1983ApJ. . .270 . .605E -3 1 jects directedawayfromnearbypre-main-sequencestars © 1983.TheAmericanAstronomicalSociety.Allrightsreserved.PrintedinU.S.A. The AstrophysicalJournal,270:605-619,1983July15 preshock densitiesof-100cm(Schwartz1975,1978; lous knots(Haro1950;Herbig1951)whoselow-excita- winds frompre-main-sequencestars(Rodriguezetal. been interpretedasevidencethatHHobjectsmaybe characterized byshockvelocitiesof*<100kms'and emission foundinthevicinityofseveralHHobjectshas material, theyaregenerallydisplacedfromthedense Loren, Evans,andKnapp1979)revealthatalthough clouds surroundingHHobjects(HoandBarrett1980; Raymond 1979;Dopita1978).Surveysofthedark provide furtherevidencethattheseobjectsaredrivenor evolved high-velocitycondensationsejectedbystellar cloud cores.Thepresenceofhigh-velocityH0maser HH objectsareoftenassociatedwithhigh-density formed intherecombinationregionsofshockwaves tion emission-Hnespectrahavebeeninterpretedasbeing interstellar materialhavebeen proposed;theseinclude excited bystellarwinds(CudworthandHerbig1979; models fortheexcitationofHHobjectsbyapre-main- Herbig andJones1981;1982).Several and Dopita1980),theinterstellar bulletmodel(Norman sequence stellarwindinteracting withanambientclumpy the acceleratedcloudletmodel (Schwartz1978;Schwartz 1980). ThelargetangentialmotionsofseveralHHob- 2 The HerbigHaro(HH)objectsaresemistellarnebu- © American Astronomical Society • Provided by theNASA Astrophysics Data System -14 12 -7 high-velocity molecularoutflowsinthevicinityofHerbig-Haroobjectsarediscussed. in theNGC1333regionnearHH12,andtwoare7129region,firstLkHa234 M yroccurforatleast10onceinthelifetimeofallstarswithmassesgreaterthan1. knots andlarge-scalemotionsoftheambientmolecularmaterialisinvestigated,properties Astronomy Observatoryrevealthreenewspatiallyextendedhigh-velocitymolecularoutflows.Oneis of theCO/=1-0transitionobtainedwith14mtelescopeFiveCollegeRadio Subject headings:interstellar:molecules—nebulae:generalstars:massloss separated by0.2-1.0pc.Weestimatethatenergeticoutflowscharacterizedmasslossrates>10 and thesecondnearafar-infraredsource.TherelationshipbetweenopticalHerbig-Haroemission 0 A surveyofhigh-velocitymoleculargastoward49Herbig-Haroobjectsispresented.Observations Of 11energeticoutflowsinthevicinityofHerbig-Haroobjects,eightarefoundfourpairs A SURVEYOFHIGH-VELOCITYMOLECULARGASINTHEVICINITY I. INTRODUCTION stars: pre-main-sequence—winds Five CollegeRadioAstronomyObservatory,UniversityofMassachusetts Received 1982October20;acceptedDecember21 Five CollegeAstronomyDepartment,Smith OF HERBIG-HAROOBJECTS.I. Ronald L.Snell Suzan Edwards ABSTRACT AND 605 (Cantó 1980;CantóandRodríguez1980). bedded star(Snell,Loren,andPlambeck1980;Bally lar materialcomesfromobservationsofhigh-velocity and Silk1979),thefocusedstellarwindmodel peak intensityoftheblueshiftedlobemoleculargas infrared source,andarespatiallycoincidentwiththe directed awayfrom1RS5inacollimatedflow(Snell, distributed inabipolarconfigurationaroundanem- molecular gas.Oftenthehigh-velocitygasis dergo dynamicalinteractionswithsurroundinginterstel- Loren, andPlambeck1980).IntheNGC1333region,a molecular gascenteredon1RS5.Themotionsofboth In LI551,thelargespacemotionHHobjects28 (Snell andEdwards1981). 7-11, arealignedalongtheaxisofbipolarmolecular string oflargenegativeradialvelocityHHobjects, and 29arecoincidentwiththeblueshiftedlobeof one mightexpecttofindhigh-velocity moleculargas flow drivenbyHH7-11IR,anembedded80L the HHobjectsandhigh-velocitymoleculargasare the high-velocitymoleculargasandopticalHHobjects. a strikingspatialandkinematicrelationexistsbetween and Lada1983).Inseveralofthesebipolarflowregions HH objectsfoundinL1551 andNGC1333isrepre- tial configurationofhigh-velocity moleculargasand toward manyoftheseobjects. Furthermore,ifthespa- 0 Additional evidencethatwindsfromyoungstarsun- If allHHobjectsresultfromwind-cloudinteractions, 1983ApJ. . .270 . .605E = 80 = = -1 12 13 The temperaturescale(T)appropriate forasourcethat (1981), 7^,canbeobtained fromtherelation= been correctedonlyfortheeffectsofEarth’satmo- addition, someofthetelescope-dependent corrections. ïJfss 0-64,andtj=0.72. sphere andambienttemperaturetelescopelosses.The temperature scalerecommendedbyKutnerandUlich perature of120Kmeasuredatthefeedhorn in thereceiverresultedasingle-sidebandnoisetem- receiver (Raisanenetal1981),andimprovementsinthe ing the1980-1981observing,receiverhadasingle- 7^*/t)fss> ^temperature scaleincludes,in During the1981-1982observingseason,improvements cludes boththeeffectsofscatteringbyspaceframe The antennaparametersweremeasuredtobe0pbw antenna producedthefollowingvalues:0pbw50", quasi-optics feedsystemof450K(Predmoreetal1980). These definitionsfollowtheconventiondescribedby and theradomealsospilloverpastsubreflector. 50", tj=0.62,and0.58.Theefficiencyin- sideband noisetemperaturemeasuredthroughthe Kutner andUlich(1981).Betweenthe1980-1981 determine thehalf-powerbeamwidth(0pbw)>ef- nately fromtheskytoanambienttemperatureload. were calibratedusingachopperwheeltoswitchalter- km s)spectralresolutionwasemployed.Thedata telescope performanceatFCRAOwereimproved.Dur- about 2'inextentmostlyfillingthemainbeam(tj). further correctiontoestimatethecouplingasource ficiency onaspatiallyextendedsource(i]),and Measurements oftheMoonandJupiterwereusedto channel filter-bankspectrometerwith250kHz(0.65 located inNewSalem,Massachusetts.Theseobserva- Astronomy Observatory(FCRAO)14mtelescope ity molecularoutflows,andwediscusstheassociationof hereafter SLP,SEI,II,andES).Wepresentherethe results ofourcompletedsurveyHHobjects,including have beenpublished(Snell,Loren,andPlambeck1980; are discussedindetailPredmoreetal(1980).A512 HH objectsandhigh-velocitymoleculargas. R tions weremadeinthefallandwinterof1980-1981 the detectionofthreepreviouslyunreportedhigh-veloc- Preliminary resultstowardseveraloftheHHobjects objects usingasaprobethe/=1-0transitionofCO. exciting starsforHHobjects.Wehaveconducteda ular flowmightlocateorconfirmsuspectedpositionsof c Snell andEdwards1981,1982; search forhigh-velocitymoleculargastoward49HH sentative ofotherflows,thepresenceabipolarmolec- 606 1981-1982 observingseasons,boththereceiverand COhavebeenobtainedusingtheFiveCollegeRadio H H 1981-1982. Thereceiverandquasi-opticalsidebandfilter fssc H c FSS 12 All linetemperatures(7^*)quotedinthispaperhave Observations ofthe/=l-0transitionCOand © American Astronomical Society • Provided by theNASA Astrophysics Data System II. OBSERVATIONS EDWARDS ANDSNELL 1 12 wings, previouslymissed,arefoundtobepresentatthe just fillsthemaindiffractionbeam,suchashigh- our earliermeasurements,andinseveralcasesweak