Future MmSubmm Instrumentation and Science Opportunities Exa

During the next decade a tremendous advance will take place in instrumentation for spectroscopy of the interstellar medium. Major new facilities (ALMA, SOFIA, APEX, LMT, Herschel and others) will be constructed and commissioned, so that the science opportu

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FUTUREMM/SUBMMINSTRUMENTATIONANDSCIENCEOPPORTUNITIES:EXAMPLE

OFDEUTERATEDMOLECULES

ThomasG.Phillips1andCharlotteVastel1

CaliforniaInstituteofTechnology,320-47,Pasadena,CA91125,U.S.A.

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v:astro-ph/0211610v1 27 Nov 2002

Abstract

Duringthenextdecadeatremendousadvancewilltakeplaceininstrumentationforspectroscopyofthein-terstellarmedium.Majornewfacilities(ALMA,SOFIA,APEX,LMT,Herschelandothers)willbeconstructedandcommissioned,sothatthescienceopportunities,inthe eldofastrochemistry,willincreasebyahugefactor.Thiswillbeenhancedbythenewreceiverswithgreaterbandwidthandsensitivity.Thenewopportunitieswillbeintheareaofastrochemistryofdistantobjects,throughgreatersensitivity,ornewspectralrangesduetotheplat-formsabovetheEarth’satmosphere.

Variousaspectsofnewspectralrangesarediscussed,withemphasisonH2Olines,featurespreviouslyhiddenun-derH2OorO2lines,lighthydridesandparticularlyondeuteriuminmolecules.Recently,multiplydeuteratedspecieshavebeendetected,e.g.ND3,incolddensere-gionsoftheinterstellarmedium.Itisarguedherethatitispossiblethatsomuchdeuteriumcouldbetrapped,bythefractionationprocess,intoheavymoleculessuchasND3,etc...,andspeciessuchasH2D+andpossiblyD2H+,thatDandHDmightbedepleted.Thiswouldbethemechanismforthelargedispersionof[D]/[H]valuesfoundintheinterstellarmedium.Lightmolecules(hydridesanddeuterides)generallyhavelargefundamentalrotationfre-quencies,oftenlyingintheHIFIbands.Thedeuteridesareaspeciallysuitablecase,becausethespeciesexistmainlyincolddenseregions,wherethemoleculesareinthegroundstatesandTHzobservationswillbestbecar-riedoutbyabsorptionspectroscopyagainstbackgrounddustcontinuumsourcessuchasSgrB2andW49N.Keywords:ISM:molecules–Astrochemistry–Deuterium–Submillimeter

Proceedingsoftheconference“ChemistryasaDiagnosticofStarFormation,”UniversityofWaterloo,Canada,21-23August2002(C.L.Curry&M.Ficheds.).