m 31 circum-nuclear region a molecular survey with the iram interferometer julien dassa-terrier参考-匠人.pdf

该【m 31 circum-nuclear region a molecular survey with the iram interferometer julien dassa-terrier参考-匠人 】是由【妙玉】上传分享，文档一共【21】页，该文档可以免费在线阅读，需要了解更多关于【m 31 circum-nuclear region a molecular survey with the iram interferometer julien dassa-terrier参考-匠人 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。:..A&A625,A148(2019)https:///-6361/-&AstrophysicsM31circum-nuclearregion:Amolecularsurveywiththe?IRAMinterferometerJulienDassa-Terrier1,Anne-LaureMelchior1,bes1,21LERMA,ObservatoiredeParis,RS,SorbonneUniversités,,75014Paris,Francee-mail:-******@,.******@,******@ègedeFrance,11,PlaceMarcelinBerthelot,75005Paris,FranceReceived10August2018/Accepted13February2019ABSTRACTWeanalysedmolecularobservationsperformedatIRAMinterferometerinCO(1-0)ofthecircum-nuclearregion(within250pc)ofAndromedawith2:900=,correspondingtoatotalmolecularmassof(8:40:4)104M.TheseclumpsfollowLarson’smass-sizerelation,butliewellabovethevelocity-,(2-1)inapreviouswork,andwe?,weshowthatthisgasisinnon-localthermalequilibriumwithalowexcitationtemperature(Tex=59K).We?ndasurfacebeam?llingfactoroforder5%andagasdensityintherange60650cm3,-to-stellarmassfractionof4104anddust-to-,,-densitypartoftheKennicutt-?:individual:M31–galaxies:kinematicsanddynamics–submillimeter:ISM–(SFR)asafunctionofcosmictime(-;Heckman&Best2014),SFRhasbeenityinthecentralkiloparsecofgalaxiesiskeytounder-mostlyquenchedinthelocalUniverse(?)().Themechanismsresponsibleforthisretion(-Bell1969;-Urry&Padovani1995),thepropertiesofthehostgalaxyaretions,Boweretal.(2017)haveshownthattheseredandbluedirectlyimpactedbythisso-calledAGNfeedback(petitionbetweenstar2012,andreferencestherein).Thescalingrelationsbetweenformation-retionontothesupermas-?oreetal.(2016)velocitydispersionofthehost(&Merritt2000;;Marconi&Hunt2003;?,these2009;Kormendy&Ho2013;McConnell&Ma2013)sug-inside-outmechanismsareprobablynotuniversalbecauseingestacloseconnectionbetweensupermassiveblackholesdenseenvironments,suchasgroupsorclustersofgalaxies,theandtheirhosts(&Rees1998;;uroutside-.(2015)arguedKing&Pounds2015).Thegrowthofsupermassiveblackholesthatthestrangulationmechanisminwhichthesupplyofcoldre-gastothegalaxyishaltedisthemainmechanismresponsi-tion(;).Indeed,galaxybleforquenchingstarformationinlocalgalaxieswithM<mergers(&Hernquist1991;;1011M.(&NormanMUSE(GASP)survey,Poggiantietal.(2017)haveexploredin1990;;Hopkins&Quataert2010)maytheopticalmorethan100galaxiesindierentenvironmentse(ía-)overafewGullieusziketal.(2017)?-?ThereducedspectraareonlyavailableattheCDSviaanony-ies,Fluetschetal.(2019)havearguedthatAGN-drivenout?-()orviahttp:arelikelycapableofclearingandquenchingthecentralregion//--bin/qcat?J/A+A/625/,page1of21essarticle,publishedbyEDPSciences,monsAttributionLicense(/licenses/by/),whichpermitsunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkisproperlycited.:..A&A625,A148(2019)?eldsobservedatIRAM-+41+41+41+41,+41?eld,thenumberofvisibilitiesacquiredper?eld,andthecorrespondingbeamandpixelsize(square).Thesamplingofthe4th?eldisworsethanfortheothers,1010M(),,weselectthecoreAndromedabelongstothetransitionregimebetweentheactiveofsigni?cantclumpsaboveagiventhresholdanddiscusstheirblue-sequencegalaxiesandpassivered-sequencegalaxies(?,putethe3Dsize,velocitydis-;),whichhappensaroundpersion