TY  - JOUR
A1  - Chen, Hsiao-Wen
A1  - Johnson, Sean D.
A1  - Straka, Lorrie A.
A1  - Zahedy, Fakhri S.
A1  - Schaye, Joop
A1  - Muzahid, Sowgat
A1  - Bouche, Nicolas
A1  - Cantalupo, Sebastiano
A1  - Marino, Raffaella Anna
A1  - Wendt, Martin
T1  - Characterizing circumgalactic gas around massive ellipticals at z approximate to 0.4-III.
BT  - the galactic environment of a chemically pristine Lyman limit absorber
JF  - Monthly notices of the Royal Astronomical Society
N2  - This paper presents a study of the galactic environment of a chemically pristine (<0.6 per cent solar metallicity) Lyman Limit system (LLS) discovered along the sightline towards QSO SDSSJ 135726.27+043541.4 (Z(QSO) = 1.233) at projected distance d = 126 physical kpc (pkpc) from a luminous red galaxy (LRG) at z = 0.33. Combining deep Hubble Space Telescope images, MUSE integral field spectroscopic data, and wide-field redshift survey data has enabled an unprecedented, ultradeep view of the environment around this LRG-LLS pair. A total of 12 galaxies, including the LRG, are found at d less than or similar to 400 pkpc and line-of-sight velocity Delta v < 600 km S-1 of the LLS, with intrinsic luminosity ranging from 0.001 L-* to 2 L-* and a corresponding stellar mass range of M-star approximate to 10(7-11) M-circle dot. All 12 galaxies contribute to a total mass of M-star = 1.6 x 10(11) M-circle dot with approximate to 80 per cent contained in the LRG. The line-of-sight velocity dispersion of these galaxies is found to be sigma (group) = 230 km s(-1) with the centre of mass at d(group) = 118 pkpc and line-of-sight velocity offset of Delta v(group) = 181 km s(-1) from the LLS. Three of these are located at d less than or similar to 100 pkpc from the LLS, and they are all faint with intrinsic luminosity less than or similar to 0.02 L-* and gas-phase metallicity of approximate to 10 per cent solar in their interstellar medium. The disparity in the chemical enrichment level between the LLS and the group members suggests that the LLS originates in infalling intergalactic medium and that parts of the intergalactic gas near old and massive galaxies can still remain chemically pristine through the not too distant past.
KW  - galaxies: elliptical and lenticular, cD
KW  - galaxies: formation
KW  - intergalactic medium
KW  - quasars: absorption lines
Y1  - 2019
U6  - https://doi.org/10.1093/mnras/sty3513
SN  - 0035-8711
SN  - 1365-2966
VL  - 484
IS  - 1
SP  - 431
EP  - 441
PB  - Oxford Univ. Press
CY  - Oxford
ER  -