{"title":"Excess cataloged X-ray and radio sources at galaxy-cluster virial shocks","authors":"Gideon Ilani, Kuan-Chou Hou and Uri Keshet","doi":"10.1088/1475-7516/2024/10/008","DOIUrl":null,"url":null,"abstract":"We detect a highly significant excess of X-ray (2RXS) and radio (NVSS, GMRT, VLSSr) catalog sources when stacked around MCXC galaxy clusters and groups, narrowly confined within ≲ 100 kpc of the ∼ 2.4 R500 virial shock radius (inferred from previous continuum stacking), with similar X-ray (∼ 4σ for 443 clusters) and radio (∼ 4σ for 485 clusters) characteristics (> 5σ joint). The excess sources show 10–100 kpc scales, LX(0.1 – 2.4 keV)≃ 1042-43 erg s-1 or νLν(ν = 1.4 GHz) ≃ 1040-41 erg s-1 luminosities, and a preferentially radial radio-polarization. The narrow localization and properties of the excess identify these sources not as AGN, often invoked speculatively for excess X-ray sources at cluster outskirts, but rather as infalling gaseous clumps interacting with the virial shock, probably galactic halos and possibly outflow remnants. The local excess of such discrete, radio-to-γ-ray sources around an object can probe its virial shock also at high redshifts and sub-cluster scales.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Cosmology and Astroparticle Physics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1475-7516/2024/10/008","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
We detect a highly significant excess of X-ray (2RXS) and radio (NVSS, GMRT, VLSSr) catalog sources when stacked around MCXC galaxy clusters and groups, narrowly confined within ≲ 100 kpc of the ∼ 2.4 R500 virial shock radius (inferred from previous continuum stacking), with similar X-ray (∼ 4σ for 443 clusters) and radio (∼ 4σ for 485 clusters) characteristics (> 5σ joint). The excess sources show 10–100 kpc scales, LX(0.1 – 2.4 keV)≃ 1042-43 erg s-1 or νLν(ν = 1.4 GHz) ≃ 1040-41 erg s-1 luminosities, and a preferentially radial radio-polarization. The narrow localization and properties of the excess identify these sources not as AGN, often invoked speculatively for excess X-ray sources at cluster outskirts, but rather as infalling gaseous clumps interacting with the virial shock, probably galactic halos and possibly outflow remnants. The local excess of such discrete, radio-to-γ-ray sources around an object can probe its virial shock also at high redshifts and sub-cluster scales.
期刊介绍:
Journal of Cosmology and Astroparticle Physics (JCAP) encompasses theoretical, observational and experimental areas as well as computation and simulation. The journal covers the latest developments in the theory of all fundamental interactions and their cosmological implications (e.g. M-theory and cosmology, brane cosmology). JCAP''s coverage also includes topics such as formation, dynamics and clustering of galaxies, pre-galactic star formation, x-ray astronomy, radio astronomy, gravitational lensing, active galactic nuclei, intergalactic and interstellar matter.