Investigating the Mini and Giant Radio Flare Episodes of Cygnus X-3

dc.contributorAalto Universityen
dc.contributor.authorEgron, Eliseen_US
dc.contributor.authorPellizzoni, Albertoen_US
dc.contributor.authorRighini, Simonaen_US
dc.contributor.authorGiroletti, Marcelloen_US
dc.contributor.authorKoljonen, Karrien_US
dc.contributor.authorPottschmidt, Katjaen_US
dc.contributor.authorTrushkin, Sergeien_US
dc.contributor.authorLobina, Jessicaen_US
dc.contributor.authorPilia, Mauraen_US
dc.contributor.authorWilms, Joernen_US
dc.contributor.authorCorbel, Stéphaneen_US
dc.contributor.authorGrinberg, Victoriaen_US
dc.contributor.authorLoru, Saraen_US
dc.contributor.authorTrois, Alessioen_US
dc.contributor.authorRodriguez, Jéromeen_US
dc.contributor.authorLähteenmäki, A.en_US
dc.contributor.authorTornikoski, M.en_US
dc.contributor.authorEnestam, Sissien_US
dc.contributor.authorJärvelä, E.en_US
dc.contributor.departmentMetsähovi Radio Observatoryen
dc.contributor.departmentDepartment of Electronics and Nanoengineeringen
dc.contributor.groupauthorAnne Lähteenmäki Groupen
dc.contributor.organizationNational Institute for Astrophysics (INAF)en_US
dc.contributor.organizationIstituto di Astrofisica Spaziale e Fisica Cosmica di Bolognaen_US
dc.contributor.organizationNASA Goddard Space Flight Centeren_US
dc.contributor.organizationSpecial Astrophysical Observatory of the Russian Academy of Sciencesen_US
dc.contributor.organizationUniversity of Cagliarien_US
dc.contributor.organizationFriedrich-Alexander University Erlangen-Nürnbergen_US
dc.contributor.organizationUniversité Paris-Saclayen_US
dc.contributor.organizationUniversity of Tübingenen_US
dc.contributor.organizationINAF - Osservatorio Astrofisico di Cataniaen_US
dc.description.abstractThe microquasar Cygnus X-3 underwent a giant radio flare in 2017 April, reaching a maximum flux of ∼16.5 Jy at 8.5 GHz. We present results from a long monitoring campaign carried out with Medicina at 8.5, 18.6, and 24.1 GHz, parallel to the Metsähovi radio telescope at 37 GHz, from 2017 April 4 to 11. We observe a spectral steepening from α = 0.2 to 0.5 (with S ν ∝ ν α) within 6 hr of the epoch of the flare's peak maximum, and rapid changes in the spectral slope in the following days during brief enhanced emission episodes while the general trend of the radio flux density indicated the decay of the giant flare. We further study the radio orbital modulation of Cyg X-3 emission associated with the 2017 giant flare and with six mini-flares observed in 1983, 1985, 1994, 1995, 2002, and 2016. The enhanced emission episodes observed during the decline of the giant flare at 8.5 GHz coincide with the orbital phase φ ∼ 0.5 (orbital inferior conjunction). On the other hand, the light curves of the mini-flares observed at 15-22 GHz peak at φ ∼, except for the 2016 light curve, which is shifted 0.5 w.r.t. the other ones. We attribute the apparent phase shift to the variable location of the emitting region along the bent jet. This might be explained by the different accretion states of the flaring episodes (the 2016 mini-flare occurred in the hypersoft X-ray state).en
dc.description.versionPeer revieweden
dc.identifier.citationEgron, E, Pellizzoni, A, Righini, S, Giroletti, M, Koljonen, K, Pottschmidt, K, Trushkin, S, Lobina, J, Pilia, M, Wilms, J, Corbel, S, Grinberg, V, Loru, S, Trois, A, Rodriguez, J, Lähteenmäki, A, Tornikoski, M, Enestam, S & Järvelä, E 2020, ' Investigating the Mini and Giant Radio Flare Episodes of Cygnus X-3 ', The Astrophysical Journal, vol. 906, no. 1, 10 .
dc.identifier.otherPURE UUID: d414ee1a-8138-479b-aabc-a5eaf4b4af82en_US
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dc.publisherIOP Publishing Ltd.
dc.relation.ispartofseriesAstrophysical Journalen
dc.relation.ispartofseriesVolume 906, issue 1en
dc.titleInvestigating the Mini and Giant Radio Flare Episodes of Cygnus X-3en
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi