# Origin of central abundances in the hot intra-cluster medium - I. individual and average abundance ratios from XMM-Newton EPIC

F. Mernier, J. de Plaa, C. Pinto, J. S. Kaastra, P. Kosec, Y. Y. Zhang, J. Mao, N. Werner

Research output: Contribution to journalArticle

28 Citations (Scopus)

### Abstract

The hot intra-cluster medium (ICM) is rich in metals, which are synthesized by supernovae (SNe) explosions and accumulate over time into the deep gravitational potential well of clusters of galaxies. Since most of the elements visible in X-rays are formed by type Ia (SNIa) and/or core-collapse (SNcc) supernovae, measuring their abundances gives us direct information on the nucleosynthesis products of billions of SNe since the epoch of the star formation peak (z ~ 2-3). In this study, we use the EPIC and RGS instruments onboard XMM-Newton to measure the abundances of 9 elements (O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni) from a sample of 44 nearby cool-core galaxy clusters, groups, and elliptical galaxies. We find that the Fe abundance shows a large scatter (~20-40%) over the sample, within 0.2$r_{500}$ and, especially, 0.05$r_{500}$. Unlike the absolute Fe abundance, the abundance ratios (X/Fe) are quite uniform over the considered temperature range (~0.6-8 keV), and with a limited scatter. In addition to a unprecedented treatment of systematic uncertainties, we provide the most accurate abundance ratios measured so far in the ICM, including Cr/Fe and Mn/Fe that we firmly detect (>4{\sigma} with MOS and pn independently). We find that Cr/Fe, Mn/Fe and Ni/Fe, differ significantly from the proto-solar values. However, the large uncertainties in the proto-solar abundances prevent us from making a robust comparison between the local and the intra-cluster chemical enrichments. We also note that, interestingly, and despite the large net exposure time (~4.5 Ms) of our dataset, no line emission feature is seen around ~3.5 keV.
Original language English A157 18 Astronomy and Astrophysics 592 https://doi.org/10.1051/0004-6361/201527824 Published - 24 Aug 2016

### Fingerprint

XMM-Newton telescope
newton
supernovae
galaxies
galactic clusters
elliptical galaxies
nuclear fusion
gravitational fields
explosions
star formation
explosion
time measurement
metal
products
metals
x rays
temperature

### Keywords

• astro-ph.GA
• astro-ph.CO
• astro-ph.HE
• X-rays: galaxies
• galaxies: clusters
• galaxies: clusters: intracluster medium
• galaxies: abundances
• supernovae
• dark matter

### Cite this

Mernier, F. ; Plaa, J. de ; Pinto, C. ; Kaastra, J. S. ; Kosec, P. ; Zhang, Y. Y. ; Mao, J. ; Werner, N. / Origin of central abundances in the hot intra-cluster medium - I. individual and average abundance ratios from XMM-Newton EPIC. In: Astronomy and Astrophysics. 2016 ; Vol. 592.
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title = "Origin of central abundances in the hot intra-cluster medium - I. individual and average abundance ratios from XMM-Newton EPIC",
abstract = "The hot intra-cluster medium (ICM) is rich in metals, which are synthesized by supernovae (SNe) explosions and accumulate over time into the deep gravitational potential well of clusters of galaxies. Since most of the elements visible in X-rays are formed by type Ia (SNIa) and/or core-collapse (SNcc) supernovae, measuring their abundances gives us direct information on the nucleosynthesis products of billions of SNe since the epoch of the star formation peak (z ~ 2-3). In this study, we use the EPIC and RGS instruments onboard XMM-Newton to measure the abundances of 9 elements (O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni) from a sample of 44 nearby cool-core galaxy clusters, groups, and elliptical galaxies. We find that the Fe abundance shows a large scatter (~20-40{\%}) over the sample, within 0.2$r_{500}$ and, especially, 0.05$r_{500}$. Unlike the absolute Fe abundance, the abundance ratios (X/Fe) are quite uniform over the considered temperature range (~0.6-8 keV), and with a limited scatter. In addition to a unprecedented treatment of systematic uncertainties, we provide the most accurate abundance ratios measured so far in the ICM, including Cr/Fe and Mn/Fe that we firmly detect (>4{\sigma} with MOS and pn independently). We find that Cr/Fe, Mn/Fe and Ni/Fe, differ significantly from the proto-solar values. However, the large uncertainties in the proto-solar abundances prevent us from making a robust comparison between the local and the intra-cluster chemical enrichments. We also note that, interestingly, and despite the large net exposure time (~4.5 Ms) of our dataset, no line emission feature is seen around ~3.5 keV.",
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Origin of central abundances in the hot intra-cluster medium - I. individual and average abundance ratios from XMM-Newton EPIC. / Mernier, F.; Plaa, J. de; Pinto, C.; Kaastra, J. S.; Kosec, P.; Zhang, Y. Y.; Mao, J.; Werner, N.

