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Title: Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters

Abstract

We investigate the occurrence of radio minihalos—diffuse radio sources of unknown origin observed in the cores of some galaxy clusters—in a statistical sample of 58 clusters drawn from the Planck Sunyaev–Zel’dovich cluster catalog using a mass cut ( M {sub 500} > 6 × 10{sup 14} M {sub ⊙}). We supplement our statistical sample with a similarly sized nonstatistical sample mostly consisting of clusters in the ACCEPT X-ray catalog with suitable X-ray and radio data, which includes lower-mass clusters. Where necessary (for nine clusters), we reanalyzed the Very Large Array archival radio data to determine whether a minihalo is present. Our total sample includes all 28 currently known and recently discovered radio minihalos, including six candidates. We classify clusters as cool-core or non-cool-core according to the value of the specific entropy floor in the cluster center, rederived or newly derived from the Chandra X-ray density and temperature profiles where necessary (for 27 clusters). Contrary to the common wisdom that minihalos are rare, we find that almost all cool cores—at least 12 out of 15 (80%)—in our complete sample of massive clusters exhibit minihalos. The supplementary sample shows that the occurrence of minihalos may be lower in lower-mass cool-core clusters. Nomore » minihalos are found in non-cool cores or “warm cores.” These findings will help test theories of the origin of minihalos and provide information on the physical processes and energetics of the cluster cores.« less

Authors:
;  [1];  [2]; ; ;  [3]
  1. Naval Research Laboratory, 4555 Overlook Avenue SW, Code 7213, Washington, DC 20375 (United States)
  2. NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  3. INAF—Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy)
Publication Date:
OSTI Identifier:
22663565
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 841; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CATALOGS; DENSITY; ENTROPY; GALAXY CLUSTERS; MASS; X RADIATION; X-RAY GALAXIES

Citation Formats

Giacintucci, Simona, Clarke, Tracy E., Markevitch, Maxim, Cassano, Rossella, Venturi, Tiziana, and Brunetti, Gianfranco, E-mail: simona.giacintucci@nrl.navy.mil. Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7069.
Giacintucci, Simona, Clarke, Tracy E., Markevitch, Maxim, Cassano, Rossella, Venturi, Tiziana, & Brunetti, Gianfranco, E-mail: simona.giacintucci@nrl.navy.mil. Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters. United States. doi:10.3847/1538-4357/AA7069.
Giacintucci, Simona, Clarke, Tracy E., Markevitch, Maxim, Cassano, Rossella, Venturi, Tiziana, and Brunetti, Gianfranco, E-mail: simona.giacintucci@nrl.navy.mil. Thu . "Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters". United States. doi:10.3847/1538-4357/AA7069.
@article{osti_22663565,
title = {Occurrence of Radio Minihalos in a Mass-limited Sample of Galaxy Clusters},
author = {Giacintucci, Simona and Clarke, Tracy E. and Markevitch, Maxim and Cassano, Rossella and Venturi, Tiziana and Brunetti, Gianfranco, E-mail: simona.giacintucci@nrl.navy.mil},
abstractNote = {We investigate the occurrence of radio minihalos—diffuse radio sources of unknown origin observed in the cores of some galaxy clusters—in a statistical sample of 58 clusters drawn from the Planck Sunyaev–Zel’dovich cluster catalog using a mass cut ( M {sub 500} > 6 × 10{sup 14} M {sub ⊙}). We supplement our statistical sample with a similarly sized nonstatistical sample mostly consisting of clusters in the ACCEPT X-ray catalog with suitable X-ray and radio data, which includes lower-mass clusters. Where necessary (for nine clusters), we reanalyzed the Very Large Array archival radio data to determine whether a minihalo is present. Our total sample includes all 28 currently known and recently discovered radio minihalos, including six candidates. We classify clusters as cool-core or non-cool-core according to the value of the specific entropy floor in the cluster center, rederived or newly derived from the Chandra X-ray density and temperature profiles where necessary (for 27 clusters). Contrary to the common wisdom that minihalos are rare, we find that almost all cool cores—at least 12 out of 15 (80%)—in our complete sample of massive clusters exhibit minihalos. The supplementary sample shows that the occurrence of minihalos may be lower in lower-mass cool-core clusters. No minihalos are found in non-cool cores or “warm cores.” These findings will help test theories of the origin of minihalos and provide information on the physical processes and energetics of the cluster cores.},
doi = {10.3847/1538-4357/AA7069},
journal = {Astrophysical Journal},
number = 2,
volume = 841,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}