The Evolution of Metals and Dust in the high-z Universe Eli Dwek - PowerPoint PPT Presentation

The Evolution of Metals and Dust in the high-z Universe Eli Dwek Observational Cosmology Lab NASA Goddard Space Flight Center Frederic Galliano NASA/GSFC, Univ of Maryland Ant Jones Institute d’Astrophysique Spatiale Claude Monet

CO emission Dust Formation at High Redshift SDSS J114816 (z ≈ 6.4) (Dwek, Galliano & Jones 2007 ApJ, 662, 927) AGN Age of the universe = 870 Gyr Age of galaxy ≈ 400 Myr (z i = 10) IR luminosity ≈ 2 x 10 13 L sun M dust ≈ (0.9 - 4) x 10 8 M sun M gas ≈ 2 x 10 10 M sun M dyn ≈ 5x10 10 M sun M dust /M gas ≈ (0.5-1) x 10 -2 SFR ≈ 4000 M sun /yr

The spectral energy distribution (SED) of J114816 Submm surveys are Only a fraction of the important for probing (see poster by UV/optical escapes the number of SF Staghun) galaxies at high-z

The Problem: How can a galaxy produce 2 x 10 8 M sun of dust in only 400 Myr? No problem: • Dust could only have formed in core collapse SN • SFR ≈ 4000 M sun /yr SN rate ≈ 30/yr (Salpeter IMF) Each SN must make only 0.02 M sun of dust

The Problem: How can a galaxy produce 2 x 10 8 M sun of dust in only 400 Myr? No problem: • Dust could only have formed in core collapse SN • SFR ≈ 4000 M sun /yr SN rate ≈ 30/yr (Salpeter IMF) Each SN must make only 0.02 M sun of dust But there are 2 problems: • SFR ≈ 400 M sun /yr SN rate ≈ 8/yr (top heavy IMF) Each SN must make ≈ 0.06 M sun of dust • SN are also very efficient destroyers of interstellar dust

The Problem: How can a galaxy produce 2 x 10 8 M sun of dust in only 400 Myr? No problem: • Dust could only have formed in core collapse SN • SFR ≈ 4000 M sun /yr SN rate ≈ 30/yr (Salpeter IMF) Each SN must make only 0.02 M sun of dust But there are 2 problems: • SFR ≈ 400 M sun /yr SN rate ≈ 8/yr (top heavy IMF) Each SN must make ≈ 0.06 M sun of dust • SN are also very efficient destroyers of interstellar dust ISM mass cleared dust yield dust-to-gas In a steady ≈ X of dust by a in SN mass ratio state single SNR Yield ≈ 0.01 x 300 ≈ 3 M sun

The cycle of dust in the ISM 1. Formation protostars stellar SN winds 2. Interstellar processing SN blast waves solar nebula Interstellar clouds 1 Antennae - IR Antennae - opt

A spherical cow may be a good representation of reality, provided you have a sufficiently limited point of view

How does the chemical evolution of dust differ from normal chemical evolution? + infall SNII, SNIa, dN A /dt = - + astration WR, AGB, - Novae outflow SNII SNIa dN A /dt = - + astration AGB WR, Novae + infall destruction accretion - + by SNR in clouds - outflow -

How does the chemical evolution of dust differ from normal chemical evolution? + infall SNII, SNIa, dN A /dt = - + astration WR, AGB, - Novae outflow SNII SNIa dN A /dt = - + astration AGB WR, Novae + infall destruction accretion - + by SNR in clouds - outflow -

Chemical evolution parameters • Chemical evolution model infall model ....................... ✦ closed box ....................... ✦ • SFR Kennicutt law: SFR~M 1.4 ✦ analytical prescription ✦ • Stellar IMF Salpeter IMF (others) ✦ • m -2.35 log(IMF) Nucleosynthesis yields • Grain Formation/destruction log(m)

Prediction A simple dust SN condensed dust evolution model and AGB dust have (Dwek 1998, distinct evolutionary Dwek, Galliano & Jones 2006) histories • Closed box model • Condensation efficiencies = 1 • Destruction m g =300 M sun ✦ • IMF Salpeter ✦ M low = 0.7 M sun ; ✤ SN AGB M up = 40 M sun ✤

H H C C H H C C C C C C H H C C C C C C H H C C H H

A trend of PAH abundance with metallicity (time) ISO (Madden et al. 2004) Spitzer (Engelbrecht et al. 2004) Existence of metallicity cutoff Correlation of PAH intensity with metallicity Milk Correlation of PAH intensity with metallicity is converted to PAH abundance versus metallicity Galliano, Dwek & Chanial 2007, astro-ph

