Abstract
The unidentified emission feature at 21 μm is now observed in 12 sources, all being objects in transition between the asymptotic giant branch and planetary nebulae phases. The relations between the 21 μm and other emission features, such as the PAH features and the broad 30 μm feature, and the possible origins of the 21 μm feature are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
