2017A&A...600A.100A


C.D.S. - SIMBAD4 rel 1.7 - 2020.05.29CEST03:21:01

2017A&A...600A.100A - Astronomy and Astrophysics, volume 600A, 100-100 (2017/4-1)

Suzaku observations of the merging galaxy cluster Abell 2255: The northeast radio relic.

AKAMATSU H., MIZUNO M., OTA N., ZHANG Y.-Y., VAN WEEREN R.J., KAWAHARA H., FUKAZAWA Y., KAASTRA J.S., KAWAHARADA M., NAKAZAWA K., OHASHI T., ROTTGERING H.J.A., TAKIZAWA M., VINK J. and ZANDANEL F.

Abstract (from CDS):

We present the results of deep 140 ks Suzaku X-ray observations of the north-east (NE) radio relic of the merging galaxy cluster Abell 2255. The temperature structure of Abell 2255 is measured out to 0.9 times the virial radius (1.9Mpc) in the NE direction for the first time. The Suzaku temperature map of the central region suggests a complex temperature distribution, which agrees with previous work. Additionally, on a larger-scale, we confirm that the temperature drops from 6 keV around the cluster center to 3keV at the outskirts, with two discontinuities at r∼5' (450kpc) and ∼12' (1100kpc) from the cluster center. Their locations coincide with surface brightness discontinuities marginally detected in the XMM-Newton image, which indicates the presence of shock structures. From the temperature drop, we estimate the Mach numbers to be Minner∼1.2 and, Mouter∼1.4. The first structure is most likely related to the large cluster core region (∼350-430kpc), and its Mach number is consistent with the XMM-Newton observation (M∼1.24: Sakelliou & Ponman, 2006MNRAS.367.1409S). Our detection of the second temperature jump, based on the Suzaku key project observation, shows the presence of a shock structure across the NE radio relic. This indicates a connection between the shock structure and the relativistic electrons that generate radio emission. Across the NE radio relic, however, we find a significantly lower temperature ratio (T1/T2∼1.44±0.16 corresponds to MX–ray∼1.4) than the value expected from radio wavelengths, based on the standard diffusive shock acceleration mechanism (T1/T2>3.2 or MRadio>2.8). This may suggest that under some conditions, in particular the NE relic of A2255 case, the simple diffusive shock acceleration mechanism is unlikely to be valid, and therefore, more a sophisticated mechanism is required.

Abstract Copyright: © ESO, 2017

Journal keyword(s): shock waves - galaxies: clusters: intracluster medium - X-rays: galaxies: clusters - galaxies: clusters: individual: Abell 2255 - radio continuum: galaxies - radio continuum: galaxies

Status at CDS:  

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 ACO 115 ClG 00 55 59.5 +26 19 14           ~ 235 1
2 ACO 426 ClG 03 19 47.2 +41 30 47           ~ 1931 1
3 ACO 3376 ClG 06 01 42.1521 -39 59 06.227           ~ 267 0
4 ClG J0603.3+4214 ClG 06 03.3 +42 14           ~ 65 0
5 NAME Coma Relic Rad 12 55 +27.2           ~ 53 0
6 NAME Lupus SN SNR 15 02 22.1 -42 05 49           ~ 1206 1
7 NAME LHB X 16 42.0 +02 19           ~ 253 0
8 ACO 2256 ClG 17 03 43.5 +78 43 03           ~ 829 1
9 ACO 2255 ClG 17 12 50.04 +64 03 10.6           ~ 501 0
10 ACO 3667 ClG 20 12 33.68 -56 50 26.3           ~ 563 1
11 NAME Sausage Cluster ClG 22 42 53.0 +53 01 05           ~ 154 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2017A&A...600A.100A and select 'bookmark this link' or equivalent in the popup menu


2020.05.29-03:21:01

© Université de Strasbourg/CNRS

    • Contact