2009A&A...505..991V


C.D.S. - SIMBAD4 rel 1.7 - 2020.02.27CET03:57:58

2009A&A...505..991V - Astronomy and Astrophysics, volume 505, 991-997 (2009/10-3)

Diffuse radio emission in the merging cluster MACS J0717.5+3745: the discovery of the most powerful radio halo.

VAN WEEREN R.J., ROETTGERING H.J.A., BRUEGGEN M. and COHEN A.

Abstract (from CDS):

Hierarchical models of structure formation predict that galaxy clusters grow via mergers of smaller clusters and galaxy groups, as well as through continuous accretion of gas. MACS J0717.5+3745 is an X-ray luminous and complex merging cluster, located at a redshift of 0.5548. The cluster is suspected to host a bright radio relic, but up until now no detailed radio observations have been reported. Here we present Giant Metrewave Radio Telescope (GMRT) radio observations at 610MHz of this cluster. The main aim of the observations is to study the diffuse radio emission within the galaxy cluster MACS J0717.5+3745 related to the ongoing merger. We have carried out GMRT 610MHz continuum observations of MACS J0717.5+3745. These are complemented by Very Large Array (VLA) archival observations at 1.4, 4.9 and 8.5GHz. We have discovered a radio halo in the cluster MACS J0717.5+3745 with a size of about 1.2Mpc. The monochromatic radio power at 1400 MHz (P1.4) is 5x1025W/Hz, which makes it the most powerful radio halo known to date. A 700kpc radio structure, which we classify as a radio relic, is located in between the merging substructures of the system. The global spectral index of radio emission within the cluster is found to be -1.24±0.05 between 4.9GHz and 610MHz. We derive a value of 5.8µG for the equipartition magnetic field strength at the location of the radio halo. The location of the relic roughly coincides with regions of the intra-cluster medium (ICM) that have a significant enhancement in temperature as shown by Chandra. The major axis of the relic is also roughly perpendicular to the merger axis. This shows that the relic might be the result of a merger-related shock wave, where particles are accelerated via the diffuse shock acceleration (DSA) mechanism. Alternatively, the relic might trace an accretion shock of a large-scale galaxy filament to the south-east.

Abstract Copyright:

Journal keyword(s): radio continuum: galaxies - galaxies: clusters: individual: MACS J0717.5+3745 - cosmology: large-scale structure of Universe

Nomenclature: Fig. 2: [VRB2009] AN (Nos H1-H2, R1-R4, C1-C2), [VRB2009] HT N=1, [VRB2009] FR-I N=1.

Status in Simbad:  being processed

Simbad objects: 9

goto Full paper

goto View the reference in ADS

Number of rows : 9

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 3C 48 QSO 01 37 41.2995845985 +33 09 35.079126038   16.62 16.20     ~ 2462 2
2 ICRF J054236.1+495107 Sy1 05 42 36.13789843 +49 51 07.2337251   18.45 17.80 17.210   ~ 1244 1
3 ClG 0657-56 ClG 06 58 29.6 -55 56 39           ~ 785 1
4 QSO B0710+439 QSO 07 13 38.16412910 +43 49 17.2071530   20.7       ~ 222 0
5 ClG J0717+3745 ClG 07 17 36.50 +37 45 23.0           ~ 339 0
6 B3 0714+378 Rad 07 17 36.50 +37 45 23.0           ~ 169 2
7 ACO 1240 ClG 11 23 32 +43 06.5           ~ 72 0
8 3C 286 Sy1 13 31 08.2885060664 +30 30 32.960825108   17.51 17.25     ~ 3660 1
9 ACO 2345 ClG 21 27 09.80 -12 09 58.8           ~ 109 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2009A&A...505..991V and select 'bookmark this link' or equivalent in the popup menu


2020.02.27-03:57:58

© Université de Strasbourg/CNRS

    • Contact