Fabio La Franca and N. Sacchi, S. Puccetti, F. Fiore, C. Gruppioni, C. Feruglio et al.
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Transcript of Fabio La Franca and N. Sacchi, S. Puccetti, F. Fiore, C. Gruppioni, C. Feruglio et al.
Fabio La Franca
and N. Sacchi, S. Puccetti, F. Fiore, C. Gruppioni, C. Feruglio
et al.
Dipartimento di Fisica
The nature and density of Spitzer selected X-ray absorbed AGN:
Identification of sources with large Identification of sources with large MIR/Optical ratios in the MIR/Optical ratios in the XMM/SWIRE/ELAIS-S1XMM/SWIRE/ELAIS-S1
Universita` degli Studi ROMA TRE
-What is the fraction of AGN among the sources with large MIR/O?
-What is the fraction of absorbed AGN?
-Is the density of absorbed AGN compatible to other estimates orextrapolations (i.e. XLF)?
QUESTIONSQUESTIONS
What do we know about the AGN evolution?
A Luminosity Dependent Density Evolution(LDDE) for X-ray AGN isobserved(e.g. Ueda+03; Fiore+03; La Franca+05;Barger+05; Hasinger+05; Gilli+07; Silverman+07; Della Ceca+08)
Lower luminosity AGNpeak at lower redshifts:DOWNSIZING(see models of galaxy andAGN formations)
La Franca+05
*) Assuming no luminosity and redshift dependences
assumed *)
expected
What do we know about the AGN evolution?
The fraction of absorbed AGN as function of LX and z
DECREASE WITH LUMINOSITYEarlier evidences of a decrease of the fraction of absorbed AGN with luminosity from Lawrence & Elvis (1982), confirmed by Ueda et al. (2003).
INCREASE WITH THE REDSHIFT
Fract
ion o
f A
bso
rbed A
GN
La Franca+05
The LX-z plane
~1x10-15@2Ms
?
X-ray stacking analysis of MIR selected AGNsX-ray stacking analysis of MIR selected AGNsallows to probe more distand, more absorbed,allows to probe more distand, more absorbed,lower luminosity, regions of the Llower luminosity, regions of the LXX-N-NHH-z plane-z plane
Many studies indicate that the majorityof the sources with extremeF(24um)/F(R) (e.g. >1000) ratios areobscured/absorbed AGNs
(see e.g. Martinez-Sansigre+05; Houck+05;Weedman+06; Brown+06; Polletta+06; Yan+07; Daddi+07; Fiore+08; Georgantopoulos+08…)
However,1) these sources are so faint, that direct optical spectroscopic classifications
is available for very few of them;2) the density estimates are based on assumptions on the NH distribution.
AREA0.6 deg2 (:0.5h, :-43.5o)
IMAGINGBVRIz (PI Franceschini; Berta+06+08)
JK (PI Cimatti/Maiolino; Dias+08)
SWIRE (PI Lonsdale & Rowan-Robinson)(3.6, 4.5, 5.8, 8.0 and 24 μm)
X-ray (PI: Fiore) by XMM 4x100Ks (Puccetti+06)
Chandra x5 (Puccetti in prep)
SPECTROSCOPY(PI La Franca; Sacchi in prep)
~100 hours withVIMOS and FORS2@VLT
Total~1500 Zs (R<24.5) (K, 3.6um and 24um sources)
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field Method: data
Catalogue of ~1700 24m sources with F24 > 0.280 mJy
Redshift for 384 sources with R<24.2
Seyfert2/AGN2 (SED:10-13) Seyfert2/AGN2 (SED:10-13)
ULIRG/Starburst (SED: 7-9)ULIRG/Starburst (SED: 7-9)
Spirals Star Forming (SED:14-20)Spirals Star Forming (SED:14-20)
Ellipticals (SED:21)Ellipticals (SED:21)
Red Power Law ~AGN1 (SED:1-6) Red Power Law ~AGN1 (SED:1-6)
Adapted from Polletta et al. (2007)
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field Method: SED templates fitting
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field Method: SED templates fitting
(see Polletta et al. 2007)
AGN2
AGN1
Normal
χ2 best fit analysis
1st choice
2nd choice 3rd choice
SED
Normal
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field SED classification of high MIR/O sources
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field SED classification of high MIR/O sources
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field SED classification of high MIR/O sources
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field SED classification of high MIR/O sources
Local relationshipun-absorbed AGN
20%20%
4343%34%34%
3%3%
What is the fraction/densityof (possibly absorbed) AGNamong these high MIR/Osources?
