COSMIC DOWNSIZING and AGN METALLICITY at HIGH REDSHIFT Roberto Maiolino INAF - Oss. Arcetri & Oss....
Transcript of COSMIC DOWNSIZING and AGN METALLICITY at HIGH REDSHIFT Roberto Maiolino INAF - Oss. Arcetri & Oss....
COSMIC DOWNSIZINGand
AGN METALLICITYat HIGH REDSHIFT
Roberto MaiolinoINAF - Oss. Arcetri & Oss. Roma
Tohru NagaoINAF - Oss. Arcetri & NAOJ
Alessandro MarconiINAF - Oss. Arcetri
Mass-Metallicity relationin galaxies at z=0
Tremonti et al. 2004
Chemical version of theChemical version of thecosmic downsizing (anti-hierarchical growth)cosmic downsizing (anti-hierarchical growth)
z=01
35
lg M* = 8
10
9
11
12
Evolution of the Mass-Metallicity relation:Evolution of the Mass-Metallicity relation: massive galaxies chemically evolve rapidly at high-zmassive galaxies chemically evolve rapidly at high-z
QSOs QSOs
(Kobulnicky et al. 2003, Shapley et al. 2005, Savaglio et al. 2005, Maiolino et al. 2006)
The metallicity of theThe metallicity of theBroad Line Region at 2<z<4.5Broad Line Region at 2<z<4.5
~ 5000 QSO optical spectra (UV-rest) from SDSS DR2~ 5000 QSO optical spectra (UV-rest) from SDSS DR2
Sample large enough to disentagle theSample large enough to disentagle thedependence on redshift and on luminositydependence on redshift and on luminosity
22 high quality composite spectra22 high quality composite spectrain bins of redshift and luminosityin bins of redshift and luminosity
Nagao, Marconi & Maiolino 2006
NV
SiII
OI+SiIICII
SiIVHeII
OIV]NIV]
CIV
“1600A bump”
OIII]AlII
SiIII]AlIII
Ly
CIII]
NIV+AlII+NIII+Fe
fit residuals
Accurate fluxes for15 emission lines
Photoionization models:- Cloudy- Integration over different distributions (in r and n) of gas clouds- Spanning various gas metallicities (abundances prop. to solar, except for N)
matching flux ratios(+ constraints from EW) Hagai (!)
“best” metallicityfor each [z,L] bin
Nagao et al. 2006
Metallicity ofMetallicity ofthe BLR at 2<z<4.5the BLR at 2<z<4.5
Average trendsAverage trends
- Significant dependenceSignificant dependence on Luminosityon Luminosity
- No evolution with redshiftNo evolution with redshift
Consequence of the mass-metallicity relationZ M* MBH LQSO
...but also dependence on accretion rate(Shemmer et al. 2004)
No metallicity evolution evenNo metallicity evolution evenin the most distant QSOs at 4.5<z<6.4in the most distant QSOs at 4.5<z<6.4
(close to re-ionization)(close to re-ionization)
From near-IR spectraFrom near-IR spectra(=UV rest-frame) of 20 QSO(=UV rest-frame) of 20 QSO
J1148+52z=6.4
QSOs probe the most extreme cases ofanti-hierarchical growth:
their host galaxies are fully evolved, from the chemicalpoint of view, already at very high redshift
z=01
35
lg M* = 8
10
9
11
12QSOs QSOs
Large number of emissionLarge number of emissionlines: possible to contrainlines: possible to contrainabundances patternsabundances patterns
Best matchesBest matcheswith abundanceswith abundancesat/after the windat/after the wind QSOs
best fit
Selection effectsSelection effectsassociated withassociated withQSO-galaxy coevolutionQSO-galaxy coevolution
Star formation +Obscured AGN
Passive evolution +Unobscured QSO
wind
Pipino & Matteucci 2004Granato et al. 2004
The Broad Lines sample only a tiny, nuclear region... not representative of the host galaxy?
Use Narrow Lines in obscured AGNs
NLR evolution at 1.2<z<3.8NLR evolution at 1.2<z<3.8
Nagao, Maiolino & Marconi 2006
- 51 optical spectra (UV-rest) of high redshift- 51 optical spectra (UV-rest) of high redshift narrow line radio galaxies (HzRG)narrow line radio galaxies (HzRG)- 10 optical spectra (UV-rest) of high redshfit X-ray- 10 optical spectra (UV-rest) of high redshfit X-ray selected QSO2 in the Chandra Deep Field Southselected QSO2 in the Chandra Deep Field South
CIV/HeII vs. CIII]/CIV diagram:CIV/HeII vs. CIII]/CIV diagram: - sensitive to metallicity- sensitive to metallicity - removes degeneracy from U- removes degeneracy from U - possible to control effects of shocks and dust- possible to control effects of shocks and dust
(local)
(local)C
IV /
HeII
1
0.5
3
CIV
/ H
eII
1
0.5
3
CIII] / CIV0.3 1
NLR evolutionNLR evolutionat 1.2<z<3.8at 1.2<z<3.8
No evolution with redshiftNo evolution with redshiftamong HzRG at 1.2<z<3.8among HzRG at 1.2<z<3.8
Dependence on LuminosityDependence on Luminosity
At z>4 little information on NLR metallicity...but information on gas in host galaxy for some QSOs
strong enrichment of carbon in thestrong enrichment of carbon in the host already at z=6.4 host already at z=6.4
J1148+52z=6.4
same [CII]/FIR as loc. ULIRGssame [CII]/FIR as loc. ULIRGssame [CII]/CO as loc. ULIRGssame [CII]/CO as loc. ULIRGs
CONCLUSIONS
Luminosity-Metallicity relation: consequence of Mass-Metallicity relation in galaxies
No metallicity evolution with redshift: QSO are extreme cases of the cosmic downsizing (in its chemical version)
BLR&NLR
Abundance patterns matching expectations ofAGN-galaxy joint evolutionary models