C IV absorption and z=3 galaxies

For N(CIV) > 1013 cm-2, the galaxy / CIV absorber cross correlation function is equal tothe LBG galaxy auto-correlation function, and it increases by a factor of 1.5-2.0 as thecolumn density is increased to N(CIV) > 1015 cm-2

Clear causal connection of “strong” CIV absorbers seen in QSO spectra with galaxies;I.e., C IV traces metal enriched gas in vicinity (80 kpc proper) of galaxies

O VI absorption and z=3 galaxies

For N(OVI) > 1013.5 cm-2, the OVI absorber temperatures, kinematics, and rate ofincidence are well explained as winds extending to 50 kpc (proper) associated withLBGs

Adelberger etal (2003, 2005)

Simcoe etal (2002)

“quasar absorption line (QAL) method”

QSOsightline

To observer

Neutral hydrogen(rest-frame velocity)

Mg II, C IV, OVI(rest-frame velocity)

Lyman series(obs wavelength)

In this toy scenario, metal enriched clouds entrained in galactic winds gives rise to absorption lines in quasar spectra, as illustrated in the above panels as are expected for COS and HIRES/UVES spectra…

Background quasar configuration…

(these are simulated spectra from our CDM simulations, see Sec 2 below for details)

3 lensed galaxies (z=2.7-3.0; R=6000) Composite spectra of z=2.0-2.6 UVselected galaxies (R=1300)

(courtesy C. Steidel)

Campaign by Steidel et al of UV (rest-frame) selected z=2-3 galaxies find winds invirtually all bright galaxies

“down the barrel method”

Mhalo ~ 1012 - 1013 M sun

Lbol ~ 1011 - 1012 L sun (r~1-2 kpc)

SFR ~ 10 - 100 Msun/yr (LIRG-ULIRG)

Vc ~ 150 km/s (Vesc ~ 450 km/s)

OUTFLOWS expected to be most common in the redshift desert, where starformation is most active

We directly observe the IGM enrichment process when it is peaking

We directly observe the interplay (fueling by infall and outflow mass loss)between galaxy evolution and the baryonic environment in the cosmologicalcontext

Gas expelled at z=1-3 could be the “refueling” material for galaxies at thepresent epoch

WINDS may (and probably do) play crucial role

- in shaping mass-metallicity relation in galaxies

- explaining difference between galaxy luminosity and mass functions (low end and/or high end mismatch)

- heating and chemically enriching of the IGM

- termination of star formation (quenching) in low mass galaxies and old stellar populations in said galaxies (the red and the dead)

1. Galaxies form in the cosmic web2. They accrete gas, form stars, and deposit energy/metals into IGM3. Extended metal enriched “halos” are observed from z=0 to z=4

Arguably, some of the most physical and visual insights are derived from simulations;- but need detailed galaxy physics AND cosmological setting - very difficult but crucial

4.5 Mpc

Zooming technique! Adaptive Refinement Tree (ART) - increase spatial resolution inproportion to where all the action is and track processes with low resolution where its not

z = 2.3

z = 1.3

stars density cm-3 temp K Z solar

1000 kpc

Example of stellar particles, and hydro gas density, temperature, and metals (20-50 pc)

- Miller-Scalo IMF Miller-Scalo (1979), Type II and Ia SNe yields fzM* Woosely & Weaver (1995)

− + - ( ) 10 CDM Hydrodynamic N body Adaptive Refinement Tree ART in Mpcbox

- Radiative( ) + ( + UVB collisional heating and cooling atomic molecular/ w dust as function of metallicity) using Cloudy grids Haardt& Madau(1996); Ferland etal(1998)

- 1 Star formation physics based upon pc high resolution simulations Kravstov(2003); & (2008)Ceverino Klypin

Kravstov etal(1997); Kravstov(1999); Kravstov, Gnede, & (2004)Klypin

- , ; , Natural gas hydro only thermal heating drives winds no velocity kicks no rolling dice

1. Use “mock” background quasar absorption line methods

2. Use “mock” starburst galaxy spectra methods

• Place “quasar beam” sightlines through simulation box, generate absorption profiles

• Shoot through target galaxies, can examine different orientations

• Create grid of sightlines to probe line of sight absorption properties spatially

• Study kinematic, equivalent width, column density, and Doppler b distributions

“down the barrel method”

• Synthesize spectrum of central star forming region of star forming galaxy

• Must account for physical extent of nuclear region

• Can examine different viewing angles

• Study kinematics of profiles, etc.

Generate “observed” spectra, analyze as an observer, quantitatively compare

Simulations are complex, involving a tonne of physics, some of which needsextensive testing; Presently, observational data of “halos” and “outflows” areunderutilized for constraining galaxy formation physics in cosmologicalsimulations… - how to do it (right)?

“QAL method”

QSO

4.5 Mpc

400 kpc

MOCK QUASAR ABSORPTION “PROBING”

Z=1.0 (M = 0.8MMW)

resolution ~ 20-50 pc

Milky way mass at z=0

- select a galaxy in the box, select orientation for “sky view”, pass line of sight through box- line of sight (LOS) is given impact parameter and passed through the entire 10 Mpc box- record the properties of all gas cells probed by the LOS

Examining Properties of Gas in Absorption

R

gas cell

QSO To observer

R = distance of cell center from galaxy centerb = impact parameter (projected R)

1. Apply the Cloudy models to obtain photoionization + collisional equilibrium ionizationfractions

2. Determine density of metal ion in cell, obtain optical depth at line of sight velocity

3. Synthesize “realistic” spectrum; analyze absorption; tie detected absorption to detectedcells

4. Examine detected cell properties

b

D , V, nH , T , Z/Zsun , fH

V

Vlos

density

temperature

metallicity

Halo constructed from stellarfeedback winds…

ρ = 10-2 - 10-6 cm-3

= 10T 5 - 106.3 K =Z 0.1 - 1 solar

QSO LOS GRID400 400 x kpcΔ = 20 kpc

@ =3z .55 a low SFR“ Lyman Break Galaxy”

Entrained material

Schematic of Velocity Flows

Filaments inflowing parallel to angular momentum vector (face on). Inner 10 kpc, hotgas outflows perpendicular to the plane, but is overwhelmed by infalling filaments andis redirected sideways into metal enriched supershells that entrain cool gas

Metals mix into filaments in inner few hundred kpc, but filaments vigorously fuel the galaxy

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Spatial location of CIV inflowQuickTime™ and aVideo decompressor

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Spatial location of CIV outflow

Spatial location of OVI inflow

Spatial location of OVI outflow

Animated Movies (rotation of structure about angular momentum vector of galaxy)

“DOWN THE BARREL” CIV & OVI ABSORPTION

3 lensed galaxiesz=2.7-3.0Red is cB58

viewed from “Side B”

viewed from “Side A”

Observed

Blended doubletR = 6000

• partial covering is ~ 80% (at any given velocity)• slow rising blue wing (wind signature) not always apparent• asymmetric for face-on view (along angular momentum vector)

Analogous to:Weiner et al (2009)Steidel, Pettini, & Shapley

(courtesy C. Steidel)

face on edge on

Absorption line centroids (not maximum velocity extent)Observations with respect to Ηα ( )nebular emission stars

Observed absorption profile meancentroid -160 is /km s

<Δvabs> - 115

RADIAL VELOCITY DISTRIBUTION

( 1997)Steidel

( )outflow nearside

( )outflow nearside

SFR ~ 10 Msun/ yr

down the barrel D = 8-40 kpc D = 40-80 kpc

STACKING: IMPACT PARAMETER BINNING

In the real world there are a multitude of background sources- they are just not bright!

To increase signal to noise, select impact parameter bins and co-add spectra in thereference frame of the intervening absorber

how to get spatial information?

D

sky view side view

- when you have 100+ fields you can getsome really good numbers per bin!

down the barrel W=1.61AD = 8-40 kpc W=1.62AD = 40-80 kpc W=0.91A

Stack 1460 galaxies Keck LRIS-B spectra

Perform similar experiment with simulationgrids…

LRIS-B mock spectra stacked by observedimpact parameter range

STACKING: IMPACT PARAMETER BINNING

courtesy C. Steidel

(singlet)

Blended doublet @v(sys) = -390 km/s

CIV λ1548

0

=0 V @λ1549.5

-500 +500

SFR ~ 10 Msun/ yr

SFR ~ 50 - 100 Msun/ yr

OUTFLOW VELOCITY - STAR FORMATION RATE SCALING

V90 = velocity is defined as the 90%percentile of the gas with outwardradial velocity greater than the escapevelocity of the galaxy

Each data point is a single galaxy

The redshift range is z=1-1.5.

Directly compared to outflows found inDEEP2 galaxies

10

500

1000

100

0.1 100

Weiner et al (2009)

Weiner et al (2009)

Ceverino et al (in preo)

In general, the wind velocity scales with SFR in a manner consistent with Mg II winds

V90 ~ SFR0.5

CONCLUDING REMARKS

Work is still at a very preliminary level….

