The spectral energy distribution of the central parsecs of the nearest AGN

21 Pages·2010·1.3 MB·English

Mon.Not.R.Astron.Soc.402,724–744(2010) doi:10.1111/j.1365-2966.2009.15897.x
The spectral energy distribution of the central parsecs of the nearest AGN
(cid:2)
M. A. Prieto,1 J. Reunanen,2 K. R. W. Tristram,3 N. Neumayer,4
J. A. Fernandez-Ontiveros,1 M. Orienti1 and K. Meisenheimer5
1IAC,38200LaLaguna,Tenerife,Spain
2TuorlaObservatory,UniversityofTurku,Va¨isa¨la¨ntie20,21500Piikkio¨,Finland
3MPIfR,AufdemHu¨gel,53121Endenich,Bonn,Germany
4ESO,Karl-Schwarzschild-Str.2,85478Garching,Germany
5MPIA,Ko¨nigstuhl17,69117Heidelberg,Germany
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Accepted2009October23.Received2009October16;inoriginalform2009July14 loa
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ABSTRACT
h
Spectral energy distributions (SEDs)of the centralfew tens ofparsec region ofsome of the ttp
s
nearest,mostwell-studied,activegalacticnuclei(AGN)arepresented.ThesegenuineAGN- ://a
c
coreSEDs,mostlyfromSeyfertgalaxies,arecharacterizedbytwomainfeatures:aninfrared a
d
(IR)bumpwiththemaximuminthe2–10μmrangeandanincreasingX-rayspectrumwith em
frequencyinthe1to∼200keVregion.ThesedominantfeaturesarecommontoSeyferttype ic.o
u
1 and 2 objects alike. In detail, type 1 AGN are clearly distinguished from type 2 by their p
.c
highspatialresolutionSEDs:type2AGNexhibitasharpdropshortwardsof2μm,withthe o
m
optical to UV region being fully absorbed; type 1s instead show a gentle 2μm drop ensued /m
n
byasecondary,partiallyabsorbedopticaltoUVemissionbump.Ontheassumptionthatthe ra
s
bulkofopticaltoUVphotonsgeneratedintheseAGNisreprocessedbydustandre-emitted /a
intheIRinanisotropicmanner,theIRbumpluminosityrepresents(cid:2)70percentofthetotal rticle
energyoutputintheseobjects,andthesecondenergeticallyimportantcontributionisthehigh -ab
s
energiesabove20keV. tra
c
GalaxiesselectedbytheirwarmIRcolours,i.e.presentingarelativelyflatfluxdistribution t/4
0
inthe12–60μmrange,haveoftenbeingclassifiedasAGN.Theresultsfromthesehighspatial 2
/2
resolution SEDs question this criterion as a general rule. It is found that the intrinsic shape /7
2
oftheinfraredSEDofanAGNandinferredbolometricluminositylargelydepartfromthose 4/1
1
derivedfromlargeaperturedata.AGNluminositiescanbeoverestimatedbyuptotwoorders 0
0
ofmagnitudeifrelyingonIRsatellitedata.WefindthesedifferencestobecriticalforAGN 19
2
luminosities below or about 1044ergs−1. Above this limit, AGN tend to dominate the light b
y
oftheirhostgalaxyregardlessoftheintegrationaperturesizeused.Althoughthenumberof g
u
e
objectspresentedinthisworkissmall,wetentativelymarkthisluminosityasathresholdto s
t o
identifygalaxy-light-dominatedversusAGN-dominatedobjects. n
1
0
Key words: techniques: high angular resolution – galaxies: nuclei – galaxies: Seyfert – A
p
infrared:galaxies–radiocontinuum:galaxies–X-rays:galaxies. ril 2
0
1
9
ofthesephenomenainvolveradiationreprocessingfromaspectral
1 INTRODUCTION
rangeintoanother.TheavailabilityoftheSEDofagalaxyallows
Thestudyofthespectralenergydistributions(SEDs)overthewidest us to determine basic parameters such as its bolometric luminos-
possiblespectralrangeisanoptimalwaytocharacterizetheproper- ity(e.g.Elvisetal.1994;Sanders&Mirabel1996;Vasudevan&
tiesofgalaxiesingeneral.Coveringthewidestspectralrangeisthe Fabian2007),andviamodellingoftheSED,itsstarformationlevel,
keytodifferentiatingphysicalphenomena,suchasdustemissionin massandage(e.g.Bruzual&Charlot2003;Rowan-Robinsonetal.
theinfrared(IR),stellaremissionintheopticaltoultraviolet(UV) 2005;Daleetal.2007).
and non-thermal processes in the X-rays and radio, which domi- TheconstructionofbonafideSEDsisnoteasyasitinvolvesdata
nate at specific spectral ranges, and to interrelating them as most acquisitionfromdifferentrangesoftheelectromagneticspectrum
usingverydifferenttelescopeinfrastructure.Thisagainintroduces
afurthercomplicationastheachievedspatialresolution,andwith
(cid:2)E-mail:[email protected] ittheaperturesizeused,varieswiththespectralrange.SEDsbased
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS
SEDofnearbygalaxycores 725
ontheintegrationoftheoverallgalaxylightmaybeverydifferent EuropeanSouthObservatory(ESO)VeryLargeTelescope(VLT);
fromthoseextracted fromonlya specificregion, e.g.the nuclear hencethisstudyreliesonSoutherntargets,allwell-knownobjects,
region. In this specific case, the aperture size is quite important, mostlySeyfertgalaxies:CentaurusA,NGC1068,Circinus,NGC
as different light sources, such as circumnuclear star formation, 1097, NGC 5506, NGC 7582, NGC 3783, NGC 1566 and NGC
theactivenucleusandthesubjacentgalaxylight,coexistonsmall 7469.Forcomparisonpurposes,theSEDofquasar3C273isalso
spatial scales and may contribute to the total nuclear output with included.
