R. Cid Fernandes UFSC – Florianópolis -Brasil
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Transcript of R. Cid Fernandes UFSC – Florianópolis -Brasil
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The New Era in Stellar Populations Synthesis:
Black Magic +
Applications to active & not-so-active galaxies
R. Cid FernandesUFSC – Florianópolis -Brasil GH2004
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The team(s)• Witchcraft: L Sodré, J Gomes, Merlin, H. Potter, ...
• Seyfert 2s: Q Gu, J Melnick, E & R Terlevich, D Kunth, R Rodrigues Lacerda & B Joguet
• LLAGN: R González Delgado, H Schmitt, L Martins,T Storchi-Bergmann, E Pérez, T Heckman, C Leitherer
• SDSS: A Mateus, L Sodré, G Stasinska, J Gomes
• Ca-Triplet: L Vega, N Asari, A Garcia-Rissman,...
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The talk: Witchcraft & applications1 Witchcraft: Spectral fits using evolutionary synthesis models
HowWhat it can(’t) do for you
2 Seyfert 2s: Spectral fits using stars + FC (=AGN power-law)Residual spectra
3 LLAGN: Spectral fits using template galaxies + dustRadial variations (long-slit)
4 SDSS: Mass, age, Z*, *, ...Correlations, correlations & correlationsComparison with Kauffman et al
• Ca-Triplet: Stellar velocity dispersions & EW(CaT)
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The Conclusions1 Witchcraft: It works!! (= it fools people!)
Recovers well M*, <t*>, <Z*>, *, AV, ... Don’t recover details (but who cares?!)
2 Seyfert 2s: Heterogeneous Star-Formation historyFits uncover reflected AGN! (BLR & FC)
3 LLAGN: LINERS are all OLD & boringTransition Objects: OLD or “YOUNG” Young-TOs are dustyYoung-TOs = S(Duper)SC at 108–109 yr?
4 SDSS: A posteriori sanity check on synthesis!Correlations, correlations & correlations Comparison with Kauffman et al:
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1 – Witchcraft: Examples
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1 – Witchcraft: The recipe
’s (+ gas + dust
+ ...) ≈ SSP’s
x1 + x2 + x3
+ ...
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1 – Witchcraft: The ingredients
• 45 SSPs from Bruzual & Charlot (2003)15 ages: t = 1 Mr – 13 Gyr3 metallicites: 0.2 – 2.5 Zo
• 1 Reddening law (Cardelli et al 1989)
• 1 Gaussian LOSVD: G(v*,*)
• 2 or 3 smart collaborators
• 1 tea spoon of huitlacoche
• 5 galons of tequila
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1 – Witchcraft: The parameters
x = x(t,Z) = light FRACTION at from population t,Z
= “population vector”
= (x1,x2,...xN) = Star Formation History
Other parameters:
AV = dust (only 1 so far...) v* = “redshift”
* = velocity dispersion
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1 – Witchcraft: The nuts & bolts
+ Movies!08 , 32 , 39
• Data: O ± ; = 3650 – 8000 Ǻ – observed spectrum
• Model: M(x,AV,v*,*) – model spectrum
• Problem: How to estimate x1...xN, AV, v* e *?~ 45 + 3 = 48 paramerters!
• Method: Markov Chain Monte CarloMetropolis-Hastings + Simulated-annealingLikelyhood guided “random” walk
Prob(x,AV,v*,*| Data) ~ exp –{2 / 2}
2 = {O – M(x,AV,v*,*)}2
2
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Simulations: output ~ input
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Simulations: but ...
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CF, Gu, Melnick, Terlevich2, Kunth, Rodrigues Lacerda, Joguet 04
2 – The SF-History of Sey 2 nuclei
• 79 galaxies 65 Sey 2s
• ~ 200 pc
• Base = BC03 + FC
Strong FC in this Sey
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Coarse (but robust) description of the st pop
INTERMEDIATE108-9 yr
OLD 1010 yr
YOUNG (+ FC)106–7 yr
• Population vector:
Reduce x from N* ~ 20 => 3 components
x = (xY,xI,xO)
xY+ xI+ xO = 1 plane
CF et al 01, 04, GD et al 04
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Result #1: SFH of Sey 2s is very heterogenous!
• Population Vector:
x = flux-fractionx = ( Y+FC , I , O )
Y/FC = 5 Myr + -1.5 FC
I = 100 Myr – 1 Gyr
O = 1 – 10 Gyr
Old pop + burst
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Result #1: SFH of Sey 2s is very heterogenous!
~ 40% Starburst
+ Seyfert 2
composites
“pure/boring” Seyfert 2
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Result #1: SFH of Sey 2s is very heterogenous!
Continuous SF
InstantaneousBursts
Power-Law + E-gal
“Broad Line Sey 2s”
or “Sey 3s”
?!
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Result #2: Weak (scattered) BLR & FC!
• Starlight-subtracted spectra reveal weak broad H in 10/65 Seyfert 2s!
• Most of these have Hidden BLRs revealed in polarized spectra (Tran 95, 01)
• Spectral synthesis finds a strong FC component (~ 20%) in these “Broad Line Seyfert 2s”
Conclusion: Scattered light!
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WK
X [OI]/H
3 – LINERs & Transition Objects
OldYoung
Young TOs OldTOs
OldLINERs
Young LINERs
AG
N
CF etal 04GD etal 0405, 06 ...
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• Long-slit spec. of ~ 50 LLAGN
• Spatial Resolution ~ 1” ~ 100 pc
• Spectral synthesis of 521 extractions
• Base of template galaxies representing Y, I & O populations
St pop, extinction & brightness profiles
3 – LINERs & TOs
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WK(r)
3 – Radial Gradients in LLAGN
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x(r)
AV(r)
3 – Dust in LLAGN: AV(r)
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• Young-TOs have much more dust than
Old-TOs or Old-LINERs
Young-TOs
Old-TOs &
LINERs
3 – Dust in LLAGN: AV(r)
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• Young-TOs have much more dust than
Old-TOs or Old-LINERs
• Central 108-9 yr population is compact
R ≤ 100 pc
• M* ~ 107 Mo
• Super Duper SC??
Young-TOs
Old-TOs &
LINERs
3 – Dust & St pops in LLAGN
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2 + 3 = Evolution of (stars in) AGN?
<t*(Sey2)> < <t*(Young-TO)> < <t*(Old-TO)> = <t*(LINER)>
<t*(Starburst)> < <t*(Young-TO)> < <t*(Old-TO)>
To be continued....
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4 – Synthesis of 50k SDSS galaxies
Abílio Mateus (IAG), Jean Michel Gomes (UFSC)Laerte Sodré (IAG) & Grazyna Stasinska (Meudon)
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Products of the synthesis x = x(t,Z) : Star-formation & chemical histories M* : stellar Mass
t* & Z* : mean stellar age & metallicity
* : velocity dispersion
AV : extinction
Observed – Model F() = pure emission spectrum Emission line fluxes Nebular metallicity, extinction, ...
4 – SDSS: 1st results (including yesterday!)
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Stellar versus nebular extinction
AV (Balmer) = 0.3 + 1.8 AV (Stellar)
Normal Emission Line Galaxies
(= non-AGN)
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Stellar age x stellar age indicator
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Stellar age x nebular age indicator
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Stellar age x stellar mass
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Stellar mass x stellar metallicity
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Roberto: Can you read this?
Stellar X nebular metallicity
hahahahaha
blab
labl
abla
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Us X Them
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4 – SDSS: 1st results
Too much information!
Parameter
But great results!! Can’t be too wrong!
brigad!!
?