Galaxy And Mass Assembly: search for a population of high-entropy galaxy groups

Richard J. Pearson; Trevor J. Ponman; Peder Norberg; Aaron S. G. Robotham; Arif Babul; Richard G. Bower; Ian G. McCarthy; Sarah Brough; Simon P. Driver; Kevin Pimbblet

doi:10.1093/mnras/stx1081

Galaxy And Mass Assembly: search for a population of high-entropy galaxy groups

Richard J. Pearson, Trevor J. Ponman, Peder Norberg, Aaron S. G. Robotham, Arif Babul, Richard G. Bower, Ian G. McCarthy, Sarah Brough, Simon P. Driver, Kevin Pimbblet

School of Physics and Astronomy

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Abstract

Observations with the ChandraX-ray Observatory are used to examine the hot gas properties within a sample of 10 galaxy groups selected from the Galaxy And Mass Assembly survey's optical Friends-of-Friends group catalogue. Our groups have been screened to eliminate spurious and unrelaxed systems, and the effectiveness of this procedure is demonstrated by the detection of intergalactic hot gas in 80 per cent of our sample. However, we find that 9 of the 10 are X-ray underluminous by a mean factor of ∼4 compared to typical X-ray-selected samples. Consistent with this, the majority of our groups have gas fractions that are lower and gas entropies somewhat higher than those seen in typical X-ray-selected samples. Two groups, which have high 2σ lower limits on their gas entropy, are candidates for the population of high-entropy groups predicted by some active galactic nucleus feedback models.

Original language	English
Pages (from-to)	3489-3504
Journal	Monthly Notices of the Royal Astronomical Society
Volume	469
Issue number	3
Early online date	6 May 2017
DOIs	https://doi.org/10.1093/mnras/stx1081
Publication status	Published - Aug 2017

Keywords

Galaxies: clusters: intracluster medium
Galaxies: groups: general
X-rays: galaxies: clusters

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10.1093/mnras/stx1081

Pearson-2017-GAMA-MNRAS-3489
© 2017, the Author(s). This work has been made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at https://doi.org/10.1093/mnras/stx1081
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http://arxiv.org/abs/1706.03361v1

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@article{17a436cb92834577904b806fc0b21fc2,

title = "Galaxy And Mass Assembly: search for a population of high-entropy galaxy groups",

abstract = "Observations with the ChandraX-ray Observatory are used to examine the hot gas properties within a sample of 10 galaxy groups selected from the Galaxy And Mass Assembly survey's optical Friends-of-Friends group catalogue. Our groups have been screened to eliminate spurious and unrelaxed systems, and the effectiveness of this procedure is demonstrated by the detection of intergalactic hot gas in 80 per cent of our sample. However, we find that 9 of the 10 are X-ray underluminous by a mean factor of ∼4 compared to typical X-ray-selected samples. Consistent with this, the majority of our groups have gas fractions that are lower and gas entropies somewhat higher than those seen in typical X-ray-selected samples. Two groups, which have high 2σ lower limits on their gas entropy, are candidates for the population of high-entropy groups predicted by some active galactic nucleus feedback models.",

keywords = "Galaxies: clusters: intracluster medium, Galaxies: groups: general, X-rays: galaxies: clusters",

author = "Pearson, {Richard J.} and Ponman, {Trevor J.} and Peder Norberg and Robotham, {Aaron S. G.} and Arif Babul and Bower, {Richard G.} and McCarthy, {Ian G.} and Sarah Brough and Driver, {Simon P.} and Kevin Pimbblet",

year = "2017",

month = aug,

doi = "10.1093/mnras/stx1081",

language = "English",

volume = "469",

pages = "3489--3504",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "Oxford University Press",

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TY - JOUR

T1 - Galaxy And Mass Assembly

T2 - search for a population of high-entropy galaxy groups

AU - Pearson, Richard J.

AU - Ponman, Trevor J.

AU - Norberg, Peder

AU - Robotham, Aaron S. G.

AU - Babul, Arif

AU - Bower, Richard G.

AU - McCarthy, Ian G.

AU - Brough, Sarah

AU - Driver, Simon P.

AU - Pimbblet, Kevin

PY - 2017/8

Y1 - 2017/8

N2 - Observations with the ChandraX-ray Observatory are used to examine the hot gas properties within a sample of 10 galaxy groups selected from the Galaxy And Mass Assembly survey's optical Friends-of-Friends group catalogue. Our groups have been screened to eliminate spurious and unrelaxed systems, and the effectiveness of this procedure is demonstrated by the detection of intergalactic hot gas in 80 per cent of our sample. However, we find that 9 of the 10 are X-ray underluminous by a mean factor of ∼4 compared to typical X-ray-selected samples. Consistent with this, the majority of our groups have gas fractions that are lower and gas entropies somewhat higher than those seen in typical X-ray-selected samples. Two groups, which have high 2σ lower limits on their gas entropy, are candidates for the population of high-entropy groups predicted by some active galactic nucleus feedback models.

AB - Observations with the ChandraX-ray Observatory are used to examine the hot gas properties within a sample of 10 galaxy groups selected from the Galaxy And Mass Assembly survey's optical Friends-of-Friends group catalogue. Our groups have been screened to eliminate spurious and unrelaxed systems, and the effectiveness of this procedure is demonstrated by the detection of intergalactic hot gas in 80 per cent of our sample. However, we find that 9 of the 10 are X-ray underluminous by a mean factor of ∼4 compared to typical X-ray-selected samples. Consistent with this, the majority of our groups have gas fractions that are lower and gas entropies somewhat higher than those seen in typical X-ray-selected samples. Two groups, which have high 2σ lower limits on their gas entropy, are candidates for the population of high-entropy groups predicted by some active galactic nucleus feedback models.

KW - Galaxies: clusters: intracluster medium

KW - Galaxies: groups: general

KW - X-rays: galaxies: clusters

U2 - 10.1093/mnras/stx1081

DO - 10.1093/mnras/stx1081

M3 - Article

SN - 0035-8711

VL - 469

SP - 3489

EP - 3504

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 3

ER -

Galaxy And Mass Assembly: search for a population of high-entropy galaxy groups

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Keywords

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