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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Proplyds are photodissociation region (PDR)-like cometary cocoons aroundyoung stars which are thought to originate through photo-evaporation of thecentral protoplanetary disk by external UV radiation from the nearby OB stars.This letter presents spatially resolved mid-infrared imaging and spectroscopyof the proplyd HST10 obtained with the VLT/VISIR instrument. These observationsallow us to detect Polycyclic Aromatic Hydrocarbons (PAH) emission in theproplyd photodissociation region and to study the general properties of PAHs inproplyds for the first time. We find that PAHs in HST10 are mostly neutral andat least 50 times less abundant than typical values found for the diffuse ISMor the nearby Orion Bar. With such a low PAH abundance, photoelectric heatingis significantly reduced. If this low abundance pertains also to the originaldisk material, gas heating rates could be too low to efficiently drivephotoevaporation unless other processes can be identified. Alternatively, themodel behind the formation of proplyds as evaporating disks may have to berevised.

PAH emission in the proplyd HST10: what is the mechanism behind photoevaporation?