comparableenergies(e.g.Genzeletal.1998;Reunanen,Prieto& The compiled SEDs make use of the highest spatial resolution
Siebenmorgen2009). dataavailablewithcurrentinstrumentationacrosstheelectromag-
InthespecificcaseofSEDsofAGN,itisoftenassumedthatthe neticspectrum.ThemainsourcesofdataincludeVLA-Aarrayand
AGN light dominates the integrated light of the galaxy at almost Australia Telescope Compact Array (ATCA) data in radio, VLT
any spectral range and for almost any aperture. This assumption diffraction-limitedimagesandVeryLargeTelescopeInterferometer
becomes mandatory at certain spectral ranges, such as the high (VLTI)interferometryinthemid-IR,VLTadaptive-opticsimages
energies,theextremeUVorthemid-to-far-IR,becauseofthespa- inthenear-infrared,andHST imagingandspectraintheoptical–
D
tialresolutionlimitationsimposedbytheavailableinstrumentation, ultraviolet.AlthoughX-raysandgammaraysdonotprovidesucha o
w
whichcurrentlyliesintherangeofseveralarcsecondstoarcminutes fineresolution,informationwhenavailableforthesegalaxiesisalso nlo
atthesewavelengths.Inthemid-tofar-IRinparticular,theavailable includedintheSEDsontheassumptionthatabove10keVorso,we ad
e
data,mostlyfromIRsatellites,arelimitedtospatialresolutionsofa aresamplingtheAGNcoreregion.Mostofthedatausedcomefrom d
fewarcsecondsatbest.Thus,theassociatedSEDsincludethecon- theChandraandInternationalGamma-RayAstrophysicsLabora- fro
m
tributionofthehostgalaxy,star-formingregions,dustemissionand tory(INTEGRAL)telescopes. h
AGN,withthefirsttwocomponentsbeingmeasuredoverdifferent The novelty in the analysis is the spatial resolutions achieved ttp
s
spatialscalesinthegalaxydependingontheobjectdistanceandthe in the IR, with typical full width at half-maximum (FWHM) (cid:3) ://a
spatialresolutionachievedatagivenIRwavelength. 0.2arcsecin1–5μmand<0.5arcsecin11–20μm.Theavailability ca
d
Inspectralrangeswherehighspatialresolution(HSR)isread- ofIRimagesatthesespatialresolutionsallowsustopinpointthe e
m
ily available, the importance, if not dominance, of circumnuclear true spatial location of the AGN – which happens not to have an ic
starformationrelativetothatoftheAGNhasbecomeclearinthe optical counterpart in most of the type 2 galaxies studied – and .ou
p
UVtoopticalrange(e.g.Munoz-Marinetal.2007)orinthenear- extract its luminosity within aperture diameters of a few tens of .c
o
IR (Genzel et al. 1998). In the radio regime, the comparison of parsec.ThenewlycompiledSEDsarepresentedinSection2.Some m
lowspatialresolutionandHSRmapsshowstheimportanceofthe majordifferencesaswellassimilaritiesbetweentheSEDsoftype /m
n
diffusecircumnuclearemissionandtheemissionfromthejetcom- 1andtype2AGNariseattheseresolutions.Thesearepresented ra
s
ponentswithrespecttothatofthecoreitself(e.g.Royetal.1994; and discussed in Sections 3, 4 and 5. The SEDs and the inferred /a
Elmouttieetal.1998;Gallimore,Baum&O’Dea2004;Lal,Shastri nuclearluminositiesarefurthercomparedwiththoseextractedin rtic
le
&Gabuzda2004).Evenwithlow-resolutiondata,amajorconcern the mid-to-far-IR from large aperture data from IR satellites, and -a
b
sharedbymostworksistherelevanceofthehostgalaxycontribu- thedifferencesarediscussedinSection6. s
tIiRo.nTtooothveerncuocmleearthiensteegmraitxeidngemefifsesciotsnifnrtormoduthceedUbVytpooooprtsicpaaltitaol traTlhwraovueglhenogutthtshiosfptahpeern,eHar0-I=R7b0rokamd-sb−a1nMdfiplct−e1rsisuusesdeda.rTehIebcaennd- tract/4
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resolution,differentstrategiesorassumptionshavebeenfollowed (0.8μm),Jband(1.26μm),Hband(1.66μm),Kband(2.18μm), 2/2
bythecommunity.Inquasars,bytheirownnature,thedominance Lband(3.80μm)andMband(4.78μm). /7
2
of the AGN light over the integrated galaxy light at almost any 4/1
wavelengthisassumed;conversely,inlowerluminosityAGN,the 2 THE HIGH SPATIAL RESOLUTION SED: 100
contributionofdifferentcomponentsisassessedviamodellingof 1
DATA SOURCE 9
the integrated light (Edelson & Malkan 1986; Ward et al. 1987; 2
b
Sandersetal.1988;Elvisetal.1994;Buchananetal.2006among ThissectiondescribesthedatausedinbuildingtheHSRSEDs.Each y g
others). AGNisanalysedinturn,andthecompiledSEDisshowninFig.1. ue
s
Inthispaper,weattempttoprovideabestestimateoftheAGN ThedatausedintheSEDsarelistedperobjectinTables1–10.For t o
light contribution on very nearby AGN by using very HSR data eachAGN,anupperlimittothecoresizedeterminedinthenear-IR n 1
over a wide range of the electromagnetic spectrum. Accordingly, withadaptiveopticsand/orinthemid-IRwithinterferometryisfirst 0 A
SEDs of the central few hundred parsec region of some of the provided.ThedatasourcesusedinconstructingtherespectiveSEDs p
nearestandbrightestAGNarecompiled.Theworkismotivatedby aredescribednext.Whenfoundintheliterature,abriefsummaryof ril 2
0
thecurrentpossibilityofobtainingsubarcsecresolutiondatainthe thenuclearvariabilitylevelsespeciallyintheIRisprovided.This 1
9
near-to-mid-IRofbrightAGNandthusatresolutionscomparable ismostlytoassesstherobustnessoftheSEDshapeandintegrated
