Mass Outflows & Galactic EcologiesThoughts, Musings, & Questions J. S. Gallagher
Issue: Assembly of Gravitationally BoundBaryonic Structures Difficult: Dissipation, feedback & heating, B fields, STARS. Hopeless!? BUT galaxies have underlying regularities. CDM / Collisionlessn-body: theory (mostly) okay (well if we knew all the boundary conditions…)
Stars Galaxies Connections: A Matter of Scales. Stars: 10—106 au Galaxies: 107—1010 au Missing some mid-scale astrophysics?
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
Binaries—shaping & channeling gas loss in planetary nebulae Key source dusty ejecta….. Red Rectangle: Cohen+ 04, AJ, 127 Central Binary Star
Cataclysmic variables: explosive mass loss + Hot H-burn nucleosynthesis
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 cluster M82-F: AGB stars in an aging SSC? Age = 60 20 Myr M(MSTO) ≈ 5 msun Mass ≈ 106msun R1/2 ≈ 3 pc n* ≈ 104 pc-3 Is this a safe place for a bloating AGB star to evolve? 430 pc 25 arcsec Gallagher & Smith 1999, MNRAS, 304, 540 Smith & Gallagher 2001, MNRAS, 326, 1027 HST angular resolution essential to measure SSC sizes!
AGB Star in a Super Star Cluster? Dust Formation? Neighborhood B Star ≈0.1 pc
Clump mode star formation— Clustered Young Massive Clusters HUDF NGC7673—nearby clumpy starburst Homeier, 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 Mixing X Her: HI--L. D. Matthews+ 2011, Al 141; Herschel FIR—Cox et al. 2012, A&A, 537 Cox, Decin, Villaver—this meeting Mira—GALEX UV
Working across scales—Galactic calibrations of SFRs Chomiuk & Povich 2011, AJ, 142
M82 CENTRAL STARBURST Polar galactic wind -gas & dust mixture T = 103 – 107 K Nearby: 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
Cloud response to steady shocking: wind mass loading via galactic “comets” Melioli et al. 2005, A&A, 443, 495
M82 SSCs & Starburst Clumps: V-band WFPC2 Starburst Clump A ~10 Myr M82-A1 SSC: M~106 M - r1/2~3 pc - t~7 Myr L. J. Smith et al. 2006, MNRAS, 370, 513 M82-A1 Star Cluster
The Extraordinary M82-A1 Cluster External Pressure: Stalls outflow and offers possibility of recollapse of gas into cluster [NII]+H [SII] L. J. Smith et al. 2006, MNRAS, 370, 513 Distance along slit -> Compact HII around M82-A1 FWHM size of M82-A1 continuum ~0.3 arcsec=6 pc HII region slightly larger, ~10 pc Example of luminous, evolved, but compact HII region; static pressure confined. Low ram pressure to survive?
ω Cen: Southern African Large Telescope Star cluster multiple generations: AGB+?HM* low velocity ejecta recycling(?) Gravity + external pressure??? Bedin+. 2004 ApJL,605
Stellar contrails—QSO Scoville & Norman 1995, ApJ, 451
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?