Search for HeH(+) in NGC 7027

摘要: The 3.3-micron spectrum of the planetary nebula NGC 7027 was searched for R(0) line fundamental vibration-rotation band molecular ion HeH(+) without detecting it. upper limit detection is 3.7 x 10 to -14th ergs/sq cm per sec, an improvement in excess 100 over previous published attempts. This low when compared expectations based on analysis processes gaseous nebulas. Likely causes are incorrect radiative association rates or inadequate representation nebular size density distribution outer boundary model used flux prediction. 39 references.