J/A+A/665/A71ivo://CDS.VizieR/J/A+A/665/A71doi:10.26093/cds/vizier.36650071CDSOsinga E.van Weeren R.J.Andrade-Santos F.Rudnick L.Bonafede A.,Clarke T.Duncan K.Giacintucci S.Mroczkowski T.Roettgering H.J.A.2025-08-11T20:01:45Z2022-09-09T09:22:45ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxy-clusterspolarimetrymagnetic-fieldsradio-continuum-emissionIt has been well established that galaxy clusters have magnetic fields. The exact properties and origin of these magnetic fields are still uncertain even though these fields play a key role in many astrophysical processes. Various attempts have been made to derive the magnetic field strength and structure of nearby galaxy clusters using Faraday rotation of extended cluster radio sources. This approach needs to make various assumptions that could be circumvented when using background radio sources. However, because the number of polarised radio sources behind clusters is low, at the moment such a study can only be done statistically. In this paper, we investigate the depolarisation of radio sources inside and behind clusters in a sample of 124 massive clusters at z<0.35 observed with the Karl G. Jansky Very Large Array. We detect a clear depolarisation trend with the cluster impact parameter, with sources at smaller projected distances to the cluster centre showing more depolarisation. By combining the radio observations with ancillary X-ray data from Chandra, we compare the observed depolarisation with expectations from cluster magnetic field models using individual cluster density profiles. The best-fitting models have a central magnetic field strength of 5-10uG with power-law indices between n=1 and n=4. We find no strong difference in the depolarisation trend between sources embedded in clusters and background sources located at similar projected radii, although the central region of clusters is still poorly probed by background sources. We also examine the depolarisation trend as a function of cluster properties such as the dynamical state, mass, and redshift. We see a hint that dynamically disturbed clusters show more depolarisation than relaxed clusters in the r>0.2R_500_ region. In the core region, we did not observe enough sources to detect a significant difference between cool-core and non-cool-core clusters. Our findings show that the statistical depolarisation of radio sources is a good probe of cluster magnetic field parameters. Cluster members can be used for this purpose as well as background sources because the local interaction between the radio galaxies and the intracluster medium does not strongly affect the observed depolarisation trend.2022A&A...665A..71Ohttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/665/A71CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/665/A71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/665/A71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/665/A71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/665/A71https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/665/A71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/665/A71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/665/A71/tablec1 (Polarised source catalogue)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/665/A71/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/665/A71/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/665/A71/tablec1?GETtext/xml+votable180.050000true227.7395.6140.005555555555555556Cone search capability for table J/A+A/665/A71/tabled1 (Full source catalogue (unpolarised))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/665/A71/tabled1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/665/A71/tabled1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/665/A71/tabled1?GETtext/xml+votable180.050000true19.7206029805056-26.97923075001670.005555555555555556Cone search capability for table J/A+A/665/A71/tablee1 (Cluster catalogue)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/665/A71/tablee1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/665/A71/tablee1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/665/A71/tablee1?GETtext/xml+votable180.050000true227.73185729980475.74806690216060.0055555555555555565/597 3183 3798 4008 5218 9714 11200 6/87 97 206-207 2488-2489 4206 4965 4976 5099 5438-5439 5524 5591 5597 5701 5712 5931 6011 6014 6017 6019 6088 6090 6867 6873 7015 7026 7242-7243 7507 7513 7768-7769 7928 8220 8222 8514 8520 9036 9050 9072 9168 9354 9366 9468 9470 9476-9477 9486 9504 9506 9508 9593 9596 9997 9999 10306-10307 10312-10313 10315-10316 10318 10378-10379 10400-10401 10527 10664 10990 11040 11042-11043 11063 11080-11081 11219 11222 11253 11467 11613 11624 11626 11809 11811 11901 12072 12253 12255 12597 12599 12640 12642 12653 12664 14879 14922 15106 15112 15283 15286 15350-15351 15357 16030-16031 16207 16229 16240 16609 16702-16703 16713 16715 17237 17456-17457 18016-18018 18566 18578 18584 18683 18778 18800 18894 19089 19091 19101 19103 19449 19451 19935 20302 21763 21766 22577 22605 22607 22618 22786 22792 23451 23454 24822-24823 24828 24943 24954 25188 25300 25302 25391 25402 25542-25543 25548 26037 26039 26080 26082 26134-26135 26140-26141 26183 26186-26187 26189 26208-26209 26299 26302 27136-27137 27417 27420 27595 27598 27660-27661 27668 27742 28180-28181 28183 28249 28251 28427-28430 28452 28617 28619-28620 28622 31515 31536-31537 31850-31851 32500 32602 32624 32686 32693 32695 35765 35808 