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Paleontology of Galaxies Recovering Star Formation & Chemical

Enrichment Histories from galaxy spectra

Roberto Cid FernandesUFSC – Florianópolis -Brasil

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STARLIGHT & its many applications

Spectral fits & star-formation histories

Asari et al 2006CF et al 2005CF et al 2004

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STARLIGHT & its many applications

UCBD galaxies

Corbin et al 2006

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STARLIGHT & its many applications

Emission line work (from residual spectra)

Stasinska et al 2006

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STARLIGHT & its many applications

HE0450-2958 – The “homeless” QSO

CaII Triplet velocity dispersions

Vega 2004, Garcia-Rissman et al 2005

Merritt et al 2006

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etc ...

Someone al 2007, 2008, ...

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Flori-where?

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The team(s)• Techniques: L Sodré, J Gomes, Merlin, Harry Potter, ...

• Seyfert 2s: Q Gu, J Melnick, E & R Terlevich, D Kunth

• LLAGN: R González Delgado, E Pérez, H Schmitt, L Martins, T Storchi-Bergmann

• SDSS: A Mateus, L Sodré, G Stasinska, J Gomes, N Asari, W Schoenell, L Vega, J P Papaqui

• Ca-Triplet: L Vega, N Asari, A Garcia-Rissman,...

• WR-galaxies: J Leão, C Leitherer

• UCBD-galaxies: M Corbin, W Vacca, ...

• The homeless QSO: D Merrit, T Storchi-Bergmann, D Axon, ...

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The talk1- STARLIGHT: Spectral fits using evolutionary synthesis models

How? What it can(’t) do for you

Miscelaneous Applications: 2 - Seyfert 2s3 - Low Luminosity AGN4 - CaT-synthesis5 - UCBDGs

6 - SDSS: Fits for 582471 galaxies! Mass, age, Z*, *, ...

Correlations, correlations & correlations...Star-Formation & Chemical enrichment Histories ...

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The Conclusions1 STARLIGHT: It works!!

Recovers M*, <t*>, <Z*>, *, AV, ... And pretty decent SF & chemical histories too!

2 Seyfert 2s: Heterogeneous Star-Formation history Fits uncover reflected AGN! (BLR + continuum)

3 LLAGN: LINERS are all OLD & boring Transition Objects = OLD or “YOUNG” Young-TOs are dusty 108–109 yr post-starbursts

...

6 SDSS: Beautiful results, but too much info to digest!!!

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Spectral synthesis ofintegrated stellar

populations:

“...a subject with bad reputation. Too much has been claimed, and too few have been persuaded.”

(Searle, 1986)

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1 – STARLIGHT fits: Examples

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1 – STARLIGHT: The recipe

’s (+ gas + dust

+ ...) ≈ SSP’s x 10-0.4

A()

x1 + x2 + x3

+ ...

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1 – STARLIGHT: The ingredients

• 150 SSPs from Bruzual & Charlot (2003)25 ages: t = 1 Mr – 18 Gyr6 metallicites: 0.005 – 2.5 Zo

• 1 Reddening law (Cardelli/Calzetti/LMC/SMC)

• 1 Gaussian LOSVD: G(v*,*)

• 2 or 3 smart collaborators/students

• lots of CPUs ... (~ 150 for ~ 6 months!)

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1 – STARLIGHT: The ingredients

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1 – STARLIGHT: 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 – STARLIGHT: The nuts & bolts

+ Movies!08 , 32 , 39

• Data: O ± ; = 3400 – 8900 Ǻ – observed spectrum

• Model: M(x,AV,v*,*) – model spectrum = SSPs

• Problem: How to estimate x1...xN, AV, v* e *?~ 150 + 3 = 153 parameters!

• Method: Markov Chain Monte CarloMetropolis-Hastings + Simulated-annealingLikelyhood guided “quasi-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 ... “AZD”

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1 – STARLIGHT: The future

+ Public version by 2006.9999 (code + SDSS fits)

+ 2006.9: -enhanced SSPs – essential for Ellipticals! (Coelho et al, …) ... Not so easy...

+ 2005.5: Nebular continuum .... Done

+ 2005.9: More than 1 extinction ... Done, but ...

