Sally OeySally OeyUniversity of MichiganUniversity of Michigan

Cathie ClarkeCathie ClarkeIoA, CambridgeIoA, Cambridge

HDFSmith et al. / MCELS

Massive Stars:Massive Stars: Feedback Effects in the Local UniverseFeedback Effects in the Local Universe

Massive Star FeedbackMassive Star Feedback

Radiative

Mechanical

Chemical

Smith et al. / MCELS

> 8 Mo 3 – 40 Myr lifetimes

THE MASSIVE STARTHE MASSIVE STAR POPULATIONPOPULATION

NN** : Clustering law, field : Clustering law, field

mm : : Stellar IMFStellar IMF

Distributions:Distributions:

NGC 346

Nota et al. 2006

The IMF Upper-mass cutoffThe IMF Upper-mass cutoff

IC 1805 24

Berkeley 86 10

NGC 7380 11

NGC 1893 19

NGC 2244 12

Tr 14 / 16 82

LH 10 65

LH 117 / 118 40

TotalTotal 263263

R136a / 30 Dor > 650

Grand TotalGrand Total > 913 > 913

Massey et al. 1995

Massey & Hunter 1998,Hunter et al. 1997

Observed OB Observed OB associationsassociations

ages ages << 3 Myr, 3 Myr,m m >> 10 M 10 Moo

Arches: Figer 2002, 2005

R136a: Weidner & Kroupa 2004,Oey & Clarke 2005

mmmaxmax expectation valueexpectation value

dMdmmmmNm

)(*

up

10

M

10upmax

upmax mm maxmN*

Mm 10

Oey & Clarke (2005)

OB + 30 Dor

OB’s

impliesimplies mmupup< < 200 M200 Moo

cf. Elmegreen (2000): Milky Way mup~10,000 Mo

P < 0.002

P < 0.12

P < 0.02

P < 0.47

Probabilities for Probabilities for mmmax assuming assuming mmupup

mmupup ~ 150 M ~ 150 MOey & Clarke 2005

see also Koen (2006)

Entire sample

A Universal Clustering LawA Universal Clustering Law

Starbursts Starbursts Meurer et al. 1995Meurer et al. 1995

Globulars and Massive young ClustersGlobulars and Massive young ClustersElmegreen & Efremov 1997, Hunter et al. 2003Elmegreen & Efremov 1997, Hunter et al. 2003

-1.95 +/- 0.03

-2.00 +/- 0.08AntennaeAntennaeZhang & Fall 1999

*2

*** )( dNNdNNN

HST / B. Whitmore

a Universal Clustering Law a Universal Clustering Law andand a Universal IMF ? a Universal IMF ?

A steep field IMF a steepening A steep field IMF a steepening NN**

(fewer massive) (more low-(fewer massive) (more low-NN**) ) Massey (1995, 2002); Kroupa & Weidner (2003)

All -2.51 +/- 0.29

No field -2.27 +/- 0.38

Oey, King, & Parker 2004

SMC

Field stars fall on clustering

law

Fraction of Field Massive Stars:Fraction of Field Massive Stars:

1up*, 5772.0 ln ~ N

35% to 7% for 35% to 7% for NN*,up*,up = 10 to 10 = 10 to 1066

SMC: expect ~20%, see ~26%

modest dependence on total SFRmodest dependence on total SFR

Oey, King, & Parker 2004

RADIATIVE FEEDBACKRADIATIVE FEEDBACKNebular emissionNebular emission

H[S II], [O III], V, R

Large Magellanic Cloud

MCELS Smith et al. 2006

HII Region LFHII Region LF

Diffuse, warm Diffuse, warm ionized mediumionized medium

1.1. Break in slopeBreak in slope

2.2. Arm populations: shallower Arm populations: shallower a a Interarm populations: Interarm populations: steeper steeper aa

3.3. Hubble Type correlationHubble Type correlation aa ~ ~ 1.7 Sc – Im 1.7 Sc – Im

aa ~ 2.0 Sb – Sc ~ 2.0 Sb – Sc aa ~ 2.6 Sa ~ 2.6 Sa

log N(L)

log L

HII Region Luminosity FunctionHII Region Luminosity Function

a Universal Clustering Law a Universal Clustering Law andand a Universal IMF ? a Universal IMF ?

Oey & Clarke 1998

Ionization of the Diffuse WIMIonization of the Diffuse WIM

Field stars:Field stars:~ 50% WIM ionized by field~ 50% WIM ionized by field Oey et al. 2004; Hoopes & Walterbos 2000

Leaky nebulae:Leaky nebulae:LMC: up to 50% ionizing photons escape LMC: up to 50% ionizing photons escape Oey & Kennicutt 1997; Gerken, Walterbos, & Oey 2003

H Milky Way

WHAM: Reynolds et al.

