Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404

H. Akamatsu, L. Gu, T. W. Shimwell, F. Mernier, J. Mao, I. Urdampilleta, J. de Plaa, H. J. A. Röttgering, J. S. Kaastra

Research output: Contribution to journalArticle

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Abstract

We present the results of Suzaku and XMM-Newton X-ray observations of the cluster pair 1E2216.0-0401 and 1E2215.7-0404. We discover an X-ray bridge between the clusters. Suzaku and XMM-Newton observations revealed that each cluster hosts gas with moderate temperature of kT0401 = 4.8 ± 0.1 keV and kT0404 = 5.8 ± 0.2 keV, respectively. On the other hand, the bridge region shows a remarkably high temperature (kT = 6.6 ± 0.5 keV). Furthermore, at the position of the bridge, we detected an enhancement in the wavelet-decomposed soft-band (0.5-4.0 keV) XMM-Newton image at 3 sigma significance, this is most likely due to a compression of the intracluster medium (ICM) as a consequence of the merging activity. This X-ray intensity and temperature enhancement are not consistent with those expected from a late phase, but are in agreement with the predictions by numerical simulations of an early phase merger. From the temperature jump at the location of the bridge, the Mach number is estimated to be M = 1.4 ± 0.1, which corresponds to a shock propagation velocity of about 1570 km s-1. From the shock properties, we estimate that core-passage will occur in 0.3-0.6 Gyr and that the age of the shock structure is 50-100 Myr. Based on the measured properties of the ICM at the bridge and estimation of timescales, we find indications for non-equilibrium ionization. We also discover possible diffuse radio emission located between the merging clusters. Combining the radio, X-ray, and optical image data, we speculate that the detected radio sources are most likely related to the merger event. Thus, 1E2216.0-0401 and 1E2215.7-0404 is a new example of an early phase cluster merger with remarkable characteristics.

Original languageEnglish
Article numberL7
Number of pages5
JournalAstronomy and Astrophysics
Volume593
Early online date8 Sep 2016
DOIs
Publication statusE-pub ahead of print - 8 Sep 2016

Fingerprint

XMM-Newton telescope
merger
newton
radio
shock
x rays
nonequilibrium ionization
temperature
augmentation
wavelet
propagation velocity
radio emission
ionization
Mach number
compression
timescale
indication
prediction
gas
simulation

Keywords

  • galaxies
  • clusters
  • X-Rays
  • shock waves

Cite this

Akamatsu, H. ; Gu, L. ; Shimwell, T. W. ; Mernier, F. ; Mao, J. ; Urdampilleta, I. ; de Plaa, J. ; Röttgering, H. J. A. ; Kaastra, J. S. / Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404. In: Astronomy and Astrophysics. 2016 ; Vol. 593.
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title = "Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404",
abstract = "We present the results of Suzaku and XMM-Newton X-ray observations of the cluster pair 1E2216.0-0401 and 1E2215.7-0404. We discover an X-ray bridge between the clusters. Suzaku and XMM-Newton observations revealed that each cluster hosts gas with moderate temperature of kT0401 = 4.8 ± 0.1 keV and kT0404 = 5.8 ± 0.2 keV, respectively. On the other hand, the bridge region shows a remarkably high temperature (kT = 6.6 ± 0.5 keV). Furthermore, at the position of the bridge, we detected an enhancement in the wavelet-decomposed soft-band (0.5-4.0 keV) XMM-Newton image at 3 sigma significance, this is most likely due to a compression of the intracluster medium (ICM) as a consequence of the merging activity. This X-ray intensity and temperature enhancement are not consistent with those expected from a late phase, but are in agreement with the predictions by numerical simulations of an early phase merger. From the temperature jump at the location of the bridge, the Mach number is estimated to be M = 1.4 ± 0.1, which corresponds to a shock propagation velocity of about 1570 km s-1. From the shock properties, we estimate that core-passage will occur in 0.3-0.6 Gyr and that the age of the shock structure is 50-100 Myr. Based on the measured properties of the ICM at the bridge and estimation of timescales, we find indications for non-equilibrium ionization. We also discover possible diffuse radio emission located between the merging clusters. Combining the radio, X-ray, and optical image data, we speculate that the detected radio sources are most likely related to the merger event. Thus, 1E2216.0-0401 and 1E2215.7-0404 is a new example of an early phase cluster merger with remarkable characteristics.",
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author = "H. Akamatsu and L. Gu and Shimwell, {T. W.} and F. Mernier and J. Mao and I. Urdampilleta and {de Plaa}, J. and R{\"o}ttgering, {H. J. A.} and Kaastra, {J. S.}",
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Akamatsu, H, Gu, L, Shimwell, TW, Mernier, F, Mao, J, Urdampilleta, I, de Plaa, J, Röttgering, HJA & Kaastra, JS 2016, 'Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404', Astronomy and Astrophysics, vol. 593, L7. https://doi.org/10.1051/0004-6361/201629275

Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404. / Akamatsu, H.; Gu, L.; Shimwell, T. W.; Mernier, F.; Mao, J.; Urdampilleta, I.; de Plaa, J.; Röttgering, H. J. A.; Kaastra, J. S.

