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 have used the Westerbork Synthesis Radio Telescope to detect HI 21cmabsorption at $z \sim 0.7645$ in the gravitational lens system towards PMNJ0134-0931. The 21cm profile has two broad components, with peak optical depthsof $0.047 \pm 0.007$ and $0.039 \pm 0.007$, at heliocentric redshifts $0.76470\pm 0.00006$ and $0.76348 \pm 0.00006$, respectively. The redshift of thestronger component matches that of CaII H and K absorption detected earlier.The absorption has a total velocity width of $\sim 500$ km/s (between nulls)and an equivalent width of $7.1 \pm 0.08$ km/s. This would imply a total HIcolumn density of $2.6 \pm 0.3 \times 10^{21}$ per cm$^2$, for a spintemperature of 200 K and a covering factor of unity. The high estimated HIcolumn density is consistent with the presence of large amounts of dust at thelens redshift; the intervening dust could be responsible for the extremely redcolour of the background quasar.Comment: 4 pages, 4 figures. Accepted for publication in A&A Letter

HI absorption in a gravitational lens atz~ 0.7645