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Mon.Not.R.Astron.Soc.000,1–7(2006) Printed5February2008 (MNLATEXstylefilev2.2) l > 0o New Planetary Nebulae in the Galactic bulge region with - II. P. Boumis1⋆, S. Akras1,2, E. M. Xilouris1, F. Mavromatakis3, E. Kapakos2, J. Papamastorakis2,4, and C. D. Goudis1,5 1InstituteofAstronomy&Astrophysics,NationalObservatoryofAthens,I.Metaxa&V.Paulou,GR–15236P.Penteli,Athens,Greece. 2DepartmentofPhysics,UniversityofCrete,P.O.Box2208,GR-71003Heraklion,Crete,Greece. 6 3TechnologicalEducationInstituteofCrete,GeneralDepartmentofAppliedScience,P.O.Box1939,GR-71004Heraklion,Crete,Greece. 0 4FoundationforResearchandTechnology-Hellas,P.O.Box1527,GR-71110Heraklion,Crete,Greece. 0 5AstronomicalLaboratory,DepartmentofPhysics,UniversityofPatras,GR-26500Rio-Patras,Greece. 2 n a J Accepted2006January9;Received2005December28;inoriginalform2005July27 9 1 ABSTRACT v 8 Thepresentationofnewresultsfroman[OIII]5007A˚ surveyinasearchforplanetarynebulae 7 (PNe) in the galacticbulge is continued.A total of 60 objects,including19 new PNe, have 1 been detected in the remaining 34 per cent of the survey area, while 41 objects are already 1 0 known.Deep Hα+[N II] CCD imagesaswellaslow resolutionspectrahavebeenacquired 6 fortheseobjects.Theirspectralsignaturessuggestthatthedetectedemissionoriginatesfrom 0 photoionizednebulae.Inaddition,absoluteline fluxeshavebeenmeasuredandthe electron / densitiesaregiven.Accurateopticalpositionsandopticaldiametersarealsodetermined. h p Keywords: surveys–planetarynebulae:general-Galaxy:bulge. - o r t s a 1 INTRODUCTION Information concerning the [O III]survey (observations and : v analysis)aregiveninsect.2,whileinsect.3thefollow-upobserva- This is the second of a series of papers presenting optical imag- i tionsarepresented(CCDimagingandspectroscopy)ofthenewly X ingandspectrophotometricresultsonnewlydiscoveredplanetary discoveredPNe.Inaddition,fluxmeasurements,diameterdetermi- r nebulae.InPaperI(Boumisetal.2003),thediscoverymethodand nation,accuratepositionsandotherphysicalpropertiesforthenew a firstresultsonthe[O III]5007A˚ survey,inthenorthernGalactic PNeare given is sect. 4. In an forthcoming paper (Paper III – in bulge,werepresented. preparation),wewillpresentphotoionizationmodellingappliedto PNearepowerfultracersofour Galaxy’sstarformationhis- thenewPNe,inordertogainmoreinsightintotheirphysicalpa- tory (Paper I; Beaulieuetal. 2000 and references therein). The rameters.Inparticular,fluxcalibratedimagesformostofthenew studyofPNecanprovideinsighttothelatestagesofstellarevolu- PNetogetherwiththeirspectroscopicresultswillbeusedinaPNe tion,thenucleosynthesisinlowandintermediatemassstars(1M⊙ photoionization model (CLOUDY;e.g.vanHoof&vandeSteene to8M⊙) and thechemical evolution ofgalaxies. Whenalow or 1999). intermediatemassstarisclosingtoitsend,itgoesthroughthered– giant (RG) phase, followed by a heavy mass–loss period known as theasymptotic–giant–branch (AGB) stage. Finally, it becomes awhite–dwarf(WD)surroundedbyaplanetarynebula(PN)made 2 THE[OIII]5007A˚ SURVEY upofionizedgasfromearlierstagesofmass–loss. PNeneartheGalacticcentercanbeconsideredtolie,roughly, 2.1 Observations&Results at the same distance. Approximately 500 PNe have been dis- The observations were performed with the 0.3 m Schmidt- covered up to now, while ∼ 3500 have been discovered in Cassegrain (f/3.2) telescope at Skinakas Observatory in Crete, our Galaxy (Paper I and references therein; Parkeretal. 