observing season,havehighersignal-to-noiseratiosthan reported anulldetectionofHVmoleculargas(SEI;SE II). Thesenewspectra,obtainedduringthe1981-1982 have reobservedmanypositionsintheNGC1333, has beendeterminedatroughlythe100mKlevel.We line towardtheopticalpositionofeachHHobject.For km s“.Attributingmoderate COUnewidthstoout- profiles toward43%ofthe objects exhibitAK<10 2068, andNGC1999regionsatwhichwepreviously most spectra,thefullvelocityextentoflineprofile velocity withrespecttothelocalstandardofrest(Fl), listed inTable1.Thislistincludes38objectsfromthe here forthesakeofcompleteness(SLP;SEI;II; vicinity ofhigh-velocitymoleculargasandareincluded objects), fiveofwhosespectraidentifythemasHH of thesurroundingmolecularcloudmaterial.The49 49 HHobjectsisplottedinFigure1.Noneofthe and thefullvelocityextent(AK)ofCOemission the fullwidthoflineathalf-intensity(AF), object inourstatistics,asarethemultipleknotsofother one telescopebeamandhavebeentreatedasasingle located 0Í5westofTTauontheinneredgeNGC (Strom, Grasdalen,andStrom1974,hereafterSGS),HH emission nebulae.TheremainingfourHHobjectsare elucidate anyphysicalrelationbetweenthesmalloptical (HV) moleculargasassociatedwithHHobjectsandto flows ofhigh-velocitygasissubject tosomeuncertainty. observed positionshavefullvelocityextentslargerthan HH objectssuchas4,6,and12. Glushkov, andDenisyuk(1978,hereaftercalledGGD “Draft CatalogueofHerbig-HaroObjects”(Herbig HH objectsobservedintheCO/=1-0transitionare HH emissionknotsandthelargerscaleradialmotions that observedtowardHH7-11 (SEI);infact,line Calvet, Cantó,andRodriguez1983;LadaGautier these objectshavebeenpreviouslyreportedtobeinthe are takenfromthereferencescitedabove.Severalof the following:Haro6-10(Elias1978),HH102inL1551 velocity moleculargasregionsobservedhere,isgivenby 100 mKlevel. 1, whichliststhepeakantennatemperature(7^*), 1974) andsevenobjectsfromthelistofGyulbudaghian, 1982). FivecatalogedHHobjects,7-11,hewithin 103 inNGC7129(SGS),andtheemissionnebulosity max SR 1555 (Schwartz1975).CoordinatesfortheseHHobjects max fwhm The resultsofourobservationsarepresentedinTable The goalofoursurveyistosearchforhigh-velocity A histogramofthedistributionAKtoward max a) Overview III. RESULTS 1983ApJ. . .270 . .605E NGC 1333region: Taurus region: LI 551region: NGC 1999region: Orion region: NGC 2068region: IC 430region: Mon/CMa region: AS 353Aregion: NGC 7129region: Cygnus region: Gautier 1982.(9)Cantóetal.1981. Rodriguez 1983.(5)Snell,Loren,and Plambeck1980.(6)SnellandEdwards1982.(7)BallyLada 1983.(8)Ladaand HH 13 HH 12 HH 14 HH 16 HH 7-11...... HH 15 HH 17 HH 6. HH 18 HH 4 HH 5 HH (NGC1555) Haro 6-10 HH 31 HH 28 HH 30 HH 29 HH 102 HH 40 HH 33 HH 3 HH 42 HH 41 HH 34 HH 35 HH 1 HH 2 HH 43 HH 36 HH38 HH 19 HH 20 HH 26 HH 21 HH 24 HH 25 HH 23 HH 22 HH 27 GGD 18 GGD 5 HH 39 HH 32 GGD 31...... GGD 33...... GGD 32 HH 103 GGD 34...... GGD 35 References.—(1) SnellandEdwards 1981.(2)Thispaper.(3)EdwardsandSnell1982.(4)Calvet, Cantó,and © American Astronomical Society • Provided by theNASA Astrophysics Data System Object 10.0 (K) 11.5 10.0 11.0 13.5 11.0 7.0 9.0 5.4 8.5 8.7 6.8 7.5 7.5 8.3 7.5 5.8 3.4 4.2 3.8 5.0 4.2 5.4 6.0 5.1 9.0 9.3 6.6 6.5 9.5 6.6 7.0 6.3 6.4 6.8 1.2 1.0 6.5 6.2 7.6 5.8 2.6 4.0 3.7 3.2 3.5 3.5 5.0 5.0 12 COObservationstowardHerbig-HaroObjects -1 (kms) -10.8 -10.8 -10.5 -17.0 -10.8 k -8.0 lsr 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 11.0 6.5 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 6.0 8.0 6.5 6.5 8.0 7.0 7.0 7.5 8.0 8.5 8.0 8.0 8.2 6.0 6.0 8.0 8.0 8.2 8.0 4.0 8.5 8.0 -1 (kms) TABLE 1 FWHM 4.5 5.0 6.0 5.5 5.0 5.0 6.0 6.0 5.1 5.2 4.0 2.9 5.5 2.8 6.3 2.5 2.6 2.3 4.2 6.0 5.0 4.0 4.6 4.0 7.5 8.0 4.0 2.3 5.0 3.2 2.2 2.0 4.4 4.0 4.0 3.9 4.5 3.8 7.8 3.9 3.2 3.0 4.5 5.5 4.8 4.8 3.8 5.0 8.0 K (km s”^ AK 20 38 20 13 11 15 12 11 11 12 11 16 11 18 22 15 17 32 14 10 max 10 12 11 16 17 16 13 15 15 8 6 8 7 9 9 8 8 9 7 9 9 9 8 Two HVoutflows 0'5 westofTTau;10kms,propertiesofthe interpretation istheobservationoflargepropermotion molecular hydrogeninaregionofHVgas.Forthose T TauristarsobservedbyKutneretal(1982).Further possibility thatveryweakbutbroadwingsarepresentat weak incomparisontothoseoutflowsfromLI5511RS5 bound motionwithavelocityof(AK/2)<5kms termine ifmassoutflowisresponsiblefortheobserved evidence whichcanlendsupporttoamassoutflow AK <10kms~\theintensityofthelinewingsisvery regions ofsmallspatialextent.Formostspectrawith have ameandensityof>10cm.Molecularcloud hereafter BL).Towardmanyoftheobjectswehave HH objectsandthepresenceofvibrationallyexcited a levelbelow100mKsuchaswasfoundtowardthe or HH7-11IR;therefore,wecannotruleoutthe densities thislargeareuncommon,buttheymayexistin distance of500pc.Aregionthissizeandmasswould can beproducedby-200MwithinaTregionat observed linewidthsasboundmotion.Forexample, observed, sufficientmassmaybepresenttoexplainthe collapse canberuledout(SEI;BallyandLada1983, be madewhentheobservedwidthsimplyvelocitiesin cases, gravitationallyboundmotionsuchasrotationor excess oftheescapevelocityforregion.Inthese values canprovideusefulinsight,amoredecisiveargu- Although acomparisonbetweentheAKandAF ment forattributingobservedlinewidthstooutflowcan 608 max max max 0 fwhmmax The propertiesofelevenfullymappedoutflowregions e TTau © American Astronomical Society • Provided by theNASA Astrophysics Data System NGC 7129far-IR AS 353A LkHa 234 CRL961 HH 24HVS HL/XZTau L1551 1RS5 HH 12HVS HH 7-11IR Edwards 1982.(10)Harvey,Cambell, andHoffman1977.(11)LadaGautier1982.(12)Harvey,Wilkings, andJoy1982. HH 26IR Snell 1982.(6)Fridlundetal.1980. (7)Snell,Loren,andPlambeck1980.(8)Calvet,Cantó,Rodriguez 1983.(9)Snelland d c b a l e Assuming SSV63isthesourceof theoutflow. Assuming HLTauisthesourceofoutflow(CohenandSchmidt 1982). Assuming thatSYS12isthesourceofoutflow. Mass lossrateestimatedassumingthatthestellarwindvelocityis200 kms~. Distance toAS353Auncertain; parameters giveninunitsoíd=distance/100pc. References.—(1) Cohenetal.1982. (2)SnellandEdwards1981.(3)Thispaper.(4)CohenKuhi 1979.(5)Edwardsand Source b d 2 C 1000 1000 200 1600 5500 Dist. (pc) 500 50-300 500 30 500 80 500 20 \00d OJd 140 28 160 >4 160 25 Parameters of11High-VelocityOutflowSourcesnearHHObjects (¿o) (km s V, 20 27 13 14 13 15 10 10 13 max 7 8 EDWARDS ANDSNELL - h R 0.9 0.04 ¿ 0.4 0.3 0.03 0.5 0.2 0.15 0.4 0.7 g 1.3 (pc) TABLE 2 4 3 4 4 3 4 4 4 5 4 5 6 X10 6 X\0d 6X10 3 X10 7 X10 2 X10 2x 10 3 X10 1X10 1X10 1X10 (yr) 12 velocity extentatzerointensity(AK)intheCOlineprofiles HH 7-11cluster,whichfallswithinonebeamofthe14m by T=R/V.Tentativesourceidentificationsare telescope andisthuscountedasoneobject. toward 49HHobjects.Themaximumvalueisfoundthe given fortheHH12and24flows.Thenextthree necessarily betowardanHHobject;theradiusof maximum velocityextentfromlinecenterfoundforany distance tothesource;luminosityof flow {R)\andthedynamicaltimescale(r¿),estimated spectrum withintheflowregion(K),whichmaynot six columnslisttheprobablesourceofoutflow; three ofwhicharereportedforthefirsttime.The max dgmax g max Fig. 1.