In: Astronomy and Astrophysics, Vol. 592, A157, 24.08.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Origin of central abundances in the hot intra-cluster medium - I. individual and average abundance ratios from XMM-Newton EPIC

AU - Mernier, F.

AU - Plaa, J. de

AU - Pinto, C.

AU - Kaastra, J. S.

AU - Kosec, P.

AU - Zhang, Y. Y.

AU - Mao, J.

AU - Werner, N.

PY - 2016/8/24

Y1 - 2016/8/24

N2 - The hot intra-cluster medium (ICM) is rich in metals, which are synthesized by supernovae (SNe) explosions and accumulate over time into the deep gravitational potential well of clusters of galaxies. Since most of the elements visible in X-rays are formed by type Ia (SNIa) and/or core-collapse (SNcc) supernovae, measuring their abundances gives us direct information on the nucleosynthesis products of billions of SNe since the epoch of the star formation peak (z ~ 2-3). In this study, we use the EPIC and RGS instruments onboard XMM-Newton to measure the abundances of 9 elements (O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni) from a sample of 44 nearby cool-core galaxy clusters, groups, and elliptical galaxies. We find that the Fe abundance shows a large scatter (~20-40%) over the sample, within 0.2$r_{500}$ and, especially, 0.05$r_{500}$. Unlike the absolute Fe abundance, the abundance ratios (X/Fe) are quite uniform over the considered temperature range (~0.6-8 keV), and with a limited scatter. In addition to a unprecedented treatment of systematic uncertainties, we provide the most accurate abundance ratios measured so far in the ICM, including Cr/Fe and Mn/Fe that we firmly detect (>4{\sigma} with MOS and pn independently). We find that Cr/Fe, Mn/Fe and Ni/Fe, differ significantly from the proto-solar values. However, the large uncertainties in the proto-solar abundances prevent us from making a robust comparison between the local and the intra-cluster chemical enrichments. We also note that, interestingly, and despite the large net exposure time (~4.5 Ms) of our dataset, no line emission feature is seen around ~3.5 keV.

AB - The hot intra-cluster medium (ICM) is rich in metals, which are synthesized by supernovae (SNe) explosions and accumulate over time into the deep gravitational potential well of clusters of galaxies. Since most of the elements visible in X-rays are formed by type Ia (SNIa) and/or core-collapse (SNcc) supernovae, measuring their abundances gives us direct information on the nucleosynthesis products of billions of SNe since the epoch of the star formation peak (z ~ 2-3). In this study, we use the EPIC and RGS instruments onboard XMM-Newton to measure the abundances of 9 elements (O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni) from a sample of 44 nearby cool-core galaxy clusters, groups, and elliptical galaxies. We find that the Fe abundance shows a large scatter (~20-40%) over the sample, within 0.2$r_{500}$ and, especially, 0.05$r_{500}$. Unlike the absolute Fe abundance, the abundance ratios (X/Fe) are quite uniform over the considered temperature range (~0.6-8 keV), and with a limited scatter. In addition to a unprecedented treatment of systematic uncertainties, we provide the most accurate abundance ratios measured so far in the ICM, including Cr/Fe and Mn/Fe that we firmly detect (>4{\sigma} with MOS and pn independently). We find that Cr/Fe, Mn/Fe and Ni/Fe, differ significantly from the proto-solar values. However, the large uncertainties in the proto-solar abundances prevent us from making a robust comparison between the local and the intra-cluster chemical enrichments. We also note that, interestingly, and despite the large net exposure time (~4.5 Ms) of our dataset, no line emission feature is seen around ~3.5 keV.

KW - astro-ph.GA

KW - astro-ph.CO

KW - astro-ph.HE

KW - X-rays: galaxies

KW - galaxies: clusters

KW - galaxies: clusters: intracluster medium

KW - galaxies: abundances

KW - supernovae

KW - dark matter

UR - https://arxiv.org/abs/1606.01165v2

U2 - 10.1051/0004-6361/201527824

DO - 10.1051/0004-6361/201527824

M3 - Article

VL - 592

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A157

ER -