tothoseavailablewithradiointerferometryandtheHubbleSpace luminosities across the spectrum. Finally, as a by-product of the
Telescope (HST) in the optical to UV wavelength range. This is analysis, an estimate of the extinction in the surrounding of the
possible, thanks to the use of adaptive optics in the near-IR, the nucleus based on near-IR colours derived from the HSR, mostly
diffractionlimitresolutionsprovidedby8–10mtelescopesinthe J −K,imagesisprovided.Thecolourimagesusedareshownin
mid-IRaswellasinterferometryinthemid-IR. Fig.2.Thesearerelativeextinctionvalues,resultingaftercomparing
The selection of targets is driven by the requirements imposed theaveragecolourintheimmediatesurroundingofthenucleuswith
bytheuseofadaptiveopticsinthenear-IR,whichlimitstheob- thatatfurthergalactocentricregions,usuallywithinthecentralfew
servationstotheavailabilityofhavingbrightpoint-liketargetswith hundred parsecs. These reference regions are selected from areas
magnitudes V< 15mag in the field, and the current flux detec- presentinglowerextinctionasjudgedfromavisualinspectionofthe
tionlimitsinmid-IRground-basedobservations.AGNinthenear colourimages.Thederivedextinctiondoesnotrefertothatinthe
Universearesufficientlybrighttosatisfythesecriteria.Thenear-to lineofsightofthenucleus,whichcouldbemuchlarger–wedonot
mid-IRhigh-resolutiondatausedinthisworkcomemostlyfromthe comparewiththenucleuscoloursbutwiththoseinitssurrounding.
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
726 M.A.Prietoetal.
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Figure1. SEDsofthecentralparsec-scaledregionoftheAGNinthisstudy.Filledpointsrepresentthehighestspatialresolutiondataavailableforthese
nuclei;thethinV-shapelineinthemid-IRregionshowninsomeSEDscorrespondstothespectrumofanunresolvedsourceasmeasuredbyVLTI/MIDI
(correlatedflux).Crossesrefertolargeaperturedatainthemid-IR(mostlyfromIRASandISO)andthemillimetrewhenavailable.Thefrequencyrangeisthe
sameinallplotsexceptforCenAand3C273whichextendsuptothegammarays.Thecontinuouslineinthe3C273plotistheSEDofthisobjectafter
applyinganextinctionAv=15mag(seeSections3).
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
SEDofnearbygalaxycores 727
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Figure1–continued 01
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2
b
Thesimplestapproachofconsideringaforegrounddustscreenis purposes. The AGN is unambiguously recognized in the near-IR y g
used.TheextinctionlawpresentedinWitt,Thronson&Capuano images of all objects as the most outstanding source in the field ue
(1992), for the UV to the near-IR, and that in Rieke & Lebofsky of 26 × 26arcsec2 covered by the VLT/NACO images. This is st o
(1985),forthemid-IR,areused. especiallythecaseforthetype2sourceswheretheAGNreveals n 1
For some objects, the near-IR adaptive optics data used to infullrealmfrom2μmlongwards.Thecomparableresolutionof 0 A
compile the SED are presented here for the first time. For com- the NACO-IR and the HST–optical images allows us to search p
pleteness purposes, Table 11 is a list of all the adaptive optics fortheopticalcounterpartoftheIRnucleus,insomecasesusing ril 2
0
VLT/NAOS-CONICA (NACO) observations used in this work. accurate astrometry based on other point-like sources in the field 1
9
Thelistoffiltersanddatesofobservationsareprovided.Thenu- (e.g.Prietoetal.2004;Fernandez-Ontiverosetal.inpreparation).
cleus of these AGN was in all cases bright enough to be used as In all the type 2 cases analysed, the counterpart optical emission
a reference for the adaptive optics system to correct for the at- is found to vanish shortwards of 1μm. Accordingly, all the type
mospheric turbulence. The optical nuclear source was used in all 2 SEDs show a data gap in the optical–UV region. In addition,
caseswiththeexceptionofCentaurusAandNGC7582,forwhich alltheSEDsshowacommondatagapspanningtheextremeUV-
the IR nucleus was used instead. The observation procedure and softX-raysregion,duetotheobservationalinaccessibilityofthis
data reduction for all the objects presented here are the same as spectralrange,andthemid-IRtomillimetrerange,duetothelackof
those discussed in detail in the references quoted in Table 11, dataatsubarcsecresolutionscales.Surprisingly,forsomeofthese
we refer the interested reader to those references for further well-studied objects, neither radio data at subarcsec scales exist,
details. e.g. Circinusgalaxy. Inthese cases,westillincludethe available
There are five type 2, three type 1 and an intermediate type arcsecresolutionradiodataintheSED.
1/low-ionizationnuclearemission-lineregion(LINER)AGNinthe TheSEDsarefurthercomplementedwithavailabledatainthe
sample, in addition to quasar 3C 273, included for comparative X-rays,whichextendupto100–200keVforallsources.Onlyfor
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
728 M.A.Prietoetal.
Table1. SEDoftheCentaurusAcoreregion. Table2. SEDoftheCircinuscoreregion.
