An Atlas of STIS-HST Spectra of Seyfert Galaxies

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

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002 yaM 62 1v3765060/hp-ortsa:viXraAnAtlasofSTIS-HSTspectraofSeyfertGalaxies

P.F.Spinelli,T.Storchi-Bergmann,C.H.BrandtInstitutodeF´isica,UFRGS,PortoAlegre,RS,Brazil

patricia.spinelli@ufrgs.br

andD.Calzetti

SpaceTelescopeScienceInstitute,Baltimore,MD21218

Received

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

ABSTRACT

Wepresentacompilationofspectraof101SeyfertgalaxiesobtainedwiththeSpaceTelescopeImagingSpectrograph(HST-STIS),coveringtheUVand/http://www.77cn.com.cnrmationonalltheavailablespectrahavebeencollectedinaMastertable,whichisaveryusefultoolforanyoneinterestedinaquickglanceattheexistentSTISspectraforSeyfertgalaxiesintheHSTarchive,anditcanberecoveredelectronicallyattheURLaddresswww.if.ufrgs.br/ pat/atlas.htm.Nuclearspectraofthegalaxieshavebeenextractedinwindowsof0′′.2foranop-timizedsampling(asthisistheslitwidthinmostcases),andcombinedinordertoimprovethesignal-to-noiseratioandprovidethewidestpossiblewavelengthcoverage.Thesecombinedspectraarealsoavailableelectronically.

1.Introduction

SpectraobtainedwiththeSpaceTelescopeImagingSpectrograph(HST-STIS)provideuniqueinformationonthespectralenergydistribution(SED)ofactivegalacticnuclei(AGN),intwoaspects:thecoverageoftheultravioletspectralrange,whichisnotobservablefromtheground,andthehighangularresolutionwhichenhancesthecontrastbetweenthenuclearcontinuumandthatofthestarsofthehostgalaxies.NowthatSTIShasceasedtowork,itistimelytocompilethedataaccumulatedbyobservationswiththisinstrumentinanAtlas.Inthepresentworkweprovidesuchcompilationfor101Seyfertgalaxies.

WehaveusedthespectratoconstructnuclearSED’sofSeyfertgalaxiesobtainedfromextractionsatanoptimizedsampling,correspondingtoanaperture0′′.2×0′′.2,as0′′.2isthewidthoftheslitinmostobservations.Thesecombinednuclearspectraareavailable

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

electronically,andcanbeusedforanumberofstudies.ThesmallextractionwindowallowsustobetterisolatethenuclearSED,minimizingthecontaminationbythebulgeofthehostgalaxies.Thesespectracanbecomparedwithdataobtainedthroughlargeaperturesusinggroundbasedtelescopesinordertoevaluatethecontributionoftheofhostgalaxies,particularlyusefulwhenstudyingsamplesofdistantAGNs.Thesespectracanalsobeusedtoinvestigatethecontributionofothersourcesveryclosetothenucleus,suchasstarbursts(Storchi-Bergmannetal.2005;Gonz´alezDelgadoetal.2004).

AlthoughtheHSTarchiveprovidesone-dimensionalspectra,whichareidenti edbytheterminations

(1)The

sx1,ourAtlashasatleastthreeadvantages:

sx1areobtainedwithaextractionwindowof11pixelsfortheUV

correspondingto0′′.27,and7pixelsfortheoptical–correspondingto0′′.35.Therefore,theextractionwindowsintheUVanopticalaredi erentanddonotmakeoptimalusetheangularresolutionprovidedbyHST.Ourextractionwindowischosentohavethesameangularextentoftheslitwidth,0′′.2inallwavelengthranges,providingspectrawithbetterangularresolution.ForAGN,asmallerextractionwindowincreasesthecontrastbetweentheactivenucleusandthehostgalaxy.

(2)InmanycasestheHSTpipelinedoesnotperformaveragesofspectra.Thisisthecaseofthe

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

theavailablespectrawehavebeencollectedininaMastertable.Itcontainsforexample,initialand nalwavelengthsofthedi erentspectrasegments,exposuretimes,gratingsandslitwidth.ThisMastertableisbyitselfaveryusefultoolforanyoneinterestedinaquickglanceattheavailableSTISspectraforSeyfertgalaxiesintheHSTarchiveandcanberecoveredelectronicallyasthespectra.

