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

We use the Karl G. Jansky Very Large Array (VLA) to conduct ahigh-sensitivity survey of neutral hydrogen (HI) absorption in the Milky Way.In combination with corresponding HI emission spectra obtained mostly with theArecibo Observatory, we detect a widespread warm neutral medium (WNM) componentwith excitation temperature <Ts>= 7200 (+1800,-1200) K (68% confidence). Thistemperature lies above theoretical predictions based on collisional excitationalone, implying that Ly-{\alpha} scattering, the most probable additionalsource of excitation, is more important in the interstellar medium (ISM) thanpreviously assumed. Our results demonstrate that HI absorption can be used toconstrain the Ly-{\alpha} radiation field, a critical quantity for studying theenergy balance in the ISM and intergalactic medium yet notoriously difficult tomodel because of its complicated radiative transfer, in and around galaxiesnearby and at high redshift.

Excitation temperature of the warm neutral medium as a new probe of the Lyman-{\alpha} radiation field