—Ahistogramoftheobserveddistributionfull 2 23.5 13.9 18.9 0.1 0.003 0.3 0.2 4.2 0.02 d 3.1 3.2 (M) Mass ö - (M kms*) g Momentum 378 2 49 21.7 84 13 15 0.01 0.8 OAd 2.4 1.2 41 45 45 45 43 43 42 46 4 4 X10 2 X10 2x 10 7 X10 3 X10 8 X10 8 X\0d 8 X10 1X10 (ergs) K.E. 1 7 6 -9 -7 -6 6 7 (A/oyr“) 4x 10~ 2X10“ 6 X10 8 X10 8 X10 1X10“ 1X10" a M 4.8 4,5 6.7 4,5 9 3,12 3,12 10,11 1.9 1,3 1,2 Vol. 270 Ref. 1983ApJ. . .270 . .605E l 14-2 4 12 -1 -1 -1 1213 No. 2,1983 f hasbeenestimatedtobe~0.25basedonmodeling columns listthecalculatedvaluesofmass,momen- p/TgV, wherevisthevelocityofstellarwind,and integrated intensityisinunitsofKkms~.Thevalue each ofthesequantitiesmaybefoundinES;webriefly each region.Adetaileddescriptionofthecalculation nebula NGC1333(Herbig 1974). Thisregionisata many withmultipleknots,lies southofthereflection given byA=3.5X10/rdu//cm,where/is summarize theirderivationhere.Thecolumndensityis tum, andkineticenergyoftheHVmoleculargasfor distance of~500pcandis associated withactivestar integrated intensityinbothlinewingsoverthespatial of theCOexcitation(SEI).Wehaveadoptedavalue the fractionofpopulationinupperstate,and gas (p)isestimatedbydeterminingthemassand extent oftheobservedpositions.ThemomentumHV H/CO =2x10tocalculatethetotalcolumndensi- velocity overseveralsmallintervalscoveringthe ties. ThemassofHVgasisestimatedbysummingthe line wingsateachpositionandthensummingthe poor inseveraloftheregions,whereacomparison been excluded,andnoattempthasmadetoin- lower limitssincetheCOHVgashasbeenassumedto momentum ineachindividualvelocityintervaloverall u The opticallythinassumptionhasbeenshowntobe clude projectioneffectsincalculatingthegasvelocity. be opticallythin,thecontributionfromemittinggasat listed inthetable.Thesevalueshavebeenestimated radial velocitiescoincidentwiththeambientgashave spatial positions.Kineticenergies(K.E.)arederivedina unity (SEII;ES). HV gasischaracterizedbyopticaldepthsgreaterthan the valuesofmass,momentum,andkineticenergyare similar fashionasthemomentum.Weemphasizethat Avrett 1982)andT=.Eruptivemasslossevents, Tg isthetimescaleoverwhichmasslossoccurs.Wehave where T<,coulddramaticallyincreasethemassloss assuming conservationofmomentum,suchthatM= gw km stoward57%ofthe49HHobjectswehave adopted v=200kms(Hartmann,Edwards,and coÄM estimates forthedurationofevent(seeSEII;ES; whether massoutflowisthelikelyinterpretationof object regionwithlinewidthsinexcessof10kmsare Mundt andHartmann1983). COtospectraatsomepositionsrevealsthatthe R 2 examined inthefollowingsectionordertodetermine surveyed. TheindividualcharacteristicsofeachHH observed velocityextents. gd gd w 12 A region20'inextentcontaining 15HHobjects, Mass lossrates(M)fromtheexcitingsourcesarealso In summary,wefindCOlinewidthsinexcessof10 © American Astronomical Society • Provided by theNASA Astrophysics Data System b) IndividualRegions i) NGC1333 MOLECULAR GASNEARHHOBJECTS -1 1 -1 1 -120 _1- 1 l Vrba, andStrom\916a)hasbeenpreviouslydescribed bipolar flowdrivenbyHH7-11IR=SVS13(Strom, located atthepositionofmaximumvelocitywidthin in Table2.TheHerbig-Haroobjects,HH7-11,are by SEI,andthepropertiesofthisflowaresummarized formation (SGS).TheAKvaluesobservedtowardthe we havereobservedeachofthosepositionsplusthefive molecular gaswasfoundtowardHH4,6,12,17,or18; blueshifted moleculargas.SEIreportedthatnoHV HH objectsrangefrom8to38kms.Theprominent blueward extentof12kms~andaredward8 has AK=20kms.Thelineisasymmetricwitha km s~fromthepeakemissionatK=7*.A flow andatthepeakofintegratedintensity additional HHobjects5,13,14,15,and16. intensity oftheblueshiftedandredshiftedgasaround integrated intensityintheredwardwingincreasesto extended andpeakstowardtheHHcluster.The the integratedintensityinbluewardwingisslightly ten-point spatialmapcenteredonHH12revealsthat objects intheNGC1333regionisshownFigure3. HH 12and7-11IRthepositionsofall 7-11 flow.Amaplocatingthecontoursofintegrated south andisprobablyduetotheredlobeofHH ward HH12at^^<3kmsis>1.6X10cm. which is35timessmallerthanthemassofHVgasin The totalmassofblueshiftedHVgasis>0.12M, HH 7-11outflowonly4'5tothesouth.Amassin max max LSR blueward extentof12kmsandaredward8 about 5'southofNGC1333.Thelineisasymmetricwitha km s“bluewardvelocityextent torepresentgravita- NGC 1333region(Ladaetal. 1974;HoandBarrett excess of1000Mwouldhavetobeconfinedwithin from thepeakemissionat^lsr“^kms. mass iscomparabletothe estimatedfortheentire a 0.15pcregioncenteiedonHH12inorderforthe 0 tionally boundmotionsuchas rotationorcollapse.This 0 12 12 The COspectrumtowardHH12showninFigure2 The peakcolumndensityofblueshiftedHVgasto- Fig. 2.—TheCOspectrumtakentowardHH12,whichlies -15 -51525 Vsr (km') L 609 1983ApJ. . .270 . .605E 1 1 610 blueshifted moleculargasasarisingfromasecondHV outflow. Supportforthisinterpretationcomesfrom(1) vicinity ofHH12(SimonandJoyce1983). flow geometry(Herbig1982;CohenandSchwartz1983) the largepropermotionsforseveralofknotsHH and (2)theexistenceofHemissioninimmediate and blueshiftedhigh-velocitygasaroundHH7-1112.The36-pointmapIR=SVS13istakenfromSnell contour fortheHH12flowisenhancedrelativeto7-11contourswithavalueof2Kkms".Filledsquareslocatepositions of K kms“exceptforthepartialcontourinvicinityofHH12,whichis2s~\andcontoursareunitssThesingle and Edwards(1981).The10-pointmaparoundHH12ispresentedhereforthefirsttime.lowestcontour7-11flow is 4 HH emissionknots,triangleslocatethepositionsofH0masers,andfilledcirclesHastarsornear-IR also alikelycandidate,theproximity ofSVS12toHH sources describedinthetext. exciting starforHH12,basedonitsproximityand 1980). Thusweinterpretthissecondmaximumof far-IR luminosityof30L(Cohenetal.1982).Al- 12 alonganaxistotallyindependentoftheHH7-11 though thepropermotionvectors indicatethatSVS11, a faintHaemissionstarassociated withnebulosity,is 12 andtothemolecularhydrogen emissionfavorsthis 2 2 Q 12 Fig. 3.