Thispaperisorganizedasfollow:section2describesoursampleselection.Section3presentstheMastertableanddescribestheinformationcontainedinit.Theextractionofthespectraisdescribedinsection4andtheircombinationisexplainedinsection5.Theresultsandsomepotencialapplicationsarediscussedinsection6.

2.SampleandData

ThesamplewasinitiallyselectedasallSeyfertgalaxieslistedinthecatalogofV´eron-Cetty&V´eron(1996)withredshiftz≤0.03,whichhadSTISspectraavailableinthearchive.WehavelatertriedtoincorporatetheremainingSeyfertgalaxies(z≥0.03).Misclassi cation,however,mayhavepreventedacomprehensiveinclusionofallSeyfertgalaxiesintheHSTarchive.Thusoursamplecomprisesmostgalaxies(101inthetotal)classi edasSeyfertwithavailableSTISspectraintheHSTarchiveuntilSeptember2004.AlthoughthemostvaluablewavelengthrangeistheUVbecauseitisnotaccessiblefromtheground,wehaveincludedintheAtlasalsothosecasesinwhichonlyopticalspectrawereavailable.ThesamplegalaxiesarelistedinTable1,whichcontainsinformationonthepositions,Hubbletype,activitytype,redshiftandreferencestopreviousworksinwhichthespectrahavebeenused.TheseventhcolumnofTable1givesthespectralcoverage(intheobservedframe)oftheresultingnuclearspectrumaftertheindividualextractionsandcombinationofthedi erentspectralsegments.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

3.

TheMastertable

Relevantinformationaboutallthetwo-dimensional(hereafter2-D)spectracollectedissummarizedinaMastertable,availableelectronicallyintheURLaddresswww.if.ufrgs.br/ pat/atlas.htm.Thecolumnsofthetablecontainthefollowinginformation:(1)thenameofthegalaxy;(2)theidenti cationofallavailableSTISspectraforthisgalaxyintheHSTarchive,oneperline;(3)thegratingusedineachobservation;(4)theslitwidthofeachobservation;(5)thecentralwavelength(intheobservedframe);(6)theinitialwavelength(intheobservedframe);(7)the nalwavelength(intheobservedframe);(8)thespectralresolution;(9)theslitorientation;(10)theexposuretime.Incolumn(11)welisttheidenti cationoftheextractedspectrumfromeachsegment,whichwillbeusefulinafewcasesinwhichwecouldnotcombinethespectraofthesamegalaxy(forexample,becausetheywereobtainedindi erentslitpositions)andwethenprovidetheindividualextractedspectrawithoutcombiningthem.Thesespectraareidenti edaccordingtofollowingconvention:compactnameofthegalaxyfollowedbyanarbitraryorderingnumberandtheslitorientation.Forexample,n3516-13.97meansthe13thspectrumofthegalaxyNGC3516whichwasobtainedatslitorientationof97degrees.Finally,incolumn(12)welisttheplatescaleoftheobservations.InTable2wepresentaprintoutofafewselectedlinesoftheMastertable(whichhas1001lines),forillustrativepurposes.

4.Extractionofthespectra

Thenuclearspectrawereobtainedfrom2-DreducedSTISspectra,whichhavebeenrecti ed,wavelengthand uxcalibrated,andareidenti edintheHSTarchivebythesu xes

sx2.Thelatteraresummed

x2dand

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

available,weusedthelatter.

One-dimensional(hereafter1-D)spectrawereextractedfromthe2-Dspectrainwindowsof0′′.2fromalong-slitspectrumusuallyobtainedthroughaslitwidth0′′.2andcovering52′′inthesky.TheIRAFtaskapallwasusedtoperformtheextractions.Weperformedtheskysubtractionby ttingastraightlinetoregionsalongtheslitwithno(ornegligible)galaxycontribution.Foreachgalaxy,di erentskywindowswerede ned,inordertoavoidincludingcontributionfromthegalaxy.Theskylevelwasalwaysnegligible,exceptintheLymanalphaGeocoronalemissionline.