Origin Hz Jy Origin Hz Jy
COMPTEL5.1MeV 1.25×1021 1.78×10−8 INTEGRAL40–100keV 1.69×1019 5.5×10−7
COMPTEL1.7MeV 3.98×1020 1.0×10−7 INTEGRAL20–40keV 7.25×1018 1.5×10−6
COMPTEL0.86MeV 2.09×1020 3.75×10−7 INTEGRAL2–10keV 1.45×1018 8.9×10−7
INTEGRAL20–100keV 1.45×1019 2.4×10−6 ROSAT1.3keV 3.25×1017 4.0×10−6
INTEGRAL2–10keV 2.42×1018 8.8×10−6 NACO-J 2.30×1014 <0.0016
Chandra1keV 2.42×1017 6.2×10−5 NACO-H 1.76×1014 0.0048
WFPC2-F555W 5.40×1014 <6.4×10−8 NACO-K 1.36×1014 0.019
WFPC2-F814W 3.68×1014 7.0×10−6 NACO-2.42μm 1.24×1014 0.031
NACO-J 2.30×1014 0.0013 NACO-L 7.90×1013 0.38
NACO-H 1.76×1014 0.0045 NACO-M 6.70×1013 1.9
NACO-2.02μm 1.48×1014 0.030 MIDIcorr-8μm 4.00×1013 0.30 Do
NACO-K 1.36×1014 0.031 MIDIcorr-9.6μm 3.10×1013 0.30 wn
NACO-L 8.57×1013 0.20 MIDIcorr-11μm 2.50×1013 0.50 lo
a
MIDI-8μm 3.70×1013 0.60 MIDIcorr-12μm 2.00×1013 1.1 de
MMIIDDII--1123μμmm 22..5300××11001133 11..13 MMIIDDII--89.μ6mμm 33..1700××11001133 62..08 d from
MIDIcorre-8.3μm 3.60×1013 0.47 VISIR-11.88μm 2.50×1013 9.3 h
MIDIcorre-9.3μm 3.20×1013 0.28 VISIR-18.72μm 1.60×1013 17.6 ttp
s
MMIIDDIIccoorrrree--1101..44μμmm 22..8683××11001133 00..2453 AATTCCAA--36ccmm 15..0000××1100190 00..005500 ://ac
a
MIDIcorre-12.6μm 2.30×1013 0.62 ATCA-13cm 2.30×109 0.070 de
VISIR-11.88μm 2.56×1013 1.1 ATCA-20cm 1.50×109 0.12 m
VISIR-18.72μm 1.70×1013 2.3 ========== ic.o
VLBA-1997 2.22×1010 1.9 IRAS-12μm 2.50×1013 19.0 up
VLBA-1997 8.40×109 1.7 IRAS-25μm 1.20×1013 68.0 .co
VLBA-1999 8.4×109 2.32 IRAS-60μm 5.00×1012 249 m/m
VLBA-1999 5.0×109 0.83 IRAS-100μm 3.00×1012 316 n
VLBA-1999 2.2×109 1.03 ra
========== Note.DatasourcesandassociatedspatialresolutionsaregiveninSection s/a
IRAS-12μm 2.50×1013 22.0 2.2.ThelargeaperturedataintheIR,shownwithcrossesintheSEDin rtic
IRAS-25μm 1.20×1013 28.0 Fig.1,areaddedattheendofthetable. le-a
IRAS-60μm 5.00×1012 2.1×102 bs
IRAS-100μm 3.00×1012 4.1×102 tra
ISO-170μm 1.76×1012 5.4×102 resolutionsallowforabetterseparationofthecoreemissionfrom ct/4
SCUBA-350μm 8.66×1011 7.7 0
SCUBA-450μm 6.67×1011 7.9 thejet.Thepeakvaluesreportedbytheauthorsareincludedinthe 2/2
SCUBA-750μm 4.07×1011 8.1 SED. /72
SCUBA-850μm 3.50×1011 8.1 In the millimetre range, peak values from Submillimeter 4/1
Common-User Bolometric Array (SCUBA) in the 350–850μm 10
Note.DatasourcesandassociatedspatialresolutionsaregiveninSection 0
rangefromLeeuwetal.(2002)areincludedintheSED.SCUBA 1
2.1.ThelargeaperturedataintheIR,shownwithcrossesintheSEDin 9
haspoorspatialresolution,FWHM∼10–15arcsec;however,we 2
Fig.1,areaddedattheendofthetable. b
takethesemeasurementsasgenuinecorefluxesastheyfollowfairly y g
well the trend defined by the higher resolution data at both radio ue
CenAand3C273,theSEDsarefurtherextendedtothegamma s
rays,thesebeingtheonlytwosofardetectedatthesehighenergies. atinodnmthiadt-ItRhewAaGveNleinsgtthhse.dTohmisincaonmtmligohnttsroeunrdceisinatshtreomngilliinmdeictrae- t on 1
range. 0 A
In the mid-IR range, VLT/VLT Spectrometer and Imager for p
2.1 CentaurusA the Mid-Infrared (VISIR) diffraction-limited data, taken on 2006 ril 2
0
CentaurusAisthenearestradiogalaxyintheSouthernhemisphere. March,at 11.9and18.7μm,fromReunanen etal.(2009)arein- 1
9
Theadoptedscaleis1arcsec∼16pc(D=3.4Mpc;Ferrareseetal. cludedintheSED.Furthermid-IRdataarefromVLTI/Mid-Infrared
2007).Thenucleusofthisgalaxybeginstoshowupintheoptical InterferometricInstrument(MIDI)interferometricobservationsin
longwards of 0.7μm (Marconi et al. 2000) and so far remains the8–12μmrangetakenon2005FebruaryandMaywithresolu-
unresolveddowntoasizeof(cid:4)1pcFWHMinthe1–10μmrange tionsof30mas(Meisenheimeretal.2007).Thevisibility’sanalysis
(fromVLTadaptiveopticsnear-IRimagingbyHaering-Neumayer indicatesthatatleast60percentoftheemissiondetectedbyMIDI
etal.2006andVLTinterferometryinthemid-IRbyMeisenheimer comefromanunresolvednucleuswithasizeofFWHM<1pcat
etal.2007). 10μm.ThisisalsoconfirmedbymorerecentMIDIobservations
ThecurrentlycompiledSEDofCenAcoreisshowninFig.1 byBurtscheretal.(inpreparation).TheSEDincludestwosetsof
(Table 1). The radio data are from Very Long Baseline Array MIDIfluxesmeasureddirectlyintheaveragespectrumfromboth
(VLBA)quasi-simultaneousobservationscollectedin1997at22.2 periods:(1)thetotalintegratedfluxintheMIDIaperture(0.52×
and8.4GHz(Marchepochwasselected)andin1999at8.4,5and 0.62arcsec2) and (2) the core fluxes measured on the correlated
2.2GHz,inallcaseswithresolutionofafewmilliarcsec(Tingay spectrum.At11.9μm,theMIDItotalfluxandtheVISIRnuclear
&Murphy2001;Tingay,Preston&Jauncey2001).Thesespatial flux, both from comparable aperture sizes, differ by 15 per cent.
