J/A+A/589/A116ivo://CDS.VizieR/J/A+A/589/A116doi:10.26093/cds/vizier.35890116CDSMossoux E.Grosso N.Bushouse H.Eckart A.Yusef-Zadeh F.,Plambeck R.L.Peissker F.Valencia-S. M.Porquet D.Cotton W.D.,Roberts D.A.2022-05-11T08:47:31Z2016-04-21T08:01:05ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyx-ray-sourcesWe present the results of the multiwavelength study of the flaring activity of the supermassive black hole named Sgr A* is located at the dynamical center of the Milky Way. We detected two X-ray flares on 2014 Mar. 10 and Apr. 2 with XMM-Newton, three near-infrared (NIR) flares with HST on 2014 Mar. 10 and Apr. 2, and two NIR flares on 2014 Apr. 3 and 4 with VLT. The X-ray flare on 2014 Mar. 10 is characterized by a long rise and a rapid decay. Its total duration is one of the longest detected so far in X-rays. Its NIR counterpart peaked well before the X-ray maximum, implying a dramatic change in the X-ray-to-NIR flux ratio during this event. This NIR/X-ray flare is interpreted as either a single flare where variation in the X-ray-to-NIR flux ratio is explained by the adiabatic compression of a plasmon, or two distinct flaring components separated by 1.2h with simultaneous peaks in X-rays and NIR. We identified an increase in the rising radio flux density at 13.37GHz on 2014 Mar. 10 with the VLA that could be the delayed radio emission from a NIR/X-ray flare that occurred before the start of our observation. The X-ray flare on 2014 Apr. 2 occurred for HST during the occultation of Sgr A* by the Earth, therefore we only observed the start of its NIR counterpart. With NIR synchrotron emission from accelerated electrons and assuming X-rays from synchrotron self-Compton emission, the region of this NIR/X-ray flare has a size of 0.03-7 times the Schwarzschild radius and an electron density of 10^8.5-10^10.2cm^-3^, assuming a synchrotron spectral index of 0.3-1.5. When Sgr A* reappeared to the HST view, we observed the decay phase of a distinct bright NIR flare with no detectable counterpart in X-rays. On 2014 Apr. 3, two 95GHz flares were observed with CARMA, where the first may be the delayed emission of a NIR flare observed with VLT.2016A&A...589A.116Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/589/A116CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/502/91 : Proper motions of stars near SgrA* (Schoedel+, 2009)J/A+A/511/A18 : NIR observations of stars near SgrA* (Schoedel+, 2010)J/A+A/534/A117 : NIR polarimetry of sources near SgrA* (Buchholz+, 2011)J/MNRAS/428/2731 : SgrA* emission at 7mm (Beaklini+, 2013)J/A+A/582/A118 : OH-streamer in SgrA at 1665 and 1667MHz (Karlsson+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/589/A116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/589/A116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/589/A116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/589/A116https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/589/A116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/589/A116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/A+A/589/A116/fig2Sgr A* light curve obtained between 2 and 10keV with XMM-Newton/EPIC (pn+MOS1+MOS2)DateObservation datetime.epoch;obsnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDCenter of the light curve bin in UTC (1)dspect.binSize;em.bindoubleCRCount rate in the light curve binct/sphot.count;em.X-rayfloate_CRError on the count ratect/sstat.errorfloatJ/A+A/589/A116/fig9Sgr A* light curve in NIR (1.53{mu}m) with HSTrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullableMJDCenter of the light curve bin in UTC (1)dspect.binSize;em.bindoubleFluxSgrAFlux density of Sgr A* in the light curve binmJyphot.flux;em.X-rayfloatFluxRefFlux density of the reference star in the light curve binmJyphot.flux;em.X-rayfloate_FluxRefError on the flux density (2)mJystat.errorfloatJ/A+A/589/A116/fig11Sgr A* light curve in NIR (2.2{mu}m) with VLTrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullableMJDCenter of the light curve bin in UTC (1)dspect.binSize;em.bindoubleFRatioSgr A*-to-S2 flux density ratiophot.flux;arith.ratiofloate_FRatioError on the Sgr A*-to-S2 flux density ratiostat.errorfloatJ/A+A/589/A116/fig12Sgr A* light curve at 95GHz with CARMArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullableMJDCenter of the light curve bin in UTC (1)dspect.binSize;em.bindoubleFluxFlux density in the light curve binJyphot.flux;em.X-rayfloatSourceObserved source (2)meta.id;meta.maincharJ/A+A/589/A116/fig13Sgr A* light curve in radio (8.56, 13.37, 1.68 and 5.19GHz) with VLArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullableMJDCenter of the light curve bin in UTC (1)dspect.binSize;em.bindoubleFluxFlux density in the light curve binJyphot.flux;em.X-raydoublee_FluxError on the flux densityJystat.error;phot.fluxdoubleFreqObserved frequency (1.68, 5.19, 8.56 and 13.37)GHzem.freqfloat