mass outflows & galactic ecologies thoughts, musings, & questions
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Mass Outflows & Galactic Ecologies Thoughts, Musings, & Questions . J. S. Gallagher. Issue: Assembly of Gravitationally Bound Baryonic Structures. Difficult: Dissipation, feedback & heating, B fields, STARS . Hopeless!? BUT galaxies have underlying regularities. CDM /. - PowerPoint PPT PresentationTRANSCRIPT
Mass Outflows & Galactic EcologiesThoughts, 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 MyrM(MSTO) ≈ 5 msunMass ≈ 106 msun
R1/2 ≈ 3 pcn* ≈ 104 pc-3
Is this a safe place for a
bloating AGB star to evolve?
Gal
lagh
er &
Sm
ith 1
999,
MN
RA
S, 3
04, 5
40
Smith
& G
alla
gher
200
1, M
NR
AS,
326
, 102
7
25 a
rcse
c
HST angular resolution essential to measure SSC sizes!
430
pcYoung 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”
Starbu
rst
Clump A
~10 Myr
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
t anc
e al
o ng
slit
->
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?