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《GALAXY FORMATION WITH COLD GAS ACCRETION AND EVOLVING STELLARINITIAL MASS FUNCTION具有冷气体吸积和演化恒星的星系形成 初始质量函数》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、TheAstrophysicalJournal,713:13011309,2010April20doi:10.1088/0004-637X/713/2/1301C2010.TheAmericanAstronomicalSociety.Allrightsreserved.PrintedintheU.S.A.GALAXYFORMATIONWITHCOLDGASACCRETIONANDEVOLVINGSTELLARINITIALMASSFUNCTIONXiKang1,2,W.P.Lin3,RaminSkibba2,4,and
2、D.N.Chen51ThePurpleMountainObservatory,2WestBeijingRoad,Nanjing210008,China;kangxi@pmo.ac.cn2Max-Planck-InstituteforAstronomy,Konigstuhl17,D-69117Heidelberg,Germany¨3KeyLaboratoryforResearchinGalaxiesandCosmology,ShanghaiAstronomyObservatory,NandanRoad80,Shanghai
3、200030,China4StewardObservatory,UniversityofArizona,933N.CherryAvenue,Tucson,AZ85721,USA5BeijingPlanetarium,No138XizhimenwaiStreet,Beijing100044,ChinaReceived2009April24;accepted2010March11;published2010April1ABSTRACTTheevolutionofthegalaxystellarmassfunctionises
4、peciallyusefultotestthecurrentmodelofgalaxyformation.ObservationaldatahaverevealedafewinconsistencieswithpredictionsfromtheΛCDMmodel.Forexample,mostmassivegalaxieshavealreadybeenobservedatveryhighredshifts,andtheyhaveexperiencedonlymildevolutionsincethen.Inconflic
5、twiththis,semi-analyticalmodels(SAMs)ofgalaxyformationpredictaninsufficientnumberofmassivegalaxiesathighredshiftandarapidevolutionbetweenredshift1and0.Inaddition,thereisastrongcorrelationbetweenstarformationrate(SFR)andstellarmassforstar-forminggalaxies,whichcanbe
6、roughlyreproducedwiththemodel,butwithanormalizationthatistoolowathighredshift.Furthermore,thestellarmassdensityobtainedfromtheintegralofthecosmicstarformationhistoryishigherthanthemeasuredonebyafactorof2.Inthispaper,westudytheseissuesusinganSAMthatincludes(1)cold
7、gasaccretioninmassivehalosathighredshift;(2)tidalstrippingofstellarmassfromsatellitegalaxies;and(3)anevolvingstellarinitialmassfunction(IMF;bottom-light)withahighergasrecyclefraction.Ourresultsshowthatthecombinedeffectsfrom(1)and(2)canpredictsufficientlymassivegal
8、axiesathighredshiftsandreproducetheirmildevolutionatlowredshift,whilethecombinedeffectsof(1)and(3)canreproducethecorrelationbetweenSFRandstellarmassforstar-for