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
SEDofnearbygalaxycores 729
Table3. SEDoftheNGC1068coreregion. Table4. SEDoftheNGC1097coreregion.
Origin Hz Jy Origin Hz Jy
INTEGRAL40–100keV 1.69×1019 9.8×10−8 ASCA2–10keV 2.42×1018 8.5×10−8
INTEGRAL20–40keV 7.25×1018 1.3×10−7 ASCA0.5–4keV 2.42×1017 2.4×10−7
EXOSAT2–10keV 1.45×1018 3.7×10−7 WFPC2-F218W 1.40×1015 1.8×10−5
Chandra1keV 2.42×1017 1.5×10−7 WFPC-F555W 5.41×1014 8.8×10−5
NACO-J 2.30×1014 <0.0024 ACSWF-F814W 3.60×1014 0.00074
NACO-H 1.76×1014 0.0056 NACO-J 2.30×1014 0.0011
NACO-K 1.36×1014 0.056 NACO-H 1.76×1014 0.0027
NACO-2.42μm 1.24×1014 0.12 NACO-K 1.36×1014 0.0039
NACO-M 6.70×1013 1.5 NACO-L 7.90×1013 0.011
MIDIcorr-8μm 3.75×1013 1.9 VISIR-11.88μm 2.50×1013 0.025
MIDIcorr-9.6μm 3.1×1013 0.4 VISIR-18.72μm 1.60×1013 0.041 Do
MIDIcorr-12μm 2.5×1013 1.2 VLA-B 1.50×1010 0.0056 wn
MIDIcorr-13μm 2.3×1013 1.9 VLA-A 8.40×109 0.0031 lo
a
Subaru-8.72μm 3.4×1013 5.81 VLA-A 4.80×109 0.004 de
SSuubbaarruu--91.06.938μμmm 32..19××11001133 43..0832 V=L=A=-=B====== 1.40×109 0.0012 d from
Subaru-11.66μm 2.6×1013 10.2 IRAS-12μm 2.50×1013 3.0 h
Subaru-12.33μm 2.4×1013 9.3 IRAS-25μm 1.20×1013 7.3 ttp
s
SKuebcakr-u2-51μ8.m5μm 11..2600××11001133 99..66 IIRRAASS--16000μμmm 35..0000××11001122 1.05×3.0102 ://ac
a
IRAM-1mm 2.30×1011 0.022 Spitzer-160μm 1.92×1012 1.5×102 de
IRAM-3mm 1.15×1011 0.036 SCUBA-850μm 3.53×1011 1.4 m
VLA-A 4.30×1010 0.013 ic.o
VLA-A 2.25×1010 0.016 Notes.DatasourcesandspatialscalesaregiveninSection2.4.Thelarge up
VLBA 8.40×109 0.0054 aperturedataintheIR,shownwithcrossesintheSEDinFig.1,areadded .co
VLBA 5.00×109 0.0091 attheendofthetable. m/m
VLBA 1.70×109 <0.0026 n
========== ra
s
IRAS-12μm 2.50×1013 40.0 /a
IIRRAASS--2650μμmm 15..2000××11001132 1.88×5.0102 Table5. SEDoftheNGC5506coreregion. rticle-a
IIRSOAS-1-71000μμmm 13..7060××11001122 23..89××110022 Origin Hz Jy bstra
MKO-390μm 7.69×1011 30.0 INTEGRAL40–100keV 1.69×1019 2.2×10−7 ct/4
CTIO-540μm 5.55×1011 7.0 INTEGRAL20–40keV 7.25×1018 5.8×10−7 02
Napoetretsu.reDdataatasoinurthceesIRan,dshsopwatniawlistchalcersosasreesginivtehneiSnESDecitnioFnig2..31.,aTrheealdadrgede IENinTsEteGinRA0.L2–24–1k0eVkeV 15..4255××11001187 62..11××1100−−66 /2/724
attheendofthetable. WFPC2-V+R 5.00×1014 <2.9×10−5 /11
NACO-J 2.30×1014 0.013 0
0
NACO-H 1.76×1014 0.053 19
NACO-K 1.36×1014 0.080 2 b
Thedifferenceisstillcompatiblewiththephotometryerrorswhich NACO-L 7.90×1013 0.29 y g
inparticularmaybelargeintheMIDIspectrumphotometry. ISO-spec-6μm 5.00×1013 0.70 ue
tcaeknTethnreeidnnaJet-a2,r-.H0IR2,Kμismanc.doTvLheerbseaednadwrseiatchnodmViLpnTlteh/meNenAnatCrerdOowwa-idbthaapnHtdiSvlTein/eWo-pfitrdieceesFfidileatletdar VVVTIIILMSSBIIMRRA---I1112189-s..987p782ecμμ-9mm.6μm 2183...57.30003××××111100001113933 0.0010...59422 st on 10 A
Planetary Camera 2 (WFPC2) data in the I band (Marconi et al. p
2000).Shortwardsofthiswavelength,CenA’snucleusisunseen. VVLLBBAI-1-1999947 55..0000××110099 00..003340 ril 20
AnupperlimitderivedfromtheHST/WFPC2imageat0.5μmis VLBA-2000 5.00×109 0.042 19
includedintheSED. PTI-1990 2.30×109 0.087
Athighenergies,CenA’snucleusbecomesvisibleagain,aswell VLBA-1997 1.60×109 0.024
as its jet. The SED includes the 1keV nuclear flux extracted by VLBA-2000 1.60×109 0.046
Evansetal.(2004)fromChandraobservationsin2001andaverage ==========
of the 100keV fluxes derived by Rothschild et al. (2006) from IRAS-12μm 2.50×1013 1.3
INTEGRAL observations collected in 2003–2004. In the gamma IRAS-25μm 1.20×1013 4.2
IRAS-60μm 5.00×1012 8.4
rays,theSEDincludesImagingComptonTelescope(COMPTEL)
IRAS-100μm 3.00×1012 8.9
measurementsinthe1–30MeVrangetakenduringthe1991–1995
campaignbySteinleetal.(1998). Note.DatasourcesandcorrespondingspatialscalesaregiveninSection2.5.