MECHANICAL FEEDBACKMECHANICAL FEEDBACK

DEM L152 R. C. Smith & MCELS

Small Magellanic CloudStaveley-Smith et al. 1997

H I H[S II], [O III]

~100 pc diameter

Superbubble size distribution

5/45/35/2

5/35/1)/( Evolution

tnLP

tnLR

i

dLLdLLN 2 )( LF Mechanical

creation constant Burst /

+

+

Oey & Clarke 1997

Global Mechanical FeedbackGlobal Mechanical Feedback

=

clustering law

prediction

observed

Oey & Clarke 1997

Velocity distributionVelocity distribution

Oey & Clarke 1998

Predicted -3.5Observed -2.9 +/- 1.4 2/7 dvvdvvN

Predicted -2.8 +/- 0.4Observed -2.7 +/- 0.6

Size distributionSize distribution

dRRdRRN )( 3

Ionizing photons escape into ISM?

...into IGM?Reionization of

Universe?Escape of hot gas, stellar

products and ionizing photons?

geometry disk for factor correction

s km 10in dispersion velocity thermalISM~

M10in mass ISM total

1-10

10ISM,10

df

v

M

Clarke & Oey 2003

-1210ISM,10crit yr M /~ 15.0SFR dfvM

The first galaxies: ?The first galaxies: ?

MW:MW:1

crit yr M 1~SFR

LBGs:LBGs: 1crit yr M 1~SFR

Starbursts:Starbursts: 1crit yr M 1 SFR

1obs yr M 1~SFR

Ambiguous porositye.g., Oey & Clarke 1997

1obs yr M 20 1~SFR

1obs yr M 50 10~SFR

Lyman cont seen?Steidel et al. 2001

Critical SF Critical SF ThresholdThreshold

Lyman cont seen in Haro 11Bergvall et al. 2006

ESO 300-G14

NGC 7713

HR-band

SINGG: Survey of Ionization in SINGG: Survey of Ionization in Neutral Gas GalaxiesNeutral Gas Galaxies

H survey of HIPASS galaxies Meurer et al. (2006)

Oey et al. (2006, in prep)

IC 5052

High SF intensity : Less WIMHigh SF intensity : Less WIM

Possible causes Possible causes for high SFI : less WIM for high SFI : less WIM

Ionization source reduced:

– Output from HII regions reduced

– Fewer field OB stars

Starbursts occupy ISM and Remaining WIM density-bounded

Ionizing photons escape

Fraction of Field Massive Stars:Fraction of Field Massive Stars:

1up*, 5772.0 ln ~ N

35% to 7% for 35% to 7% for NN*,up*,up = 10 to 10 = 10 to 1066

SMC: expect ~20%, see ~26%

modest dependence on modest dependence on total SFRtotal SFR

Oey, King, & Parker 2004

recall

Diffuse fraction vs. total SFR Diffuse fraction vs. total SFR

geometry disk for factor correction

s km 10in dispersion velocity thermalISM~

M10in mass ISM total

1-10

10ISM,10

df

v

M

Clarke & Oey 2003

-1210ISM,10crit yr M /~ 15.0SFR dfvM

MW:MW:1

crit yr M 1~SFR

LBGs:LBGs: 1crit yr M 1~SFR

Starbursts:Starbursts: 1crit yr M 1 SFR

1obs yr M 1~SFR

Ambiguous porositye.g., Oey & Clarke 1997

1obs yr M 20 1~SFR

1obs yr M 50 10~SFR

Lyman cont seene.g., Steidel et al. 2001

Critical SF Critical SF ThresholdThreshold

J0355-42

recall

Trend for HI-poor galaxiesTrend for HI-poor galaxies

Ionization source reduced:

– Output from HII regions reduced

– Fewer field OB stars

Starbursts occupy ISM and Remaining WIM density-bounded

Ionizing photons escape

Likely

?

Possible causes Possible causes for high SFI : less WIM for high SFI : less WIM

LyC seen from Haro 11Bergvall et al. 2006

CHEMICAL FEEDBACKCHEMICAL FEEDBACK

Q: filling factor

n: generations

n

jjZZ

1

ZNPZN j

n

jj

1ISM

ZNPDn

ZN j

n

jkkjk

n

j

1

,11

kDk 1

Stochastic Inhomogeneous evolutionInhomogeneous evolution

Oey 2000, 2003

data: Carney et al. (1996)

Simple: Halo isSimple: Halo is evolved evolved

SIM: Halo is SIM: Halo is unevolvedunevolved

(Oey 2003)

Thick disk MDFThick disk MDF

Thin disk MDFThin disk MDF

Thick disk MDF

Bensby & Oey (2006), in prep

data: Nordstrom et al. (2004)

selection: Bensby et al. (2003, 2005)

Halo MDF

ZNPD

PD

j

n

jkkjk

n

j

n

kkk

F

,11

1,11

III

Zero-metallicity (Pop III) starsZero-metallicity (Pop III) stars

(Oey 2003)

ForFor Galactic halo model Galactic halo model

FIII ~ 4e-2

vs.vs. Observed Observed

FIII < 4e-4

Clear discrepancy!

