Multivariate Properties of Multivariate Properties of Galaxies at Low RedshiftGalaxies at Low Redshift

Galaxy Properties from Galaxy Properties from ImagingImaging

Luminosity Luminosity functionsfunctions

Star formation rateStar formation rate Stellar massStellar mass MorphologyMorphology Color-magnitude Color-magnitude

relationrelation EnvironmentEnvironment Photometric redshiftPhotometric redshift 2-D Clustering2-D Clustering

2 6-color SDSS scans of 2.5°x2.5°.

Galaxy Properties from Galaxy Properties from SpectroscopySpectroscopy

Detailed star Detailed star formation formation historyhistory

Dynamical mass Dynamical mass MetallicityMetallicity Dust contentDust content 3-D clustering3-D clustering AGN activityAGN activity

Galaxy Surveys: Optical & Galaxy Surveys: Optical & NIRNIR

•DEEP2AEGIS

•MS1054

•COMBO17 •MUSYC•Steidel •ELAIS-S1

Where is the stellar mass?Where is the stellar mass? Galaxies at Galaxies at

~10~1010.510.5-10-1011.511.5MM contain most of contain most of stellar mass.stellar mass.

SFR and DSFR and Dnn show show bimodality.bimodality.

Some, not Some, not much, much, environmental environmental dependencedependence

Kauffmann et al. 2004

Bivariate LF’s: Bivariate LF’s: MorphologyMorphology

Sersic index n: Sersic index n:

n=4: ellipticaln=4: elliptical n=1: spiraln=1: spiral

Ellipticals dominate Ellipticals dominate bright end; later bright end; later types at faint end.types at faint end.

Faint end slope varies Faint end slope varies with n; Bright end with n; Bright end truncation invariant.truncation invariant.

SB trends similar; SB trends similar; high SB’s have higher high SB’s have higher n.n.

Ball et al 2005

Bivariate LF’s: Bivariate LF’s: ColorColor

u-r measures u-r measures (roughly) ratio of (roughly) ratio of current to past star current to past star formation.formation.

Red galaxies dominate Red galaxies dominate at bright end.at bright end.

Blue galaxies have Blue galaxies have steeper faint-end steeper faint-end slope.slope.

r-z distribution shows r-z distribution shows less trend, because less trend, because fewer blue galaxies.fewer blue galaxies.

Ball et al 2005

LF’s in Field vs. LF’s in Field vs. ClustersClusters

Field R-band LF Field R-band LF (SDSS) well-fit by (SDSS) well-fit by Schechter function, Schechter function, with with ~-1.26.~-1.26.

Clusters show an Clusters show an excess population excess population of small galaxies.of small galaxies.

GALEX data shows GALEX data shows faint-end upturn is faint-end upturn is from passive from passive dwarfs.dwarfs.

Trentham et al 2005

Cortese et al. 2005

Stellar Mass Fcn Stellar Mass Fcn in Field vs. in Field vs.

ClustersClusters Near-IR (J, K) allow Near-IR (J, K) allow

more direct tracer more direct tracer of Mof M**..

Clusters show Clusters show steeper faint end, steeper faint end, field is shallow.field is shallow.

Non-emission line Non-emission line field galaxies field galaxies show very shallow show very shallow slope.slope.

Balogh et al 2001

Morphology-Morphology-Density RelationDensity Relation

Ellipticals prefer denser Ellipticals prefer denser environments.environments.

Discovered in the 80’s, Discovered in the 80’s, regarded as a regarded as a fundamental aspect of fundamental aspect of environment.environment.

Why does it occur?Why does it occur? Ram-pressure stripping? Ram-pressure stripping? Merging? Merging? Harassment? Harassment? Starvation?Starvation?

Goto et al. 2004

It’s star It’s star formation formation

history, stupid!history, stupid! At fixed luminosity At fixed luminosity

and color, there is and color, there is no strong no strong relationship relationship between density between density and either Sersic and either Sersic index or surface index or surface brightnessbrightness. .

It’s not morphology-density, it’s color-density, or perhaps star formation history-density relation.

Blanton et al. 2005

Color, magnitude, Color, magnitude, morphologymorphology

Ellipticals (high-Ellipticals (high-n) tend to be n) tend to be red and high-red and high-SB.SB.