2003, Greece in June 14–23 & 26–28 and July 16–20, 2001. An 2005a,b; Jacoby&vandeSteene 2004). These numbers are con- [OIII]5007A˚ interferencefilterwithan28A˚ bandwidthwasused sideredsmallwhencomparedwiththatgenerallyexpected(15000 incombinationwithaThomsonCCD(1024×1024).Thisconfigu- to30000;Ackeretal.1992a;Zijlstra&Pottasch1991).Therefore, rationresultsinascaleof4.12arcsecpixel−1 andafieldofview ourGalaxyandespecially,theBulgeareaiswellsuitedtosearch of71×71arcmin2 onthesky.Inoursurveyweobservedthere- fornewPNe. gions 10o < l < 20o, −10o < b < −3o and 0o < l < 20o, 3o < b < 10o (FieldsAand BinFig.1- totalcoverage onsky ∼220 square degrees). The filled dark rectangles in Fig. 1 repre- ⋆ e-mail:[email protected] sent the observed fields. The remaining region of 34 per cent of 2 P.Boumiset al. theproposedgrid(63fieldsoutof179)iscovered,whichwasnot thecentreofeachimageandanarrowpointstotheirexactposition. observed because of the availability of the telescope. All targets Theimagesizeis150arcseconbothsides.Northistothetopand wereobservedbetweenairmass1.4to2.0insimilarobservingand easttotheleft.Thefollow–upobservationswereperformedinthe seeing(1–2arcsec)conditions. Hα+[N II] filter to study the morphology of the PNe candidates Two exposures in [O III] 5007 A˚ of 1200 s and three expo- andmeasuretheirangularextent. suresinthecontinuum,eachof180s,wereobtainedtoidentifyand FollowingtheidentificationofthePNecandidates, anastro- removeanycosmicrayhits.Twodifferentcontinuumfilterswere metricsolutioninallimageswasperformedusingthemethodpre- used, depending ontheiravailability.Detailsabout thefilters,the sentedinPaperI.Thus,thecoordinatesofthePNecandidateswere selectioncriteriaandthedetectionmethodaregiveninPaperI.Af- calculatedwithimprovedaccuracy.Thetypicalrmserrorintheas- teradetailedandsystematicvisualinvestigationoftheremaining trometricsolutionswasfoundtobe∼0.3arcsec.NotethatthePN 63fields,60objectswereidentified.Imagesoutliningtheanalysis positionalestimatesareexpectedtobeaccurateto0.5to1.0arcsec. procedurethroughthevariousstepscanbefoundinPaperI. ThecoordinatesofallnewPNecandidatesaregiveninTable1. AfteridentifyingthePNecandidates,apreliminaryastrometry solutionwasobtainedforallimagescontainingoneormorecan- didates (seePaper I for details). Sixty(60) objects weredetected 3.2 Spectroscopy in these images. In order to identify the already known PNe, we Lowdispersionspectrawereacquiredwiththe1.3mtelescopeat usedup–to–datepublishedcataloguesrelatedtoplanetarynebulae SkinakasObservatoryduring2002inJune24–28,July16–17,23– (see Table 3 in Paper I). The search showed that among the ob- 25 and August 12, 20–25. A 1300 line mm−1 grating was used jects found in our survey, 41 of them are known PNe, while 19 inconjunctionwitha2000×800SITeCCDcoveringwavelengths objects are new PNe candidates. Note that independent work by from 4750A˚ to 6815A˚. This range was selected in order to ob- Parkeretal. (2003, 2005b) resulted in a new catalogue of PNe, servesimultaneouslytheHβ,theHαandthesulphurlinesinasin- where 9 of our new PNe candidates are included as new or can- glespectrumwithacceptableresolution.Unfortunately,thishard- didatePNe(seeTable1). wareconfigurationdoesnotallowthecoverageofawiderrangeof As in Paper I, a search in the IRAS Point Source Catalog wavelengths as wellas thevelocity determination. Theslit width (1988) wasperformedforthepresenceofdustatthepositionsof was 7.7 arcsec and it was always oriented in the south–north di- thenew PNecandidates. Thecorrelationrevealed 4matches (see rection. Note that the ∼1A˚/pixel and the dispersion of 1300 line Table1).Takingintoaccounttheirlowfluxqualitydensity,area- mm−1 result in a resolution of ∼8 A˚ and ∼11A˚ in the red and sonable number of themsatisfythestandardcriteria(F12/F25 6 bluewavelengths, respectively. Theexposure timeof theindivid- 0.35 and F25/F60 > 0.3 – Pottaschetal. 