Althoughtheredshiftrangeforthesampleis0≤z≤0.37,onlyfor15%ofthegalaxiesz≥0.06,suchthatthe0′′.2aperturecorrespondsatthegalaxiestomorethan200pc.For60%ofthesample,0′′.2correspondsto<60pcatthegalaxies,whilefor30%ofthesampleitcorrespondsto<20pc.Wearethussamplingaverysmallregionaroundtheactivenucleus,providingthebestpossiblecontrastbetweentheAGNandgalaxybulge.

Weextractedonlynuclearspectrawhichweidenti edasbeingcenteredatthepeakofthecontinuum uxalongtheslit.Thiswasdonebyinspectingthespatiallightdistributioninaspectralregiondevoidofemissionorstrongabsorptionlines(thecontinuum)andcenteringtheextractionwindowatthepeakofthecontinuum uxdistribution.Inafewcasesthe2-Dspectracontainedonlyemission-lines,withnocontinuum.Inthesecases,forwhichwecouldnotidentifyacontinuumsourcewedidnotextractthespectra,buttheinformationontheavailable2-DspectraarestilllistedintheMastertable,withacautionarynoteexplainingwhythespectrahavenotbeenextracted.

Inthecasesforwhichthereweremorethanonecontinuumsourceweextractedthebrightestone.Althoughwecannotbeabsolutelysureforallcases,Seyfertgalaxiesareusuallythebrightestobject.Therearetwoexceptions,forwhichwedidnotextractthespectrabecausethetwosourceswereequallybright.Thesetwocaseshavealsobeen

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

identi edintheMastertablewithacautionarynote.

Afterextractingthespectra,forthegalaxieswhichhadmorethanoneexposureforeachspectralrange(andwiththesamespectralresolution,orientationandplatescale),weconstructedaveragestoimprovethesignal-to-noiseratio,eliminatingalsocosmic-raysandotherdefectswhendetected.Theaveragewasonlyconstructedaftercheckingalsoifthespectrahadsimilar uxlevel.FortheconstructionoftheaveragespectrawehaveusedthetaskscombineinIRAF,withtherejectionalgorithmavsigclipwhenthreeormorespectrawereavailableorminmaxwhentherewereonlytwospectra.ThisstepisillustratedinFig.1.

http://www.77cn.com.cnbinationofthespectra

The nalspectrawereobtainedbycombiningthedatafromthedi erentspectralrangesusingthesametaskscombineinIRAF,aftereditingoutnoisyregionsatthebordersofeachspectralsegment,andcheckingthattherewerenosigni cantdi erencesbetweentheir uxes.Wedidnot ndsuchdi erencesformostofthecasesinwhichtherewasasigni cantsuperpositionofadjacentspectralsegments.This nalstepisillustratedinFig.2.

InthecaseoftheSeyfert1galaxiesthereistheissueofvariability,sothatspectraobtainedindi erentdatesmayshowdi erent uxes,inlineandcontinua.Wehavecheckedthedatesandfoundonly vecasesofSeyfert1galaxieswithspectralsegmentsobtainedindi erentdates:NGC4151,NGC4258,PKS1739+184andAKN564.InthecaseofIRAS13224-3809,2ofthecombined7spectrawereobtainedonedaylatterthantheother5,thusthee ectofvariabilityshouldbeminimal.Wehaveidenti edthesecaseswithanoteinTable1andintheMastertable.Nevertheless,wedidnot ndanyobvious

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

discrepancyin uxeswhencombiningthedi erentspectralsegmentsofthesegalaxies.

Finally,wewouldliketopointoutthat,priortotheextraction,the uxunitswereergs 1cm 2 A 1arcsec 2(seeSTISDataHandbook).Whenweperformedtheextractionwithapalltosumoverafewpixels(0′′.2aperture)alongtheslitdirection,theextractedspectrumisinunitsequivalenttopixel×ergs 1cm 2 A 1arcsec 2.Then,inordertoconsistentlyprovidethe uxintegratedintheextractionwindow,inunitsofergs 1cm 2 A 1,wemultipliedeachsegmentbyafactorwhichistheproductoftheslitwidthandplatescale.Forexample,foronesegmentwithaslitwidthof0′′.2andplatescale0′′.024pixel 1,thefactoris0.0048arcsec 2pixel 1.Foranothersegmentwithplatescale0′′.05pixel 1,withthesameslitwidth,thefactoris0.01arcsec 2pixel 1.

