The Prevalence and Properties of
This presentation is the property of its rightful owner.
Sponsored Links
1 / 29

The Prevalence and Properties of Outflowing Galactic Winds at z = 1 PowerPoint PPT Presentation


  • 39 Views
  • Uploaded on
  • Presentation posted in: General

The Prevalence and Properties of Outflowing Galactic Winds at z = 1. ETH Zurich February 2012. Katherine A. Kornei (UCLA) Alice Shapley, Crystal Martin, Alison Coil. Galaxies are not closed boxes. outflows?. outflows?. IGM. Outflows.

Download Presentation

The Prevalence and Properties of Outflowing Galactic Winds at z = 1

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The prevalence and properties of outflowing galactic winds at z 1

The Prevalence and Properties of

Outflowing Galactic Winds at z = 1

ETH Zurich

February 2012

Katherine A. Kornei (UCLA)

Alice Shapley, Crystal Martin, Alison Coil


The prevalence and properties of outflowing galactic winds at z 1

Galaxies are not closed boxes.

outflows?

outflows?

IGM

Outflows

enrich the intergalactic medium in metals

…quench star formation

…regulate black hole growth

cold streams?

AGN feedback?

AGN feedback?


The prevalence and properties of outflowing galactic winds at z 1

Outflows are seen in local starbursts.

6”

M82 (z=0.0008)

HST/ACS BVIHα (M. Westmoquette)


The prevalence and properties of outflowing galactic winds at z 1

Outflows can be inferred through line offsets.

Given outflowing material between the observer and the galaxy:

MgII 2796/2803

[OII] 3727 Å

Nebular line – at zsys

zsys

MgI 2852

MgI

Weiner et al. 2009

MgII

DN/sec/pixel

Outflowing gas will be blueshifted with respect to nebular lines tracing star forming regions.

Velocity (km/sec)


The prevalence and properties of outflowing galactic winds at z 1

A variety of absorption lines are used to probe outflows.

z

z = 0.5

1.0

3.0

Na I D ≈ 5900 Å

Fe II/Mg II ≈ 2600 Å

H I + others ≈ 1200 Å

Reddy et al. 2008


The necessary data set

The necessary data set.

Spectroscopy of lines tracing outflowing gas

lines tracing the systemic redshift

The ideal data set.

+ Photometry for calculating stellar masses, etc.

+ Ancillary data for obtaining dust-corrected SFRs, morphologies, galaxy inclinations, etc.


The prevalence and properties of outflowing galactic winds at z 1

DEEP2 survey (the origin of our sample).

Slitmasks with 120 targets

50,000 galaxies at z ≈ 1 in 3.5 deg2

DEIMOS on Keck II (90 nights: ‘02-’05)

R = 5000 (70 km s-1)

B-R

Resolved [OII] doublets

z < 0.75

z > 0.75

DEEP2 Team

R-I

Color cuts in 3/4 fields for z > 0.75

≈ 1 hour integration


The prevalence and properties of outflowing galactic winds at z 1

Extended Groth Strip – no color cuts and lots of ancillary data.

GALEX imaging

(FUV, NUV)

F606W

http://aegis.ucolick.org/

HST imaging

(F606W, F814W)

6”

  • The ideal data set.

  • Photometry, imaging

  • The necessary data set.

  • Lines tracing outflows & systemic z

Spitzer imaging (IRAC, MIPS)


The prevalence and properties of outflowing galactic winds at z 1

LRIS observations to cover lines tracing winds.

[OII] (zsys)

CIV, FeII, MgII, MgI (zout)

LRIS: 7200-9000 Å

LRIS: 3400-6700 Å

DEIMOS: 6500-9100 Å

212 objects; B < 24.5

1.19 < z < 1.35 =

CIV 1549, MgI 2852 coverage

Normalized Flux

Mg I

Al II

Fe II

Fe II

Si II, C IV

Mg II

Rest Wavelength (angstroms)


The prevalence and properties of outflowing galactic winds at z 1

Many analyses are possible.

LRIS spectroscopy

measure fine structure

FeII* emission lines

definezsys([OII], Balmer series)

fit FeII absorption lines

characterize MgII emission

HST imaging

morphologies

colors

galaxy areas

inclinations

SFRs, dust attenuations from GALEX


The prevalence and properties of outflowing galactic winds at z 1

Blue, star-forming galaxies at z = 1.

Kornei et al., in prep.

Kornei et al., in prep.


The prevalence and properties of outflowing galactic winds at z 1

Defining systemic and outflow velocities.

Define a systemic reference frame.

Fit multiple emission lines ([OII], OIII, Balmer) using template spectra.

2250, 2260 2344, 2374 2587 Å

Measure an outflow velocity.

