J/MNRAS/474/219ivo://CDS.VizieR/J/MNRAS/474/219doi:10.26093/cds/vizier.74740219CDSSzymczak M.Olech M.Sarniak R.Wolak P.Bartkiewicz A.2024-08-18T20:17:13Z2021-03-04T09:06:21ZCDS support team

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

cds-question@unistra.frastrophysical-masersradio-astronomyradio-sourcesWe report results of 6.7GHz methanol maser monitoring of 139 star-forming sites with the Torun 32-m radio telescope from 2009 June to 2013 February. The targets were observed at least once a month, with higher cadences of two to four measurements per week for circumpolar objects. Nearly 80 per cent of the sources display variability greater than 10 per cent on a time-scale between a week and a few years, but about three quarters of the sample have only one to three spectral features that vary significantly. Irregular intensity fluctuation is the dominant type of variability and only nine objects show evidence for cyclic variations with periods of 120 to 416d. Synchronized and anticorrelated variations of maser features are detected in four sources with a disc-like morphology. Rapid and high-amplitude bursts of individual features are seen on three to five occasions in five sources. Long (>50d to 20 months) lasting bursts are observed mostly for individual or groups of features in 19 sources and only one source experienced a remarkable global flare. A few flaring features display a strong anticorrelation between intensity and line-width that is expected for unsaturated amplification. There is a weak anticorrelation between the maser feature luminosity and variability measure, i.e. maser features with low luminosity tend to be more variable than those with high luminosity. The analysis of the spectral energy distribution and continuum radio emission reveals that the variability of the maser features increases when the bolometric luminosity and Lyman flux of the exciting object decreases. Our results support the concept of a major role for infrared pumping photons in triggering outburst activity of maser emission.2018MNRAS.474..219Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/474/219CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/474/219https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/474/219http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/474/219https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/474/219https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/474/219http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/474/219GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/474/219/table1 (List of 6.7GHz methanol maser sites monitored)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/474/219/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/474/219/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/474/219/table1?GETtext/xml+votable180.050000true276.9356667-11.24836110.0055555555555555565/7383 6/3011 3061 3303 14063 14309 14317 14353-14356 14594 14604 14622 14626 14630 14655 14671 14692 14704 15368 15390 15671 15681 21510 23764 23969 24325 24365 24554 29511 29522 29529 30218-30219 30222 30241 30244-30245 30256 30258-30259 30262 30268-30269 30312-30313 30315 30317-30319 30328 30330 30405 30416-30417 30420 30422-30423 30425 30595 30600 30604-30605 30616-30618 30622 30644 30694 30710 30712 30715 307194.439466485724119e-24 4.439466485724119e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/474/219?format=asciiRadiodefaultJ/MNRAS/474/219/table1List of 6.7GHz methanol maser sites monitoredrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (GLLL.lll+B.bbb)meta.id;meta.maincharr_Name[a-p] Reference for positions (1)meta.ref;pos.framecharn_NameNotes (2)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainOffset? Offset of the actual pointing from the maser positionarcminpos;arith.difffloatnullableVsysSystemic velocitykm/sphys.velocfloatr_Vsys[1/2]? References for systemic velocity (3)meta.ref;pos.frameintnullableFDist[KT] Distance adopted: T = Trigonometric, K = Kinematicmeta.codecharNoteNote (4)meta.notecharJ/MNRAS/474/219/table2Variability properties of 6.7GHz methanol maser features (for the 139 sources of table1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (GLLL.lll+B.bbb)meta.id;meta.maincharMJDsModified Julian Date at the start of the observationdtime.epochintTsTotal time-span of the observationstime.expointNoTotal number of observationsmeta.numberintCAverage observation cadence, in month^-1^obs.param;obsfloatVpPeak velocity at 6.7GHzkm/sspect.dopplerVelocfloatSpAverage peak flux density at 6.7GHzJyphot.flux.density;em.radio.6-12GHzfloatVIVariability indexmeta.code;src.var.indexfloatFIFluctuation indexsrc.var.indexfloatchi2rReduced chi^2^stat.fit.chi2floatchi299.9? Corresponding value of reduced chi^2^ for a 99.9% significance level of variabilitystat.fit.chi2floatnullableJ/MNRAS/474/219/table3List of short-lived burstsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (GLLL.llll+B.bbb)meta.id;meta.maincharVpVelocity of bursting featurekm/sphys.velocfloatMJDTime of flare peak (MJD)dtime.epochintSpPeak flux density at 6.7GHzJyphot.flux.density;em.radio.6-12GHzfloatRRelative amplitudespect.line.intensity;arith.ratiofloatJ/MNRAS/474/219/table4List of long-lived burstsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoSequential numbermeta.recordintNameName (GLLL.llll+B.bbb)meta.id;meta.maincharVpVelocity of bursting featurekm/sphys.velocfloatMJDTime of flare peak (MJD)dtime.epochinttrRise timedtime.epochinttdDecay timedtime.epochintSmaxMaximum flux density at 6.7GHzJyphot.flux.density;em.radio.6-12GHzfloatRRelative amplitudespect.line.intensity;arith.ratiofloatln(Deltav)/ln(S)? Slope fitted to the relationship between the line-width {Delta}v and flux densitystat.fit.paramfloatnullabler? Correlation coefficient of the slopestat.fit.paramfloatnullable