Final fit to galaxy’s SED A fit to the dust emission from HI and HII regions is necessary in order to determine the ISRF that heats the PAHs (Galliano, Dwek, & Chanial 2007)

The delayed injection of PAHs by AGB stars into the ISM : A natural explanation for the PAH abundance trend with metallicity 14

Models are greatly simplified at high redshift • Instantaneous recycling approximation • The contributioon of AGB stars can be neglected • Parameters for the closed box model: ✦ the gas mass fraction ✦ the mass of stars formed per SN event (M sn ) ✦ the mass of ISM gas cleared of dust by a single SNR (M g ) • Same results are obtained for an infall model

Simple Chemical Evolution Model: Closed box model, no Infall/Outflow The evolution of the gas dM g dt = − ( 1 − R ) ψ ( t ) � k � M g SFR Initial gas mass ψ ( t ) = ψ 0 M 0 M 0 Evolution of gas mass fraction ( ) k = 1 µ ( t ) ≡ M g ( t ) � � ψ 0 � � = exp − ( 1 − R ) t M 0 M 0

The evolution of the dust Z d ≡ M d M g dM d dt = − Z d ψ ( t )+ Y d R SN − M d R SN = ψ ( t ) τ d � m SN � M g dy τ d = General type dx = f ( x )+ g ( x ) y m g R SN � M 0 � Solution µ ( 1 − µ ν ) M d ( t ) = Y d m g + � m SN � R ν ≡ m g + � m SN � R � m SN � ( 1 − R ) � M g ( t ) � ( 1 − µ ν ) M d ( t ) = Y d m g + � m SN � R

Supernovae destroy dust during the remnant phase of their evolution Cygnus Loop: X-rays (Einstein) Cygnus Loop: IR emission from dust collisionaly-heated by the shocked gas Cygnus Loop: Infrared (IRAS)

Grain Destruction Processes Thermal sputtering Vs > 200 km/s Cratering Vs ≈ 50- 200 km/s Fragmentation Vs ≈ 20- 50 km/s 46

Grain destruction efficiencies (Jones, Tielens, Hollenbach, & McKee 1994, 1996) Mass of dust destroyed by a single SNR � v f � dM ISM � M d = Z d f d ( v s ) dv s dv s v 0

SN Yield Required to Produce an Observed Z d � m g + � m SN � R � Y d = Z d ( t ) 1 − µ ν m g (M sun ) Milky Way value No grain destruction Largest observed SN yield (Sugerman et al. 2006)

SN 1987A Yield of Condensable Elements 25 Msun (Woosley & Weaver 1995) Element Y(M sun ) C/O > 1 _____________ C 0.1 O 0.4 Mg 0.02 Si 0.3 Fe 0.07 _____________ Dust ≈ 1 M sun Silicates: SiO 2 Carbon: C 22

Multiwavelength Observations of Cas A Chandra 2.25–7.50 keV 1.65–2.25 keV Opt - Hubble IR - Spitzer Dust mass ≈ 10 − 2 M ⊙

SCUBA 450 & 850 µ m observations of Cas A: Evidence for massive amounts of cold dust? (Dunne et al. 2003) 450 µ m 850 µ m Thermal Dust 114 K 18 K Synchrotron 850 µ m – synchr . Dust Mass (M sun ) M 114 K ≈ 10 -3 M 18 K ≈ 2–20

Problems with the Dunne et al. interpretation: (1) The 170 µ m flux is an (2) Needles could ISO detection alleviate the large mass of (Tuffs et al.) dust implied by the 450 µ m SCUBA “detections” but ..... needles (3) The 450 µ m emission arises from a cloud along the LOS of Cas A

Conclusion: sofar there is no evidence that SNe make massive amount of dust • ≈ 10 − 2 M ⊙ Cas A: Spitzer has detected of dust in the ejecta (Rudnick et al. 2006) • SN 2003gd in NGC 628: ✦ Progenitor mass: ≈ 12 M ⊙ ✦ mass of condensable elements: ≈ 0 . 3 M ⊙ ✦ Observed dust mass: (Sugerman et al. 2006) ≈ 0 . 04 M ⊙ • SN1987A < 10 -3 M sun ✦ Detected dust mass • Dust needs to survive its injection into the ISM ✦ reverse shocks

Conclusions • Massive amount of dust at high redshift requires an additional source of dust • Dust accretion onto pre-existing dust cores in molecular clouds is most obvious source ✦ Complex chemistry and accretion efficiency ✤ Cosmic rays, minimum dust temperature ~ T cmb ≈ 22 K ✦ Cycling between cloud-intercloud medium ✤ ISM morphology, SN rates, cooling/heating of ISM

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