Corrections to the magnitudes of high redshift objects due to intergalactic attenuation are computed using current estimates of the properties of the intergalactic medium. The results of numerical simulations are used to estimate the contributions to reson
Colourcorrectionsforhighredshiftobjectsduetointergalacticattenuation
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Figure3.IntergalacticattenuationkIGM-correctionsasafunctionofsourceredshiftfora600Myrstarburst(solidlines),a3Myrstarburst(long-dashedlines),aTypeIQSO(dot-dashedlines)andaTypeIIQSOwithhighequivalentwidthemissionlines(dottedlines).ThereislittlevariationbetweenthesourcesexceptfortheTypeIIQSObecauseofthepresenceofstrongemissionlines.Therowscorrespondtothefollowing ltersystems.Firstrow:Sloan;secondrow:SteidelUnGR ltersandI-band;thirdrow:HSTbandsB435,V606,i775andJWSTm070;fourthrow:Sloanz′,HSTz850andJ110andUKIDSSY.ThekIGM-correctionsarenegligiblefortheHSTH160,JWSTm150andUKIDSSJ,HandKbandsforz<8.5.
andcoloursof0.5 1magnitudeforbandscontainingrest-frameLyαandshorterwavelengths.
IntergalactickIGM-correctionsareprovidedfor ltersystemsusedincurrentorplanneddeepopticalandinfra-redsurveys,viz.theSloanu′g′r′i′z′system,SteidelUnGRandtheI-band,UKIDSSZYJHK,theHSTB435,V606,i775,z850,J110andH160bands,andtheJWSTF070WandF150Wbands.
Coloursbasedontheabovebandsareprovidedforstar-burstsofages3Myrand600Myr,typicalofz≈3LymanBreakGalaxies,andTypeIandTypeIIQSOs,overthered-shiftrange2.5<z<8.5.Theresultsshowwhichcoloursaremoste ectivefordistinguishingbetweendi erentob-c2005RAS,MNRAS000,000–000
jectsandthetypicalvaluestoexpect,whichmaybeused
fortheplanningandanalysisofcurrentandupcomingdeepsurveys.
ACKNOWLEDGMENTS
TheauthorthanksDrSteveWarrenforkindlyprovidingtotalresponsecurvesfortheUKIDSS ltersystem.
REFERENCES
BithellM.,1991,MNRAS,253,320
