. Unlike in Fig. 1, a uniform offset has been added in order to optimize the match with the near-IR extinction shown in b). (Indeed, the Herschel mapping does not constrain the zero level of the background emission.) b) Near-IR extinction map of the same field based on 2MASS data (see Bontemps et al. 2010) and expressed in units of column density, using the relation . The resolution is 2.