1988; vandeSteene ualspectrarangesfrom3600to3900 sdepending ontheobserv- 1995) used to consider a new object as a probable PN. A cross– ingwindowofeachobject.Thespectrophotometricstandardstars check of our new PNe list was also performed with the 2MASS HR5501, HR7596, HR9087, HR718, and HR7950 (Hamuyetal. PointSourceCatalog(2000),theMSXinfraredastrometricCata- 1992)wereobservedfortheabsolutecalibrationofthespectra.The log(Eganetal.1999)andtheradioknownPNecatalog.However, low resolution spectra were taken on the relatively bright optical theresultswerenegativeanditmaybethatthelowsensitivityof partofeachPNcandidate. Theactual spectracanbeseeninFig. these surveys prevented a positive identification. In a very recent 3, while in Table 3 the line fluxes, corrected for interstellar red- paper,Luoetal.(2005)presentedradioidentificationsfor315re- dening, are given. The interstellar extinction c(Hβ) and observa- centlydiscoveredPNeusingthe1400MHz(NVSS)images.Since tionalreddeningEB−Vwerederivedusingtheequationspresented theradiocataloguewasjustpublished,allournewPNe(including inPaperI.Duetothehighinterstellarextinctioninthedirectionof thoseofPaperI)wereexamined.Adetailedcheckofthiscatalogue thebulge,asecondestimationofEB−V wasmadeusingtheSFD showedthatthereisapossibilityofcorrelationbetweentheradio code(Schlegel,Finkbeiner&Davis1998).Thecomparisonshows sourcesandanumberofournewPNe.FollowingLuoetal.(2005), ageneralagreement betweenthetwoEB−V calculationswithina iftheoffsetbetweentheopticalandtheradiopositionislessthan 3σerror.Thesignaltonoiseratiosdonotincludecalibrationerrors, 20′′,theradiosourceisprobablyidentifiedwithaPN,whileoffsets which,typically,arelessthan10percent.TheabsoluteHαfluxes lessthan10′′areconsideredpositiveidentifications.Therefore,15 (inunitsof10−16 ergs−1 cm−2 arcsec−2),theexposure timeof ofournewPNewereidentifiedwithradiosources.InTable2,we each individual spectra, the interstellar extinction c(Hβ) with its presentthecoordinatesoftheradiosources(Luoetal.2005)which estimatederrorandthereddeningEB−V(resultingfromourobser- probablycorellatewithourPNe,theirmeasuredradiofluxandthe vationsandSFDmaps)arelistedinTable4. differenceinarcsecondsbetweentheopticalandtheradiocentres. 4 DISCUSSION 3 THE1.3METERTELESCOPEOBSERVATIONS TheHα+[NII]imagesaswellasthelowresolutionspectraofthe newly discovered PNe candidates were used for a more detailed 3.1 Imaging study.InFig.4(a),theIRAScolour–colourdiagramisplottedfor OpticalimagesofthenewPNecandidateswerealsoobtainedwith 13ofourobjects(includingtheseofPaperI)overlaidonthecor- the 1.3 m (f/7.7) Ritchey-Cretien telescope at Skinakas Observa- respondingcolour–colourplotofknownPNe(Ackeretal.1992b), toryduring2002inMay19–21, June10–14usinganHα+[N II] forcomparisonreasons.TheknownPNeusedinthisdiagrampos- interferencefilter(75A˚ bandwidth).Thedetectorwasa1024×1024 sessgoodfluxquality(filledcircles)andpoorquality(openrectan- SITeCCDwithafieldofviewof8.5×8.5arcmin2.Oneexposure gles).Itseemsthatthenewobjectsbelong,orareclose,tothere- intheHα+[NII]filterof1800sandtwoexposuresinthecontin- gionofPNeaccordingtothecriteriapresentedinSect.2.1.Inaddi- uum,eachof180s,weretaken.AllnewPNecandidatesobserved tion,thediagnosticdiagramoflog(Hα/[NII])vs.log(Hα/[SII])of withtheHα+[NII]filtercanbeseeninFig.2.Notethattheyareat Garciaetal.