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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Temperature is a crucial parameter in circumstellar disk evolution and planetformation, because it governs the resistance of the gas to gravitationalinstability and sets the chemical composition of the planet-forming material.We set out to determine the gas temperature of the young disk-like structurearound the Class 0 protostar IRAS 16293$-$2422A. We use Atacama LargeMillimeter/submillimeter Array (ALMA) observations of multiple H$_2$CS $J=7-6$and $J=10-9$ lines from the Protostellar Interferometric Line Survey (PILS) tocreate a temperature map for the inner $\sim$200 AU of the disk-like structure.This molecule is a particularly useful temperature probe because transitionsbetween energy levels with different $K_{\rm{a}}$ quantum numbers operate onlythrough collisions. Based on the H$_2$CS line ratios, the temperature isbetween $\sim$100$-$175 K in the inner $\sim$150 AU, and drops to $\sim$75 K at$\sim$200 AU. At the current resolution (0.5$^{\prime\prime} \sim$70 AU), nojump is seen in the temperature at the disk-envelope interface. The temperaturestructure derived from H$_2$CS is consistent with envelope temperature profilesthat constrain the temperature from 1000 AU scales down to $\sim$100 AU, butdoes not follow the temperature rise seen in these profiles at smaller radii.Higher angular resolution observations of optically thin temperature tracersare needed to establish whether cooling by gas-phase water, the presence of aputative disk or the dust optical depth influences the gas temperature at$\lesssim$100 AU scales. The temperature at 100 AU is higher in IRAS 16293Athan in the embedded Class 0/I disk L1527, consistent with the higherluminosity of the former.

Temperature profiles of young disk-like structures: The case of IRAS 16293A