Evidence for spatial variation of the fine structure constant.pdf

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1、EvidenceforspatialvariationofthenestructureconstantJ.K.Webb1,J.A.King1,M.T.Murphy2,V.V.Flambaum1,R.F.Carswell3,andM.B.Bainbridge11SchoolofPhysics,UniversityofNewSouthWales,Sydney,NSW2052,Australia2CentreforAstrophysicsandSupercomputing,SwinburneUniversityofTechnology,Mai

2、lH39,POBox218,Victoria3122,Australiaand3InstituteofAstronomy,MadingleyRoad,Cambridge,CB30HA,England.(Dated:August25,2010)WepreviouslyreportedobservationsofquasarspectrafromtheKecktelescopesuggestingasmallervalueofthenestructureconstant,,athighredshift.Anewsampleof153meas

3、urementsfromtheESOVeryLargeTelescope(VLT),probingadierentdirectionintheuniverse,alsodependsonredshift,butintheoppositesense,thatis,appearsonaveragetobelargerinthepast.Thecombineddatasetiswellrepresentedbyaspatialdipole,signicantatthe4.1level,inthedirectionrightascensio

4、n17:30:6hours,declination619degrees.Adetailedanalysisforsystematics,usingobservationsduplicatedatbothtelescopes,revealsnonewhicharelikelytoemulatethisresult.PACSnumbers:06.20.Jr,95.30.Dr,95.30.Sf,98.62.Ra,98.80.-k,98.80.Es,98.80.JkQuasarspectroscopyasatestoffundamental

5、moreextensiveskycoverage.TheESOmidaspipelinephysics.

6、Thevastlight-traveltimestodistantquasarswasusedfortherstdatareductionstep,includingwave-allowsustoprobephysicsathighredshift.Therela-lengthcalibration,althoughenhancementsweremadetotivepositionsofwavenumbers,!z,ofatomi

7、ctransitionsderiveamorerobustandaccuratewavelengthsolutiondetectedatredshiftz=obs=lab1,canbecom-fromanimprovedselectionofthorium-argoncalibrationparedwithlaboratoryvalues,
!0,viatherelationshiplampemissionlines[10].Echellespectralordersfromsev-!=!+Q22=2andthecoecie

8、ntQmea-eralexposuresofagivenquasarwerecombinedusingz0z00suresthesensitivityofagiventransitiontoachangeinuvespopler[11].Atotalof60quasarspectrafromthe.ThevariationinbothmagnitudeandsignofQfordif-VLThavebeenusedforthepresentwork,yielding153ferenttransitionsisasignicantadva

9、ntageoftheManyabsorptionsystems.AbsorptionsystemswereidentiedMultipletmethod[1,2],helpingtocomb