Dasadia, S.S.DasadiaSun, M.M.SunSarazin, C.C.SarazinMorandi, A.A.MorandiMarkevitch, M.M.MarkevitchWik, D.D.WikFeretti, L.L.FerettiGiovannini, GabrieleGabrieleGiovanniniGOVONI, FEDERICAFEDERICAGOVONIVACCA, VALENTINAVALENTINAVACCA2020-05-192020-05-1920162041-8205http://hdl.handle.net/20.500.12386/24963Deep (103 ks) Chandra observations of Abell 665 have revealed rich structures in this merging galaxy cluster, including a strong shock and two cold fronts. The newly discovered shock has a Mach number of M = 3.0 ± 0.6, propagating in front of a cold disrupted cloud. This makes Abell 665 the second cluster, after the Bullet cluster, where a strong merger shock of M ≈ 3 has been detected. The shock velocity from jump conditions is consistent with (2.7 ± 0.7) × 10<SUP>3</SUP> km s<SUP>-1</SUP>. The new data also reveal a prominent southern cold front with potentially heated gas ahead of it. Abell 665 also hosts a giant radio halo. There is a hint of diffuse radio emission extending to the shock at the north, which needs to be examined with better radio data. This new strong shock provides a great opportunity to study the re-acceleration model with the X-ray and radio data combined.STAMPAenArticle10.3847/2041-8205/820/1/L202-s2.0-84962226398000372352000020https://iopscience.iop.org/article/10.3847/2041-8205/820/1/L202016ApJ...820L..20DFIS/05 - ASTRONOMIA E ASTROFISICA