(1991),togetherwithourmeasuredrelativelinefluxes NewPNe intheGalacticbulge– II 3 Table1.NewlydiscoveredPNe. Object PNG RA Dec IRASsource F12 F25 F60 F100 FQuality Refa (lll.l±bb.b) (J2000) (J2000) (Jy) (Jy) (Jy) (Jy) (12,25,60,100µm) PTB26 008.3+09.6 172913.1 −164742.6 1b PTB27 008.4−02.8 181512.7 −230103.8 2a PTB28 008.6+06.7 174021.1 −180508.9 17374−1803 4.71 2.97 0.51 4.32 3,3,1,1 PTB29 008.7−04.2 182108.2 −232356.9 2a PTB30 010.1+04.4 175146.6 −180405.0 1a PTB31 011.0−02.9 182053.7 −204810.9 18179−2049 0.36 0.67 3.1 88.6 1,3,3,1 1b PTB32 011.3−09.1 184510.2 −232139.7 PTB33 011.4−05.3 183041.9 −213151.0 2b PTB34 011.8−05.0 183007.7 −210502.6 PTB35 012.1−02.6 182143.7 −193945.7 1a PTB36 013.2−05.0 183245.3 −194932.2 1a PTB37 013.7−04.7 183234.6 −191403.7 1a PTB38 013.8−02.0 182304.3 −175331.5 18201−1755 1.58 1.05 22.4 258 1,3,1,1 PTB39 014.2−03.4 182900.2 −181046.2 PTB40 014.3−07.2 184339.6 −194830.9 PTB41 014.8−02.7 182726.6 −172410.0 PTB42 015.3−03.3 183022.9 −171153.7 PTB43 016.6−04.0 183555.8 −162120.5 18330−1623 1.14 1.46 4.4 68.8 3,3,1,1 PTB44 016.9−09.7 185739.8 −183616.0 aIndependentlydiscoveredbyParkeretal.(2003,2005b)asnewPNe(1a,2a)andcandidatePNe(1b,2b). Table2.Radiosources(Luoetal.2005)whichprobablyarecorrelatedwiththenewPNe.NotethatradioidentificationforthePNeofPaperIcanalsobe seen. Object RAa Deca S1.4GHz differenceb (J2000) (J2000) (mJy) (arcsec) PTB01 174338.88 -243158.2 4.3 6.81 PTB05 174138.97 -214433.9 4.5 4.19 PTB11 181340.63 -235738.0 2.7 5.93 PTB12 174715.74 -195723.3 2.3 4.76 PTB13 175107.74 -192540.8 3.0 14.8 PTB15 17575.85 -171105.5 2.2 5.51 PTB17 175710.61 -155620.5 3.7 3.55 PTB19 175826.35 -142522.6 8.5 5.66 PTB20 175214.97 -111037.6 7.6 2.05 PTB23 183151.05 -141519.6 10.9 10.3 PTB25 183204.70 -132616.3 5.9 3.86 PTB26 172912.73 -164745.7 2.4 6.20 PTB27 181513.07 -230105.2 3.2 13.5 PTB30 175144.84 -180425.5 3.8 32.5 PTB31 182053.71 -204813.6 15.0 2.74 PTB32 184511.09 -232121.7 2.9 21.7 PTB34 183008.17 -210510.1 3.6 10.0 PTB35 182143.32 -193944.5 2.5 5.52 PTB38 182304.51 -175336.2 10.1 5.52 aRA,Decoftheradiosource. bDifferencebetweentheopticalandtheradiocentre. confirmthephotoionizationorigin(Fig.4(b))ofthecandidatePNe. scopeandwereestablishedwiththemethoddescribedbelow.This The[SII]/Hαratiosareinallcaseslessthan0.3.Nineofthemdis- method was applied because, especially for the faint PNe, it was playverylowS/Nratiointheir[NII]and[SII]emissionlinesand difficult to accurately calculate the diameters because their outer arenotpresentedinTable3.However,their[SII]/Hαislessthan areaswere below the 3σ level inthe original images. Inthe case 0.2. of elliptical shells, the major and the minor axes are given. The methodusedtodeterminetheangulardiametersinvolvesthecon- Theangular diametersofthenewPNecandidateshavebeen versionoftheirintensityvaluesinascalerangingfrom0to1000. measuredintheHα+[N II]imagesacquiredwiththe1.3mtele- 4 P.Boumiset al. In particular, for intensities higher than 85% of the maximum, a lar arise from higher mass stars, while elliptical originate from a valueof1000wasassigned,whileforvaluesbetween65%to85%, rangeofmassesoftheprogenitors.Furthermore,themorphologi- 50%to65%, 35% to50%, 20%to35%, 10% to20%and below caldifferencescanalsobeattributedtothePNstageofevolution. 10%ofthemaximumintensity,valuesof800, 600,400, 200,50, Compactnebulaeintheirfirststagesofexpansionappearstellarand 25 were given. The advantage of this transformation is that hav- relativelybright,whilelargenebulaewithfaintsurfacebrightness ing this wide range of values, the intensity of the object can be areintheirlateevolutionarystage. distinguishedfromtheskybackgroundwithmuchbetteraccuracy, Following the procedure described in Paper I and assuming and consequently, their outer part can be clearly determined. For a temperature of 104 K (Cuisinieretal. 