MUSEQuBES: Connecting H <scp>i</scp> Absorption with Ly<i>α</i> Emitters at <i>z</i> ≈ 3.3

Abstract We present a comprehensive analysis of H i absorption around 96 Ly α emitters (LAEs) at z ≈ 3.3 (median Ly α luminosity ≈10 42 erg s −1 ). These LAEs were identified within eight MUSE fields, each <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mi>′</mml:mi> <mml:mo>×</mml:mo> <mml:mn>1</mml:mn> <mml:mi>′</mml:mi> </mml:math> on the sky and centered on a bright background quasar, as part of the MUSEQuBES survey. Using Voigt profile fitting for all H i absorbers detected within ±​​​​​​500 km s −1 of these LAEs, we compiled a catalog of 800 H i absorption components. Our analysis shows that H i absorption is enhanced near the LAEs compared to the intergalactic medium. However, no trend is found between the column densities of H i absorbers and their impact parameters from the LAEs (spanning ​​​​​​≈54–260 pkpc). Additionally, all galaxies associated with Lyman-limit systems have impact parameters &gt;50 pkpc from the quasar sightlines, suggesting that true absorber hosts may be too faint to detect. The LAEs show an overall H i covering fraction ( f c (H i )) of ≈88% for a threshold <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>N</mml:mi> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> </mml:math> (H i ) = 15. Notably, at the same threshold, the LAEs in pairs/groups exhibit a 100% H i covering fraction out to ≈250 pkpc. In contrast, isolated LAEs consistently show a lower f c (H i ) of ≈80%. This environmental influence on f c (H i ) is also evident up to ≈300 km s −1 in differential bins of line-of-sight velocity. We find an anticorrelation between f c (H i ) and the equivalent width of rest-frame Ly α emission (EW 0 ). Based on the Ly α shell model, this could imply that gas-rich galaxies tend to reside in gas-rich environments or that the LAEs with higher EW 0 are more efficient at ionizing their surrounding medium.