English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Simple and complex organic molecules (COMs) are observed along differentphases of star and planet formation and have been successfully identified inprestellar environments such as dark and translucent clouds. Yet the picture oforganic molecule formation at those earliest stages of star formation is notcomplete and an important reason is the lack of specific laboratory experimentsthat simulate carbon atom addition reactions on icy surfaces of interstellargrains. Here we present experiments in which CO molecules as well as C- andH-atoms are co-deposited with H$_2$O molecules on a 10 K surface mimicking theongoing formation of an "H$_2$O-rich" ice mantle. To simulate the effect ofimpacting C-atoms and resulting surface reactions with ice components, aspecialized C-atom beam source is used, implemented on SURFRESIDE$^3$, an UHVcryogenic setup. Formation of ketene (CH$_2$CO) in the solid state is observed"in situ" by means of reflection absorption IR spectroscopy. C$^1$$^8$O and Disotope labelled experiments are performed to further validate the formation ofketene. Data analysis supports that CH$_2$CO is formed through C-atom additionto a CO-molecule, followed by successive hydrogenation transferring the formed:CCO into ketene. Efficient formation of ketene is in line with the absence ofan activation barrier in C+CO reaction reported in the literature. We alsodiscuss and provide experimental evidence for the formation of acetaldehyde(CH$_3$CHO) and possible formation of ethanol (CH$_3$CH$_2$OH), two COMderivatives of CH$_2$CO hydrogenation. The underlying reaction network ispresented and the astrochemical implications of the derived pathways arediscussed.

Hydrogenation of accreting C-atoms and CO molecules -- simulating ketene and acetaldehyde formation under dark and translucent cloud conditions