Abstract Details
| Name: Arabindo Roy Affiliation: CEA, France Conference ID: ASI2015_473 Title : The Line-mass Power Spectrum of Interstellar Filaments - A Possible Link to the IMF ? Authors and Co-Authors : Roy, A., Andr'e, Ph., CEA, Saclay, France Arzoumanian, D., et al., IAS, Orsay, France Abstract Type : Oral Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : Herschel observations (Konyves et al. 2010 & Andre' et al. 2013) have revealed that a majority of prestellar cores (>70%) are formed along thermally supercritical filaments due to gravitational instability. The virtue of being supercritical, however, is not a sufficient condition for the formation of prestellar cores because in theory, a supercritical filament (M_line > 2Cs^2/G) collapses radially into a line without any fragmentation. The presence of longitudinal line-mass perturbation modes along the z axis of the filaments combined with self-gravity assists in the formation of cores. Interestingly, the statistical properties of the perturbations are directly linked to the statistics of prestellar core masses. Analytically, Inutsuka (2001) showed that a line mass fluctuating field along a filament characterized by a power spectrum slope of -1.5 generates a mass spectrum of collapsed cores i.e., dN/dM proportional to M^-2.5, similar to the Salpeter mass function. Our analysis on the Herschel Gould Belt Survey dust emission data has revealed that the line mass fluctuations along the long axes of filaments (Roy et al. 2014) have a characteristic 1-D power spectrum slope of -1.7+/-0.3. The power spectrum slope bears a striking similarity with 1-D Kolomogorov turbulence spectrum of -1.67. The observational derivation of the characteristic power spectrum slope may have implications on our understanding of the IMF. The observationally derived power spectrum slope (-1.7) in the present study suggests that thermally supercritical filaments will fragment into a core population whose mass function approaches dN/dM proportional to M^-2.3. This is very close to the Salpeter slope pointing to the possibility that the density perturbations due to turbulence is prerequisite for generating a Salpeter-like mass function toward the high mass end. References Andre', P., Di Francesco, J., Ward-Thompson, D., et al. 2013, PPVI Inutsuka, S.-i. 2001, ApJ, 559, L149 K¨onyves, V., Andr´e, P., Men’shchikov, A., et al. 2010, A&A, 518, L106 Roy, A., Andre', P., Arzoumanian, D., et al. 2014, to be submitted |