A FLATTENED CLOUD CORE IN NGC-2024

被引:15
作者
HO, PTP
PENG, YL
TORRELLES, JM
GOMEZ, JF
RODRIGUEZ, LF
CANTO, J
机构
[1] CSIC, INST ASTROFIS ANDALUCIA, E-18080 GRANADA, SPAIN
[2] Univ Nacl Autonoma Mexico, INST ASTRON, MEXICO CITY 04510, DF, MEXICO
[3] NANJING UNIV, NANJING, PEOPLES R CHINA
关键词
ISM; INDIVIDUAL; (NGC-2024); JETS AND OUTFLOWS; MOLECULES; RADIO LINES;
D O I
10.1086/172614
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The (J, K) = (1, 1) and (2, 2) NH, lines were mapped toward a molecular cloud core in NGC 2024 using the VLA in its C/D-configuration. This region is associated with one of the most highly collimated molecular outflows. We find that the molecular condensations associated with the far-infrared sources FIR 5, FIR 6, and FIR 7 have kinetic temperatures T(K) congruent-to 40 K. We also find line broadening toward FIR 6 and FIR 7. This suggests that these condensations may not be protostars heated by gravitational energy released during collapse but that they have an internal heating source. A flattened structure of ammonia emission is found extending parallel to the unipolar CO outflow structure, but displaced systematically to the east. If the NH3 emission traces the denser gas environment, there is no evidence that a dense gas structure is confining the molecular outflow. Instead, the location of the high-velocity outflow along the surface of the NH3 structure suggests that a wind is sweeping material from the surface of this elongated cloud core.
引用
收藏
页码:565 / 572
页数:8
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