2000), an estimation of PNe with well defined outer edges (i.e. with a steep drop-off of the electron density n was made, with the “temden” task of [SII] thesurfacebrightness),itwaseasytomeasurethediameterusing the “nebular” package in IRAF, for each specific Sulfur line ra- either the original Hα+[N II] image or the above method. How- tio ([S II] 6716A˚/[S II] 6731A˚). The electron densities and their ever, in case of faint PNe the direct use of the images results in associated errors are given in Table 4. In addition, using the ob- largererrorscomparedtothismethod.Thiswasalsodemonstrated served[NII]6548+6584A˚/[N II]5755A˚ ratios,anestimateofthe byRuffleetal.(2004)(andreferencestherein)whoshowedthatthe electrontemperatureT wasmade,wheneverpossible.Infact, [NII] fluxdropsveryfastbetweenintensitylevelsintheintervalof15to onlyforthreeofournewPNetemperaturescloseto10000Kwere 5per cent of thepeak surface brightness andtherefore, itishard found. ThehighinterstellarextinctiontowardstheGalacticbulge todeterminetheactualboundaryofthePN.Inourcase,valuesbe- aswellasthelowsurfacebrightnessformanyofthenewPNepre- tween10to20percentofthepeaksurfacebrightnesscontourwere ventedtheregistrationofhighqualityspectra.Thisaffectsmainly selectedinordertomeasurethediameterofeachobjectandinall thelowerintensitylineslike[SII]orHeII5411&6234A˚,which casestheestimatednumbersaregreaterthanthe3σlimit.Anexam- are faint or even undetectable. For all the PNe candidates in our pleofthemethodisshowninFig.5,whereanenlargementofthe survey,Hα,[OIII]andHβ emissionlinescouldbemeasuredand originalHα+[N II]imageofPTB34canbeseeninFig.5(a).The inmostcases,[NII]6548&6584A˚.However,thespectraofsome image of the same PN is shown in Fig.5(b), which is derived by ofthenewPNe(e.g.PTB36)havealowsignaltonoiseandonly applying the method described above. The angular diameter was Hβ,Hαand[OIII]arewelldetermined.SincethesePNearefound measured in both images but the results from the second image inaregionof significantextinctionshorter wavelengthsaremore weremoreaccurate.Theresultingimageswerealsousedtodeter- affectedthanlongerwavelengths. minethemorphologicaltypeofeachPN.Alldimensionsaregiven InTable3welistthefluxes,measuredinourlong–slitspectra, inTable4.ThirteenofthenewPNearecharacterizedbydiameters correctedforinterstellarextinction,whereitisevidentthatalmost less than 20 arcsec (Bulge limit – Gathieretal. 1983), three are allPNedisplayverystrong[OIII]5007A˚ emissionrelativetoHα. closetothislimit,and threeby diameters greater than30 arcsec. ItisknownthattheN/OandHeabundancesreflectthemassdis- Thepossibilitythatthelatteraremoreevolved and/or arenearby tributionoftheprogenitor star,withmoremassiveobjectshaving cannotbeexcluded. higherN/OandHeabundancesincomparisonwiththelow–mass ThedistributionofthenewPNe(a)ingalacticlatitudeand(b) objects(Cuisinieretal.2000).Inourcase,theabundancesinN/O inangulardiametershowsastrongconcentrationtowardsthebulge andHearegenerallylowimplyingoldprogenitorstars.Thelatter andespecially,when−6o < b < 6o andbetween4to20arcsec. suggests that they belong to the Galactic bulge region according BothresultsareinagreementwithwhatisexpectedforPNeinthe toWebster(1988)andCuisinieretal.(2000).Bothauthorsshowed Galacticbulge.Notethatduetothehighinterstellarextinctionno thattheGalacticbulgePNeoriginatefromoldprogenitorswithlow observationswereperformedintherange−3o < b < 3o,while, N/O and He abundances. The excitation classes of our new PNe due to the limited resolution of the survey observations, objects werestudiedaccordingtotheclassificationcriteriaofAller(1956), withdiameterssmallerthan4arcseccouldnotbeidentified. Feast(1968)andWebster(1975).Theyarederivedbasicallyfrom AmorphologicaltypewasassignedtothenewPNe(Table4) theratiosof[OIII]/Hβ,HeII4686A˚/Hβ,[OII]3727A˚/[OIII]4959 accordingtotheclassificationofManchadoetal.