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Title: TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. I. VARIED SHOCK SPEEDS

Journal Article · · Astrophysical Journal
; ; ; ;  [1]
  1. Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

The discovery of decay products of a short-lived radioisotope (SLRI) in the Allende meteorite led to the hypothesis that a supernova shock wave transported freshly synthesized SLRI to the presolar dense cloud core, triggered its self-gravitational collapse, and injected the SLRI into the core. Previous multidimensional numerical calculations of the shock-cloud collision process showed that this hypothesis is plausible when the shock wave and dense cloud core are assumed to remain isothermal at approx10 K, but not when compressional heating to approx1000 K is assumed. Our two-dimensional models with the FLASH2.5 adaptive mesh refinement hydrodynamics code have shown that a 20 km s{sup -1} shock front can simultaneously trigger collapse of a 1 M{sub sun} core and inject shock wave material, provided that cooling by molecular species such as H{sub 2}O, CO, and H{sub 2} is included. Here, we present the results for similar calculations with shock speeds ranging from 1 km s{sup -1} to 100 km s{sup -1}. We find that shock speeds in the range from 5 km s{sup -1} to 70 km s{sup -1} are able to trigger the collapse of a 2.2 M{sub sun} cloud while simultaneously injecting shock wave material: lower speed shocks do not achieve injection, while higher speed shocks do not trigger sustained collapse. The calculations continue to support the shock-wave trigger hypothesis for the formation of the solar system, though the injection efficiencies in the present models are lower than desired.

OSTI ID:
21392413
Journal Information:
Astrophysical Journal, Vol. 708, Issue 2; Other Information: DOI: 10.1088/0004-637X/708/2/1268; ISSN 0004-637X
Country of Publication:
United States
Language:
English