It is very expensive to run many galaxies to get statistics on the absorption quantities,which aren’t really published yet!

We are only making qualitative comparisons at this time, though the absorption linework has constrained the SFR efficiencies from earlier work

It is clear that cold flows are prominent and required to fuel the continuation of starformation

The scaling of the outflow velocity with SFR qualitatively is promising in its comparisonwith observations

The absorption gas method is probably the most promising in that it incorporates thesensitivity functions of detecting the gas in observed spectra

plane of sky+18 kpc

2-comp sub-DLA

MgII: Plane of sky, -150<v<80 km s-1

MgII 18 kpc behind pos,0<v<+100 km s-1

Two main sights for HI

Two sights for CIVabsorption- photoionized,not a single cloud!

Extended sights for OVIabsorption- photo andcollisionally ionization, nota single cloud!

EVOLUTION FROM Z=3.5 TO Z=1 density

• baryons continue to fall into galaxy

• local web thins out

• entrained gas from earlier wind extends to 200 kpc, evolution not symmetric about galaxy

EVOLUTION FROM Z=3.5 TO Z=1 temperature

• Xray “coronal” conditions within 80 kpc, non uniform (due to filaments)

• too much gas cooled to T=104 K?

• OVI collisional ionization condition present in post shock filaments

EVOLUTION FROM Z=3.5 TO Z=1 metallicity

• Even though gas is cooling, metals ejected to 200-300 kpc

• At high z, NB filaments enriched by mixing, but haven fallen into galaxy, at low z, Z~10 -2

• metals spread out in more diffuse lower density gas

Using Galaxy Winds to Constrain Galaxy EvolutionChristopher Churchill1, Anatoly Klypin1, Daniel Ceverino2, Glenn Kacprzak3, Jessica Evans1, & Elizabeth Klimek1

(1) New Mexico State University, (2) Hebrew University of Jerusalem, (3) Swinburne University

z=3.5 <v> FWHMOVI 115 223CIV 86 357Lyα -27 129

=1z .0 < > v FWHMOVI -142 225CIV -132 200Lyα -78 176

=3z .5

=1z .0

OUTFLOW TO INFLOW EVOLUTION

Dominated by filamentary inflow

Distribution of Radial Velocity of Absorbing Cells Giving Rise to Detected Absorption

1. INTRODUCTION, MOTIVATION, AND SIMULATIONS

2. BACKGROUND QSO METHOD: EXAMINING GALACTIC WINDS

3. EVOLUTION OF WINDS

4. STACKING - “DOWN THE BARREL”

5. STACKING - IMPACT PARAMETER BINS, V90, & SFR

5. A WORK IN PROGRESS

The spectra of bright z=2-3 star bursting galaxies exhibit many “interstellar” lines in absorption and these lines indicate outflow on the order of 1000 km/s.

The signal to noise of the individual spectra are low, so it is necessary to stack the spectra in the rest-frame of each galaxy in order to obtain a higher signal-to-noise composite spectrum.

The continuum source is the nuclear region of the galaxy, thus the term “down the barrel”.

(RIGHT) The panel on right shows a composite spectrum of Steidel and collaborators (unpublished) for which the mean galaxy properties are given. Also shown are expanded views of absorption for three bright lensed galaxies.

(LEFT) The profiles we obtain from our simulations using the “down the barrel” technique. Our simulation galaxies show similar profiles (though we do not reproduce the slow recovery of flux in the blue wing). Our ultimate goal is to obtain quantitative comparison- but there are few published observations at this time.

(RIGHT) The observed distribution of velocities in absorption (blue) and the distribution of Lyman α emission peaks (red) from starburst galaxies (Steidel, 1997, private comm). The absorption velocities are of the mean optical depth centroids.

(FAR RIGHT) The distribution of absorption velocities from the down the barrel spectra from our simulations for CIV, OVI, and Lymanα(in absorption). The mean outflow velocity of OVI is 115 km/s, which compares to the mean observed velocity of 165 km/s. (note the axes are in opposite directions).

(observations)

(simulations)

(observations vs. simulations)

(LEFT) The schematic illustration of the experiment of stacking the background galaxies in various impact parameter bins. In the side view, the observer is to the left.

(ABOVE LEFT) Observational results for three impact parameter bins, D=0 (red), 8-40, (blue) and 40-80 (magenta) kpc (Stiedel, private com).

