Mass Outflows & Galactic Ecologies

Thoughts, Musings, & Questions

J. S. Gallagher

Issue: Assembly of Gravitationally Bound Baryonic Structures

CDM/

Collisionless n-body: theory (mostly) okay (well if we knew all the boundary conditions…)

Difficult: Dissipation, feedback & heating, B

fields, STARS. Hopeless!? BUT galaxies

have underlying regularities.

Stars Galaxies Connections: A Matter of Scales.Stars: 10—106 au Galaxies: 107—1010 au

Missing some mid-scale astrophysics?

Beware: non-linear system with wide range of scales!

Biases in Observables: E. G., Dust Production Component “j” versus

Production (& Evolution !)

?

Macro-grain impact?

”… A small leak will sink a great ship." Benjamin Franklin …Or “Can many weak sources a

surprisingly dusty galaxy make?”

Companionship: Three out of every two stars is in a binary (multiple) star system

changes in mass loss efficiency—e.g. common

envelope phase

modify time scales for mass loss

tidal effects on stellar spin

energetics of outflows—e.g. novae

radiation fields—XRBs, microquasars

chemical evolution—e.g. CNO/dust

Binaries: interact with neighbors—common envelopes Livio & Iben 1993, PASP, 105 -- R. Webbink

Red Rectangle: Cohen+ 04, AJ, 127 Central Binary Star

Binaries—shaping & channeling gas loss in planetary nebulaeKey source dusty ejecta…..

Cataclysmic variables: explosive mass loss + Hot H-burn nucleosynthesis

Be star XRBs/TeV gammas; Thorne-Zytkow objects?

Stellar clustering—increasing factor at high SFR densities

interactions with neighbors—modified

stellar outflows

evolution of binary populations

radiation field modification of dust

production (???)

HD5980, binary LBV:Isolated—cluster

runaway?Low Density ISM

“Cosmic Grenades?”

Chandra x-ray

Young massive star clusters: star crowding; binary evolution

Age = 60 20 Myr

M(MSTO) ≈ 5 msun

Mass ≈ 106 msun

R1/2 ≈ 3 pc

n* ≈ 104 pc-3

Is this a safe place for a

bloating AGB star to evolve?

Gal

lagh

er &

Sm

ith

1999

, MN

RA

S, 3

04, 5

40

Sm

ith

& G

alla

gher

200

1, M

NR

AS

, 326

, 102

7

25 a

rcse

c

HST angular resolution essential to measure SSC sizes!

430

pc

Young massive star cluster M82-F: AGB stars in an aging SSC?

NeighborhoodB Star

≈0.1 pc

AGB Star in a Super Star Cluster?Dust Formation?

Clump mode star formation—Clustered Young Massive Clusters

HUDF

NGC7673—nearby clumpy starburstHomeier, Gallagher, Pasquali—WFPC2

Wider Galactic Environments

velocity relative to surroundings—ram pressure & shocks; virialization of ejecta—spheroids vs disks.

State of ISM—gas flows; “stellar contrails” ISM characteristics—densities/pressures:

bubble/HII structures Gravitational potential – gas

escape/retention.

AGB Bow Shocks & Tails—Stellar MixingX Her: HI--L. D. Matthews+ 2011, Al 141; Herschel FIR—Cox et al. 2012, A&A, 537

Mira—GALEX UV

Cox, Decin, Villaver—this meeting

Kobulnicky+ 1997, ApJ, 477

Chomiuk & Povich 2011, AJ, 142

Working across scales—Galactic calibrations of SFRs

M82 CENTRAL STARBURSTNearby: D=3.9 Mpc

1 arcsec ≈ 20 pc

High SFR in small galaxy; few Msun/yr in <1/2

kpc2.

L(FIR) >> L(opt)

Extensive “socialized” photoionization

Sustained mechanical energy inputs from

young massive stars leads to galactic wind.

Supersonic gas outflow; archetypical relatively organized large scale

galactic wind.

Stellar disk

Polar galactic wind-gas & dust mixtureT = 103 – 107 K

Melioli et al. 2005, A&A, 443, 495

Cloud response to steady shocking: wind mass loading via galactic “comets”

Star

burs

t

Clum

p A

~10 M

yr

M82 SSCs & Starburst Clumps: V-band WFPC2

M82-A1 SSC: M~106 M - r1/2~3 pc - t~7 MyrL. J. Smith et al. 2006, MNRAS, 370, 513

M82-A1 Star Cluster

[NII]+H [SII]

Dis

tanc

e al

o ng

sli t

->

Compact HII around M82-A1

FWHM size of M82-A1 continuum ~0.3 arcsec=6 pc

HII region slightly larger, ~10 pcExample of luminous, evolved, but compact HII region; static pressure confined. Low

ram pressure to survive?

The Extraordinary M82-A1 ClusterExternal Pressure: Stalls outflow and offers possibility

of recollapse of gas into cluster

L. J. Smith et al. 2006, MNRAS, 370, 513

ω Cen: Southern African Large Telescope

Bedin+. 2004 ApJL,605

Star cluster multiple generations: AGB+?HM*

low velocity ejecta recycling(?)

Gravity + external pressure???

Scoville & Norman 1995, ApJ, 451

Stellar contrails—QSO

• Do we need to become more serious about the origins & evolution of binaries in considering mass, dust, abundance & energy fluxes in galaxies?

• Does the degree to which stars, particularly OB stars, are clustered matter at a significant level? Rotation, binarity, runaways, dust, winds?

• Much of our information is based on the behavior of stars in the solar neighborhood; a nice low density, low ISM pressure, low SFR environment. To what degree does this information transfer to other more extreme situations?