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Roberto Cid Fernandes UFSC – Florianópolis -Brasil

Paleontology of Galaxies Recovering Star Formation & Chemical Enrichment Histories from galaxy spectra. Roberto Cid Fernandes UFSC – Florianópolis -Brasil. STARLIGHT & its many applications. Spectral fits & star-formation histories. Asari et al 2006 CF et al 2005 CF et al 2004.

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Roberto Cid Fernandes UFSC – Florianópolis -Brasil

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  1. Paleontology of Galaxies Recovering Star Formation & Chemical Enrichment Histories from galaxy spectra Roberto Cid Fernandes UFSC – Florianópolis -Brasil

  2. STARLIGHT & its many applications Spectral fits & star-formation histories Asari et al 2006 CF et al 2005 CF et al 2004

  3. STARLIGHT & its many applications UCBD galaxies Corbin et al 2006

  4. STARLIGHT & its many applications Emission line work (from residual spectra) Stasinska et al 2006

  5. STARLIGHT & its many applications HE0450-2958 – The “homeless” QSO CaII Triplet velocity dispersions Merritt et al 2006 Vega 2004, Garcia-Rissman et al 2005

  6. etc ... Someone al 2007, 2008, ...

  7. Flori-where?

  8. 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, ...

  9. The talk • 1- STARLIGHT: Spectral fits using evolutionary synthesis models • How? • What it can(’t) do for you • Miscelaneous Applications: 2 - Seyfert 2s • 3 - Low Luminosity AGN • 4 - CaT-synthesis • 5 - UCBDGs • 6 - SDSS: Fits for 582471 galaxies! • Mass, age, Z*, s*, ... • Correlations, correlations & correlations... • Star-Formation & Chemical enrichment Histories ...

  10. The Conclusions • 1 STARLIGHT: It works!! • Recovers M*, <t*>, <Z*>, s*, 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!!!

  11. Spectral synthesis ofintegrated stellar populations:“...a subject with bad reputation. Too much has been claimed, and too few have been persuaded.” (Searle, 1986)

  12. 1 – STARLIGHT fits: Examples

  13. 1 – STARLIGHT: The recipe = S’s (+ gas + dust + ...)≈ SSSP’s x 10-0.4 A(l) • x1 + x2 + x3 + ...

  14. 1 – STARLIGHT: The ingredients • 150 SSPs from Bruzual & Charlot (2003) • 25 ages: t = 1 Mr – 18 Gyr • 6 metallicites: 0.005 – 2.5 Zo • 1 Reddening law (Cardelli/Calzetti/LMC/SMC) • 1 Gaussian LOSVD: G(v*,s*) • 2 or 3 smart collaborators/students • lots of CPUs ... (~ 150 for ~ 6 months!)

  15. 1 – STARLIGHT: The ingredients

  16. 1 – STARLIGHT: The parameters x = x(t,Z) = lightFRACTION at l0 from population t,Z = “population vector” = (x1,x2,...xN) = Star Formation History Other parameters: AV = dust (only 1 so far...) v* = “redshift” s* = velocity dispersion

  17. 1 – STARLIGHT: The nuts & bolts • Data:Ol± sl ; l = 3400 – 8900 Ǻ – observed spectrum • Model:Ml(x,AV,v*,s*) – model spectrum = SSSPs • Problem: How to estimate x1...xN, AV, v* e s*? • ~ 150 + 3 = 153 parameters!  • Method:Markov Chain Monte Carlo • Metropolis-Hastings + Simulated-annealing • Likelyhood guided “quasi-random” walk Prob(x,AV,v*,s*| Data) ~ exp –{c2 / 2} c2 = S {Ol – Ml(x,AV,v*,s*)}2 lsl2 + Movies! 08 , 32 , 39

  18. Simulations: output ~ input 

  19. Simulations: but ... “AZD” 

  20. 1 – STARLIGHT: The future +Public version by 2006.9999 (code + SDSS fits) +2006.9: a-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, …)

  21. 2 – The SF-History of Sey 2 nuclei CF, Gu, Melnick, Terlevich2, Kunth, Rodrigues Lacerda, Joguet 2004, MNRAS Strong FC in this Sey 1  • 79 galaxies • 65 Sey 2s • ~ 200 pc • Base = BC03 + FC

  22. Result #1: SFH of Sey 2s is very heterogenous! Instantaneous Bursts ?! Continuous SF “Broad Line Sey 2s” or “Sey 3s” Power-Law + E-gal

  23. Result #2: Weak (scattered) BLR & FC! • Starlight-subtracted spectra reveal weak broad Hb 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!

  24. 3 – LINERs & TOs • 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 CF + Gonzalez Delgado et al 2004, 2005 Gonzalez Delgado + CF et al 2004

  25. 3 – Dust in Young TOs: AV(r) x(r) AV(r)

  26. 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....

  27. 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: s*

  28. 4 – Calcium Triplet work Garcia-Rissman et al 2005 Fits with a base of observed stars (kinematical templates) plus a fake continuum

  29. 5 – Ultra Compact Blue Dwarf galaxies Corbin et al 2006

  30. 5 – Ultra Compact Blue Dwarf galaxies Corbin et al 2006 • Fits with: • - 25 ages • - Z0/50 SSPs • SMC ext curve • Nebular Cont.

  31. 5 – Ultra Compact Blue Dwarf galaxies Corbin et al 2006 Light dominated by young stars But most mass is in old generations NOT primaeval! age

  32. 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

  33. 6 – Synthesis of 350k SDSS galaxies A journey through the fascinating (but scary) world of Mega Data Bases

  34. 6 – SDSS: 1st results (CF et al 05, MNRAS) • Products of the synthesis • x = x(t,Z) : Star-formation & chemical histories • M* : stellar Mass • t* & Z* : mean stellar age & stellar metallicity • s* : velocity dispersion • AV : extinction • Observed – Model F(l) = pure emission spectrum • Emission line fluxes • Nebular metallicity, extinction, ...

  35. Stellar versus nebular extinction AV (Balmer) = 0.3 + 1.8 AV (Stellar) Normal Emission Line Galaxies (= non-AGN)

  36. Stellar age x stellar age indicator

  37. Stellar age x nebular age indicator

  38. Stellar Mass x velocity dispersion  :s* < 70 km/s = 0!

  39. Stellar X nebular metallicity! • Very interesting prospects for chemical evolution studies ... • Confirmed, but NOT cited, by a recent paper in MNRAS  Normal Star Forming Galaxies (= non-AGN)

  40. Stellar age x stellar mass More massive galaxies are older. “Downsizing” “Anti-Hierarchical” scenario too old too faint ...

  41. a-enhancement in massive gals.

  42. Going one step further: SFHs Idea: Dissect the SFH = SFR(t) along the left wing of the Seagull (normal SF galaxies) angle f ~ Z(gas)

  43. Going one step further Mass Xf ~ Z(gas) Z(stars) Xf ~ Z(gas)

  44. Going one step further Small, ~ HII galaxies Dominated by ~ 1 burst mean age Big, ~ Starburst nuclei Mixture of bursts

  45. 6 – SDSS: bottomline • Too much information! Parameter brigad!! ? • But great results!! Can’t be too wrong!

  46. 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

  47. The “homeless” QSO – not homeless! HE0450-2958 Magain et al 2005 QSO ULIRG companion galaxy star 100 Myr burst ~ interaction age But not homeless afterall... Just a NLSy1 with a wrongly calculated Black Hole mass! Merritt et al 2006

  48. 5 – Ultra Compact Blue Dwarf galaxies Corbin et al 2006

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