35947 35950 36017 36434 38852-38853 40809 43948 43950 43977 44817 44820 45044 45046 48734-48735 48964 48966https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/665/A71?format=asciiRadiodefaultJ/A+A/665/A71/tablec1Polarised source cataloguerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[] Source right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Source declination (J2000) (DEC)degpos.eq.dec;meta.mainMajSource major axis (Maj)arcsecphys.angSizefloatMinSource minor axis (Min)arcsecphys.angSize;srcfloatPA[] Source position angle (PA)degpos.posAngfloatPFExtDepol? Best fit intrinsic polarisation fraction (PolFrac_ExtDepol)phys.polarizationfloatnullablee_PFExtDepol? Lower error (PolFrac_ErrNeg_ExtDepol)stat.errorfloatnullableE_PFExtDepol? Upper error (PolFrac_ErrPos_ExtDepol)stat.error;stat.maxfloatnullableIAExtDepol? Best fit intrinsic polarisation angle (IntrAngl_ExtDepol)radpos.posAng;phys.polarizationfloatnullablee_IAExtDepol? Lower error (IntrAngl_ErrNeg_ExtDepol)radstat.errorfloatnullableE_IAExtDepol? Upper error (IntrAngl_ErrPos_ExtDepol)radstat.error;stat.maxfloatnullableRMExtDepol? Best fit RM (RM_ExtDepol)rad.m**-2phys.polarization.rotMeasuredoublenullablee_RMExtDepol? Lower error (RM_ErrNeg_ExtDepol)rad.m**-2stat.errordoublenullableE_RMExtDepol? Upper error (RM_ErrPos_ExtDepol)rad.m**-2stat.error;stat.maxdoublenullablesigRMExtDepol? Best fit depol (sigmaRM) (sigmaRM_ExtDepol)rad.m**-2phys.polarization.rotMeasuredoublenullablee_sigRMExtDepol? Lower error (sigmaRM_ErrNeg_ExtDepol)rad.m**-2stat.errordoublenullableE_sigRMExtDepol? Upper error (sigmaRM_ErrPos_ExtDepol)rad.m**-2stat.error;stat.maxdoublenullableI0ExtDepol? Best fit I0 (I_0_ExtDepol)mJystat.fit.param;meta.modelleddoublenullablee_I0ExtDepol? Lower error (I_0_ErrNeg_ExtDepol)mJystat.errorfloatnullableE_I0ExtDepol? Upper error (I_0_ErrPos_ExtDepol)mJystat.error;stat.maxfloatnullableaExtDepol? Best fit spectral index (a_ExtDepol)spect.indexfloatnullablee_aExtDepol? Lower error (a_ErrNeg_ExtDepol)stat.errorfloatnullableE_aExtDepol? Upper error (a_ErrPos_ExtDepol)stat.error;stat.maxfloatnullablechi2QU? Chi2 value for QU fit (chi2_QU)stat.fit.chi2doublenullablebestz? Best-estimate redshift (z) (bestz)src.redshiftfloatnullablee_bestz? Error on best-estimate z (bestz_err)stat.errorfloatnullabler_bestz[0/4]? Source of best estimate z (bestz_source) (1)meta.ref;pos.frameintnullablernorm? Radius/R500 to cluster centre (rnorm)phys.size.radius;arith.ratiofloatnullablethetapRadius to pointing centre (theta_p)arcminphys.angSizefloatClusterName of target cluster (Cluster)meta.id.parentcharRAodeg? Best estimate optical host right ascension (J2000) (ra_opthost)degpos.eq.ranullableDEodeg? Best estimate host declination (J2000) (dec_opthost)degpos.eq.decnullableMultiFlag[0/1] If Source is multicomponent (MultiCompFlag)meta.codeintFlagged[0/1] If Source was flagged (Flagged)meta.code.errorintNoteAdditional notes (Note)meta.notecharJ/A+A/665/A71/tabled1Full source catalogue (unpolarised)PASource position angle (PA)degpos.posAngdoubleFtotSource total flux from PyBDSF (Total_flux)mJyphot.flux.density;em.radiodoublee_FtotError on total flux (E_Total_flux)mJystat.errordoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[] Source right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Source declination (J2000) (DEC)degpos.eq.dec;meta.mainMajSource major axis (Maj)arcsecphys.angSizedoubleMinSource minor axis (Min)arcsecphys.angSize;srcdoubleFpeakSource peak flux from PyBDSF (Peak_flux)mJy/beamphot.flux.density;em.radiodoublee_FpeakError on peak flux (E_Peak_flux)mJy/beamstat.errordoublebestz? Best estimate redshift (bestz)src.redshift;pos.heliocentricdoublenullablee_bestz? Error on best estimate redshift (bestz_err)stat.errordoublenullabler_bestz[0/4]? Source of best estimate z (bestz_source)meta.ref;pos.frameintnullableClusterName of target cluster (GLLL.ll+BB.bbb) (Cluster)meta.id.parentcharPFlim? Upper limit on polfrac at 1.5 GHz (polfrac_uplim)phys.polarizationdoublenullablernorm? Radius/R500 to cluster centre (rnorm)phys.size.radius;arith.ratiodoublenullablethetapRadius to pointing centre (theta_p)arcminphys.angSizedoubleVisIns[0/1] If Source was visually inspected (VisuallyInspected)meta.codeintRAodeg? Optical counterpart right ascension (J2000) (ra_opthost)degpos.eq.ranullableDEodeg? Optical counterpart declination (J2000) (dec_opthost)degpos.eq.decnullableMultiFlag[0/1] If Source has multiple components (MultiCompFlag)meta.codeintNoteAddtional notes (Note)meta.notecharJ/A+A/665/A71/tablee1Cluster cataloguerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster name in paper (GLLL.ll+BB.bbb) (Cluster)meta.id.parentcharPSZ2Cluster name in PESZ catalogue (PSZ2 Name)meta.idcharAbellCluster name in Abell catalogue (Abell name)meta.idcharRAJ2000Cluster right ascension (J2000) from X ray (cRA)degpos.eq.ra;meta.mainDEJ2000Cluster declination (J2000) from X ray (cDEC)degpos.eq.dec;meta.maincz? Cluster redshift (cz)src.redshift;pos.heliocentricdoublenullableRApdegPointing right ascension (J2000) used on target (pRA)degpos.eq.raDEpdegPointing declination (J2000) used on target (pDEC)degpos.eq.decM500? Cluster M500 (M500)phys.massdoublenullableR500? Cluster R500 (R500)phys.size.radiusdoublenullableDS-CSBCluster dynamical state according to C_SB (DS_CSB)meta.codecharRadioHalo[0/1] If the cluster has a radio halo (RadioHalo)meta.codeintSimbadNameSimbad column added by the CDSmeta.idcharnullable