6.Results

ThecombinedspectrapresentingthelargestspectralcoverageareshowninFigs.3and4.Thereareonly9galaxiesforwhichwecouldobtainthecompleteSTISUV-opticalspectralcoverage(～1000–10000 A).

InFigs.5,6and7weshowtheredshiftcorrectedspectraforthegalaxieswithAwavelengthrange,usefulforlookingforsignaturesofUVcoverageinthe1100–1600

starbursts.Inordertodothat,wehavedrawninthe guresverticallinesatthelocationsoftheabsorptionfeaturescharacteristicofstarbursts.Whilemostlinesareinterstellar,weidentifybyasteriskstheoneswhichoriginateintheatmosphereofyoungstars(Kinneyetal.1993;Vazquezetal.2004),whichareCIIIλ1175.65,NVλλ1238.81,1242.80,CIIλλ1334.53,1335.70,SiIVλλ1393.76,1402.77,andCIVλλ1548.20,1550.77.BoththeinterstellarandstellarfeaturesofastarbursthavebeenfoundintheUVspectrumofNGC1097,aspointedoutbyStorchi-Bergmannetal.(2005).Figure5showsthatthesame

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

featuresseemtobepresentinthespectrumofNGC3227,suggestingthat,alsointhiscase,asinNGC1097,thereisastarburstcloserthan8pcfromthenucleusinNGC3227(thedistanceatthegalaxycorrespondingto0′′.1theangulardistancefromthenucleuscoveredbytheapertureofthenuclearextraction).Indeed,thepresenceoftracesofyoungstellarpopulationinanopticalnuclearspectrumofNGC3227havebeenpreviouslyreportedbyGonz´alezDelgado&Perez(1997).ThesefeaturesseemalsotobepresentinthespectrumofNGC4151,butthishastobeinvestigatedfurther,astheymaybeduetoabsorptionsinourgalaxy,duetotheproximityofNGC4151.AnobviouscaseofinterstellarabsorptionsfromourgalaxycanbeobservedintheUVspectrumofNGC3516(Fig.5),whereabsorptionsfromOIλ1302.08+SiIIλ1304.40andCIIλλ1334.53,1335.70originatingintheMilkyWayappearblueshiftedfromtheirwavelengthsduetotheshiftofthespectrumtotherestframeofthegalaxy.

AllspectraareavailableelectronicallyattheURLaddress:www.if.ufrgs.br/ pat/atlas.htm,wheretheycanbevisualizedandrecoveredbyclickingonthenameofthegalaxy.WealsomakeavailableattheaboveaddresstheMastertable,whichhasacompilationoftherelevantinformationoneachspectrumusedinthecombination.

Finally,wepointoutthatthereareseveralspectrawhichwereobtainedonlywiththehighestresolutiongratings,thereforecoveringashortwavelengthrange.Inmanycasesthereisalsoasequenceofsuchspectraobtainedatadjacentslitpositions,apparentlyforkinematicstudies.Inthesecases,wedidnotcombinethespectrabutprovideinsteadtheindividualextractionsinatar le.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

REFERENCES

Barth,A.J.etal.2001,ApJ,555,685BBarth,A.J.etal.2001,ApJ,546,205B

Bellamy,M.J.&Tadhunter,C.N.2004,MNRAS,353,105BBowen,D.V.2002,ApJ,580,169B

Bradley,L.D.,Kaiser,M.E.,Baan,W.A.2004,ApJ,603,463BCappellari,M.etal.2002,ApJ,578,787C

Capetti,A.,Marconi,A.,Macchetto,D.&Axon,D.2005, a,431,465Cecil,G.etal.2002,ApJ,568,627C

Chandar,R.,Ford,H.C.&Tsvetanov,Z.2001,AJ,122,1330CChandar,R.,Ford,H.C.&Tsvetanov,Z.2001,AJ,122,1342C