—AmapoftheNGC1333region'showingspatialdistributionintegratedintensity/=1-0COinredshifted Cohen andSchwartz(1983)suggestthatSVS12isthe © American Astronomical Society • Provided by theNASA Astrophysics Data System + 31°14' — 5 O 6 m ■+ 30°51'- Q 00 o i o hms 03 2630201000504025 55' 10' Beam Size EDWARDS ANDSNELL HH 17■^ 271 + ■ HH4 H 18 H 7-I + 270 HH5 HH 6 R A(I950.0) SVS I2 ■ HH16 if theextendedredshiftedflowfromHH7-11IRcon- and 12areindicatedinFigure3.Abipolarconfigura- source astheexcitingstar.ThepositionsofbothSVS11 ceals asecondweakerlobeofredshiftedHVgasfrom tion ofHVmoleculargascouldbepresentinthisregion blueshifted. AlthoughthemajorityofHVflowsare the HH12outflow.Otherwise,onemustconcludethat the HVmoleculargasassociatedwithHH12isentirely nantly blueshiftedflowofmolecularmaterialisnot dominated byredshiftedemission(BL),apredomi- T Tauisprimarilyblueshifted material(ES).The unprecedented; theHVmolecularflowassociatedwith inferred masslossrateforthe excitingsourcearegiven momentum andkineticenergy forthisflowandthe in Table2. /+ HH I HH15 SVS II •SVSI 3 12 ‘ JL HH 14 H 13 Vol. 270 1983ApJ. . .270 . .605E 4 -1 12 12 - emission centeredonTTauintheregionofNGC1555 HH objects. HL/XZ Tau,andLI5511RS5)areinthevicinityof pedestal foundinspectratowardtheTauruscloudLI527 Frerking andLanger(1982)suggestthatthelow-velocity unknown sourceinTMC-2(Lichten1982).Inaddition, Cantó, andRodríguez1983),LI5511RS5(SLP),an may beduetogasoutflow.Threeoftheseflows(TTau, between HH39andRMon,themostwidelyseparated No. 2,1983 (Jones andHerbig1982).IftheHHobjectsinNGC observed outflows.Thiswouldrequirethattheexcita- HH objectsinthisvicinityisoneortheotheroftwo HH objecttravelingwiththewindfromayoungstar system foundtodateconsistingofalargepropermotion angular separationofHH14from7-11IRisabout if any,relationexistsbetweentheseHHobjectsandthe imply thatcolumndensitiesofanyHVmoleculargasat of theregionaroundNGC1333,wecannotstatewhat, HH 7-11or12.Withoutacompletelysampledmap HH 13-18,buttheyaremuchweakerthanthosetoward more compact,lowervelocitymoleculargasfromthis tance asgreat2.2pcfromtheexcitingsource(the tion mechanismforHHobjectscanoperateatadis- have beendescribedbyESandaresummarizedinTable scale iscomparabletothedynamicaltimefor the 2.2pcfromHH7-11IRisroughly10yr.Thistime (AKax =8-15kms)towardthesenineHHobjects likely excitingstarforHH17onthebasisofitsnear have notdepositedlargeamountsofmomentumtothe characteristic velocities<100kms~\thenthesesources objects isexcitedbyseparatesourcesofshockswith HH 7-11or12outflows.Ifeachofthesenine ties ofthewingsandmoderateCOvelocityextents two HVflowsthatwehaveidentified.Theweakintensi- velocity widthoftheCOprofile (AF=20kms') 0'5 westofTTauarecoincident withthemaximum 2. TheHHemissionandreflectionnebulositylocated source (SEI). these positionsaremodestincomparisontothosethe molecular gasneartheopticalobjects.Forexample, Cohen andSchwartz(1983)havesuggestedSYS5asa redshifted HVgas.Radialvelocities ofthenebulosityin spatial coincidencewiththefan-shapednebulosityof and withthepeakintensity ofbothblueshiftedand molecular gasintheTaurusdarkcloudcomplex originating fromTTau(ES),HL/XZ(Calvet, 15'). Thisdistanceisonly30%largerthantheseparation this object. 1333 regionareejected“bullets”movingatvelocitiesof ~ 200kms~\thenthetimescaleforHH14totraverse m max The physicalpropertiesoftheextendedblueshifted An alternatepossibilityisthatthesourceofall Weak wingshavebeendetectedtowardHH4-6and There areatleastfouroutflowsofhigh-velocity © American Astronomical Society • Provided by theNASA Astrophysics Data System ii) Taurus MOLECULAR GASNEARHHOBJECTS -1 l 12 12 _ 1 -1 -120 -1 -1 12 -1 12 The recentdetectionofaninfraredcompaniontoTTau physically relatedtotheblueshiftedHVmoleculargas. possibly arisingfromanoutwardexpansionofgasand (Dyck, Simon,andZuckerman1982)thediscovery not agreewiththepositionofradiocontinuum of deVegt(1982)thattheopticalpositionTTaudoes molecular outflow. raise thequestionofwhichsourceisresponsiblefor dust awayfromTTauatavelocityof~95kms.If this regionhavebeeninterpretedbySchwartz(1975)as source detectedbyCohen,Bieging,andSchwartz(1982) toward HH102,anamorphouselongatedpatchof Table 2.TheobservedvaluesofAFatthepositions true, thiswouldsuggestthattheopticalnebulosityis of thefourHHobjectsrangefrom8to18kms~.The Cantó, andRodriguez1983).Thephysicalpropertiesof west of1RS5andmaydelineatethelocation boundary oftheblueshiftedlobemoleculargassouth- maximum velocityextentofCOinthisregionisfound and Vrba1976ó)HL/XZTau,aresummarizedin these flows,drivenby1RS5=SSV(Strom,Strom, two distinctoutflowshavebeenfound(SLP;Calvet, (SGS). HighspatialresolutionCOmaps(Snelland nebulosity 2'westof1RS5withaF=-55kms lar flowcenteredonHL/XZTau. relative totheblueshiftedlobeofHVmoleculargasin shock frontresponsibleforboththeopticalemission the largepropermotionHHobjects28and29 and theHVmoleculargas.Thestrikingplacementof Schloerb 1983)showthatHH102iscoincidentwiththe ern redshiftedHVlobefrom1RS5andthemolecu- the bipolarflowfrom1RS5iswellknown(SLP).The V380 Ori,isshowninFigure4.Alow-intensityredward proper motionsdirectedoppositelyawayfromthe illuminated bytheAestarV380Ori,containsfiveHH studies tobeexcitedbyHLTau(CohenandSchmidt fourth object,HH30,shownbyspectropolarimetric wing isclearlypresent,extending12kmsfromline The spectrumtowardHH35,whichliesL5northwestof objects, twoofwhich(HH1andHH2)exhibitlarge molecular gasatF>11kmsis3X10cm.SE center atF=8kms.Thecolumndensityof Herbig andJones1981).Thedistancetothisregion, wing extending8kmsfrom linecenter.OurCO the fiveHHobjectsrangesfromAk^=8-17kms. and Jones1981).TheCOfullvelocitywidthtoward suspected tobeintheOrioncomplex,is460pc(Herbig Cohen-Schwartz (C-S)star(CohenandSchwartz1979; HH 1and2theC-S star;our1982observa- II reportedanulldetectionof HVmoleculargastoward max tions towardHH2showaweak, butdefinite,redward LSR 1982), liesinanintensityminimumbetweenthenorth- LSR LSR In theLI551region,whichcontainsfourHHobjects, The regionaroundNGC1999,areflectionnebula in) NGC1999 611 1983ApJ. . .270 . .605E 1 12 -1 - 612 km s".ThefourobjectsHH24-27arefoundwithin molecular gas. is neededtodiscoverthenatureofmotion star andV380Ori,donotshowwingsasstrongthose and atsixotherpromisingpositions,includingtheC-S spectra towardtheremainingHHobjectsinthisvicinity possible sourceofthissecondbipolarflowisHH24 (referred toasHH24HVS).Theseflowshavebeen LI630 atadistanceof500pc.AsymmetricCOpro- seen towardHH35.Afullysampledmapofthisregion the reflectionnebulaNGC2068indarkcloud IR =SSV63(Strom,Strom,andVrba1976«;seeSE described inSEIIandaresummarizedTable2.A unknown sourcelyingbetweenHH24and25 26 IR=SSV59(Strom,Strom,andVrba1976¿z)an files arefoundtowardallnineobjectswithAK=7-22 intensity ofCOineitherflow.Theweakwings the boundaryoftwoHVbipolaroutflowsdrivenbyHH varying intensityseentowardthefiveobjectsHH19-23, map oftheregionhasnotbeenmade,itispossiblethat tended regioninthiscloud.Althoughafullysampled which he>4'fromtheflowboundaries,indicatethat within Tofthepeakvelocitywidthandmaximumwing moderate-velocity moleculargasispresentoveranex- II). OfthesefourHHobjects,25and26arelocated that havebeenfound. all nineHHobjectsareexcitedbythetwobipolarflows kpc (Racine1968),isilluminated byasmallclusterof max low-intensity redwardwingextending12kmsfromlinecenter about F5NWofNGC1999.Thelineisasymmetricwitha at F=8kms^ lsr 12 The HHobjects,19-27,lieroughly10'southof The reflectionnebulaNGC 7129, atadistanceof1 Fig. 4.