Forcomparativepurposes,Fig.1includeslargeaperturedata– ThelargeaperturedataintheIR,shownwithcrossesintheSEDinFig.1,
identifiedwithcrosses–inthemid-to-far-IRregionselectedfrom areaddedattheendofthetable.
InfraredSpaceObservatory(ISO;Stickeletal.2004,)andInfrared
AstronomicalSatellite(IRAS;Sandersetal.2003).Forconsistency
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
730 M.A.Prietoetal.
Table6. SEDoftheNGC7582coreregion. Table8. SEDoftheNGC3783coreregion.
Origin Hz Jy Origin Hz Jy
SAX20–100keV 1.45×1019 8.1×10−7 OSSE50–150keV 2.42×1019 2.9×10−7
XMM2–12keV 1.69×1018 1.4×10−6 INTEGRAL17–60keV 9.31×1018 1.3×10−6
ASCA0.5-2-keV 3.03×1017 1.46×10−7 XMM2–10keV 1.45×1018 3.9×10−6
WFPC2-F606W 5.00×1014 3.0×10−6 Einstein0.2–4keV 5.25×1017 7.9×10−6
NICMOS-F160W 1.88×1014 0.011 FUSE-1040A 3.00×1015 0.001
NACO-2.06μm 1.46×1014 0.018 STIS-1150A 2.70×1015 0.0016
NACO-L 7.89×1013 0.096 STIS-1346A 2.20×1015 0.0023
NACO-4.05μm 7.41×1013 0.11 STIS-1480A 2.00×1015 0.0025
TIMMI2-spec-8.5μm 3.53×1013 0.3 STIS-2279A 1.30×1015 0.0045
TIMMI2-spec-9μm 3.33×1013 0.2 STIS-2419A 1.20×1015 0.0056
TIMMI2-spec-9.6μm 3.13×1013 0.08 STIS-2640A 1.13×1015 0.0065 Do
TIMMI2-spec-11μm 2.73×1013 0.2 STIS-2900A 1.00×1015 0.0075 wn
TIMMI2-spec-12μm 2.50×1013 0.4 STIS-3100A 9.70×1014 0.0076 loa
VISIR-11.88μm 2.52×1013 0.40 LCO-U 8.19×1014 0.0056 de
VVLISAIR-A-18.72μm 18..6400××1100193 0.00.05659 AACCSS--FF554570MM 55..4485××11001144 00..00006606 d from
VLA-A 5.00×109 0.0095 WFPC2-F814W 3.68×1014 0.0099 h
========== NACO-J 2.30×1014 0.023 ttp
s
IIRRAASS--1225μμmm 21..5200××11001133 27..34 NNAACCOO--KL 17..3960××11001143 00.0.1773 ://ac
a
IRAS-60μm 5.00×1012 5.2 VISIR-11.88μm 2.50×1013 0.54 de
IRAS-100μm 3.00×1012 8.3 VISIR-18.72μm 1.60×1013 1.47 m
VLA-A 8.40×109 0.0080 ic.o
Note.DatasourcesandspatialscalesaregiveninSection2.6.Thelarge VLA-A 4.80×109 0.013 up
aperturedataintheIR,shownwithcrossesintheSEDinFig.1,areadded VLA-A 1.40×109 0.023 .co
attheendofthetable. ========== m
/m
IRAS-12μm 2.50×1013 0.84 n
IRAS-25μm 1.20×1013 2.5 ra
s
IRAS-60μm 5.00×1012 3.3 /a
IRAS-100μm 3.00×1012 4.9 rtic
le
Table7. SEDoftheNGC1566coreregion. Note.DatasourcesandcorrespondingspatialscalesaregiveninSection2.8. -ab
Origin Hz Jy TarheealdadrgedeaaptethrteuerenddaotfatihnetthaeblIeR.,shownwithcrossesintheSEDinFig.1, strac
t/4
SAX20–100keV 1.45×1019 5.6×10−7 02
Einstein2–4keV 5.25×1017 2.8×10−6 purposes,giventhepoorspatialresolutionoftheSCUBAdata,these /2/7
FOS-1300A 2.30×1015 5.6×10−5 2
FOS-1400A 2.10×1015 8.0×10−5 arealsolabelledwithcrossesintheSED. 4/1
FOS-1800A 1.67×1015 0.00016 CenAisastronglyvariablesourceathighenergies,whereflux 10
0
FOS-2100A 1.40×1015 0.00021 variationscouldbeuptoanorderofmagnitude(Bondetal.1996). 19
WFPC2-160BW 1.87×1015 0.00011 However,duringtheCOMPTELobservationsusedintheSEDthe 2 b
WFPC2-F336W 8.92×1014 0.00038 observedvariabilityonthescalesoffewdaysisreportedtobeatthe y g
WFPC2-F547M 5.48×1014 0.00050 2σlevelatmost(Steinleetal.1998).CombiningtheOrientedScin- ue
WWNNAAFFCCPPOOCC22--JK--FF585154WW 5321....46330878××××1111000011114444 0000..00..0000000012571139 tgliuelmltaictiinoGonsaimStypm(e5ac0tRrkoaemyVeE–txe1prGeEreixVmp)eervniatmrTieeenlsetbs(ycOo4Sp0SepE(eE)r,GcCeRnOEtM.TN)P,oTthrEeeLpgoaarmntodmnEav-narerariy-- st on 10 A
abilitymonitoringofthissourceintheIRwasfound.Thecompar- p
NVAISCIRO--1L1.88μm 27..5900××11001133 00.0.005798 isonbetweentheVLT/VISIRdatausedinthisworkandequivalent ril 20
VISIR-18.72μm 1.60×1013 0.11 mid-IRdataobtained4yrapart,2002,byWhysong&Antonucci 19
ATCA-8.4GHz 8.40×109 0.0080 (2004) using Keck and Siebenmorgen, Krugel & Spoon (2004)
PTI-2.3GHz 2.30×109 0.0050 usingESO/ThermalInfraredMultimodeInstrument(TIMMI2),in-
