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

How galaxies acquire material from the circumgalactic medium (CGM) is a keyquestion in galaxy evolution. Recent observations and simulations show that gasrecycling could be an important avenue for star formation. This paper presentsKeck Cosmic Web Imager (KCWI) integral field unit spectroscopic observations ona type-II quasar, Q1517+0055 at z = 2.65, a pilot study of our Ly${\alpha}$nebulae sample at $z\approx 2$. We revealed diffuse emission of the Ly$\alpha$1216, HeII 1640, and CIV 1549 on the projected physical scale of 122 kpc, 45kpc, and 79 kpc, respectively. The total Ly$\alpha$ luminosity is L$_{\rmLy\alpha}$ = $3.04\pm 0.02 \times 10^{44}$ erg s$^{-1}$. The line ratiodiagnostics shows that HeII/Ly$\alpha$ $\approx$0.08 and CIV/Ly$\alpha$$\approx$0.28, consistent with the photoionization including recombination andphoton pumping. We also identify the associated HI and CIV absorption from thespectra. By fitting the spectra, we derive both the column density and thevelocity. We find that the velocity profile from both the absorption and theHeII emission exhibit increasing trends. Moreover, both the line ratiodiagnostic from the emission and the column density ratio from the absorptionconfirm that the cool gas metallicity is $\geq Z_{\odot}$. From detailedmodeling and estimation, gas recycling might be a more plausible interpretationcompared with the scenario of a powerful outflow.

astrophysical journal/the astrophysical journal

Revealing the Gas Recycling in the Circumgalactic Medium (CGM) Utilizing  a Luminous Ly$\alpha$ Nebula Around a Type-II Quasar at z=2.6 with the Keck  Cosmic Web Imager (KCWI)