—TheCOspectrumtakentowardHH35,whichlies © American Astronomical Society • Provided by theNASA Astrophysics Data System iv) NGC2068 v) NGC7129 1 VLsR (km5) EDWARDS ANDSNELL 13 3 13 13_1 -1 12 -1 13 1213 1 1213 1213 _1 -1 13 1 13 =1 early-type stars,includingthetwoHerbigAe-Bestars within a10'radiusofthevisiblenebulosity(SGS; fim surveyofthisregion(Strom,Vrba,andStrom masers (Rodriguezetal1980;SandellandOlofsson jim sourceslocatedwithinamolecularridgethatborders Gyulbudaghian, Glushkov,andDenisyuk1978).The has atotalluminosityof200Landiscoincidentwith molecular lineandfar-infraredsurveyrevealedtwo160 for whichnoopticalspectroscopicdatayetexist.A2 two uncertainHHidentificationsareGGD33and34, lobes ofhigh-velocitygasinCOthatareorienteda far-infrared sourceiscoincidentwithLkHa234andhas N-S directionalongwhatheinterpretsastherotation ular cloud(Bechisetal1978;Harvey,Wilking,andJoy the visiblenebulosity(Bechisetal1978).Thenorthern the COcolumndensitypeakofNGC7129molec- a totalluminosityof10L,andthesouthernsource LkHa 234areshowninFigure5.Toward234, probe thisregionfurther.Theresultant98-pointmap metries andstrengthsofthelinewingsinducedusto positions, theCOspectrumalsoshowsablueward revealed complex,extendedHVCOemission.Repre- axis ofthemolecularcloud. 1981) andthreeorpossiblyfiveHHobjectsarepresent velocity extentissimilartothe(0,0)position.Atboth of thepeakCOemissionatF=-10kms.To blueward wingwithan11kmsextentandaweak position (0,0),theCOspectrumshowsaprominent this regionrangefrom8to15kms.Variableasym- position, assumingthattheterrestrialisotopicratioof center. ThemaximumCOwingemissionisfoundat extension. TheCO/COratiooftheHVgasvariesas redward wingwitha7.5kms~extentfromthevelocity sentative COandspectraattwopositionsnear 1976¿>) revealednoembedded,nonvisualsources.A down to2intheblueshiftedmoleculargasatthis (1,1), withtheCO/ratioincreasingfrom5to36 + 65°1637andLkHa234(Herbig1960).Threewater a functionofspatialpositionandvelocityfromline the bluewardwingreachesamaximum,although the northeast,atposition(1,1),emissionintensityin south ofLkHa234(Fig.6)showstheblue-redspatial sponds toopticaldepthsrangingfromgreaterthan10 at velocities2-5kmsfromlinecenter.Thiscorre- 0 1982) . Inaddition,Loren(1977)foundevidencefortwo redward wingintensityhassignificantly decreased,and shows aprominentredwardwingextending10kms separation thatcharacterizesabipolarflow.Theposi- from thepeakemissionofCOlinecenterat 89 isapplicable. a prominentbluewardwingextends 10kms~fromthe tion (0,-3)isclosetothesouthernfar-IRsourceand 0 LSR COpeakvelocity. Fr -10kms“.Twominutes south,at(0,-5),the LS 12 1213 The COAFvaluestowardthefiveHHobjectsin A secondpairofCOandspectraobtained max Vol. 270 1983ApJ. . .270 . .605E _1 121 _1 13 l 21- No. 2,1983 wings wasperformedareF=-20to-12kms The velocityintervalsoverwhichtheintegrationof blueshifted high-velocitygasispresentedinFigure7. with prominentCObluewardwingsextending11kms~from Asymmetric profilesareseeninbothisotopesatpositions, (0,0) andNEofLkHa234(1,1)intheNGC7129region. The distributionofHVmoleculargasisclearlycomplex km srepresentsthewidthofambientcloudpro- masers, andfar-infraredsourcesoutliningthecon- the velocityofpeakemissionatCO. file, determinedbyspectraattheboundaryofflow. and -8to0kms~.TheintervalfromK12 tours oftheintegratedintensityinredshiftedand lated inTable2,alongwiththeimpliedmasslossrates blueshifted and6.2Minredshiftedgas.Themomen- gas is37M.Thenorthernflowcontains23.5,with region is>1.3X10cm,andthetotalmassofHV from thesourcesdrivingflows. Thelackofanyother source forthenorthernflow isLkHa234andforthe far-IR sourcesinthisregion suggeststhattheexciting sists almostentirelyofredshiftedmoleculargas. the southernoneisbipolar,andnortherncon- and appearstobedividedintotwoseparateHVflows; southern flowisthefar-IRsource foundbyBechisetal tum andkineticenergiesinthesetwoflowsaretabu- and thesouthernflowcontains13.9M,with7.7in 5.1 Minblueshiftedgasand18.4redshiftedgas, LSR LSR 0 0 G0 0 1213 A mapofthisregionlocatingtheHHobjects,H0 Fig. 5.—TheCOandspectratakentowardLkHa234 The peakcolumndensityofHVmoleculargasinthis 2 © American Astronomical Society • Provided by theNASA Astrophysics Data System 1 V(kms-) LSR MOLECULAR GASNEARHHOBJECTS 12 (1978). Thisidentificationissupportedbytheclose high velocities,whichcouldbeinterpretedasresulting is coincidentwiththewesternboundaryofNGC molecular emissionalongthisridgeisalmostentirelyat (see Fig.7).ThewesternedgeofthesouthernHVflow association oftheH0maserswiththesetwosources cloud edge. from thelowresistanceofferedbycloudboundary 7129 molecularcloudouthnedbyBechisetalThe spatial extentoftheblueshiftedgasinsouthernflow to theexpandingshellofHVmoleculargas.Thelarger thus mayalsoresultfromtheloweredresistanceat blueshifted lobeofthesouthernHVflowtowardHH flow boundariesisnotsuggestiveofcollimatedejection connection mayexistbetweentheopticalnebulaeand as inLI551andHH7-11.Thesecondpeakthe blueshifted gas. 2 emission knotsmightdetermineifsuchaconnection exists betweentheHHobjectsandextended the molecularflow.AradialvelocitystudyofHH blueshifted high-velocitywingscharacteristic ofabipolarflow. and (0,-5)southofLkHa234 in theNGC7129region.The HH 32,andGGD31.Thefirstofthese,5,is found towardthefourHHobjectsGGD5,18, COspectraclearlyshowthespatially separatedredshiftedand 103 andGGD32offersthepossibilitythataphysical 1 1213 The locationoftheHHobjectsatperiphery Velocity widthsrangingfrom16to32kmsare Fig. 6.—TheCOandspectra takenatpositions(0,—3) vi) OtherRegions 613 1983ApJ. . .270 . .605E - ! _1 614 suspected HHobjectsaremarkedbyfilledsquares,andpositionsofH0maserstriangles. level is2Kkmsandcontourintervalsare.Filledcirclesindicatepositionswherespectrawereobtained.PositionsofHH or separated flows;thesouthernoneisbipolar,andnorthernconsistsalmostentirelyofredshiftedmoleculargas.Thelowestcontour and blueshiftedhigh-velocitygasinthevicinityofLkHa234southernfar-IRsource.Theissituatedtwospatially be madeinordertodeterminethesourceandextentof broad linewidthstowardthepositionofS235B,afew located nearS235,aregionofcomplexmolecularemis- ring here,althoughacompletemapofthisregionmust bipolar HVgasmappedbyLadaandGautier(1982). The fullvelocitywidthof32kmsobservedtoward arc minutesfromGGD5.Massoutflowmaybeoccur- sion describedbyEvansandBlair(1981).BLreport Table 2. observed inCRL961.Thepropertiesofthisoutflow, GGD 18iscomparabletothehighestvelocitygas this HVgas.ThesecondHHobject,GGD18,islocated T TauristarAS353A.BoththeandHHobject taken fromLadaandGautier(1982),aresummarizedin uncertain, butalowerlimitwas estimatedtobe150pc 2 centered onAS353A.The distancetoAS353Ais are coincidentwiththemaximum velocityextentand the peakintegratedintensity ofaflowHVgas < 1'northwestofCRL961,withintheboundaries 12 Fig. 7.