PTI-1.7GHz 1.70×109 <0.006 dicatesadifferencewithVISIRinthe40–50percentrange.CenA’s
========== nucleus is the single source in this study whose HSR SED, from
IRAS-12μm 2.50×1013 1.9 radio to millimetre to IR, can be fitted with a single synchrotron
IRAS-25μm 1.20×1013 3.0 model (Prieto et al. 2007; see also end of Section 6.3). Thus, a
IRAS-60μm 5.00×1012 22.0 fluxdifferenceofafactorof2intheIRisconsistentwithgenuine
IRAS-100μm 3.00×1012 58.0
nuclearvariabilityandthedominanceofanon-thermalcomponent
Spitzer-160μm 1.92×1012 1.0×102
intheIRspectralregionofthisnucleus.
Note.DatasourcesandspatialscalesaregiveninSection2.7.Thelarge RelativeextinctionvaluesinthenuclearregionofCenAwere
aperturedataintheIR,shownwithcrossesintheSEDinFig.1,areadded measured from VLT/NACO J − K (Fig. 2) and H − K colour
attheendofthetable. maps.TheaveragereddestcoloursaroundthenucleusareJ −K∼
1.5andJ−H∼1.5,andthebluestcolourswithin∼100pcdistance
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
SEDofnearbygalaxycores 731
Table9. SEDoftheNGC7469coreregion. Table10. SEDofthe3C273coreregion.
Origin Hz Jy Origin Hz Jy
INTEGRAL17–60keV 9.31×1018 5.1×10−7 1GeV 2.42×1023 1.4×10−11
XMM2–10keV 1.45×1018 2.9×10−6 300MeV 7.25×1022 8.8×10−11
ROSAT0.1–2.4keV 2.42×1017 9.1×10−6 100MeV 2.42×1022 4.8×10−10
WFPC2-F218W 1.36×1015 0.0027 3MeV 7.25×1020 5.6×10−8
ACS-F330W 8.92×1014 0.0031 1MeV 2.40×1020 1.8×10−7
WFPC2-F547M 5.47×1014 0.0029 500keV 1.21×1020 2.9×10−7
ACS-F550M 5.38×1014 0.0022 100keV 2.42×1019 1.1×10−6
ACS-F814W 3.75×1014 0.0042 50keV 1.21×1019 1.6×10−6
NACO-J 2.37×1014 0.0080 20keV 4.84×1018 3.3×10−6
NACO-H 1.81×1014 0.015 10keV 2.42×1018 4.2×10−6
NICMOS-F187N 1.60×1014 0.019 5keV 1.21×1018 5.9×10−6 Do
NACO-K 1.38×1014 0.020 2keV 4.84×1017 8.7×10−6 wn
NACO-L 7.89×1013 0.084 1keV 2.42×1017 1.4×10−5 lo
a
NACO-4.05μm 7.41×1013 0.096 0.5keV 1.21×1017 2.9×10−5 de
VVIISSIIRR--1118..8782μμmm 21..5630××11001133 01..5237 00..21kkeeVV 42..8442××11001166 29..458××1100−−54 d from
VLA-A 1.49×1010 0.011 1300A 2.31×1015 0.012 h
VLA-A 8.40×109 0.015 2100A 1.43×1015 0.019 ttp
s
MVLEBRILIN 52..0300××110099 00..001124 3U000A 98..9597××11001144 00..002257 ://ac
a
VLBI 1.70×109 0.021 B 7.00×1014 0.027 de
========== V 5.50×1014 0.029 m
IRAS-12μm 2.50×1013 1.6 R 4.43×1014 0.027 ic.o
Spitzer-15μm 2.00×1013 1.5 I 3.37×1014 0.028 up
Spitzer-20μm 1.50×1013 3.2 NACO-J 2.30×1014 0.032 .co
IRAS-25μm 1.20×1013 6.0 NACO-H 1.76×1014 0.047 m/m
Spitzer-30μm 9.99×1012 7.8 NACO-K 1.36×1014 0.068 n
IRAS-60μm 5.00×1012 27.3 NACO-L 7.90×1013 0.17 ra
s
IRAS-100μm 3.00×1012 35.2 NACO-M 6.70×1013 0.17 /a
Caltech-350μm 8.57×1011 2.23 VLBI-2mm 1.47×1011 2.2 rtic
SCUBA-850μm 3.53×1011 0.19 VLBI-3mm 1.00×1011 8.0 le-a
Note.DatasourcesandspatialscalesaregiveninSection2.9.Thelarge VVLLBBII 48..3600××11001100 76..8686 bstra
aaptethrteuerenddaotfatihnetthaeblIeR.,shownwithcrossesintheSEDinFig.1,areadded VVLLBBAI 12..5200××11001100 49..9198 ct/40
2
VLBI 5.00×109 12.7 /2
========== /7
fromthenucleusareJ−K=0.68andJ−H=1.04.Takingthese ISO-6.7μm 4.44×1013 0.19 24/1
asreferencecoloursfortheCenAstellarpopulation,theinferred ISO-14.3μm 2.00×1013 0.29 10
extinction around the nucleus is AV ∼ 5–7mag. By comparison, ISO-80μm 3.70×1012 1.29 01
9
theextinctioninferredfromthedepthofthesilicate9.6μmfeature ISO-100μm 2.90×1012 1.35 2
inthelineofsightofthenucleus–fromtheVLT/MIDI-correlated ISO-120μm 2.52×1012 1.55 by
spectra–isafactor2–3larger,A ∼13–19mag(seeTable12). ISO-150μm 1.86×1012 1.11 gu
v ISO-170μm 1.72×1012 1.29 es
ISO-180μm 1.62×1012 1.06 t on
2.2 Circinus ISO-200μm 1.47×1012 1.09 1
0
A
Circinus is the second closest AGN in the Southern hemisphere. Note.TheSEDfrom1GeVtotheI bandistakendirectly p