Colina,L.,Gonz´alezDelgado,R.,Mas-Hesse,J.M.&Leitherer,C.2002,ApJ,579,545CCollier,S.etal.2001,ApJ,561,146CCollins,N.R.etal.2005,ApJ,619,116CCrenshaw,D.M.etal.2000,ApJ,545,27CCrenshaw,D.M.etal.2001,ApJ,555,633CCrenshaw,D.M.etal.2002,ApJ,566,187CEdelson,R.2000,ApJ,534,180EFarrah,D.etal.2005,ApJ,62670F

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Ferruit,P.etal.2004,MNRAS,352,1180F

Gonz´alezDelgado,R.M.&Perez,E.1997,MNRAS,284,931Gonz´alezDelgado,R.etal.2004,ApJ,65,127Ho,L.C.etal.2002,PASP,114,137HHughes,M.A.etal.2003,AJ,126,742HHughes,M.A.etal.2005,AJ,130,73HHutchings,J.B.etal.1998,AJ,116,634HHutchings,J.B.etal.1999,AJ,118,2101HHutchings,J.B.etal.2002,AJ,124,2543HJenkins,E.B.etal.2003.AJ,125,2824JKaiser,M.E.etal.2000,ApJ,528,260K

Kinney,A.,Bohlin,R.C.,Calzetti,D.,Panagia,N.,&Wuse,R.F.G.1993,ApJS,86,5Kraemer,S.B.etal.2000,ApJ,531,278KKraemer,S.B.etal.2000,ApJ,544,763KKraemer,S.B.etal.2001,ApJ,551,371KLeighly,K.M.2004,ApJ,611,125L

Leighly,K.M.,Moore,J.R.2004,ApJ,611,107LNelson,C.H.2000,ApJ,531,257NO’Dea,C.etal.2003,PASA,20,80

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Penton,S.V.,Stocke,J.T.&Shull,J.M.2004ApJS,152,29P

Pogge,R.,Fields,D.L.,Martini,P.&Shields,J.2003,inActiveGalacticNuclei:from

CentralEnginetoHostGalaxies,eds.S.Collin,http://www.77cn.com.cnbes&I.Schlosman,ASPConf.Ser.,Vol.290,p.239.Romano,P.etal.2004,ApJ,604,635RRuiz,JosR.etal.2001,AJ,122,296Sabra,B.M.etal.2003,ApJ,584,164SSarzi,M.etal.2001,ApJ,550,65SSarzi,M.etal.2002,ApJ,567,237SSarzi,M.etal.2005,ApJ,628,169S

Storchi-Bergmann,T.etal.2005,ApJ,624,L13Tadhunter,C.etal.2003,MNRAS,342,861T

V´eron-Cetty,M.P.&Veron,P.1996,ESOScienti cReport,Garching:EuropeanSouthern

Observatory,7thed.

Vazquez,G.A.,etal.2004,ApJ,600,162

Whittle,M.,Rosario,D.J.,Silverman,J.D.,Nelson,C.H.&Wilson,A.S.2005,AJ,129,

104W

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.1.—IllustrationoftheprocessofaveragingthreeUVspectra(observedframe)ofthegalaxyNGC1097.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

gg336x280();8_1188-16-0-1375-16.jpg" alt="An Atlas of STIS-HST Spectra of Seyfert Galaxies" />

Fig.2.—Illustrationoftheprocessofcombiningdi erentspectralsegments(observedframes)forthegalaxyNGC1097.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.3.—Illustrationof5ofthe9spectrawithwidestspectralcoverage,Thespectrahavebeenshiftedtotherestframeofthegalaxies.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.4.—SameasFig.3foranother4spectra.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.5.—Illustrationof4ofthe12spectrawithUVcoverageinthe1100–1600 Awavelengthrange.Thespectrahavebeenshiftedtotherestframeofthegalaxies.Theverticaldashedlinesshowthelocationofabsorptionfeaturestypicalofstarbursts.Asterisksidentifytheabsorptionlineswhichoriginateintheatmosphereofearly-typestars.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.6.—SameasFig.5foranother4spectra.

We present a compilation of spectra of 101 Seyfert galaxies obtained with the Space Telescope Imaging Spectrograph (HST-STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, whi

Fig.7.—SameasFig.5foranother4spectra.

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