—AmapoftheNGC7129regionshowingspatialdistributionintegratedintensity/=1-0COinredshifted The thirdHHobject,32,lieslessthanTfromthe © American Astronomical Society • Provided by theNASA Astrophysics Data System EDWARDS ANDSNELL R A(1950.0) _1 by ES;wesummarizethepropertiesofAS353A outflow inTable2asafunctionofitsdistanceunits velocity components(Blitz1980).Ourspectrumtoward covered byMundt,Stocke,andStockman(1983).The emitting gasaroundAS353Ahasbeenrecentlydis- of 100pc.Inaddition,thebipolarnatureoptically fourth HHobject,GGD31,liesinCygnusnearDR6 a regionofcomplexmolecularemissionwithmultiple observed velocityextentof16kms.Anattemptto GGD 31showsabroadlinecoreequaltoone-halfthe nents inthisregionwouldrequireconsiderableeffort. sort thecontributionofanyHVmoleculargasarising identified towardthecomplexemissionnebulosityin from astellaroutflowthemultiplevelocitycompo- regions ofHVmoleculargas (Zuckerman,Kuiper,and Orion Nebula(Munch1977).Thisobjectlies0'5north Rodriguez Kuiper1976;Kwan andScoville1976).We and 0'9westofonethe mostthoroughlystudied did notincludethisobjectin thestatisticsofoursurvey An additionalHHobject(M421)hasbeen Vol. 270 1983ApJ. . .270 . .605E -1 =- 4 _ 1 No. 2,1983 -1 which liesL3westandL6northofCepA(Rodríguez, molecular flowshavebeenfoundinthevicinityof since itslocationinthecomplexOrionNebularegion (Fischer 1981). km s;BL)incomparisontotheotherHVflows 6334 ataposition3'5westand2'9southofGGD24 (AKmax 60kms‘)havealsobeenobservedinNGC Ho, andMoran1980);GGD12-15(Rodriguezetal several suspectedHHobjects.TheseincludeGGD37, outlined inTable2. cally relatedtotheOrionmolecularoutflow,itwouldbe HV moleculargas(Ericksonetal1982),anditsoptical HH objectandtheOrionmolecularoutflow.However, renders highlyuncertainanyassociationoftheoptical L) andaflowofextremevelocitywidth(AF~127 associated withasourceofhighluminosity(L>10 sion, hasonecomponentblueshifted240kmsrelative spectrum, characterizedbydouble-componentlineemis- S68 (SerpensObject;BL).Finally,largevelocitywings to theambientnebularUnes.IfthisHHobjectisphysi- the objectliesnearblueshiftedlobeofbipolar 1982); andGGD29,whichliesL5west0Í5northof 0max high-velocity molecularoutflows,mostopticalobjects in manycasesHHobjectsarelocatedthevicinityof radial motionofthemolecularmaterialinvicinity This premiseissupportedbyourobservationsofthe are notspatiallycoincidentwiththepositionof connection existsbetweentheopticalobjectsand HH objectscanbeusedtoexaminewhetheradirect objects. Morespecifically,ourobservationsofthebulk periphery orseveralarcminutesbeyondtheboundaries in thevicinityofHHobjectssummarizedTable2, surrounding molecularmaterial.Wefindthatalthough frequent associationofHVmoleculargaswithHH stellar windinteractionwithinterstellarmatteriscentral intensity asymmetricwingstructure. Itisconceivable recognized HVoutflow.Atthese moredistantpositions, outflow. However,atotalof31objectsarefoundasfar to allcurrenttheoriesfortheexcitationoftheseobjects. of theHVgas.Oneobject,HH14,islocated15'froma seven haveanHHobjectwithinVofthecenter ity COemission. largest velocityorthemaximumintensityofhigh-veloc- as 10'fromthese11flows,manyofthemlocatedonthe the maximumvelocityextent of theambientCOisoften < 10kms,althoughtheline profilemayhavelow- In additiontotheHHobjectssurveyedhere,bipolar The fundamentalpremisethatHHobjectsresultfrom Of the11fullymappedoutflowsofHVmoleculargas © American Astronomical Society • Provided by theNASA Astrophysics Data System a) RelationshipbetweenHHObjectsandHV vii) SuspectedHHObjects IV. DISCUSSION Molecular Gas MOLECULAR GASNEARHHOBJECTS -1 ! 12 1 jects areblueshiftedrelativetotheambientgas.Table3 been identified. which high-velocitymoleculargashasbeendetected great as2pcfromtheoutflowsource.Anadditional observed molecularflows,althoughthiswouldrequire HV flowregionareexcitedbythesourcesdriving HH excitationmechanismstooperateatdistancesas that thoseobjectslocatedbeyondtheboundariesofa less than8kmsthroughoutthewind-affectedarea GGD 31)arelocatedlessthan10'frompositionsat seven HHobjects(HH1-3,35-36,GGD5,and (Cantó etal.1981).RMon,apre-main-sequencestarat (AK >15kms),butnooutflowsourceshaveyet velocity fortheseobjectsare notyetavailable.Ifthe vicinity ofHVmolecularoutflows,orwhetherthey,like stellar windsourceappearstohavemolecularlinewidths prove tobedirectionallycoincident withthevelocityof molecular gasthatischaracterizedbyalargerblueward HV moleculargas(HH31,Haro6-10,HH33,40, our surveywhoseCOspectragavenoindicationof in thenebulaappearstobeexpandingawayfrom the apexofcometaryreflectionnebulaNGC2261,is radial velocitiesfortheseoptical emissionknotsalso dominant redwardCOemissionisfoundtowardHH30, indicates thatinmostcasestheblueshiftedHHobjects in Table3.VelocitiesofHHobjectsandHVmolecular outflow regions. of theseareasmightstillrevealthepresencenearby gas exhibitsnolargeradialmotions.Sinceourobserva- HH 39,arefoundinregionsweretheambientmolecular HH 34,41,42,43,and38)areinthe a tangentialvelocityof290kms~*.Inaddition,thedust the coneandisdrivingHH39alongaxiswith the sourceofawindthathassweptoutinterior spectra ofsufficientresolution todeterminetheradial 35, GGD5,33,34,and35.Optical 31, andGGD32)arealsospatiallycoincidentwith in theHHspectra.Atotalof15additionalobjects molecular gasinthisregion. could explainthelackofsubstantialhigh-velocity outflow predominantlytangentialtothelineofsight R Monatvelocitiesof<40kms“(JonesandHerbig than redwardvelocityextent.Ontheotherhand,pre- molecular gas,althoughmuchlargervelocitiesarefound cloud material.AspointedoutbySGS,mostHHob- gas aregivenrelativetotheLSRvelocityofambient spatially coincidenthigh-velocitymoleculargasismade the maximumvelocityextentfromlinecenterof tions onlyyieldinformationonthemoleculargaswithin (HH 13,14,15,5,28,36,19,20,21,22,23,24,26,GGD are spatiallycoincidentwithpredominantlyblueshifted 1' oftheopticalpositionanobject,thoroughmapping max 1982). SmallcolumndensitiesofHVmoleculargasor At leastoneHHobjectregionwitharecognized We havenotdeterminedwhetherthenineobjectsin A comparisonofradialvelocitiesHHobjectsand 