Feedback:in the form of outflow
AGN driven outflow
M82Blue: ChandraRed: SpitzerCyan: Optical
Star formation driven outflow
Two categories of the gas in a SF/SB galaxy wind
• Ambient interstellar medium
• Energetic fluid created by thermalization of the SB’s stellar eject or AGN
The hydrodynamical interaction between these two generates the multiphase starburst-driven galactic wind.
Observations of multiphase wind (cold, warm, hot gas & dust)
• X-ray
• Morphology and kinematics of interstellar emission lines (e.g. Ha…)
• Outflow kinematics in the interstellar absorption lines (e.g. MgII, NaD)
From X-ray: Hot Gas Escapes from Dwarf Starbursts
Martin 1999, Heckman et al 2000, Martin 2004
Rotation Speed Tremonti et al. 2004
Vc= 130 km/s
From optical absorption lines--NaD(5890,5896A)Low- ionization potential 5.1eV(Martin et al. 2005, 2006)
V = -96 km/s
V = -435 km/s
Circular velocity Star formation rate
Ou
tflo
w v
eloc
ity
isothermal escape speed
From optical absorption lines (Rupke et al. 2005a,b,c)
Murray et al. 2004, Martin 2005
Stack spectrum and stellar continuum
Mg I
He I
Na I
Two-component fit of ISM Na DTwo-component fit of ISM Na D
• Line center shift: outflow velocity Voff
• Line strength (EW): covering factor Cf • Line width b
• Line ratio τ0
Two-component fit of ISM Na DTwo-component fit of ISM Na D
• Line center shift: outflow velocity Voff
• Line strength (EW): covering factor Cf • Line width b
• Line ratio τ0
Inclination effectInclination effect
face on
edge on
Isolate the main driver of the observedcorrelation: Disk-like components
Isolate the main driver of the observedcorrelation: outflow components
Outflow velocity vs. SFROutflow velocity vs. SFR
Voff ~ SFR0.3
Martin et al. 2009
Spectra from LRIS on Keck I
Using multi-components to fit each absorption line
Through the fitting in last slides, they find that components with different velocity have different covering factoroutflow is accelerating