(2000).Approx- A˚ andHeII4686A˚/HeI5876A˚.Inourcase,followingtherelation imately,28percentofthenewPNedisplayspherical,well-defined 2.1aofDopita&Meatheringham(1990),the[OIII]/Hβratiosug- shells, 42 percent appear elliptical and therest are bipolar or un- geststhat our new PNebelong tothe low (2–4) and medium (4– clear. The different morphological PNe classes seen in our sur- 6)excitationclasses.ItisonlyPTB42showinganexcitationclass veycanbefoundinBoumis&Bryce(2004).ObjectslikePTB34, greater than 6and therefore, it must be highly ionized. However, PTB36 display a ring–like structure, while for example, PTB26, theHeII4686A˚ and[OII]3727A˚ emissionlinesareoutsidethe PTB32 posses incomplete bright shells. Bright compact nebulae observed range due to the hardware configuration (see Sect. 3.2) like PTB28, PTB38, PTB42, PTB43 are also detected. However, and thus, it is not possible to better confine the actual excitation theirmorphologicaltypecannotberesolvedclearlywiththecurrent classofeachPN. data.Moreover,themorphologicalclassofsomePNecouldnotbe determinedunambiguouslyandeventhough,thesehavebeenclas- sifiedasround,thepossibilitythattheyareellipticalcannotberuled 5 CONCLUSIONS out.Theelectrondensitieswerefoundtobedifferentforeachmor- phologicalclass.Themedianvalueforellipticalsishigherthanthat Wepresentedresultsfromthenarrowband[OIII]5007A˚ survey forroundandbipolarPNe.Also,atafirstglancethe[NII]/Hαand ofPNeintheGalacticbulge(l > 0o).Coveringtheremaining34 N/Oratiosarehigher forround thanfor ellipticalPNe.Themor- percent of our selected region, we detected 60 objects, including phologyofPNeprovidestheopportunitytoobtainabetterunder- 41knownPNeand19newPNe.Hα+[NII]imagesaswellaslow standingoftheevolutionofstars.Itisgenerallyacceptedthatthe resolutionspectraofthenewPNeweretakenwhichconfirmedthe differentPNemorphologiesareattributedtoprogenitorsofdiffer- photoionized natureof theemission. About 84percent of thede- entmasses.AccordingtoPhillips(2003)(andreferencestherein), tectedobjectshaveangular sizes6 20–25 arcsec, whileallshow circularPNearisefromstarswithlowmassprogenitors,thebipo- Hα/[OIII]5007A˚ ratioslessthan1.Four(4)ofournewPNeare NewPNe intheGalacticbulge– II 5 Table3.Linefluxes. Line(A˚) PTB26 PTB27 PTB28 PTB29 PTB30 PTB31 PTB32 Hβ4861 100(45)a 100(21) 100(26) 100(21) 100(14) 100(25) 100(15) [OIII]4959 49(33) 330(42) 312(52) 233(37) 252(24) 203(40) 159(26) [OIII]5007 154(54) 926(78) 864(90) 725(70) 770(43) 601(73) 455(65) HeII5411 − − − − − − − [NI]5200 − − 16(11) − − − − [NII]5755 − − 4(4) − − − − HeI5876 15(26) − 15(14) 11(10) − 14(15) 15(7) HeII6234 − − − − − − − [OI]6300 − 4(12) 32(34) − − − − [SIII]6312 − − 8(10) − − − − [OI]6363 − − 8(11) − − − − [ArV]6435 − − − − − − − [NII]6548 34(50) 5(20) 65(42) 20(14) − 5(17) 79(43) Hα6563 285(147) 285(129) 285(98) 285(84) 285(60) 285(177) 285(86) [NII]6584 90(85) 12(28) 210(85) 65(36) 16(12) 12(31) 236(81) HeI6678 5(13) − 7(8) − − 4(15) 5(8) [SII]6716 22(34) 4(20) 41(27) 9(11) − 2(9) 36(27) [SII]6731 15(28) 3(18) 44(30) 7(9) − 2(7) 27(22) Line(A˚) PTB33 PTB34 PTB35 PTB36 PTB37 PTB38 PTB39 Hβ4861 100(11) 100(61) 100(26) 100(13) 100(16) 100(17) 100(35) [OIII]4959 200(23) 207(100) 240(54) 303(33) 231(30) 429(65) 389(77) [OIII]5007 637(44) 611(182) 711(100) 919(63) 643(57) 1242(125) 1130(140) HeII5411 − 8(25) − − − − − [NI]5200 − − − − − − − [NII]5755 − − − − − − − HeI5876 9(5) 4(19) 6(14) − − 16(22) 13(29) HeII6234 − − − − − − − [OI]6300 − − 7(22) − − 5(12) − [SIII]6312 − 2(8) − − − 2(5) − [OI]6363 − − 3(16) − − 2(3) − [ArV]6435 − 1(7) − − − − − [NII]6548 38(16) 0.4(8) 184(142) − − 9(32) 2(11) Hα6563 285(47) 285(250) 285(195) 285(76) 285(85) 285(225) 