Evolution of the Cool Gas in the Circumgalactic Medium (CGM) of Massive Halos -- A Keck Cosmic Web Imager (KCWI) Survey of Ly$\alpha$ Emission around QSOs at $z\approx 2$

Abstract

Motivated by the recent discovery of the near-ubiquity of Ly$\alpha$ emission around $z\gtrsim 3$ QSOs, we performed a systematic study of QSO circumgalactic Ly$\alpha$ emission at $z\approx 2$, utilizing the unique capability of the Keck Cosmic Web Imager (KCWI) -- a new wide-field, blue sensitive integral-field spectrograph (IFU). In this paper, we present KCWI observations on a sample of 16 ultraluminous Type-I QSOs at $z=2.1-2.3$ with ionizing luminosities of $L_{{\nu }_{\mathrm{LL}}}=10^{31.1-32.3}$ erg s${}^{-1}$ Hz${}^{-1}$. We found that 14 out of 16 QSOs are associated with Ly$\alpha$ nebulae with projected linear-sizes larger than 50 physical kpc (pkpc). Among them, four nebulae have enormous Ly$\alpha$ emission with the Ly$\alpha$ surface brightness $S{B}_{\mathrm{Ly}\alpha }>10^{-17}$ erg s${}^{-1}$ cm${}^{-2}$ arcsec${}^{-2}$ on the $>100$ kpc scale, extending beyond the field of view of KCWI. Our KCWI observations reveal that most $z\approx 2$ QSO nebulae have a more irregular morphology compared to those at $z\gtrsim 3$. In turn, we measure that the circularly-averaged surface brightness (SB) at $z\approx 2$ is 0.4 dex fainter than the redshift-corrected, median SB at $z\gtrsim 3$. The Ly$\alpha$ SB profile (SB${}_{\mathrm{Ly}\alpha }$) of QSOs at $z\approx 2$ can be described by a power law of SB${}_{\mathrm{Ly}\alpha ,\mathrm{z}\approx 2.3}=3.7\times 10^{-17}\times (r/40{)}^{-1.8}$ erg s${}^{-1}$ cm${}^{-2}$ arcsec${}^{-2}$, with the slope similar to that at $z\gtrsim 3$. The observed lower redshift-corrected, circularly-averaged SB may be mainly due to the lower covering factor of cool gas clouds in massive halos at $z\approx 2$.

23 pages, 15 figures, Accepted for Publications in ApJS

References in corpus (12)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey
• Moving mesh cosmology: tracing cosmological gas accretion
• The first ultraviolet quasar stacked spectrum at z=2.4 from WFC3
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• Neutral hydrogen in galaxy halos at the peak of the cosmic star formation history
• The large and small scale properties of the intergalactic gas in the Slug Ly-alpha nebula revealed by MUSE HeII emission observations
• Inspiraling Halo Accretion Mapped in Lyman-$\alpha$ Emission around a $z\sim 3$ Quasar
• A Deep Narrowband Imaging Search for CIV and He II Emission from Ly$\alpha$ Blobs
• The Properties of Lyman Alpha Nebulae: Gas Kinematics from Non-resonant Lines
• Where is the fuzz? Undetected Lyman alpha nebulae around QSOs at z~2.3

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