Gamma-Ray Bursts as a Cosmic Window for Galaxy Evolution

Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1) to probe the his

GAMMA-RAYBURSTSASACOSMICWINDOWFORGALAXYEVOLUTION

I.F.Mirabel1,2,D.B.Sanders3,E.LeFloc’h1,4

1

2

3

4CEA/DSM/DAPNIA/SAp.Centred’EtudesdeSaclay.91191.Gif/Yvette.FranceIntitutodeAstronom´ ayF´ sicadelEspacio.Conicet.ArgentinaInstituteforAstronomy,UniversityofHawaii,2680WoodlawnDr.,Honolulu,HI96822EuropeanSouthernObservatory.Casilla19001,Santiago19.Chile

arXiv:astro-ph/0004022v1 3 Apr 2000Abstract:Presentknowledgeindicatesthatgamma-rayburstsarelinkedwithmassivestars.Theywillbecomeinvaluableprobesoftheearlyuniverseandgalaxyformation.Inthefuture,itwillbepossibletousegamma-rayburstsfortwopurposes:1)toprobethehistoryofmassivestarformationintheUniversebytherateofoccurenceofgamma-raybursts,and2)forthestudyofgalaxyevolutionatalllookbacktimesbydeterminingthenatureofthegalaxyhosts.Becausegamma-raysarenotattenuatedbyinterveningdustandgas,theselectionofthecosmicsitesofmassivestarformationbythismethodislessa ectedbythebiasesassociatedwithoptical-uvsurveys(e.g.UV-dropouttechniques).Infraredandsub-millimeterfollowupstudiesofthehostsofgamma-rayburstsmay:1)revealaputativepopulationofreddened(R K≥4)galaxiesathighredshifts,and2)detectverymassivestars(populationIII)formedatz≥5.DustystarburstsandAGNsathighredshiftOpticalsurveyswiththeHubbleSpaceTelescopeandlargegroundbasedtelescopeshaveenabledinrecentyearsthestudyofluminousUVgalaxiesouttoredshiftsz~4(Madauetal.1996;Steideletal.1998).FromtheearlyanalysisofgalaxiesintheHDF,Madauetal.(1996)concludedthatthereseemedtobelittleevidenceforsubstantialamountsofdustobscurationinhighredshiftgalaxies.Itisremarkablehowquicklythispicturehaschangedaftertherecentdeep eldsurveysinthemid-infrared,far-infrared,

andsubmillimiterwavelengths(e.g.Smailetal.1997;Hughesetal.1998;Bargeretal.1998;Blainetal.1999;Elbazetal.1999).ThesenewsurveyshavediscoveredastronglyevolvingpopulationofLuminousInfraredGalaxies(seeSanders&Mirabel1996,forareview)thatcouldbetheprogenitorsofthepresent-daypopulationofmassivespheroidalgalaxies.

TheimportanceofdustathighredshiftshasalsobeenpointedoutbyFabian(1999),

whoproposesalargepopulationofdustenshroudedAGNsatz>1toaccountfortheX-raybackground.Thispredictionhasrecentlybeencon rmedbythediscoverywithChandraofalargepopulationofX-raypointsourceswith“extremelyfaint,orinsomecasesundetectable”(i.e.I>26)“opticalcounterparts”(Mushotzkyetal.2000).Further-more,atmillimeterandsubmillimeterwavelengthsthermalemissionfromdustiscurrentlydetectedfromquasarsuptoredshiftsof5(e.g.Omontetal.1996;Carrilietal.2000).>1013L⊙,dustmasses~>108M⊙,andmolecularTheimpliedfar-infraredluminositiesare~gasmassesofafew×1010M⊙.Thesemajoreventsingalaxyevolutionathighredshifts

Word文档免费下载Word文档免费下载:Gamma-Ray Bursts as a Cosmic Window for Galaxy Evolution (共4页,当前第1页)

Gamma Ray Bursts as a Cosmic Window for Galaxy Evolution相关文档

最新文档

返回顶部