285(190) [NII]6584 105(28) 2(8) 569(255) − − 29(72) 3(16) HeI6678 − 2(15) 5(19) − − 3(16) 2(14) [SII]6716 30(12) 0.8(9) 20(41) − − 3(13) − [SII]6731 27(10) 0.6(8) 15(33) − − 6(23) − Line(A˚) PTB40 PTB41 PTB42a PTB43a PTB44 Hβ4861 100(25) 100(24) 100(24) 100(45) 100(35) [OIII]4959 376(57) 212(43) 895(89) 238(80) 363(51) [OIII]5007 1146(103) 609(79) 2620(161) 710(147) 1085(96) HeII5411 − 9(8) 5(6) − − [NI]5200 − − − − − [NII]5755 − − 44(32) 3(13) − HeI5876 4(8) − 13(12) 19(44) − HeII6234 − − − − − [OI]6300 − − 20(21) 3(18) − [SIII]6312 − − − 5(23) − [OI]6363 − − − − − [ArV]6435 − − − − − [NII]6548 − − 182(83) 5(32) − Hα6563 285(101) 285(140) 285(99) 285(219) 285(89) [NII]6584 − 2(4) 607(147) 16(65) 10(8) HeI6678 − − 4(8) 4(25) − [SII]6716 − − − 1(11) − [SII]6731 − − − 2(16) − aNumbersinparenthesesrepresentthesignaltonoiseratioofthelinefluxes,measuredatthecenterofthecorrespondingemissionlineprofile. AllfluxesarenormalizedtoF(Hβ)=100andarecorrectedforinterstellarextinction. 6 P.Boumiset al. Table4.Exposuretimeandbasicphysicalparameters. Object Exp.time1 Diameter2 M.Type3 F(Hα)4 c(Hβ)5 σ6 E7 σ8 E9 n10 σ11 c(Hβ) B−V(OBS) EB−V B−V(SFD) [SII] n[SII] PTB26 3600 28.5×16.0 B 5.8 0.62 0.03 0.43 0.02 0.39 <0.07 − PTB27 3600 12.0 R 4.7 1.86 0.10 1.29 0.07 1.45 0.36 0.15 PTB28 3600 4.5 − 4.1 0.69 0.05 0.48 0.03 0.48 0.65 0.03 PTB29 3600 37.0×34.0 E 7.4 0.92 0.04 0.64 0.03 0.66 0.16 0.03 PTB30 3600 26.0 R 2.1 1.57 0.15 1.08 0.10 0.99 − − PTB31 3900 15.5 R 10.7 2.72 0.14 1.88 0.10 1.91 0.67 0.33 PTB32 3600 135.0×115.0 E 1.5 0.74 0.11 0.51 0.08 0.39 <0.07 − PTB33 3600 17.0 R 2.0 0.58 0.11 0.39 0.08 0.49 0.38 0.07 PTB34 3900 12.5 R 36.6 1.08 0.02 0.74 0.01 0.71 <0.07 − PTB35 3900 15.0×11.5 E 16.6 1.89 0.05 1.31 0.03 1.47 <0.07 − PTB36 3900 22.0 B 2.5 1.02 0.16 0.71 0.11 0.62 − − PTB37 3900 16.0×14.0 E 4.3 1.01 0.07 0.71 0.05 0.68 − − PTB38 3900 5.5 − 20.7 2.47 0.10 1.71 0.07 2.07 27.0 4.7 PTB39 3900 8.0×6.5 E 12.0 1.46 0.03 1.01 0.03 1.01 − − PTB40 3900 11.5×10.0 E 10.9 0.99 0.06 0.69 0.04 0.46 − − PTB41 3600 10.5×8.0 E 11.2 1.72 0.06 1.19 0.03 1.08 − − PTB42 3600 4.0 − 12.7 1.41 0.04 0.98 0.03 0.69 − − PTB43 3900 5.0 − 26.6 1.24 0.02 0.86 0.01 0.62 4.4 1.09 PTB44 3900 58.0 E 4.5 0.92 0.04 0.64 0.03 0.24 − − 1Totalexposuretimeinsec. 2Opticaldiametersinarcsec. 3MorphologicalclassificationaccordingtoManchadoetal.(2000),whereR(=round),E(=elliptical)andB(=bipolar). 4AbsoluteHαfluxinunitsof10−16ergs−1cm−2arcsec−2. 5LogarithmicextinctionatHβ(seeSect.3.2). 61σerroronthelogarithmicextinction. 7Observedreddening(seeSect.3.2). 8Errorontheobservedreddening. 9ReddeningaccordingtothemapsofSchlegeletal.(1998)(seeSect.3.2). 10Electrondensityinunitsof103cm−3(seeSect.5). 11Errorontheelectrondensity. foundtobeassociatedwithIRASsources.Radiosourcesforfifteen REFERENCES (15) ofour new PNe(including thoseofpaper I)wereidentified. Acker,A.,Cuisinier,F.,Stenholm,B.&Terzan,A.,1992a,A&A, All new PNe display low N/O and He abundances implying old 264,217 progenitorstars,whichisoneofthecharacteristicsoftheGalactic Acker, A., Ochsenbein, F., Stenholm, B., Tylenda, R., Marcout, bulgePNe.Inaforthcomingpaper(paperIII),theuseofthepho- J. & Schohn, C., 1992b, in the Strasbourg-ESO Catalogue of toionizationmodel CLOYDYwillprovideadeeper insight tothe GalacticPlanetaryNebulae,Parts1and2(Strasbourg:ESO) physicalparametersofthenewPNe.Theinformationpresentedin Aller,L.H.,1956,GaseousNebulae(NewYork:Wiley) papersIandII,alongwiththeresultsthatwillbeobtainedfromthe Beaulieu,S.F.,Freeman,K.C.,Kalnajs,A.J.,Saha,P.&Zhao, CLOUDYmodelwillofferavaluabletooltostudiesofthedynam- H.,2000,AJ,120,855 icsandkinematicsoftheGalacticbulge. Boumis, P., Paleologou, E. V., Mavromatakis, F.