J/A+A/708/A321ivo://CDS.VizieR/J/A+A/708/A321CDSBause M.L.Kaur K.Rammala-Zitha I.Spitler L.G.2026-05-04T07:43:19Z2026-04-21T12:43:33ZCDS support team

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

cds-question@unistra.frneutron-starsradio-sourcesMagnetars are neutron stars that occupy the extreme end of the neutron star population, with magnetic field strengths of more than 1012G. They have been proposed as one of the most likely progenitor models for the phenomenon of energetic, ms-duration, extragalactic radio bursts (FRBs), which have been increased even further due to the FRB-like bursts emitted from the galactic Magnetar SGR 1935+2154. However, only a low fraction of the magnetars (six in total) have been detected in the radio regime and thus most magnetars are radio quiet. We conducted regular observations of 13 radio quiet magnetars to probe the long-term radio quietness using the most sensitive telescope in the southern hemisphere: MeerKAT. These observations provide deep constraints on the radio emission of magnetars, relevant for the progenitor models of FRBs Given that MeerKAT is an interferometer, we probe the magnetars for radio emission in both imaging and time domain. We search in the time domain in a DM range of 20pc/cm^3^ to 10000pc/cm^3^ for single pulses using a TransientX-based search pipeline (the FRB perspective) as well as from a pulsar perspective by folding the data using the X-ray ephemeris. On the other hand, we use the imaging domain to search for persistent radio emission in total intensity and circular polarisation, as well as to create light curves using snapshot imaging, having the long transient perspective as well. We find no radio emission in the time domain for any of the observed magnetars. Nevertheless, we are providing deep limits of the mean flux density (52uJy to 68uJy) and the single pulse fluence 39mJy.ms to 52mJy.ms. From the image domain, we provide individual upper limits on the persistent radio emission and the light curve for the 13 magnetars. Additionally, an ultra-long period transient and an additional magnetar happened to be in the imaging beam for which be provide lower limits as well. We provide an extensive series of deep upper limits in the time domain, but also as a novelty limits from the imaging domain for the magnetars. As the current magnetar radio emission models are based on a few radio loud magnetars, we encourage monitoring of radio quiet magnetars independent of their X-ray flux with high cadence for further insights into their potential for emitting in the radio regime.2026A&A...708A.321Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A321CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A321https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/A321http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/A321https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/A321https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/A321http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/A321GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/A321/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A321/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A321/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A321/list?GETtext/xml+votable180.050000true162.5296-59.889430.0055555555555555566/14342 29090 29116 29532 30315 30607 37930 41814 42206 42215 42444 47726https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/A321?format=asciiRadiodefaultJ/A+A/708/A321/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullableFreqObserved frequencyGHzem.freqdoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharSimbadNameSimbad column added by the CDSmeta.idcharnullable