Fit multiple FeII absorption lines.

zsys

zout

FeII


The prevalence and properties of outflowing galactic winds at z 1

A physical model for fitting absorption lines.

covering fraction

Primary quantity of interest is λ0, from which we estimate an outflow velocity.

op. depth at line center

line center

Doppler parameter

A single component fitwith 4 free parameters.


The prevalence and properties of outflowing galactic winds at z 1

BlueshiftedFeII absorption features are not ubiquitous in the sample.

12100420 z = 1.20

Velocities from FeII

Inflow?

Martin et al., in prep.

Kornei et al., in prep.

Inflows

Outflows

Other outflow diagnostics: MgII, FeII*


The prevalence and properties of outflowing galactic winds at z 1

The strength of outflows is correlated with various galaxy properties.

Na D

ULIRGs

face-on

outflow velocity (km/s)

dwarf

starbursts

edge-on

Chen et al. 2010

Martin 2005

SFR (M*/yr)

Outflows not seen in edge-on systems.

Outflow velocity increases with increasing star formation rate.

face-on

edge-on


The prevalence and properties of outflowing galactic winds at z 1

No trend between outflow velocity and star-formation rate.

1000 Msun yr-1

0.1 Msun yr-1

Martin 2005


The prevalence and properties of outflowing galactic winds at z 1

Are outflows correlated with star-formation rate surface densities?

6”

F606W

Σ

SFR estimate

Clumpy objects at high z – need a better area estimate that traces luminous regions.

area estimate

UV, 24 μm, emission lines, etc.

Half-light radius?

Petrosian radius?

A = πR2


The prevalence and properties of outflowing galactic winds at z 1

A new technique for estimating galaxy areas.

Petrosian

area

Clump

area

F606W

Include only those pixels brighter than a certain surface brightness threshold, thereby flagging clumps.

Given “clumpy” galaxies:


The prevalence and properties of outflowing galactic winds at z 1

Higher star-formation rate surface density objects show larger Fe II blueshifts.

Kornei et al., in prep.


The prevalence and properties of outflowing galactic winds at z 1

Composite spectra show same trends as individual objects.

Star-formation rate surface density composites::

High density

Low density

Bright clumps

Interclump

regions

Vfe2 = 44 ± 15 km s-1

Vfe2 = -31 ± 7 km s-1

Kornei et al., in prep.

Mg II shows more kinematic variation than Fe II

Genzel et al. 2011


Theory supports a correlation between outflows and the density of star formation

Theory supports a correlation between outflows and the density of star formation.

Fe II

Star clusters eject gas at velocities proportional to the gas surface density squared (Murray et al. 2011).

[Kennicutt-Schmidt Law]

Chen et al. 2010


The prevalence and properties of outflowing galactic winds at z 1

The geometry of outflowing winds at z = 1.

Na D

face-on

edge-on

Chen et al. 2010

Estimate inclination from axis ratios from HST imaging:

a

face-on

edge-on

i = cos-1(b/a)

b


The prevalence and properties of outflowing galactic winds at z 1

Face-on galaxies show stronger blueshifts than edge-on systems.

Inclination composites::

Low

High

More edge-on: dV = 28 ± 11 km s-1

More face-on: dV = -19 ± 9 km s-1

Mg II equivalent width

Bordoloi et al. 2011

face-on

edge-on

Azimuthal angle relative to galaxy disk axis


The prevalence and properties of outflowing galactic winds at z 1

Mergers are not required to drive outflows.

Law et al. 2007

high G

low G

Gini (G) – measure of how light is distributed in a galaxy

Lotz et al. 2008

Kornei et al., in prep.

low M20

high M20

M20 – second order moment of a galaxy’s 20% brightest pixels


The prevalence and properties of outflowing galactic winds at z 1

Fine structure FeII* emission.

Does this emission come from star

forming regions or from outflows?

zsys

v = 0

F606W

Leitherer et al. 2010

probing very different scales at z = 1 and z = 0

v = +100

v = -100

8400 pc/”

16 pc/”

Kornei et al., in prep.

2626 Å (fine structure)

Fe II 2600 Å (resonance)


The prevalence and properties of outflowing galactic winds at z 1

Complexities of the MgII feature at ≈ 2800 Å.

MgII and FeII absorption are kinematically distinct.

The composite spectrum shows MgII in absorption.

Some individual spectra show

MgII in emission

MgII

Martin et al., in prep.


Mapping winds

Mapping winds.

What are the kinematics and extent of galactic winds?

IFU observations with MUSE.

Prochaska et al. 2011


The prevalence and properties of outflowing galactic winds at z 1

Summary.

Reddy et al. 2008

[OII] (zsys)

CIV, FeII, MgII, MgI (zout)

LRIS: 7200-9000 Å

LRIS: 3400-6700 Å

DEIMOS: 6500-9100 Å

Petrosian

area

Clump

area

Outflow velocity most strongly correlated with the concentration of star formation.

Kornei et al., in prep.


  • Login