Ssp vs galaxies
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Galaxy: Complex chemistry Age distribution. Differential extinction In space In age. Held et al 04. SSP vs Galaxies. SSP: Chemically Homogeneous Coheval Seldom affected by differential extintion Single IMF. Variable IMF ?. S: stellar birth rate

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SSP vs Galaxies

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Ssp vs galaxies

  • Galaxy:

  • Complex chemistry

  • Age distribution

  • Differential extinction

    • In space

    • In age

Held et al 04

SSP vs Galaxies

  • SSP:

  • Chemically Homogeneous

  • Coheval

  • Seldom affected by differential

  • extintion

  • Single IMF

  • Variable IMF ?


Chemo spectrophotometric population synthesis

S: stellar birth rate

fl: star(M,t,Z) spectrum

Without dust a bare integral !

All difficulties in St. Evol. And St. Atmosph. !!

If S=y(t)*f(m)(Bruzual 86) then integrate SSP instead of single stars !

y(t) & Z(t) provided by chemical evolution

Chemo-Spectrophotometric Population Synthesis

First consistent chemo + stellar evolution + spectral code by Bressan et al 94

Many other synth. tools, e.g. Bruzual & Charlot 90-06…, Jimenez et al 00… etc..


Chemical evolution of galaxies

CHEMICAL EVOLUTION OF GALAXIES

  • A simple model:

    • Close model (no inflow and/or outflow of gas)

    • IMF constant in time

    • Instantaneous mixing of ejected material

    • Initial gas is primordial

Initial conditions


Ssp vs galaxies

E(t): the rate of gas ejection by dying stars

mr is the mass of the remnant

tm is the lifetime of the star with mass m

EZ(t): the rate of metal ejection by dying stars

pZm : mass fraction of newly produced and ejected

elements


Instantaneous recycling appr

Instantaneous Recycling Appr.

  • Stars with mass < mI (=1 MŸ) never daytm = ∞

  • Stars with mass ≥ mI have negligible lifetimetm = 0

  • R is the mass returned to the ISM by a simple stellar population

  • R is constant as long as mr does not depend on Z


Ssp vs galaxies

NOTE: Independent from the mass of the galaxy

Other physics needed to interpret Z-Mass relations

For Z << 1:


For a more detailed description

For a more detailed description:

  • Stellar Evolution:

    • lifetimes

    • detailed ejecta (vs. mass & composition, SNIa)

  • Gas:

    • mixing processes, inflow & outflow, heating and cooling

  • Stellar birthrate:

    • star formation efficiency & IMF

    • (e.g. revs. by Matteucci 03, Pagel 03)


Stellar yields

StellarYields

From Portinari et al 98

NS

RM

Yields computed adopting

ejecta (Mo) vs MCOof

Woosley &Weaver 95


Sn ia yields

SN Ia yields

Element M/Mo

Nomoto et al 84


Observations thin thick disk

Observations: Thin & Thick Disk

A04 = AllendePrieto et al. (2004) B03 = Bensby et al. (2003)

B04a= Bensby et al. (2004)C00 = Chen et al. (2000)

E93= Edvardsson et al. (1993)F00 = Fulbright (2000)

G03= Gratton et al. (2003)M04 = Mishenina et al. (2004)

N97 = Nissen & Schuster (1997)P00 = Prochaska et al.(2000)

R03 = Reddy et al. (2003)

(from Soubiran & Girard 05)


Linear trends

Linear Trends

  • For the thin disk :

    • [Mg/Fe]=-0.37[Fe/H]-0.040 s =0.067 dex

    • [a/Fe]=-0.29[Fe/H]-0.029 s =0.052 dex

  • For the thick disk :

    • [Mg/Fe]=-0.41[Fe/H]+0.097, s =0.092 dex

    • [a/Fe]=-0.30[Fe/H]+0.071, s =0.069 dex

  • (from Soubiran & Girard 05)


    Observations and chemical ev model for solar vicinity

    Observations and Chemical Ev. Model for Solar Vicinity

    Chemo-kinematical parameters for 424 stars Rocha-Pinto et al. 04


    Ssp vs galaxies

    Cayrel et al 00

    Need some Yield adjustement !!!!

    corrected


    Ssp vs galaxies

    Caffau et al. 06


    With detailed sfr chemistry

    With detailed SFR & chemistry

    • Gas fraction and Z

      • dust fraction

    • SNIa, Ib/c and II rates

      • SNIIs allow prediction of radio emission

    • Detailed abundance of gas going into SF(t)

      • effects of enhancement in norrow band indices


    Ngc 4435

    (Panuzzo et al 06)

    NGC4435

    • NGC4435 is an SB0(7) in interaction with NGC4438 (spiral): nearest passage about 100 Myr ago(Vollmer et al 05)

    • MBH by Coccato et al 05

    • Opt. Pop. Study by Sarzi et al 05

    • MIR spectrum typical of a star forming object (spiral NGC7331)


    Uv nir mir fir radio old starburst

    GRASIL FIT

    OLD

    MC

    Diffuse dust

    NGC

    4435

    UV+NIR+MIR+FIR + RadioOLD+Starburst


    Best fit model of central 5 with grasil silva et al 98 vega et al 05

    Best fit model of central 5” with GRASIL (Silva et al 98, Vega et al 05)

    Old M ~ 8 109M⊙ Age ~ 9 Gyr Z = 0.02

    Young:

    post starburstwith residual SFR~0.07 M⊙/yr

    Age~ 180 Myr

    <SFR>~0.7 M⊙/yr

    MBURST~ 1.2 108M⊙~ 1.5% MGAL (5 arcsec)

    PAH model (Li & Draine 01, Vega et al 05) needs revison above 14 mm


    Today more complex models

    Today more complex models

    • Multi-phase models (heating, cooling of gas)

    • Semi-analitic models (Durham, Munich, etc..)

    • Effects of dust reprocessing (e.g. GRASIL)

    • Galaxy-AGN co-evolution (e.g. Granato et al 04)


    Ssp vs galaxies

    SSP in the MIR

    10µm bump:Dusty AGB envelopes ?

    • O-rich SSP models

      (Bressan et al 98)

    • The emission feature is very similar to observed O-rich AGB outfows

      (ISO, Molster et al. 2000)


    Emission lines 2 galaxies 12

    Emission Lines 2 galaxies (12%)

    N4636[NeII]12.8 mm [NeIII]15.5 mm [SIII]18.7 mm

    N4486[ArII]7 mm [NeII]12.8 mm [NeIII]15.5 mm [SIII]18.7 mm

    ( M87 )


    Pahs 2 galaxies 12

    PAHs 2 Galaxies (12%)

    N45506.2, 7.7, 8.6, 11.3, 11.9, 12.7mm

    N44356.2, 7.7, 8.6, 11.3, 11.9, 12.7, 16.4mm

    also [ArII]7 mm, [NeII]12.8 mm, [NeIII]15.5 mm, H2S(1)17.04 mm [SIII]18.7 mm


    M87 a young nuclear population

    Total fluxes

    Total fluxes

    Nuclear Fluxes

    Nuclear Fluxes

    M87 a young nuclear population?


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