SIMBAD references

2006ApJ...637..811T - Astrophys. J., 637, 811-822 (2006/February-1)

The circumstellar structure of the class I protostar TMC-1 (IRAS 04381+2540) from Hubble Space Telescope NICMOS data.


Abstract (from CDS):

The class I protostar TMC-1 (IRAS 04381+2540) is oriented favorably for determining the properties of its circumstellar envelope and outflow cavity. Deep, high spatial resolution Hubble Space Telescope (HST) NICMOS images at 1.6 µm exhibit both a narrow jet and a wide-angle conical outflow cavity. Model images of the scattered-light distribution fit the data well, reproducing the intensity level, cavity width, and observed limb brightening. The best-fit geometry for TMC-1 has a 45°±5° source inclination and an 80°±5° deprojected wind opening angle (full width). The age, normally a poorly known quantity, is well constrained; the protostar age, i.e., time since the onset of cloud collapse, is 1x105 yr to within a factor of 2. We offer a possible resolution to the well-known luminosity problem. By considering the efficiency of infall onto the protostar, we find that plausible parameters can give an efficiency, and hence accretion luminosity, as low as 10% of the value derived from the collapsing cloud core. The efficiency, together with a luminosity constraint, leads to a mass estimate that ranges from about 0.1 Mfor high efficiency to 0.2 Mfor low accretion efficiency onto the protostar. Similarly, the estimated mass accretion rate onto the protostar ranges over roughly (0.9-1.4)x10–6 M/yr, which is smaller than the (1.6-3.5)x10–6 M/yr infall rate of the cloud. If low efficiency rates are prevalent for protostars, one important consequence is that it will take longer to assemble the central star than the time t=Min/M{dot}in, a time that assumes all of the infalling material lands on the protostar.

Abstract Copyright:

Journal keyword(s): Stars: Circumstellar Matter - ISM: Jets and Outflows - Stars: Formation - stars: individual (TMC-1) - stars: individual (IRAS 04381+2540)

Simbad objects: 5

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