Abstract Details

Name: Juhi Tiwari
Affiliation: Indian Institute of Science Education and Research Mohali
Conference ID: ASI2021_271
Title : Hercules cluster in X-rays with XMM-Newton and Chandra
Authors and Co-Authors : Juhi Tiwari, IISER Mohali; Kulinder Pal Singh, IISER Mohali
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : We present for the first time a detailed X-ray study of the central subcluster of the nearby (z~0.0368) Hercules cluster (Abell 2151) identified as A2151C, using high-resolution data from the XMM-Newton and Chandra space observatories. A2151C shows a bimodal structure. A bright clump of hot gas with X-ray emission extending to radius r~304 kpc and X-ray luminosity L_X = 3.03 {+0.02;-0.04} x 10^{43} erg s^{-1} in the 0.4--7.0 keV energy range is seen as a fairly regular subclump towards the west (A2151C(B)). An irregular, fainter and cooler subclump with radius r~364 kpc is seen towards the east (A2151C(F)) and has L_X = 1.13 {+0.02;-0.02} x 10^{43} erg s^{-1} in the 0.4--7.0 keV energy band. The average temperature and elemental abundance of A2151C(B) are 2.01 {+0.05;-0.05} keV and 0.43 {+0.05;-0.05} Z_{solar} respectively, while these values are 1.17 {+0.04;-0.04} keV and 0.13{+0.02;-0.02} Z_{solar} for A2151C(F). Low temperature {1.55}{+0.07;-0.07} keV and a short cooling time (~0.81 Gyr) within the central 15 arcsec region confirm the presence of a cool core in A2151C(B). We identify several compact groups of galaxies within A2151C(F). We find that A2151C(F) is a distinct galaxy group in the process of formation and likely not a ram-pressure stripped part of the eastern subcluster in Hercules (A2151E). X-ray emission from A2151C shows a region of overlap between A2151C(B) and A2151C(F) but without any enhancement of temperature or entropy in the two-dimensional (2D) projected thermodynamic maps that could have indicated an interaction due to a merger between the two subclumps.