X Y i M82 Blue: Chandra Red: Spitzer Green & Orange: Hubble Face-on i = 0 Edge-on i = 90 Absorption-line probes of the prevalence and properties of outflows in the present-day star-forming galaxies? Chen, Y.-M.(UW-Madison/NJU), Tremonti, C., Heckman, T., Kauffmann, G., Chen, Y.-M.(UW-Madison/NJU), Tremonti, C., Heckman, T., Kauffmann, G., Weiner, B., Brinchmann, J., Wang, J.

Outline Background Sample Data analysis Results

Outflow velocity vs. SFR

V off ~ SFR 0.35 Martin 2005

Sample: SDSS DR7 star forming galaxies 0.05<z<0.18 r-band fracDeV<0.8 D4000<1.5

Main steps of data analysis stellar Disk-like （ v=0 ） ISM ISM outflow Na D Absorption 1. stack spectra (i, Av, SFR, SSFR, M *...) 2. subtract stellar contribution (CB08) 3. fit ISM absorption with two components

Stack spectrum and stellar continuum Mg I He I Na I

Two-component fit of ISM Na D Line center shift: outflow velocity Voff Line strength (EW): covering factor Cf Line width b Line ratio τ 0

Two-component fit of ISM Na D Line center shift: outflow velocity Voff Line strength (EW): covering factor Cf Line width b Line ratio τ 0

Inclination effect face on edge on

Isolate the main driver of the observed correlation: Disk-like components

Isolate the main driver of the observed correlation: outflow components

Outflow velocity vs. SFR V off ~ SFR 0.3

Summary outflow is perpendicular to the disk and has an opening angle of ～ 60 degree disk component is highly dependent on the dust extinction, and secondarily on SFR surface density outflow component depends on SFR surface density strongly and secondarily on Av we do not find the correlation between outflow velocity and SFR from our sample, more observations on the low SFR end are needed

Thanks!

From optical absorption lines (Rupke et al. 2005a,b,c) dwarf galaxies from Schwartz & Martin 2004  = Starbursts  = Seyfert 2s Background

Outflow velocity vs. SFR Background

Martin et al 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 factor  outflow is accelerating

From optical absorption lines —NaD(5890,5896A) (Rupke et al. 2005a,b,c) Larger sample New method for Fitting NaD -- line shift  Velocity -- doublet ratio  Optical depth -- line strength  covering factor

Circular velocityStar formation rate Outflow velocity isothermal escape speed From optical absorption lines (Rupke et al. 2005a,b,c) Murray et al. 2004, Martin 2005

Spectra from LRIS on Keck I Using multi-components with different velocity to fit each absorption line Martin et al. 2009

Outflows are ubiquitous in galaxies in which the global SFR per unit area exceeds roughly 0.1 solar mass per year per kpc^2 (Heckman et al. 2002) Are there any outflows in local normal star forming galaxies?

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 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 optical absorption lines --NaD(5890,5896A) Low- ionization potential 5.1eV (Martin et al. 2005, 2006) V = -96 km/s V = -435 km/s He I

Disk-like component

Outflow component

From X-ray: Hot Gas Escapes from Dwarf Starbursts Martin 1999, Heckman et al 2000, Martin 2004 Rotation Speed  Tremonti et al V c = 130 km/s