In: Astronomy and Astrophysics, Vol. 593, L7, 08.09.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Suzaku and XMM-Newton observations of the newly discovered early-stage cluster merger of 1E2216.0-0401 and 1E2215.7-0404

AU - Akamatsu, H.

AU - Gu, L.

AU - Shimwell, T. W.

AU - Mernier, F.

AU - Mao, J.

AU - Urdampilleta, I.

AU - de Plaa, J.

AU - Röttgering, H. J. A.

AU - Kaastra, J. S.

PY - 2016/9/8

Y1 - 2016/9/8

N2 - We present the results of Suzaku and XMM-Newton X-ray observations of the cluster pair 1E2216.0-0401 and 1E2215.7-0404. We discover an X-ray bridge between the clusters. Suzaku and XMM-Newton observations revealed that each cluster hosts gas with moderate temperature of kT0401 = 4.8 ± 0.1 keV and kT0404 = 5.8 ± 0.2 keV, respectively. On the other hand, the bridge region shows a remarkably high temperature (kT = 6.6 ± 0.5 keV). Furthermore, at the position of the bridge, we detected an enhancement in the wavelet-decomposed soft-band (0.5-4.0 keV) XMM-Newton image at 3 sigma significance, this is most likely due to a compression of the intracluster medium (ICM) as a consequence of the merging activity. This X-ray intensity and temperature enhancement are not consistent with those expected from a late phase, but are in agreement with the predictions by numerical simulations of an early phase merger. From the temperature jump at the location of the bridge, the Mach number is estimated to be M = 1.4 ± 0.1, which corresponds to a shock propagation velocity of about 1570 km s-1. From the shock properties, we estimate that core-passage will occur in 0.3-0.6 Gyr and that the age of the shock structure is 50-100 Myr. Based on the measured properties of the ICM at the bridge and estimation of timescales, we find indications for non-equilibrium ionization. We also discover possible diffuse radio emission located between the merging clusters. Combining the radio, X-ray, and optical image data, we speculate that the detected radio sources are most likely related to the merger event. Thus, 1E2216.0-0401 and 1E2215.7-0404 is a new example of an early phase cluster merger with remarkable characteristics.

AB - We present the results of Suzaku and XMM-Newton X-ray observations of the cluster pair 1E2216.0-0401 and 1E2215.7-0404. We discover an X-ray bridge between the clusters. Suzaku and XMM-Newton observations revealed that each cluster hosts gas with moderate temperature of kT0401 = 4.8 ± 0.1 keV and kT0404 = 5.8 ± 0.2 keV, respectively. On the other hand, the bridge region shows a remarkably high temperature (kT = 6.6 ± 0.5 keV). Furthermore, at the position of the bridge, we detected an enhancement in the wavelet-decomposed soft-band (0.5-4.0 keV) XMM-Newton image at 3 sigma significance, this is most likely due to a compression of the intracluster medium (ICM) as a consequence of the merging activity. This X-ray intensity and temperature enhancement are not consistent with those expected from a late phase, but are in agreement with the predictions by numerical simulations of an early phase merger. From the temperature jump at the location of the bridge, the Mach number is estimated to be M = 1.4 ± 0.1, which corresponds to a shock propagation velocity of about 1570 km s-1. From the shock properties, we estimate that core-passage will occur in 0.3-0.6 Gyr and that the age of the shock structure is 50-100 Myr. Based on the measured properties of the ICM at the bridge and estimation of timescales, we find indications for non-equilibrium ionization. We also discover possible diffuse radio emission located between the merging clusters. Combining the radio, X-ray, and optical image data, we speculate that the detected radio sources are most likely related to the merger event. Thus, 1E2216.0-0401 and 1E2215.7-0404 is a new example of an early phase cluster merger with remarkable characteristics.

KW - galaxies

KW - clusters

KW - X-Rays

KW - shock waves

UR - http://www.scopus.com/inward/record.url?scp=84986286549&partnerID=8YFLogxK

UR - https://arxiv.org/abs/1608.01669

U2 - 10.1051/0004-6361/201629275

DO - 10.1051/0004-6361/201629275

M3 - Article

VL - 593

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - L7

ER -