银心附近高速度弥散云观测研究

Bania’s Clump 2 (位于L=3°-3.5°)和L=5.5°复合体在整个银河系的分子云复合体中拥有最强的速度弥散（>150 km/s），但其中似乎没有（或很弱）的恒星形成活动。因此，它们提供了非常理想的场所来验证气体湍流加热理论。甲醛和氨分子都是致密气体探针，曾被证实是非常理想的致密分子云温度计。本项目计划观测研究Bania’s Clump 2和L=5.5°复合体中的H2CO(4-3)和NH3(1,1)-(7,7)跃迁：（1）测量致密团块的温度和温度结构；（2）对比研究气体和尘埃温度的关系；（3）探寻温度和气体加热机制（例如，湍流，辐射）的关系；（4）揭示高温是否抑制致密团块中的恒星形成活动。

Bania's Clump 2 (located at L=3-3.5 deg) and the complex located at L=5.5 deg exhibit the most prominent high-velocity dispersions (>150 km/s) of all Galactic molecular complexes, but show little/no star formation. Therefore, they provide exceptional locations to test the turbulent heating hypothesis. Formaldehyde (H2CO) and ammonia (NH3), molecules which trace the dense molecular gas, have been proven to be excellent tracers for estimates of the kinetic temperature of dense molecular clouds. We propose to observe the transitions of H2CO (4-3) and the metastable inversion transitions of NH3 (1,1)-(7,7) toward Bania's Clump 2 and the L=5.5 deg complex: (1) to obtain the gas kinetic temperatures and temperature structures of dense clumps, (2) to compare these results with those obtained from dust, (3) to seek for links between kinetic temperature and gas heating mechanisms (e.g., turbulence, radiation), and (4) to reveal whether high temperatures are responsible for suppressing star formation.