Neutral carbon in the protoplanetary nebulae CRL 618 and CRL 2688
Abstract
The 609u 3P1 -> 3P0 line of neutral atomic carbon has been detected in the protoplanetary nebulae CRL 618 and CRL 2688. CI appears to be about 7% as abundant as CO in CRL 2688, and 70% as abundant as CO in CRL 618. CI emission arises primarily from the slow component of the wind from these objects. The data presented here indicate that CI gradually becomes more abundant as the star leaves the AGB, and CI is significantly enhanced relative to CO before the star develops a large HII region.
0
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.