Detection of infall in the protostar B335 with ALMA

Artículo de publicación ISI ; Observations of the isolated globule B335 with ALMA have yielded absorption features against the continuum that are redshifted from the systemic velocity in both HCN and HCO+ lines. These features provide unambiguous evidence for infall toward a central luminosity source. Previously developed models of inside-out collapse can match the observed line profiles of HCN and HCO+ averaged over the central 50 AU. At the new distance of 100 pc, the inferred infall radius is 0.012 pc, the mass infall rate is 3 x 10(-6) M-circle dot yr(-1), the age is 5 x 10(4) years, and the accumulated mass in the central zone is 0.15 M-circle dot, most of which must be in the star or in parts of a disk that are opaque at 0.8 mm The continuum detection indicates an optically thin mass (gas and dust) of only 7.5 x 10(-4)M(circle dot) in the central region, consistent with only a very small disk mass. ; Basic Science Research Program through the National Research Foundation of Korea (NRF) NRF-2015R1A2A2A01004769 Korea Astronomy and Space Science Institute under the RD program 2015-1-320-18