The JCMT Legacy Survey of the Gould Belt: a first look at Taurus with HARP - Astrophysics > Astrophysics of GalaxiesReportar como inadecuado

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Abstract: As part of a JCMT Legacy Survey of star formation in the Gould Belt, wepresent early science results for Taurus. CO J=3-2 maps have been secured alongthe north-west ridge and bowl, collectively known as L 1495, along with deep13CO and C18O J=3-2 maps in two sub-regions. With these data we search formolecular outflows, and use the distribution of flows, HH objects and shockedH2 line emission features, together with the population of young stars,protostellar cores and starless condensations to map star formation across thisextensive region. In total 21 outflows are identified. It is clear that thebowl is more evolved than the ridge, harbouring a greater population of T Tauristars and a more diffuse, more turbulent ambient medium. By comparison, theridge contains a much younger, less widely distributed population of protostarswhich, in turn, is associated with a greater number of molecular outflows. Weestimate the ratio of the numbers of prestellar to protostellar cores in L 1495to be ~ 1.3-2.3, and of gravitationally unbound starless cores togravitationally bound prestellar cores to be ~ 1. If we take previousestimates of the protostellar lifetime of ~ 5 x 10^5 yrs, this indicates aprestellar lifetime of 9+-3 x 10^5 yrs. From the number of outflows we alsocrudely estimate the star formation efficiency in L 1495, finding it to becompatible with a canonical value of 10-15 %. We note that molecularoutflow-driving sources have redder near-IR colours than their HH jet-drivingcounterparts. We also find that the smaller, denser cores are associated withthe more massive outflows, as one might expect if mass build-up in the flowincreases with the collapse and contraction of the protostellar envelope.

Autor: C.J. Davis, A. Chrysostomou, J. Hatchell, J.G.A. Wouterloot, J.V. Buckle, D. Nutter, M. Fich, C. Brunt, H. Butner, B. Cavanagh, E


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