(ABOVE RIGHT) Simulation result for comparison. Note the trend for lower optical depth with increasing impact parameter is duplicated.

(FAR LEFT) V90 from many galaxies in our simulations vs star formation rate. We find V90 ~ SFR0.5. The blue, green and red points are the results of Weiner etal, which fairly well match our simulations. The absorption profiles for MgII are shown for the three galaxies.

Analysis of mock quasar spectra of metal absorption lines in the proximity of formed galaxies in cosmological simulations is a promising technique for understanding the role of galaxies in IGM physics, or IGM physics in the role of galaxy formation. We are undertaking a wholesale approach to use CDM simulations to interpret absorption line data from redshift 1-3 starbursting galaxies (Lyman Break Galaxies, etc). We compare to DEEP galaxies (Weiner et al. 2009) and the collective work of Steidel et al. (2009, private comm) on z=2-3 galaxies. The simulations are performed using the Eulerian Gasdynamics + Nbody Adaptive Refinement Tree (Kravstov 1999) code with resolutions of 20-50 pc.

Here, we motivate and present our work in progress to compare the absorption line properties obtained from the gas in the simulations to the observed absorption properties.

1. Gas phase baryonicstructures are observable inabsorption (bright starforming galaxies + QSOabsorption lines) with equalvisibility at all redshifts,including z=1 to z=3

2. Gas flows into and/or out ofgalaxies and baryonic halosare sensitively probed in UVabsorption lines; cold IGMgas in, heated gas out

3. Observations indicate thatz~2-3 galaxies withmoderately high starformation rates are blowingout significant amounts ofmetal enriched gas (courtesy C. Steidel)

Direct line of sight “Down the Barrel” configuration…

In this toy scenario, Lyman α emission is powered by correlated supernovae (star bursting phase). Lyman α emission is redshifted out of the rest-frame of the wind on the observer side and is seen in emission, whereas the metal lines are seen blue shifted in absorption.

grid of LOS

Geometric distribution of infalling and outflowing gas (determined from abs spectra)

Z=3.5 Z=1.0 Z=3.5 Z=3.5 Z=1.0Z=1.0

Using the absorption profiles from the simulations selected by OVI (red), CIV (blue) and Lyman α absorption (green), we plot the cell radial velocity relative to the simulated galaxy for z=3.5 and z=1.0. The simulations winds peter out and become infall by z=1.0. (We believe this is due to undesired overcooling.)

JUST THE FACTS…

ABSORPTION

SIMULATIONS

[kpc][cm-3]

D = position on LOS Z/Zsun = gas metallicity nH = hydrogen number density V = cell volume fH = HI ionization fraction T = gas temperature

= cell velocity

consider a random gas cell in the simulations

Lin

e o

f S

igh

t C

ell

Pro

pe

rtie

sS

imu

late

d S

pe

ctra

sky view

line of sight (LOS)

(observer)background galaxies; spectra are co-added in various impact parameter bins

target galaxy

red = side A blue = side Bobserved simulations

simulated spectra

observed simulations

CONCLUDING REMARKS

Work is still at a very preliminary level….

It is very expensive to run many galaxies to get statistics on the absorption quantities,which aren’t really published yet!

We are only making qualitative comparisons at this time, though the absorption linework has constrained the SFR efficiencies from earlier work

It is clear that cold flows are prominent and required to fuel the continuation of starformation

The scaling of the outflow velocity with SFR qualitatively is promising in its comparisonwith observations

The absorption gas method is probably the most promising in that it incorporates thesensitivity functions of detecting the gas in observed spectra

REFERENCES:

Ceverino, D., & Klypin, A. 2009, ApJ, 695, 292 Ferland, G., et al., 1998, PASP, 110, 761Haardt, F., & Madau, P. 1996, ApJ, 461, 20Kravstov, A., Klypin, A., & Khokhlov, A. 1997, ApJS, 111, 73 Kravstov, A. 1999, PhD, New Mexico State UniversityKravstov, A. 2003, ApJ,L, 590, L1Kravstov, A., Gneden, O., & Klypin, A. 2004, ApJ, 609, 482

Miller, G., & Scalo, J. 1979, ApJS, 41, 513Steidel, C. 2009, private communicationWeiner, B., et al. 2009, ApJ, 692, 197Woosley, S., & Weaver, T. 1995, ApJS, 101, 181

(courtesy C. Steidel)

Steidel et al. (private comm)

Ceverino & Klypin (2009)