& Papamas- torakis,J.,2003,MNRAS,339,735(PaperI) Boumis,P.&Bryce,M.,2004,inASPConf.Ser.31,Asymmetri- calPlanetaryNebulaeIII:Winds,StructureandtheThunderbird, eds.M.Meixner,J.H.Kastner,B.Balick&N.Soker.,3,26 ACKNOWLEDGMENTS Cuisinier,F.,Maciel,W.J.,Ko¨ppen,J.,Acker,A.&Stenholm,B., 2000,A&A,353,543 The authors would like to thank the referee Q. Parker for Dopita,M.A.&Meatheringham,S.J.,1990,ApJ,357,140 his comments and suggestions and for providing us the Edin- burgh/AAO/Strasbourg Catalogue of Galactic Planetary Nebulae Egan,M.P.,etal.,1999,inAstrophysicswithInfraredSurveys,A andtheMacquarie/AAO/StrasbourgHαPNCatalogue.Wewould PreludetoSIRTF,ed.M.D.Bicay,R.M.Cutri,&B.F.Madore, alsoliketothankA.AckerforprovidingustheFirstSupplementto ASPConf.Ser.,177,404 theStrasbourg–ESOCatalogueofGalacticPlanetaryNebulae.The FeastM.W.,1968,MNRAS,140,345 helpofE.Semkov,G.Paterakis,A.KougentakisandA.Strigachev Garc´ıa-Lario,P.,Manchado, A.,Riera,A.,Mampaso, A.&Pot- duringtheseobservationsisacknowledged.SkinakasObservatory tasch,S.R.,1991,A&A,249,223 isacollaborativeprojectoftheUniversityofCrete,theFoundation Gathier, R., Pottasch, S. R.,Goss, W. W.& van Gorkom, J. H., forResearchandTechnology-Hellas,andtheMax-Planck-Institut 1983,A&A,128,325 fu¨rextraterrestrischePhysik. Hamuy,M.,Walker,A.R.,Suntzeff,N.B.,Gigoux,P.,Heathcote, NewPNe intheGalacticbulge– II 7 GALACTIC BULGE REGION R.A. h h h 19 18 17 50 40 30 20 10 50 40 30 20 10 =75’x75’ −2.5 Previous =field o −5o l=20 observed =Field observed −7.5 =galactic coordinates o −10 Dec o l=10 −12.5 o −15 −17.5 o −20 o l= 0 −22.5 o −25 b=−10o b=−3o b= 3o b=10o FIELD A FIELD B Figure1.Optical imagingsurveygridinequatorial coordinates. Galactic coordinates arealsoincluded (dashlines)topermitanaccurate drawingofthe selectedBulgeregion(boldsolidlines).Thedarkfilledandlightfilledrectanglesrepresenttheremainingobservedfieldandtheobservedfieldsintheyear 2000,respectively. S.R.&Phillips,M.M.,1992,PASP,104,533 Acker,A.,Morgan,D.,Beaulieu,S.,Morris,R.,&Cohen,M., IRASPointSourceCatalog,Version2,1988,JointIRASScience 2005a,MNRAS,362,689 WorkingGroup(Washington,DC:GPO) Parker,Q.A.,Acker,A.,Frew,D.J.,Hartley,M.,Peyaud,A.E.J., Jacoby,G.H.,vandeSteene,G.C.,2004,A&A,419,563 Phillips,S.,Russeil,D.,Beaulieu,S.,Cohen,M.,etal.,2005b, Luo,S.G.,Condon,J.J.&Yin,Q.F.,2005,ApJS,159,282 MNRAS,submitted 2MASS Point Source Catalog, 2000, NASA/IPAC Infrared Sci- Phillips,J.P.,2003,MNRAS,340,883 enceArchive,JetPropulsionLaboratory(CaliforniaInstituteof Pottasch, S. R., Bignell, C., Olling, R. & Zijlstra, A. A., 1988, Technology) A&A,205,248 Manchado,A.,Villaver,E.,Stanghellini,L.&Guerrero,M.,2000, Ruffle,P.M.E.,Zijlstra,A.A.,Walsh,J.R.,Gray,M.D.,Gesicki, in ASP Conf. Ser. 199, Asymmetrical Planetary Nebulae II. K.,Minniti,D.&Comeron,F.,2004,MNRAS,353,796 FromOriginstoMicrostructures,eds.Kastneretal.,17 Schlegel, D. J., Finkbeiner, D. P.& Davis, M., 1998, ApJ, 500, Parker, Q. A., Hartley, M., Russeil, D., Acker, A., Morgan, D., 525 Beaulieu, S., Morris, R., Phillips, S. & Cohen, M., 2003, IAU vandeSteene,G.C.,1995,PhDthesis,Univ.Groningen Symposium No. 209, Planetary Nebulae: Their Evolution and vanHoof,P.A.M.&vandeSteene,G.C.,1999,308,623 Role in the Universe (Canberra, Australia, November 19 - 23 Webster,L.,1975,MNRAS,173,437 2001),p.41 Webster,L.,1988,MNRAS,230,377 Parker, Q.A.,Phillips,S.,Pierce,M. J.Hartley,M., Russeil,D., ZijlstraA.A.&PottaschS.R.,1991,A&A,243,478 8 P.Boumiset al. Figure2.Hα+[NII]imagesofallnewPNetakenwiththe1.3mtelescope.Thearrowspointtotheirposition.Theimageshaveasizeof150′′onbothsides. Northisatthetop,Easttotheleft. NewPNe intheGalacticbulge– II 9 Figure2.continued 10 P.Boumiset al.