615 1983ApJ. . .270 . .605E 616 EDWARDSANDSNELLVol.270 with aStellarwind.ThedistributionofHHobjectsover high spacemotionscharacterizemanyobjects,suggests nearby outflowsourcesoracceleratedviainteraction large areasofthesky.Fouroutflowsourcesthat with HVmoleculargasmaybelocatedbysearchesover ity ofthenineHHobjectsthathavenotbeenidentified exciting sources.Therefore,outflowsourcesinthevicin- centers inagivenregion,combinedwiththefactthat distances ofupto-2pcfromtheonlyknownoutflow NGC 7129far-IR)areaccompaniedbyhigh-velocity we havestudied(HH7-11IR,TTau,LkHa234,and the HHcondensationshaveeitherbeenejectedfrom that theHHobjectsmaybedrivenfarfromtheir hydrogen emissionwouldlieprimarilybehindobscuring evidence thatbotharedrivenbythesamestellarwinds. molecular hydrogenemission.The energetic outflowregionsinwhichtheyhavedetected the ambientmoleculargas,thiswouldprovidestrong This wouldsupportthehypothesis ofanevolutionary mass outflowthanthemajority oftheopticalHH H0 maseremissionthatliesclosertothecenterof phenomena withblueshiftedHVgas. planation fortheobservedassociationofbothshock interstellar materialandwouldprovideaplausibleex- emission knotsineachregion (Haschicketal.1980; emission intheseregionsisfoundtobepreferentially Simon andJoyce(1983)findasimilarphenomenonin associated withblueshiftedHVmoleculargas.Receding Knapp andMorris1976;Sandell andOlofsson1981). shocks producingredshiftedHHemissionormolecular 2 The precedingobservationsfavoramodelinwhich © American Astronomical Society • Provided by theNASA Astrophysics Data System -1 HH 7 HH 11 HH 10 HH 8...... HH(NGC 1555) HH 12 HH 29 HH 1 HH 102 HH 2 HH 24B HH24 A. HH 3 HH 32 HH 103 with Llsr=4-314kmsandthesecondK=4-20±15.Recent observations byMundt,Stocke,andStockman1983showthatbothblue- redshifted HHemissionliewithinourbeamwidthatthisposition. LSR b a Dopita 1978givesvelocitiesfortwocomponentsinthebroadlinesofHH32,one LsR takenfromSGS,Dopita1978,andSchwartz1975. L Source A ComparisonofRadialVelocitiesHHObjectsandthe Spatially CoincidentHigh-VelocityMolecularGas a K(HH Object) lsr - ! (km s) -139 -22 -37 -51 -39 -12 -58 -55 -40 -88 -61 33 10 7 b TABLE 3 progression ofhigh-velocitycondensationsfromH0 masers toHHobjectsasproposedbyNormanandSilk (1979) andRodríguezetal.(1980). luminosity. blueshifted andredshiftedemission lobestobelabeled characterized byanasymmetricmorphologicalstruc- emission thatfrequentlyaccompaniessourcesofhigher predominantly aroundlow-luminositysourcesofHV of relativelylowluminosityincomparisontotheHV HH objectsdescribedinTable2arepoweredbysources chance fordiscoveringanHHobjectisdiminishedin outflows couldresultfromselectioneffects,inthatthe (Cohen andKuhi1979).ThelocationofHHobjects flow sourcescompiledbyBL.Theluminositiesof1-100 HH 26IR,CRL961,andNGC7129far-IR)arechar- 234. FiveoftheHVflows(HH7-11IR,LI5511RS5, around HH7-11IR,26CRL961,andLkHa and HH12HVS,whilethereverseistrueforflows that oftheredshiftedHVgasinflowsaroundTTau ture. ThemassofblueshiftedHVgasismorethantwice the presenceofbrightreflectionnebulosityorHn static equilibriumcontractiontowardthemainsequence L areconsistentwith1-3Mstarsinquasihydro- unambiguous bipolarflows. The remainingflowsmay acterized bysufficientlystrong, spatiallyextended also bebipolar,buttheylack eithersufficientspatial 2 0 -1 Each oftheoutflowregionssummarizedinTable2is Most oftheHVmolecularoutflowsinvicinity J'HH Kmb (kms) -146 -44 -58 -29 -20 -65 -46 -48 -62 -98 -53 -1 23 2 b) GeneralPropertiesoftheOutflows (km s'’) -25 -25 -25 -12 -25 -14 -12 -14 -11 -5 -6 5 8 1983ApJ. . .270 . .605E -2 -1 12 6-1 15 4 -1 -14 No. 2,1983 lobes tomakeaclearbipolaridentification.Themecha- bipolar flowsmaybepresentinmostregions,sincethe have beenproposedtoaccountforwell-collimatedout- nism responsibleforproducingsuchasymmetricout- cient columndensityofHVgasinonethesuspected resolution oftheblueshiftedandredshiftedgasorsuffi- which istheangleinhalfofflowsaremore plane ofthesky,is30°.Applyingcorrectionfora inclined andhalfarelesswithrespecttothe randomly orientedinspace,thenthemedianangle, energy isgivenby(sin0),thatforthedynamicaltime by (sin#).Similarly,thecorrectionrequiredfor it andtodeterminethetrueoutflowvelocity mechanism, whereradiocontinuumobservationsreveal flows (SLP;Konigl1982;Draine1982).Well-collimated flows isnotwellunderstood,althoughseveralmodels km s~therefore,themedianoutflowvelocityforthese given by(sin0tan0)~\Ifweassumethattheflowsare scale isgivenbytan0,andthatforthemasslossrate onto theplaneofskywillaffectourabilitytodetect great as0.5pc(SLP). Bieging, andSchwartz1982)COobservations 1RS 5setsastringentconstraintonthecollimation spatial resolutiononthesourceandinclinationof apparent morphologicalstructureisdeterminedbythe the flowtoplaneofsky.ThearoundLI551 loss rateof-7x10“Myr,wherewehaveex- observed radialvelocityoftheflowsinTable2is-15 flow inclinedatthisangleresultsinanoutflowvelocity geometrical correctionfactorthatisrequiredtoproduce dynamical timescale.Iftheoutflowisorientedatan show thattheflowremainscollimatedoverdistancesas a collimatedjetwithin~10cmof1RS5(Cohen, values. median timescaleof~2X10yrandamass namical timescaleandthemasslossrateresultsina that istwicetheobservedradialvelocity.Theaverage angle, 0,withrespecttotheplaneofsky,then the truevaluesofvelocityandmomentumisgiven dynamical timescalesfortheflowsinTable2willbe cluded thesourceswithmaximumandminimum sponding correctiontotheobservedvaluesofdy- sources wouldbe-30kms.Applyingthecorre- due inparttoprojectioneffects.Althoughastatistical yr andwererandomlyorientedinspace.Infact,twoof roughly consistentwiththedistributionthatwouldbe cal timescales,whichiswhat wouldbeexpectedifall expected ifallflowswerecharacterizedbyvelocitiesof analysis ofoursmallsampledataisnotwarranted, the observeddistributionofvelocitiesandtimescalesis flows werecharacterizedby comparable velocitiesand some ofthesmallestvelocities, andthuslargestdynami- the sourceswithlargeprojected sizesarefoundtohave 0 - 20-30kmsandbydynamicaltimescalesof10 The projectionofacollimateddirectionalHVoutflow The observedvariationsintheflowvelocitiesand © American Astronomical Society • Provided by theNASA Astrophysics Data System MOLECULAR GASNEARHHOBJECTS -4521 45 -71 4 -1 inclined fromtheplaneofsky.Thedistribution velocity materialthatprimarilyaccountsforthe would notbeconsistentwithuniformvaluesforall known flowsvariesbyseveralordersofmagnitudeand is 6X10tokpcyr.Thiscomparable between 10andyr.Iftheseoutflowsoccuronly parent durationoftheoutflowslistedinTable2is results ofBL,Rodriguezetal.