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 report on the discovery of a peculiar Broad Absorption Line (BAL) quasaridentified in our Gaia-assisted survey of red quasars. The systemic redshift ofthis quasar was difficult to establish due to the absence of conspicuousemission lines. Based on deep and broad BAL troughs (at least SiIV, CIV, andAlIII), a redshift of z=2.41 was established under the assumption that thesystemic redshift can be inferred from the red edge of the BAL troughs.However, we observe a weak and spatially-extended emission line at 4450 AA mostlikely due to Lyman-alpha emission, which implies a systemic redshift of z=2.66if correctly identified. There is also evidence for the onset of Lyman-alphaforest absorption bluewards of 4450 AA and evidence for H-alpha emission in theK-band consistent with a systemic redshift of z=2.66. If this redshift iscorrect, the quasar is an extreme example of a detached low-ionisation BALquasar. The BAL lines must originate from material moving with very largevelocities ranging from 22000 to 40000 km/s. To our knowledge, this is thefirst case of a systemic-redshift measurement based on extended Lyman-$\alpha$emission for a BAL quasar, a method that should also be useful in cases ofsufficiently distant BL Lac quasars without systemic-redshift information.

Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities