Molecular survival in evolved planetary nebulae: Detection of H ₂CO, c-C₃H₂, and C₂H in the helix

Physics & Astronomy

• planetary nebulae 100%
• helices 83%
• observatories 75%
• formaldehyde 34%
• clumps 31%
• photodissociation 29%
• molecules 29%
• radiative transfer 28%
• ultraviolet radiation 27%
• envelopes 23%
• chemistry 23%
• telescopes 20%
• stars 18%
• kinetics 16%
• temperature 8%

Earth & Environmental Sciences

• observatory 75%
• radio 73%
• detection 48%
• planetary evolution 45%
• ultraviolet radiation 31%
• physical conditions 30%
• formaldehyde 28%
• radiative transfer 26%
• relative abundance 25%
• material 22%
• transition 17%
• kinetics 17%
• temperature 10%
• analysis 7%