| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
1. Discovery of two extreme young protostars in Barnard 1
We have discovered two previously unknown submillimeter-millimeter dust continuum sources in the dark cloud B1 (Barnard 1). Two sources, designated as B1-bN and B1-bS, are separated by 20" and embedded in the dense core of -6 M_<<of sun>> located at -1_1 east of IRAS 03301+3057. The dust continuum data from 350 mum to 3.5 mm reveal that two sources have similar physical properties ; T_<dust> - 18 K, M = 1.6-1.8 M_<<of sun>>, and L_<bol> = 2.6-3.1 L_<<of sun>>. Although there is no clear evidence of mass outflow from these two sources, the detection of them by the interferometer suggests that both two sources have already formed compact protostellar objects at their centers. The high fraction of Lsubmm to the bolometric luminosities L_<bol>, L_<bol>/L_<snbmm> = 10-11, suggests that both sources are very young Class 0 protostars. Toward two dust continuum sources, the fractional abundance of H^<13>CO^+ molecule clearly decreases by
… More
a factor of -10, suggesting that the H^<13>CO^+ molecule is heavily depleted on dust grains. The depletion of H^<13>CO^+ observed in two sources suggests that they are in the earlier evolutionary stages than most of the Class 0 sources whose envelopes are traced well with the H^<13>CO^+ emission.
2. The powering source and origin of the quadrupolar molecular outflow in L723
We have performed the single-dish observation of CS J=2-1 and J=3-2 and interferometric observations of CO J=1-0 toward the center of the quadrupolar molecular outflow in L723. We found that the both CS condensation and CO outflow are centered at the northeastern radio continuum source VLA 2. This suggests that the source VLA 2 is the young stellar object that is powering the conspicuous molecular outflow system and that the other source VLA 1 does not contribute to the morphology of the quadrupolar outflow. The high-veolcity CO distribution suggests that the outflow in L723 is a single bippolar outflow with a wide opening angle of 120ﾟ-170ﾟ. Less
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