TY - JOUR

T1 - Probing the intra-group medium of a z=0.28 galaxy group

AU - Bielby, R.

AU - Crighton, N. H. M.

AU - Fumagalli, M.

AU - Morris, S. L.

AU - Stott, J. P.

AU - Tejos, N.

AU - Cantalupo, S.

N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version R. Bielby, N. H. M. Crighton, M. Fumagalli, S. L. Morris, J. P. Stott, N. Tejos, S. Cantalupo; Probing the intra-group medium of a z = 0.28 galaxy group. Mon Not R Astron Soc 2017; 468 (2): 1373-1386. doi: 10.1093/mnras/stx528 is available online at: https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stx528

PY - 2017/6

Y1 - 2017/6

N2 - We present new MUSE observations of a galaxy group probed by a background quasar. The quasar sightline passes between multiple z = 0.28 galaxies, whilst showing at the same redshift low-ionized metal line species, including Ca II, Mg I, Mg II and Fe II. Based on the galaxy redshifts measured from the MUSE data, we estimate the galaxies to be part of a small galaxy group with a halo mass of approximate to 6 x 10(12) M-circle dot. We use the MUSE data to reveal the two-dimensional dynamical properties of the gas and stars in the group galaxies, and relate these to the absorber kinematics. With these data, we consider a number of scenarios for the nature of the gas probed by the sightline absorbers: a corotating gas halo associated with a single galaxy within the group; outflowing material from a single group member powered by recent star-formation; and cool dense gas associated with an intra-group medium. We find that the dynamics, galaxy impact parameters, star formation rates and the absorber strength suggest that the cool gas cannot be clearly associated with any single galaxy within the group. Instead, we find that the observations are consistent with a superposition of cool gas clouds originating with the observed galaxies as they fall into the group potential, and are now likely in the process of forming the intra-group medium.

AB - We present new MUSE observations of a galaxy group probed by a background quasar. The quasar sightline passes between multiple z = 0.28 galaxies, whilst showing at the same redshift low-ionized metal line species, including Ca II, Mg I, Mg II and Fe II. Based on the galaxy redshifts measured from the MUSE data, we estimate the galaxies to be part of a small galaxy group with a halo mass of approximate to 6 x 10(12) M-circle dot. We use the MUSE data to reveal the two-dimensional dynamical properties of the gas and stars in the group galaxies, and relate these to the absorber kinematics. With these data, we consider a number of scenarios for the nature of the gas probed by the sightline absorbers: a corotating gas halo associated with a single galaxy within the group; outflowing material from a single group member powered by recent star-formation; and cool dense gas associated with an intra-group medium. We find that the dynamics, galaxy impact parameters, star formation rates and the absorber strength suggest that the cool gas cannot be clearly associated with any single galaxy within the group. Instead, we find that the observations are consistent with a superposition of cool gas clouds originating with the observed galaxies as they fall into the group potential, and are now likely in the process of forming the intra-group medium.

KW - galaxies: groups: general

KW - galaxies: kinematics and dynamics

KW - quasars: absorption lines

KW - MG II ABSORPTION

KW - BARYONIC STRUCTURE SURVEY

KW - STAR-FORMING GALAXIES

KW - LYMAN-ALPHA ABSORBERS

KW - SIMILAR-TO 3

KW - METAL-LINE ABSORPTION

KW - CIRCUMGALACTIC MEDIUM

KW - LY-ALPHA

KW - INTERGALACTIC MEDIUM

KW - CROSS-CORRELATION

U2 - 10.1093/mnras/stx528

DO - 10.1093/mnras/stx528

M3 - Journal article

VL - 468

SP - 1373

EP - 1386

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -