研究成果藝廊
Detection of Multiple Bipolar Flows in NGC 7027 with SMA
Left - HST (optical and infrared) images of NGC 7027. Magenta is molecular hydrogen (H2) line emission. White is H-alpha (nebular line). Courtesy HSTScI. Right - False color-scale image of HCO+(3-2) emission (at the systemic velocity) that is moving sideways. Red and Blue contours indicate HCO+(3-2) that are moving away from us and moving toward us, respectively. These horizontal components correspond to the equatorial ring of H2 emission seen in magenta in the left image. The white contours correspond to the magenta image of H2 emission in the left figure.
Circumstellar envelopes around evolved stars can be imaged in both continuum and spectral lines. The chemical and excitation variations within these envelopes can be used to probe the activities near the evolved stars. The images here are young planetary nebula NGC 7027, that is just after the ejection and in the early phase of ionization. With the SMA, we imaged the molecules that are now being destroyed and turned into formyl ion (HCO+) before completely destroyed into H, C, O. These atoms will become H+, C+, O+ (inonized) in a few thousand years. (Huang et al. 2010, ApJ, 722, 273)