+ 3001.2: Smarter/faster method to explore huge parameter spaces

(adaptative-MCMC, Genetic-MCMC, …)

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CF, Gu, Melnick, Terlevich2, Kunth, Rodrigues Lacerda, Joguet 2004, MNRAS

2 – The SF-History of Sey 2 nuclei

• 79 galaxies 65 Sey 2s

• ~ 200 pc

• Base = BC03 + FC

Strong FC in this Sey

1

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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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• 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

CF + Gonzalez Delgado et al 2004, 2005Gonzalez Delgado + CF et al 2004

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x(r)

AV(r)

3 – Dust in Young TOs: AV(r)

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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 – Calcium Triplet work

A Garcia Rissman (LNA), L Vega (Córdoba/UFSC), N Vale Asari (UFSC), CF, H Schmit (NRL),

R González Delgado (IAA), T Storchi-Bergmann (UFRGS)

Garcia-Rissman et al 2005, MNRAS+ Vega et al 2006 (in prep)

+ Barbosa et al 2006 (IFU => v-field)

Different application of the same code: *

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4 – Calcium Triplet work Garcia-Rissman et al 2005

Fits with a base of observed stars (kinematical templates) plus a fake continuum

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5 – Ultra Compact Blue Dwarf galaxies

Corbin et al 2006

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5 – Ultra Compact Blue Dwarf galaxies

Corbin et al 2006

Fits with:

- 25 ages- Z0/50 SSPs- SMC ext curve- Nebular Cont.

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5 – Ultra Compact Blue Dwarf galaxies

Corbin et al 2006

age

Light dominated by young stars

But most mass is in old generations

NOT primaeval!

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6 – Synthesis of 582k SDSS galaxies

N Asari, J Gomes, W Schoenell, J P Papaqui (UFSC)A Mateus (IAG), L Sodré (IAG) & G Stasinska (Meudon)

The SEAGal Collaboration: Semi-Empirical Analysis of Galaxies

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6 – Synthesis of 350k SDSS galaxies

A journey through the fascinating (but scary) world of Mega Data Bases

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Products of the synthesis x = x(t,Z) : Star-formation & chemical histories M* : stellar Mass

t* & Z* : mean stellar age & stellar metallicity

* : velocity dispersion

AV : extinction

Observed – Model F() = pure emission spectrum Emission line fluxes Nebular metallicity, extinction, ...

6 – SDSS: 1st results (CF et al 05, MNRAS)

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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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: * < 70 km/s = 0!

Stellar Mass x velocity dispersion

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Stellar X nebular metallicity!

Normal Star Forming Galaxies (= non-AGN)

• Very interesting prospects for chemical

evolution studies ...

• Confirmed, but NOT cited, by a recent paper

in MNRAS

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Stellar age x stellar mass

More massive galaxies are older.

“Downsizing”

“Anti-Hierarchical” scenario

too old too faint ...

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-enhancement in massive gals.

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Going one step further: SFHsIdea:

Dissect the SFH = SFR(t) along the left wing of the Seagull (normal SF galaxies)

angle ~ Z(gas)

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Going one step further

Mass X ~ Z(gas) Z(stars) X ~ Z(gas)

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Going one step furtherSmall, ~ HII galaxiesDominated by ~ 1 burst

Big, ~ Starburst nucleiMixture of bursts

mea

n ag

e

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6 – SDSS: bottomline

Too much information!

Parameter

But great results!! Can’t be too wrong!

brigad!!

?

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A nagging question: Which base?Results change if one allows for Z < 0.2 Z0 populations in the base!

• 1/5 < Z < 2.5

• 1/200 < Z < 2.5

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HE0450-2958

Merritt et al 2006

The “homeless” QSO – not homeless!

ULIRG companion galaxy

100 Myr burst ~ interaction age

But not homeless afterall...Just a NLSy1 with a wrongly calculated Black Hole mass!

QSO

star

Magain et al 2005

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5 – Ultra Compact Blue Dwarf galaxies

Corbin et al 2006

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5 – Ultra Compact Blue Dwarf galaxies

Corbin et al 2006

Fits with:

- 25 ages- Z0/50 SSPs- SMC ext curve- Nebular Cont.

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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* ~ 45 => 3 components

x = (xY,xI,xO)

xY+ xI+ xO = 1 plane

CF et al 01, 03, 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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WK

X [OI]/H

3 – LINERs & Transition Objects

OldYoung

Young TOs OldTOs

OldLINERs

Young LINERs

AG

N

CF et al 04, 05GD et al 04, 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

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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Flori-where? You are here...

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The Star Formation

History of Galaxies

(as revealed by their spectra)Roberto Cid Fernandes

UFSC – Florianópolis -Brasil