Quenched and Quenching Galaxies at Low to High

RedshiftsS.M. Faber & UCSC and CANDELS collaborators

Dekel60 FestDecember 13, 2011

M31: UV GALEX

Quenching Scenarios for Central Galaxies

Halo-based Massive halo quenching: “cold flows” to hot halos + AGN (“radio mode”)

Bulge-building Major merger -> starburst + AGN Minor mergers + AGN Disk instability + AGN Disk secular evolution + AGN Morphological quenching (Toomre Q)

Hopping/rejuvenation Mergers Stochastic accretion

Correlate with galaxy properties

Correlate with halo properties

Part I:Quenching of central SDSS

galaxies at z ~ 0 with halo mass vs. stellar mass

Joanna Woo & Avishai Dekel

Joanna

Probability of quenching vs. M* and Mhalo

Woo et al. 2011

Contours run vertically.

Quenching correlates better with halo mass than with stellar mass.

Part II:HST UV images of nearby Green Valley

galaxiesJerome Fang, Samir Salim, S. M. Faber, et al.

Jerome

HST UV images of SDSS green valley galaxies

Fang, Salim et al. 2011

20 galaxies imaged with HST SBC.

Sample lies in bluer part of green valley.

HST FUV images

Fang, Salim et al. 2011

HST sample vs. general green valley

Fang, Salim et al. 2011

Many more GV galaxies with similar properties.

Colors imply underlying substrate of older stars

Fang, Salim et al. 2011

ESFETGs

Mass-matched in blue cloud

Fang, Salim et al. 2011

HST FUV images

Fang, Salim et al. 2011

GALEX: M31

Part III:Structure of AEGIS galaxies on Red Sequence vs. Blue Cloud at z ~ 0.8

Edmond Cheung, Liz McGrath, & David Koo

Edmond

Try different combinations of mass and radius

Cheung et al. 2011

DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.

Mass M/reff M/reff2

None work perfectly. There is always overlap region.

Cheung et al. 2011

DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.

Mass M/reff M/reff2

Surface density Kauffmann+06

Cheung et al. 2011

Is there a second structural variable?

Cheung et al. 2011

DEEP2 survey: spec z’s and photoz’s. Redshift range z = 0.5-0.8.

U-B

U-B

U-B

Bulge M* is higher

Bulge radius is smaller

Bulge M*/re is lower

Cheung et al. 2011

AEGIS galaxies have bulge-disk decompositions using GIM2D.

In the overlap region, the color change is accompanied by structural changes.

Stellar mass becomes more concentrated.

Sersic index: looks like a threshold, except for outliers

Cheung et al. 2011

outliers

See also Bell+08, Bell+11

Inner mass surface density increases across color divide

McGrath, Koo et al. 2011

Rejuvenation model no good; one way trip

Structure is better predictor of quenching than halo or stellar mass

Part IV:Pre- and post-quenched galaxies in

CANDELS at z ~ 2

Mark Mozena, Tao Wang, JS Huang, and CANDELS team

Mark

Color-mass diagram: CANDELS/ERS in GOODS-S

✖ Spheroid

✖ Mixed or Irr

✖ Disk

Z = 1.5-2.5

Mozena et al. 2011

Visual classes:

Note color-mass relation already

at z~2!

Massive galaxies > 1010.8 M at z~2 in Gini/M20

Quiescent

Star-forming

Wang et al. 2011

Half quenched, half star-forming.

Strong correlation with morphology.

These SFR galaxies will all be quenched by z~1.

WFC3-IR images from CANDELS and ERS in GOODS-S

Radius-mass diagram: GOODS-S

✖ Spheroid

✖ Mixed or Irr

✖ Disk

Z = 1.5-2.5

Mozena et al. 2011

Also Cirasuolo et al. 2011

Visual classes:

Radius-mass diagram: GOODS-S

✖ Spheroid

✖ Mixed or Irr

✖ Disk

Z = 1.5-2.5

Mozena et al. 2011

Also Cirasuolo et al. 2011

Visual classes:

Almost bimodal!

Radius-mass diagram: GOODS-S

✖ Spheroid

✖ Mixed or Irr

✖ Disk

Z = 1.5-2.5

Mozena et al. 2011

Also Cirasuolo et al. 2011

Visual classes:

X5

Conclusions: There exist structural parameters that are better predictors of quenching than either halo or stellar mass. An indispensible ingredient in the quenching process at all redshifts is either caused by (or leaves its imprint on) the stellar mass distribution – stars move to center. At low z, this process does not involve major mergers or a large change in radius. At high z, gross shrinkage in radius of x5 occurs.

Is the process the same or different at high z?