TY - JOUR
T1 - Warm-hot gas in X-ray bright galaxy clusters and the HI-deficient circumgalactic medium in dense environments
AU - Burchett, Joseph N.
AU - Tripp, Todd M.
AU - Daniel Wang, Q.
AU - Willmer, Christopher N.A.
AU - Bowen, David V.
AU - Jenkins, Edward B.
N1 - Funding Information:
obtained for HST programmes 7778, 13833, 13342, and 13491, with financial support through NASA grants HST-GO-13342.002-A and HST-GO-13491.001-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. This work is partly based on observations taken at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.
Funding Information:
The authors would like to thank Mary Putman and Joo Heon Yoon for insightful discussion and sharing their data. Also, Benjamin Weiner provided extremely helpful advice for the Hectospec target selection strategy. Hsiao-Wen Chen also provided helpful comments on an earlier draft. The observations in this paper were obtained for HST programmes 7778, 13833, 13342, and 13491, with financial support through NASA grants HST-GO-13342.002-A and HST-GO-13491.001-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. This work is partly based on observations taken at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.
Publisher Copyright:
© 2017 The Author(s).
PY - 2018/4/1
Y1 - 2018/4/1
N2 - We analyse the intracluster medium (ICM) and circumgalactic medium (CGM) in seven X-ray-detected galaxy clusters using spectra of background quasi-stellar objects (QSOs) (HSTCOS/ STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray imaging/spectroscopy (XMM-Newton and Chandra). First, we report a very low covering fraction of HI absorption in the CGM of these cluster galaxies, fc = 25 -15 +25per cent, to stringent detection limits (N(H I) < 1013 cm-2). As field galaxies have an HI covering fraction of ~ 100 per cent at similar radii, the dearth of CGM HI in our data indicates that the cluster environment has effectively stripped or overionized the gaseous haloes of these cluster galaxies. Secondly, we assess the contribution of warm-hot (105-106 K) gas to the ICM as traced by OVI and broad Ly a (BLA) absorption. Despite the high signal-to-noise ratio of our data, we do not detect OVI in any cluster, and we only detect BLA features in the QSO spectrum probing one cluster. We estimate that the total column density of warm-hot gas along this line of sight totals to ~ 3 per cent of that contained in the hot T > 107 K X-ray emitting phase. Residing at high relative velocities, these features may trace pre-shocked material outside the cluster. Comparing gaseous galaxy haloes from the low-density 'field' to galaxy groups and high-density clusters, we find that the CGM is progressively depleted of HI with increasing environmental density, and the CGM is most severely transformed in galaxy clusters. This CGM transformation may play a key role in environmental galaxy quenching.
AB - We analyse the intracluster medium (ICM) and circumgalactic medium (CGM) in seven X-ray-detected galaxy clusters using spectra of background quasi-stellar objects (QSOs) (HSTCOS/ STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray imaging/spectroscopy (XMM-Newton and Chandra). First, we report a very low covering fraction of HI absorption in the CGM of these cluster galaxies, fc = 25 -15 +25per cent, to stringent detection limits (N(H I) < 1013 cm-2). As field galaxies have an HI covering fraction of ~ 100 per cent at similar radii, the dearth of CGM HI in our data indicates that the cluster environment has effectively stripped or overionized the gaseous haloes of these cluster galaxies. Secondly, we assess the contribution of warm-hot (105-106 K) gas to the ICM as traced by OVI and broad Ly a (BLA) absorption. Despite the high signal-to-noise ratio of our data, we do not detect OVI in any cluster, and we only detect BLA features in the QSO spectrum probing one cluster. We estimate that the total column density of warm-hot gas along this line of sight totals to ~ 3 per cent of that contained in the hot T > 107 K X-ray emitting phase. Residing at high relative velocities, these features may trace pre-shocked material outside the cluster. Comparing gaseous galaxy haloes from the low-density 'field' to galaxy groups and high-density clusters, we find that the CGM is progressively depleted of HI with increasing environmental density, and the CGM is most severely transformed in galaxy clusters. This CGM transformation may play a key role in environmental galaxy quenching.
KW - Galaxies: clusters: intracluster medium
KW - Galaxies: evolution
KW - Galaxies: groups: general
KW - Galaxies: haloes
KW - Quasars: absorption lines
KW - X-rays: galaxies: clusters
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U2 - 10.1093/mnras/stx3170
DO - 10.1093/mnras/stx3170
M3 - Article
AN - SCOPUS:85046006932
SN - 0035-8711
VL - 475
SP - 2067
EP - 2085
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -