the evolution of interstellar dust · 2010-11-18 · interstellar dust processing stellar...

Eli Dwek Observational Cosmology Lab

NASA Goddard Space Flight Center

The Origin of Dust in the Early Universe

Isabelle Cherchneff Univ. of Basel - Basel

arXiv: 1011.1303

1Wednesday, November 10, 2010

AGB SNe

Novae WR

accretioncoagulation

chemical reactions

destruction by SN

blast waves

dust sources

molecular clouds diffuse ISM

interstellar dustprocessing

stellar explosions winds

star formationcloud disruption

cycling between ISM phases

The journey of interstellar dust


Chemical EvolutionThe Rate of Change in the Dust Mass

destruction by SN blast waves

added/removedto/from ISM by

infall/outflow

source function

removed from the ISM by

star formation

Equation applicable to any elementMd → MA

τd → ∞τd → τ1/2

stable

radioactive


Chemical EvolutionThe rate of change in the gas mass

SFRMass returned by stars

infall/outflow

instantaneous recycling approximation


Chemical Evolution Dust-to-Gas mass ratio


Chemical Evolution Integral solutions

Integration factor

Solutions


Chemical Evolution A simple differential equation


Chemical Evolution The Source Function


Cygnus Loop detail(HST)

GRAIN DESTRUCTION

Cygnus Loop(ROSAT)


Grain Destruction in the ISM

• 24, 70, 160 µm

MolecularCloud

Bright Eastern Knot (BEK)

Spitzer observations of Puppis AArendt et al. 2010, ApJ in press


~ 1’

Cloud spectraZubko et al dust model

Post shock spectrapre-shock dust predictstoo much NIR emission

Grain Processing in Puppis A

Spitzer• MIPS 24 µm


Grain destruction in Puppis A

pre-shock ZDA grain size distribution

post-shock

About 30% of the dust mass is destroyed in the

~ 500 km/s shock

This is a lower limit!


Grain destruction efficiencies

Mass of dust destroyed by a single SNR

(Jones, Tielens, Hollenbach, & McKee 1994, 1996)

Md = Zd

� vf

v0

fd(vs)

�dMism

dvs

�dvs


Destruction

The dust lifetime

Dusty ISMExpanding SNRs

• For the MW galaxy:

✦ Md ≈ 3x107 Msun RSN ≈ 0.02 yr-1 md ≈ 3 Msun

d ≈ 500 Myr

τd(t) ≡Md

md RSN

The mass, locked up in dust, that is returned to the gas phase by a

single SNR

md


DUSTFORMATION:

Supernovae


Spitzer spectra of Cas A ≈ 0.02–0.04 Msun (Rho et al. 2008)

Akari/BLAST search for warm (~ 35 K) dust

≈ 0.06 Msun (Sibthorpe et al. 2009)

Observations

Dust Formation in Cas A

Herschel (~ 35 K) dust ≈ 0.08 Msun

(Barlow et al. 2009)

total ≈ 0.1 – 0.12 Msun


Theoretical calculations

Chemical kinetic calculations for Pop III stars

(Cherchneff & Dwek 2010)

Dust Formation in SNe

Dust yield in a 20 Msunprimordial CCSNe

≈ 0.15 Msun


Eta Carinae

DUSTFORMATION:

quiescent outflows(AGB, WR stars)


Dust sources: AGB stars

O-richC/O < 1

C ≈ O

C-richC/O > 1

silicates

carbon dustPAHs

MgS


Dust Yield in AGB StarsKarakas & Lattanzio (2007)


AGB stars WR starsSupernovae

AGB stars80%

Supernovae18%

WR stars2%

The relative contribution of the different dust sources

In a steady state


The dust composition MUST evolve !

• SN are the primary sources of silicate dust

✦ they return their processed ejecta “promptly” back to the ISM

• AGB stars (Msun ≈ 1-8 Msun) are the primary sources of carbon dust

✦ they return their processed material a considerable time after their birth

✤ The IMF-averaged mass of a carbon star is ~ 3 Msun

• The dust composition will therefore change over time

✦ extinction, composition, IR emission will therefore depend galactic age

• How can we observationaly test it?

✦ find proxy for AGB dust

✦ observe galaxies at different ages or metallicities

32 Myr

116 Myr

470 Myr

1.1 Gyr

2.8 Gyr

10 Gyr


AGB

SNe

The delayed injection of AGB dust into the ISM

Dwek (2005)

Galliano et al. (2008)

PAHs are proxies for AGB-condensed dust


The high-z universe


What is the Origin of Dust inthe high redshift quasarSDSS J114816+5251 ?

Detected in a search for i (7481 Å) dropouts in the Sloan Digital Sky Survey

(Fan 2003)Follow-up spectroscopy

z = 6.4

2.5 m

AGN

M(H2) = 1.6× 1010 M⊙

Mdyn = (4− 6)× 1010 M⊙

MBH = 3× 109 M⊙

Mbulge = 5× 1011 M⊙


The Spectral Energy Distribution of J1148

Searches for lensing effects were negative

dust emission

Ltot ≈ 1× 1014 L⊙

LIR ≈ 2× 1013 L⊙


Spectral FITS to theFIR Flux of J1148+5251

LFIR = 2× 1013 L⊙

ΣSFR(M⊙ yr−1 kpc−2) = 2.5× 10−4 Σ1.4g (M⊙ pc−2)

CO mass500± 240

Star formation rate (Msun yr-1)

ψ(M⊙ yr−1) = 1.7× 10−10LFIR(L⊙)IR luminosity

∼ 3400

However the SRF can be much lower if the AGN contributes

significantly to the FIR luminosity

3x108 Msun 4x108 Msun

1x108 Msun

Dust Masses

~(1–4)x108 Msun

Dust Mass in J1148

Milky Way Mdust ≈ 3x107 Msun


The SN Scenario

Can SNe produce the required dust mass?

(Dwek et al. 2007)


Age of the universe at z=6.4: 890 Myr

z = 10 Univ = 490 Myr, Gal age = 400 Myrz = 20 Univ = 190 Myr, Gal age = 700 Myrz = 30 Univ = 100 Myr, Gal age = 790 Myr

32 Myr

116 Myr

470 Myr

1.1 Gyr

2.8 Gyr

Can SN produce the required mass of dust?

NO PROBLEM!

SN rate ≈ 70 per yr

in 400 Myr ≈ 3x1010 SNe

Each SN needs to make 5x108 / 3x1010

≈ 0.02 Msun of dust

These calculations neglect:(1) the effect of grain destruction(2) the finite effective SF time

If galaxy is young enough then AGBs have not yet evolved

off the main sequence


SN Yield Required to Produce an Observed Dust-to-Gas Mass Ratio, Zd

(Dwek, Galliano & Jones 2007, ApJ, 662, 927)

mg(Msun)

Milky Way destruction

No grain destruction

Largest observed SN yield

SN yieldsneeds to be 1 Msun/SN

With grain destruction

SN yieldscan be

0.15 Msun/SN

Without grain destruction


The AGBScenario

Can AGB stars produce the required dust mass?

(Valiante et al. 2009)


Galaxy needs to be older than ≈ 400 Myr


The star formation history of high-z quasars in hierarchical galaxy merger models

(Li et al. 2007) SFR used by Valiante et al. 2009


The Evolution of Dust in J1148+5251

Note the delayed injection of AGB dust

closed box model Schmidt-type SFR-Mgas relation


The Evolution of Stellar Mass

and Luminosity


How unique is the star formation history implied

by the merger scenarioS?


The Dependence of the Dust Abundance on the Star

Formation History

✦ SFR = 1000 Msun/yr✦ 100 Myr duration✦ no grain dstruction

during burst

onset of starburst

first AGB stars evolve off the MS

dust lifetime(Myr)


The Contribution of Succesive Bursts of Star Formation

Approximation the merger history with discrete bursts

The cumulative contribution of the bursts to the dust mass


Can SN form the dust with a yield of

0.15 Msun/event?


Is the SN scenario a viable alternative?

YES!provided that we are

observing a very young starburst


Can we discriminate between the SN and the

AGB models from the galaxy’s spectral energy

distribution (SED)?


The SED of J1148+5251

The SN model

The AGB model

All UV-optical is produced by stars

All UV-optical is produced by the

AGN


Could the UV-NIR SED of J1148+5251 be purely AGN?

The probability of the photometric spectral index


Can we discriminate between the SN and the AGB scenarios from the

frequency of J1148-type

objects?


21 QSOs@ z ≈ 6

Comovingnumber density≈ 10–9 Mpc–3

High redshift (z ≈ 6) QSOs(Jiang et al. 2010)

dust free dust free

dust free?


How rare are J1148-type objects?The AGB Scenario

Press-Schechter (PS) formalism

7x1011 Msun objects must have formed

at z≈8.5

Mhalo ≈ 4x1012 Msun

✦ PS formalism predicts that the number density of

such objects is ≈ 10–12 Mpc-3

✦ But the comoving number density of z ≈ 6 QSOs is ≈ 10–9 Mpc-3

comoving number density of collapsed halos (Mpc-3)


How rare are J1148-type objects?

PS formalism may underestimates the

number of collapsed halos

✦ So AGB scenario may be consistent with observations if PS formalism is wrong by factor of 1,000 !

✦ All QSOs could be hyperluminous IR objects,✦ But J1148-type objects are more probably very rare among z~6 QSOs

The AGB Scenario


How rare are J1148-type objects?The SN scenario

1x1011 Msun objects must have formed

at z≈7

PS formalism predicts that the number density of

such objects is ≈ 10–5 Mpc-3

The GOODS survey (Stark 2009)

Rough agreement with the comoving number density of objects with stellar masses of ~ 1011 Msun


How rare are J1148-type objects?The SN scenario

Comoving luminosity density vs redshift (Franceschini 2010)

If all M*≈1011 Msun galaxies had LIR ≈2x1013 Lsun

2x108 Lsun Mpc-3

Comoving luminosity density of SF galaxies

(Franceschini 2010)

log10(L) = 13.2~10–7 Mpc-3

If J1148-type objects are powered by SNe, they should be

“common”

but veryluminous

objects arerare


Is grain growth in molecular clouds

important in J1148+5251?


• Accretion time must be less that the cloud lifetime

• The condition is fulfilled in J1148+5251, so grain growth in MCs can be important in this object

• However, grain growth in MCs is not required to explain the origin of the dust in this object

Conditions for net grain growth in Molecular clouds

τacc ≡�

1

ρgr

dρgrdt

�−1

∼ a

nc T 1/2≈ 3× 106 yr

τc =Mc

ψ∼ 2× 1010

3000≈ 7× 106 yr

τacc < τc


Is grain growth in molecular clouds important in the

Milky Way?


14

Condensation in the Sources(Field 1974) Accretion in the

ISM (Snow 1975)

Destruction in the ISM (Dwek & Scalo 1980)

What is the Origin of the Interstellar Depletion Pattern?

TcondU0

Iion


The Evolution of Dust in the Local Neighborhood

(VERY preliminary result)

Only ~ 10% of the interstellar dust in the MW was formed in stars!

MdustMgas/100

5× 106 M⊙

Hernandez et al. (2000)

stochastic SF in the solar neighborhood


Do AGN form dust?


Dust formation in AGN winds(Elvis+ 2002; Maiolino+ 2006)

(Kartje & Konigl 2006)

{n, T} conditions similar to those in AGB outflows

BUT: is the dust in the BELC (broad emission line clouds) newly-formed or “just” reformed

Conditions are conducive to dust formation


• Dust evolution models are a useful tool for describing the evolution of dust mass - a new formalism

• Local universe - PAH vs metallicity

• Early universe

✦ AGB likely scenario, but:

✤ may require a massive galaxy - objects rare✤ however SFH not unique

✦ SN are not likely to be the source of dust

✤ SN yields too low, grain destruction too efficient✤ predicts too many hyperluminous IR galaxies

✤ requires contrived star formation history

✤ More common objects than the AGB scenario

✦ Grain growth in clouds can be important but is not necessary

Conclusions


The Origin of Dust at High RedshiftSUMMARY

SF history@ z~6 growth

of BH mass

frequencyof J1148-

type objects

dustformationSNe, AGB

ISM processing

dynamical-stellar mass


END60Wednesday, November 10, 2010

the evolution of interstellar dust · 2010-11-18 · interstellar dust processing stellar...

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