,andtotal?uxofthesecoreclumpsfollowingthemethodthestellarmassof31010M().proposedbyRosolowsky&Leroy(2006).,wedis-,(PCA)statisticalmethodtodiscriminatereliablecan-starformation,whiletheblackholeisbasicallyquietanddidatesusingthedescriptiveparametersoftheprevioussubsec-hassomemurmurs().?nalcheckisperformedwithavisualinspectionofeachM31nucleus,bes(2017),,wesumupourprocedureandisnogaswithinthesphereofin??,-tributionandshowevidenceofapastactivityrichincolli-(,2014;;-PdBinterferometermosaic2006;;;?eldscoveringthecentreofAndromedaanda?eld2018).However,theexactmechanismquenchingtheactivityofviewofabout2arcmino-centredtothesouth-().bes(2017),theinitialmotivationBlocketal.(2006)proposedafrontalcollisionwithM32,whichoftheseobservationswastosearchformoleculargasnexttotheountforthetworingstructuresobservedinthedustblackhole,andtheregioncorrespondingtothesphereofin?u-(2011,2016)showedthepres-enceofM31’sblackhole,14pc,.(2007),butwasexcludedata9(2013)estimatedaminimumtotalmassofdetectedasmall2000Mclump,mostprobablylyingoutside4:2104Mofmoleculargaswithina(projected)distancetothethesphereofin?uenceoftheblackhole,whichisseeninpro-,weextendthis?rstexplorationtothethanthemoleculargaspresentinthecentralmolecularzoneofwholedatacubethatcoverstheequivalentofthecentralmolec-theMilkyWay(Pierce-;).ularzonefortheMilkyWay(Morris&Serabyn1996;,whilelargeamountsofdensegasarepresent1996).Theobservationswereperformedin2012withthe?veinthecentralregion,al.(2014)discussedthedif-antennacon?,whichwidevelocityband[3000;6000]kms1andhasavelocityres-wasobservedtobeafactortentimesweakerthanexpected(v=5:07kms1andapixelsizeof0:).?eldswereobservedatthepositionsprovidedinTable1andInthisarticle,-obtainedwithIRAMPlateau-de--:37002:4500(PA=70)andapixelsizeof0:(K-Slaw).Westudythepropertiesofthisgasandhowitfocusourworkonthe[600;0]kms1velocityband,,wepresenttheanalysisofthedatacube,enablingAquickviewofthedatacubecon?,,therearenumer-,,weobserveanon-Gaussian??gura-tion,weperformedaone-(1-0)ofthisregionandthereforewecannotcorrecttheWedescribetheidenti?cationofmolecularclumpsintheobservationsfrommissingshort-spacing?,astheIRAM-,wedescribetheIRAM-PdBsignalsarenotextendedandrelativelyweak,itisnotpossibleA148,page2of21:..-Terrieretal.:M31circum-nuclearregionconsecutivechannelsat3,thiscriteriawasusedtoselectthecoreofpossibleclumps,pixelswithhighsignal-to-noiseratio(S/N).Weexcluded142pixels(65positiveand77negative)()pixelsgatheredin54positive()3%()3clumpshaveamean?uxof766mJybeam1().clumps).Thenumberofpixelsathalf-powerbeamwidth(HPBW)isabout25pixels,paredto25,(leftpanel)andnegative(rightpanel)3peakdetectionsabove3(SNRpeak)associatedwithdetected3clumpsastheratioofthepeak?uxpeakofthe3.TheaverageSNRpeakforthepositive()3()with28positive()3clumpsshowingapeaksignalhigherthan4noise(noise),and3positive3clumpswithpeakS/?cantlybrighterthanthelevelofnoise,erently,moreinvestigationsarerequiredtoselectgenuinemolecularcloudswithcon?:probabilitydensityfunctionofthedistributionof?uxesInthethreenextsubsections,wecalculateglobalproperties,withinthedatacubeandtheassociatedGaussian?t(reddashedcurve).excludesidelobes,andapplyPCAtomakeour?correspondstothe?uxofeachpixel(inthe3Ddatacube),:residuesassociatedwiththedistributionanditsGaussian?,,showingInordertofurthercharacterisethedetectionofmolecularclouds,thatthesignalisveryfaintandneedsadvanceddetectionme