TY - JOUR
T1 - Deep Chandra observations of the stripped galaxy group falling into Abell 2142
AU - Eckert, D.
AU - Gaspari, M.
AU - Owers, M. S.
AU - Roediger, E.
AU - Molendi, S.
AU - Gastaldello, F.
AU - Paltani, S.
AU - Ettori, S.
AU - Venturi, T.
AU - Rossetti, M.
AU - Rudnick, L.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - In the local Universe, the growth of massive galaxy clusters mainly operates through the continuous accretion of group-scale systems. The infalling group in Abell 2142 is the poster child of such an accreting group, and as such, it is an ideal target to study the astrophysical processes induced by structure formation. We present the results of a deep (200 ks) observation of this structure with Chandra that highlights the complexity of this system in exquisite detail. In the core of the group, the spatial resolution of Chandra reveals a leading edge and complex AGN-induced activity. The morphology of the stripped gas tail appears straight in the innermost 250 kpc, suggesting that magnetic draping efficiently shields the gas from its surroundings. However, beyond -300 kpc from the core, the tail flares and the morphology becomes strongly irregular, which could be explained by a breaking of the drape, for example, caused by turbulent motions. The power spectrum of surface-brightness fluctuations is relatively flat (P2Dk-2.3), which indicates that thermal conduction is strongly inhibited even beyond the region where magnetic draping is effective. The amplitude of density fluctuations in the tail is consistent with a mild level of turbulence with a Mach number M3D - 0.1 - 0.25. Overall, our results show that the processes leading to the thermalization and mixing of the infalling gas are slow and relatively inefficient.
AB - In the local Universe, the growth of massive galaxy clusters mainly operates through the continuous accretion of group-scale systems. The infalling group in Abell 2142 is the poster child of such an accreting group, and as such, it is an ideal target to study the astrophysical processes induced by structure formation. We present the results of a deep (200 ks) observation of this structure with Chandra that highlights the complexity of this system in exquisite detail. In the core of the group, the spatial resolution of Chandra reveals a leading edge and complex AGN-induced activity. The morphology of the stripped gas tail appears straight in the innermost 250 kpc, suggesting that magnetic draping efficiently shields the gas from its surroundings. However, beyond -300 kpc from the core, the tail flares and the morphology becomes strongly irregular, which could be explained by a breaking of the drape, for example, caused by turbulent motions. The power spectrum of surface-brightness fluctuations is relatively flat (P2Dk-2.3), which indicates that thermal conduction is strongly inhibited even beyond the region where magnetic draping is effective. The amplitude of density fluctuations in the tail is consistent with a mild level of turbulence with a Mach number M3D - 0.1 - 0.25. Overall, our results show that the processes leading to the thermalization and mixing of the infalling gas are slow and relatively inefficient.
KW - galaxies: clusters: general
KW - galaxies: clusters: intracluster medium
KW - galaxies: groups: general
KW - large-scale structure of Universe
KW - x-rays: galaxies: clusters
UR - http://www.scopus.com/inward/record.url?scp=85028773306&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201730555
DO - 10.1051/0004-6361/201730555
M3 - Article
AN - SCOPUS:85028773306
SN - 0004-6361
VL - 605
SP - 1
EP - 12
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A25
ER -