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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  • 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

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

  • 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


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.

  • 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


NOTE: Independent from the mass of the galaxy

Other physics needed to interpret Z-Mass relations

For Z << 1:


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)


StellarYields

From Portinari et al 98

NS

RM

Yields computed adopting

ejecta (Mo) vs MCOof

Woosley &Weaver 95


SN Ia yields

Element M/Mo

Nomoto et al 84


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

  • 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

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


    Cayrel et al 00

    Need some Yield adjustement !!!!

    corrected


    Caffau et al. 06


    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


    (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)


    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)

    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

    • 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 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%)

    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%)

    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


    Total fluxes

    Total fluxes

    Nuclear Fluxes

    Nuclear Fluxes

    M87 a young nuclear population?


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