The adopted scale is 1arcsec ∼ 19pc (D = 4.2Mpc; Freeman fromTurleretal.(1999).Furtherdataarecompiledinthis ril 2
etal.1977).Circinus’snucleusistheonlyoneinoursamplethat workandthesourcesaregiveninSection3forthisobject. 01
ThelargeaperturedataintheIR,shownwithcrossesinthe 9
is spatially resolved in the VLT/ NACO adaptive optics images
SEDinFig.1,areaddedattheendofthetable.
from2μmonwards.Thenucleusresolvesintoanelongated,∼2pc
size, structure oriented perpendicular to the ionization-gas cone
axis(Prietoetal.2004).ItsSEDiscompatiblewithdustemission reference are used in the SED. The beam sizes at the available
at a characteristic temperature of 300K; this structure has thus frequencies are6×5.4arcsec2 at20cm,3.4×3.1arcsec2 at13
most of the characteristics of the putative nuclear torus (Prieto cm,1.4×1.3arcsec2at6cmand0.9×0.8arcsec2at3cm.
et al. 2004). Further VLTI/MIDI interferometry in the 8–12μm Mid-IR nuclear fluxes are taken from VLT/VISIR diffraction-
rangealsoresolvesthecentralemissionintoastructureofthesame limited images at 11.9 and 18.7μm (Reunanen et al. 2009). Fur-
characteristics(Tristrametal.2007). thermid-IRdataaretakenfromVLTI/MIDIinterferometryspectra
Circinus’sSEDisshowninFig.1(Table2).Thehighestspatial covering the 8–13μm range (Tristram et al. 2007). Two sets of
resolutionradiodataavailableforthissource–intherangeofafew MIDI data are included in the SED: the correlated fluxes, which
arcsecs only – are presented by Elmouttie et al. (1998). Because correspond to an unresolved source detected with a visibility of
ofthispoorresolution,onlythecentralpeakvaluesgivenbythat 10percent,andthetotalfluxesthataremeasuredwithintheMIDI
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
732 M.A.Prietoetal.
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Figure2. Near-IRcolourmapsofthegalaxiesinthisstudy.MostareJ −KorJ–narrow-bandKmapswhenavailable.Onlytheverycentral2–3arcsec
radiusFoVisshown.ThesmallbaratthebottomofeachpanelindicatesthespatialresolutionofthemapsandinturntheupperlimitsizetotheAGNcorein
theKband.Contoursareover-plottedonsomegalaxiestohelpvisualizethecolourmapstructure.
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744
SEDofnearbygalaxycores 733
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Figure2–continued 0
1
9
2
0.52×0.62arcsec2slit.Inthelattercase,onlyfluxesat8and9.6μm adaptiveopticsimagesbyPrietoetal.(2004).Shortwardsof1μm, by
g
areincluded.Forsakeofsimplicity,fluxmeasurementsatthelonger Circinus’s nucleus is undetected; an upper limit at 1μm derived u
e
MIDIwavelengthsarenotincludedastheyareinverygoodagree- fromtheNACOJ-bandimageisincludedintheSED. st o
ment with the VISIR flux at 11.9μm within 5 per cent. Near-IR Atthehighenergies,theSEDincludestheROSAT1keVfluxafter n
1
nuclear fluxes, in the 1–5μm range, are taken from VLT/NACO correction for the hydrogen column density, derived by Contini, 0
A
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Table11. Galaxiesobservedwithadaptiveopticsinthenear-IRwithVLT/NACO. 01
9
Name Filters(observingdate) Reference
CenA J,H,NB-2.02μm,L(2003March–May),K(2004March) Haering-Neumayeretal.(2006)
Circinus J,K,NB-2.42μm,L,M(2003March–May) Prietoetal.(2004)
NGC1068 K,M(2002November–December),J,H(2004January)J,NB-2.42μm(2005January) Hoenigetal.(2008)
NGC7582 2.06μm(2005May–June),L,NB-4.05μm(2005December) Fernandez-Ontiverosetal.(inpreparation)
NGC5506 J,K,L,M(2003June) Thiswork
NGC1097 J,H,K(2002August),L(2005January) Prietoetal.(2005)
NGC1566 K,L(2005January),J(2005November) Thiswork
NGC3783 J,K,L(2005January) Thiswork
NGC7469 J,H,K(2002November),L,NB-4.05μm(2005December) Thiswork
3C273 J,K,L,M(2003May) Thiswork
Note.Galaxiessortedbydistance.
(cid:3)C 2010TheAuthors.Journalcompilation(cid:3)C 2010RAS,MNRAS402,724–744