OB clustering

H II LF, WIM

Superbubbles

*2

*** )( dNNdNNN

dvvdvvN

dRRdRRN

)(

)(

2/7

3

1up*, 5772.0 ln NField fraction:Field fraction:

ionizing WIM, IGM relation to IMF

ISM structure, evolution

mup ~ 150 Mo

Massive Star FeedbackMassive Star Feedback

Superwind Superwind thresholdthreshold

Metal enrichmentMetal enrichment

ZNPD

PD

j

n

jkkjk

n

j

n

kkk

F

,11

1,11

III

zNPzN j

n

jj

1ISM

zNPDn

zN j

n

jkkjk

n

j

1

,11

Simple Inhomogeneous Model GCE of unevolved systems

A self-consistent analytic approach

-11210ISM,10crit yr M ~15.0SFR

dfvM

starburst feedback to IGM

Massive Star FeedbackMassive Star Feedback OB population: clustering law, IMF

Radiative: HII LF, diffuse 104 K gas

Mechanical: superbubbles, superwinds diffuse 106 – 107 K gas

Chemical: inhomogeneous chemical evolution

Adiabatic shell evolutionAdiabatic shell evolution

SNe

ndstellar wi 2

1

e

51*

2

5/45/35/2

5/25/1

exp

5/35/1

t

ENL

vML

tnLP

tn

L

dt

dRv

tn

LR

i

L = mech luminosityn = ambient densityt = age

0.03

0.3

1.0

0.3

23

0.01 – 0.2

0.2

~ 1

M31

M33

LMC

SMC

IC 10

LG dwarfs

Milky Way (HII LF)

Milky Way (SN rate)

QGalaxy

Porosity: Hot, ionized mediumPorosity: Hot, ionized medium

Oey & Clarke 1997, Oey et al. 2002

volume filling factor of hot ISM

SFR tot

2/5H

~ )( ..

25

16.

e

min

MdRRNMM

RCTk

mM

R

R

superwind mass-loss rate

Mac Low & McCray (1988)

clustering = 2

e

min

e3D 1

1~ R

R

LQ

Starbursts (Clarke & Oey 2002)

Distributed Distributed

vsvs

NuclearNuclear

Equal contrib to porosity Equal contrib to porosity by all superbubble by all superbubble RR

Oey & Clarke 1997

He 2-10: He 2-10: Chandar et al. 2003

• Field population = SSC’sField population = SSC’s• LF LF LL-2-2

• Field OB’s formed Field OB’s formed in situin situ

R136a / 30 DorR136a / 30 DorConsistent with no mup Massey & Hunter 1998; Massey 2003

Suggests mup~ 150 Mo Selman et al. 1999

Consistent with Salpeter slope

Expect (14, 19)Expect (14, 19)

having having m > m > 120 M120 Moo

FoundFound (2, 9) stars (2, 9) stars

If no mup: 1.7x N*(85 – 120 Mo)

Massey & Hunter 1998

(See also Weidner & Kroupa 2004)

*

*

constant

2 Saturated""

/

varies

2 d"Unsaturate"

NL

l

a

NL

l

a

Monte Carlo modelMonte Carlo model

Oey & Clarke 1998

zero-age evolved

dmmdmmn

dNNdNNN

)(

)(

35.2

*2

***

upmax mm

CHEMICAL FEEDBACKCHEMICAL FEEDBACK

NucleosynthesisNucleosynthesis

Chemical evolutionChemical evolution

• MIXING : localMIXING : local

• HOMOGENIZATION : globalHOMOGENIZATION : global

• IN/OUT-FLOW : open boxIN/OUT-FLOW : open box

Simple Inhomogeneous Model Simple Inhomogeneous Model

Q: filling factor = const

n: generations

n

jjZZ

1

n

jnjj

QP

QQj

nP

jP

1

1 objects by occup.

0

ZNPZN j

n

jj

1ISM

ZNPDn

ZN j

n

jkkjk

n

j

1

,11

kDk 1

(Oey 2000, 2003)

Early times: Stochastic Inhomogeneous evolutionInhomogeneous evolution

*NL

2/33

LM

LRV

zRV

MZ z 1

)( 2 :2 dZZdZZf

Multi-generationMulti-generation

Parent metallicity distribution functionParent metallicity distribution function

Inhomogeneous evolution:Inhomogeneous evolution:

DispersionDispersion

Argast et al. (2000)-4.0 -3.0 -2.0 -4.0 -3.0 -2.0 [Fe/H][Fe/H]

Audouze & Silk (1995)

Thin disk: Oey & Bensby

McWilliam (1997)

Cayrel et al. (2005)

mtl-rich + old: high mtl-rich + old: high Q Q e.g.,e.g., BulgeBulge

mtl-poor + old: low mtl-poor + old: low Q Q e.g.,e.g., I Zw 18I Zw 18

n = 4

Q = 0.72

n = 24

Q = 0.72

n = 24

Q = 0.12

Evolution parameter: Evolution parameter: nQnQ

= nQ

2= nQ(1-Q)