(1982),Levreault(1983), evolution andonmolecularclouddynamics.Combining of crucialimportanceinassessingtheirimpactonstellar chanical luminosityintheflow. plete samplingofthe1kpcregionaroundSun,and luminosities ofmanythesources,existence determined tobesitesofenergeticoutflows.Theap- Lichten (1982),andourown,thereare20regionswithin observed correlationbetweensourceluminosityandme- flows; infact,itisthevariationmassofhigh- time scales,butinthesecasestheflowwasonlyslightly by M>10yr. present statistics,starswithmassesgreaterthan1M rate ofstarsthatundergoaphaseenergeticmassloss once duringthelifetimeofastar,thenformation the totalmassofmaterialathighvelocitiesamong must undergoaphaseofenergeticoutflowcharacterized our estimatethatthedynamicaltimescalesmaybeas four pairsofflowsseparatedby0.2-1pc,theincom- M. SimilarresultsarefoundbyRodríguezetai(1982) short as~10yr,allsuggestthattoaccountforthe and Beckwith,Natta,Salpeter(1983).Thelow to thetotalstarformationratecomputedbyMillerand Scalo (1979),forstarswithmassesgreaterthan1.5-4 1 kpcoftheSunthathavebeencarefullystudiedand in theoutflow(L=K.E./t¿),photonmomentum The stellarluminosity(L*),themechanical correlation betweentheluminosityofstellarsource (MV) forthe11sourcesinTable2arelisted.Alinear observed high-velocityflowsarecomparedinTable4. luminosity ofthesourceandmomentumfluxin luminosities. Alinearrelationisalsofoundbetweenthe coefficient of0.70.AsimilarrelationisfoundbyBLfor given bylogL=-3.0+1.03L*,withacorrelation and themechanicalluminosityinoutflowisfound, flux (L^/c),andthemomentumofoutflow o 0 luminosity thereisanearlylinear relationwithmechani- q cal luminosityandmomentum flux. outflow, describedbylogMF(Mkmsyr)= a setofsourcescharacterizedbypredominantlyhigher outflow tothemomentumflux intheavailablestellar two andone-halfordersofmagnitudeinthestellar m M 0 -5.5+ 0.92logL*(L).Itisremarkablethatinover q Knowledge oftheformationratetheseHVflowsis The energyexpendituresofthesourcesproducing A comparisonoftheobserved momentumfluxinthe c) EnergeticsoftheOutflows 617 1983ApJ. . .270 . .605E 12 45 618 photons revealsthatinall11sources,MV>L^/c,and in thecaseoflow-luminosity,high-surfacegravity pressure. Althoughinallcasestheluminousstellar in sixsources,MV>100L^/c.Ourconclusionsagain ity starscanhaveasignificantdynamicalimpactonthe mechanical energyarerequiredtoproducetheobserved efficient mechanismsforconversionofluminousto energy exceedsthemechanicalinflow,highly vastly differingformationratescannotbemadedueto energy requiredtoproducethederivedmassfluxes mass lossrates.Thisneedismostseverelydemonstrated scatterings arerequiredtodrivethewindsbyradiation agree withthoseofBL,inthatanexcessivenumber however, itisclearthattheHVflowsfromlow-luminos- port forgiantmolecularclouds.Onamorelocalscale, we donotattempttoestimatewhethertheobserved luminosity istransferredtothesurroundingcloud.Thus, ity pre-main-sequencestars.Inaddition,littleisknown ity impliesthattheflowluminosityiscorrelatedwith energy (L*). (GMM/R) maybe5%-30%oftheavailableluminous stars, suchasTTauorpossiblyLI5511RS5,wherethe over thedurationofflowlifetimefromstarswith relative contributionoftheappropriateflowluminosity mass ofthesource.Arealisticattempttointegrate correlation betweenflowluminosityandsourceluminos- COhasrevealedthreenew high-velocitymolecular formation rateofHVflowscanprovidepressuresup- and Barrett1980). flow (7X10ergs)iscomparabletothetotalK.E.of ambient cloud.Forexample,theK.E.ofHH7-11 about theefficiencywithwhichmechanicalflow the unknownmass-luminosityrelationforlow-luminos- flow centersissubjecttouncertainty.Theobserved served flowsongiantmolecularcloudswithmultiple the 230McloudfragmentsurroundingHH7-11(Ho 0 A surveyof49HHobjectsin theJ=1-0transitionof An assessmentofthedynamicalimpactob- © American Astronomical Society • Provided by theNASA Astrophysics Data System T Tau1.4-1.9-6.3-4.4 NGC 7129far-IR...2.3-0.8-5.4-3.3 AS 353A—0.2+2logd-1.7-7.921og¿-4.8log¿ CRL961 3.71.0-4.0-2.2 HH24HVS 1.3-0.6-6.4-3.6 HH 26IR1.7to2.5-0.3-6.0to-5.2-4.0 HL/XZTau 1.2-3.3-6.5-5.8 LI551 1RS51.4-1.6-6.3-4.1 HH12HVS 1.5-1.2-6.2-3.9 HH 7-11IR1.90.5-5.8-3.0 LkH« 2343.0-0.6-4.7-3.1 V. CONCLUSIONS !1 Source (L)(Myr’kmskms*) 0 logL* logLa,L*/cMV EDWARDS ANDSNELL Energetics ofSources TABLE 4 12 The majorityofthe32HHobjectsinvicinity outflows inthevicinityofHHobjects,sevenhave outflows. Ofthe11recognizedhigh-velocitymolecular optical knotsofHHemissionwithinVtheircenter. mapped regions,thenatureorinsomecasespres- or beyondthetraceableboundariesoftheseoutflows. ence ofhigh-velocitymoleculargasremainsuncertain. these 11identifiedoutflowsarelocatedattheperiphery For anadditional16HHobjectsineightincompletely infrared andCOemissionintheseregionscouldre- boundaries oftheobservedhigh-velocitymoleculargas, ity sources.Themomentum fluxes areconsiderablyin velocity moleculargasdrivenbyrelativelylowluminos- ity ofHHobjectsdescribedherearecharacterizedby distances asgreat2pcfromtheirexcitingsource.We may indicatethatexcitationofHHobjectscanoccurat winds. Thenumberofnewhigh-velocity outflowsources HH objectsaswellmorecompletemapsoffar- sources thathavenotyetbeenidentified.Furtherspec- great distances.Analternateexplanationwouldbethat for the32nearbyHHobjectsandthatejectionor high-velocity moleculargasarguesinsomecasesforthe nism otherthanradiationpressure isdrivingthestellar excess ofthestellarphoton fluxes, indicatingamecha- solve thisquestion. troscopic andpropermotiondataontheseperipheral these peripheralHHobjectsareexcitedbymorelocal acceleration hasdistributedtheHHobjectstosuch tentatively suggestthatthe11outflowsareresponsible found within10'oftheoutflowsources,butbeyond excitation ofHHobjectsbythesamewindthatdrives molecular gasintheHH7-11andLI551flowsarenot asymmetric andoftenbipolarconfigurationsofhigh- optically emittingshocksandthelarge-scaleambient representative ofmosttheregionssurveyed.However, the molecularoutflow.ThelargenumberofHHobjects a directionalcoincidenceinradialvelocitybetweenthe tionships betweentheHHobjectsandhigh-velocity The 11high-velocitymolecularoutflowsinthevicin- We findthatthestrikingspatialandkinematicrela- Vol. 270 1983ApJ. . .270 . .605E -7_14 No. 2,1983 that havebeenfoundandthediscoveryoffourclosely may undergoaphaseofmasslosscharacterizedby estimate thatallstarswithmassesgreaterthan1M spaced pairsofhigh-velocityflowsseparatedbyless lar cloud. evolution ofyoungstarsandtheirsurroundingmolecu- M>10 Myrforaperiodofatleast10 than 1pcindicatethattheseoutflowsarecommon.Our suggests thatthesemasslosseventsareimportantinthe 0 0 Bechis, K.P.,Harvey,P.M,Campbell,M.F.,andHoffman, Bally, J.,andPredmore,R.1983,Ap.265,778. 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