CMD shows CMD shows bimodality: bimodality: “red sequence” “red sequence” & “blue cloud”.& “blue cloud”.

Color-SB Color-SB relation shows relation shows similar similar bimodality.bimodality.

Red sequence Red sequence evolutionevolution

Red sequence Red sequence in place at z~1 in place at z~1 (10 Gyr ago).(10 Gyr ago).

Gets slowly Gets slowly redder with redder with time; ztime; zff~2+.~2+.

Dominated by Dominated by early-types early-types (not dusty (not dusty spirals).spirals).

Mass-Metallicity RelationMass-Metallicity Relation SDSS emission line SDSS emission line

galaxies, central galaxies, central regions.regions.

MM**-Z shows a strong -Z shows a strong trend up to trend up to MM**~10~1010.510.5MM, then , then flattens to higher Mflattens to higher M**..

Scatter is small: 0.2 Scatter is small: 0.2 dex at low-M, 0.07 dex at low-M, 0.07 dex at high-M.dex at high-M.

Origin yet unclear, Origin yet unclear, but outflows likely but outflows likely needed.needed. Tremonti et al. 2004

Lee et al. 2006

Tully-Fisher and MTully-Fisher and M**/L/L Stellar/baryonic mass Stellar/baryonic mass

vs. dynamical mass.vs. dynamical mass. ~x7 M~x7 M**/L variation in B, /L variation in B,

~x2 in K (for spirals). ~x2 in K (for spirals). Tightest with B-R color.Tightest with B-R color.

With MWith M**/L(color), TF has /L(color), TF has MM**vv4.54.5..

With HI data, baryonic With HI data, baryonic TF MTF Mbbvv3.53.5±±0.20.2..

Extending to lower Extending to lower masses suggests Mmasses suggests Mbbvv44: : variation with Mvariation with Mbb??

Recall MRecall Mhalohalovv33, so at , so at face value small halos face value small halos have less baryons: have less baryons: MMbb/M/Mhhvv0.50.5..

Lv3

Lv4

Bell & de Jong 2001

McGaugh 2004

AGNs: Where do they AGNs: Where do they live?live?

In M*>10In M*>101010MM.. MorphologicallMorphologicall

y similar to y similar to early-types.early-types.

OTOH, recent OTOH, recent SF similar to SF similar to late-types (esp. late-types (esp. in strong AGN).in strong AGN).

Kauffmann et al 2003

AGNs and AGNs and galaxy galaxy

evolution evolution AGNs roughly occupy AGNs roughly occupy

“green valley”.“green valley”. Black hole growth Black hole growth

occuring in Moccuring in M**~10~1010.510.5--10101111 M M galaxies. galaxies.

Same MSame M** as transition as transition in colors, SFRs, etc. in colors, SFRs, etc.

Cause or effect?Cause or effect?

Kauffmann et al 2004

Clustering: 2PCFClustering: 2PCF =(r/r=(r/r00))--, , ~1.8 and ~1.8 and

rr00~5 Mpc/h.~5 Mpc/h. Departs significantly Departs significantly

from pure power law.from pure power law. Red galaxies have Red galaxies have

steeper x slope.steeper x slope. Mild luminosity Mild luminosity

dependence, dependence, strongest at strongest at luminous end.luminous end.

Zehavi et al. 2003, 2004

Norberg et al 2001

Halo Occupation Halo Occupation DistributionDistribution HOD = P(NHOD = P(Ngg,M,Mhh).).

Made up of “1-halo” Made up of “1-halo” and “2-halo” terms.and “2-halo” terms.

From this, get bias: From this, get bias: bb≡(≡(gggg//mmmm))1/21/2..

<N(M)> has <N(M)> has character-istic shape; character-istic shape; can derive by can derive by matching matching (r).(r).

Yang et al 2004

Zehavi et al 2003

Conditional Luminosity Conditional Luminosity FunctionFunction

(L|M)dL: (L|M)dL: Luminosity Luminosity fcn in bins of fcn in bins of halo mass.halo mass.

Tune Tune (L|M) (L|M) to reproduce to reproduce LF, LF, (L), and (L), and T-F.T-F.

Depends on Depends on cosmology, cosmology, or anything or anything that affects that affects halo halo abundance.abundance.

Yang et al 2003