2014ApJ...796..140P

We survey the incidence and absorption strength of the metal-line transitions C II 1334 and C IV 1548 from the circumgalactic medium (CGM) surrounding z ∼ 2 quasars, which act as signposts for massive dark matter halos M_halo~ 10^12.5 M_☉. On scales of the virial radius (r_vir~ 160 kpc), we measure a high covering fraction f_C= 0.73±0.10 to strong C II 1334 absorption (rest equivalent width W₁₃₃₄ ≥ 0.2 Å), implying a massive reservoir of cool (T ∼ 10⁴ K) metal enriched gas. We conservatively estimate a metal mass exceeding 10⁸ M_☉. We propose that these metals trace enrichment of the incipient intragroup/intracluster medium that these halos eventually inhabit. This cool CGM around quasars is the pinnacle among galaxies observed at all epochs, as regards covering the fraction and average equivalent width of H I Lyα and low-ion metal absorption. We argue that the properties of this cool CGM primarily reflect the halo mass, and that other factors such as feedback, star-formation rate, and accretion from the intergalactic medium are secondary. We further estimate that the CGM of massive, z ∼ 2 galaxies accounts for the majority of strong Mg II absorption along random quasar sightlines. Last, we detect an excess of strong C IV 1548 absorption (W₁₅₄₈ ≥ 0.3 Å) over random incidence to the 1 Mpc physical impact parameter and measure the quasar-C IV cross-correlation function: ζ_CIV -Q(r) = (r/r₀)^–γ with r₀ = 7.5_–1.4^+2.8 h^–1 Mpc and γ = 1.7_–0.2^+0.1. Consistent with previous work on larger scales, we infer that this highly ionized C IV gas traces massive (10¹² M_☉) halos.