A Metal-poor Damped Ly α System at Redshift 6.4 by Bañados, Eduardo, Rauch, Michael, Decarli, Roberto, Farina, Emanuele P, Hennawi, Joseph F, Mazzucchelli, Chiara, Venemans, Bram P, Walter, Fabian, Simcoe, Robert A., Prochaska, J Xavier, Cooper, Thomas, Davies, Frederick B, Chen, Shi-Fan S.

“…However, in order to match the data a contribution of an intergalactic medium 5%-38% neutral or additional weaker absorbers near the quasar is also required. …”
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An 800-million-solar-mass black hole in a significantly neutral Universe at a redshift of 7.5 by Bañados, Eduardo, Venemans, Bram P, Mazzucchelli, Chiara, Farina, Emanuele P, Walter, Fabian, Wang, Feige, Decarli, Roberto, Stern, Daniel, Fan, Xiaohui, Davies, Frederick B, Hennawi, Joseph F, Simcoe, Robert A., Turner, Monica Lisa, Rix, Hans-Walter, Yang, Jinyi, Kelson, Daniel D, Rudie, Gwen C, Winters, Jan Martin

“…We see strong evidence of absorption of the spectrum of the quasar redwards of the Lyman α emission line (the Gunn-Peterson damping wing), as would be expected if a significant amount (more than 10 per cent) of the hydrogen in the intergalactic medium surrounding J1342 + 0928 is neutral. …”
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The Carbon Content of Intergalactic Gas at Z=4.25 and Its Evolution toward Z=2.4 by Simcoe, Robert A.

“…Our results imply that ~50% of the heavy elements seen in the intergalactic medium at z ~ 2.4 were deposited in the 1.3 Gyr between z ~ 4.3 and z ~ 2.4. …”
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PREDOMINANTLY LOW METALLICITIES MEASURED IN A STRATIFIED SAMPLE OF LYMAN LIMIT SYSTEMS AT Z = 3.7 by Cooksey, Kathy L., O’Meara, John M., Glidden, Ana, Cooper, Thomas Jared, Simcoe, Robert A.

“…Recent models of galaxy evolution propose that galaxies replenish their gas from the low-metallicity intergalactic medium (IGM) via high-density H i "flows" and eject enriched interstellar gas via outflows. …”
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DISCOVERY OF THREE z > 6.5 QUASARS IN THE VISTA KILO-DEGREE INFRARED GALAXY (VIKING) SURVEY by Venemans, B. P., Findlay, J. R., Sutherland, W. J., De Rosa, G., McMahon, R. G., Kuijken, K., Lewis, J. R., Simcoe, Robert A., Gonzalez-Solares, E. A.

“…Studying quasars at the highest redshifts can constrain models of galaxy and black hole formation, and it also probes the intergalactic medium in the early universe. Optical surveys have to date discovered more than 60 quasars up to z [~ over _] 6.4, a limit set by the use of the z-band and CCD detectors. …”
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THE INCIDENCE OF LOW-METALLICITY LYMAN-LIMIT SYSTEMS AT z ~ 3.5: IMPLICATIONS FOR THE COLD-FLOW HYPOTHESIS OF BARYONIC ACCRETION by Simcoe, Robert A., O'Meara, John M., Cooper, Thomas Jared, Cooksey, Kathy, Torrey, Paul A.

“…In simulations, cold streams manifest as Lyman-limit absorption systems (LLSs) with low heavy-element abundances similar to those of the diffuse intergalactic medium (IGM). Here we report on an abundance survey of 17 H i-selected LLSs at z = 3.2–4.4 which exhibits no metal absorption in Sloan Digital Sky Survey spectra. …”
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QUASARS PROBING QUASARS. VI. EXCESS H I ABSORPTION WITHIN ONE PROPER Mpc OF z ~ 2 QUASARS by Prochaska, J. Xavier, Hennawi, Joseph F., Lee, Khee-Gan, Cantalupo, Sebastiano, Bovy, Jo, Djorgovski, S. G., Ellison, Sara L., Lau, Marie Wingyee, Martin, Crystal L., Myers, Adam, Rubin, Kate H. R., Simcoe, Robert A.

“…In contrast to measurements along the line-of-sight, regions transverse to quasars exhibit enhanced H I Lyα absorption and a larger variance than the ambient intergalactic medium, with increasing absorption and variance toward smaller scales. …”
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Mg II ABSORPTION AT 2 < z < 6 WITH MAGELLAN/FIRE. II. A LONGITUDINAL STUDY OF HI, METALS, AND IONIZATION IN GALACTIC HALOS by Matejek, Michael Scott, Simcoe, Robert A., Cooksey, Kathy, Seyffert, Eduardo N.

“…We speculate that if weaker Mg II systems represent accreting gas as suggested by recent studies of galaxy-absorber inclinations, then their high metal abundance suggests re-accretion of recently ejected material rather than first-time infall from the metal-poor intergalactic medium, even at early times.…”
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THE IDENTIFICATION OF z -DROPOUTS IN PAN-STARRS1: THREE QUASARS AT 6.5< z < 6.7 by Simcoe, Robert A., Chen, Shi-Fan S., Miller, Daniel Robert, Sullivan, Peter W.

“…Luminous distant quasars are unique probes of the high-redshift intergalactic medium (IGM) and of the growth of massive galaxies and black holes in the early universe. …”
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