First look at the OPT spectra…
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field OPTICAL VLT SPECTROSCOPY of faint (R>22) high MIR/O sources
TOTAL: 384 spectra
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field OPTICAL VLT SPECTROSCOPY of faint (R>22) high MIR/O sources
composite spectraTOTAL: 384 spectra
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field OPTICAL VLT SPECTROSCOPY of faint (R>22) high MIR/O sources
82% of SED-PWL are optical 82% of SED-PWL are optical AGNAGN93% of SED-ULIRG are optical 93% of SED-ULIRG are optical ELGELGSED-Seyfert2: no preferencesSED-Seyfert2: no preferences
composite spectraTOTAL: 384 spectra
40% AGN2 (& AGN1)
60% ELG
56 spectra
What about their SED?
X-ray detections and stacking (filled symbols)
STACKED DATA
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field X-ray stacking analysys of faint (R>22) high MIR/O sources
82% of OPT-AGN82% of OPT-AGNare X-ray absorbed AGNare X-ray absorbed AGN
85% of OPT-ELG85% of OPT-ELGare mildly X-ray are mildly X-ray absorbed withabsorbed withLL2-102-10~10~1041-4241-42
MID TERM SUMMARY:SED-PWL --> optical AGN(2) --> X-ray absorbed AGNSED-ULIRG --> optical ELG --> mildly absorbed low LX
Spec. and phot. redshiftsSpec. and phot. redshifts
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field SED classification of high MIR/O sources
The sources with F24/FR>120 havez>0.6 and LogL24>44
Analysis for ∆z=0.6-1.3*
i.e.∆LogL24=44-45.5
*) At z>1.3 the sample is incomplete becouse of fainter R>25 unindentified sources
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field X-ray properties of low MIR/O sources
X-ray detections and stacking (filled symbols)
Low MIR/O sources show low LX and mild absorption,compatible with absorbed X-ray spectra of strongstar-forming galaxies
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field X-ray properties of high MIR/O sources
X-ray detections and stacking (filled symbols)
SOFT0.3-1.5 keV
HARD1.5-6 keV
R>25
SED-SEY2
SED-Red PWL
What are their densities?…
73% of large MIR/O (F24/R>120) sources are absorbed AGN
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field Density of X-ray absorbed large MIR/O sources
The density is compatible with the extrapolations
coming from previous estimates at z~1of the XLF of Compton thin AGN
LogNH~22.3
LogNH~23.1
~1x10-15@2Ms
Looking for absorbed AGN in the XMM/SWIRE/ELAIS-S1 field Density of X-ray absorbed large MIR/O sources
?
We have probed a one decade less luminous region at z~1 or a 0.7 larger redshift at LogL2-10~42.5
-We have carried out optical spectroscopic identification of 56 sourceswith F24/R>120 and R<24.2.
- The fraction of optically classifiedoptically classified (or X-ray luminous) AGN is 40(45)%. SED-PWL --> optical AGN(2) --> X-ray absorbed AGN SED-ULIRG --> optical ELG --> mildly absorbed, low LX
-According to the X-ray stacking analysis, 73% of the sources are absorbed(22<LogNH<23.5) AGN with Log(L2-10)>42 cgs.
-Their density is compatible with the extrapolations at z~1 of the XLFof Compton thin AGN.
SUMMARY